985 resultados para 0.22 per mil


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OBJECTIVES: To measure the thickness at which primary schoolchildren apply sunscreen on school day mornings and to compare it with the thickness (2.00 mg/cm(2)) at which sunscreen is tested during product development, as well as to investigate how application thickness was influenced by age of the child (school grades 1-7) and by dispenser type (500-mL pump, 125-mL squeeze bottle, or 50-mL roll-on). DESIGN: A crossover quasiexperimental study design comparing 3 sunscreen dispenser types. SETTING: Children aged 5 to 12 years from public primary schools (grades 1-7) in Queensland, Australia. PARTICIPANTS: Children (n=87) and their parents randomly recruited from the enrollment lists of 7 primary schools. Each child provided up to 3 observations (n=258). INTERVENTION: Children applied sunscreen during 3 consecutive school weeks (Monday through Friday) for the first application of the day using a different dispenser each week. MAIN OUTCOME MEASURE: Thickness of sunscreen application (in milligrams per square centimeter). The dispensers were weighed before and after use to calculate the weight of sunscreen applied. This was divided by the coverage area of application (in square centimeters), which was calculated by multiplying the children's body surface area by the percentage of the body covered with sunscreen. RESULTS: Children applied their sunscreen at a median thickness of 0.48 mg/cm(2). Children applied significantly more sunscreen when using the pump (0.75 mg/cm(2)) and the squeeze bottle (0.57 mg/cm(2)) compared with the roll-on (0.22 mg/cm(2)) (P<.001 for both). CONCLUSIONS: Regardless of age, primary schoolchildren apply sunscreen at substantially less than 1.00 mg/cm(2), similar to what has been observed among adults. Some sunscreen dispensers seem to facilitate thicker application than others.

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The giant freshwater prawn (Macrobrachium rosenbergii) or GFP is one of the most important freshwater crustacean species in the inland aquaculture sector of many tropical and subtropical countries. Since the 1990s, there has been rapid global expansion of freshwater prawn farming, especially in Asian countries, with an average annual rate of increase of 48% between 1999 and 2001 (New, 2005). In Vietnam, GFP is cultured in a variety of culture systems, typically in integrated or rotational rice-prawn culture (Phuong et al., 2006) and has become one of the most common farmed aquatic species in the country, due to its ability to grow rapidly and to attract high market price and high demand. Despite potential for expanded production, sustainability of freshwater prawn farming in the region is currently threatened by low production efficiency and vulnerability of farmed stocks to disease. Commercial large scale and small scale GFP farms in Vietnam have experienced relatively low stock productivity, large size and weight variation, a low proportion of edible meat (large head to body ratio), scarcity of good quality seed stock. The current situation highlights the need for a systematic stock improvement program for GFP in Vietnam aimed at improving economically important traits in this species. This study reports on the breeding program for fast growth employing combined (between and within) family selection in giant freshwater prawn in Vietnam. The base population was synthesized using a complete diallel cross including 9 crosses from two local stocks (DN and MK strains) and a third exotic stock (Malaysian strain - MY). In the next three selection generations, matings were conducted between genetically unrelated brood stock to produce full-sib and (paternal) half-sib families. All families were produced and reared separately until juveniles in each family were tagged as a batch using visible implant elastomer (VIE) at a body size of approximately 2 g. After tags were verified, 60 to 120 juveniles chosen randomly from each family were released into two common earthen ponds of 3,500 m2 pond for a grow-out period of 16 to 18 weeks. Selection applied at harvest on body weight was a combined (between and within) family selection approach. 81, 89, 96 and 114 families were produced for the Selection line in the F0, F1, F2 and F3 generations, respectively. In addition to the Selection line, 17 to 42 families were produced for the Control group in each generation. Results reported here are based on a data set consisting of 18,387 body and 1,730 carcass records, as well as full pedigree information collected over four generations. Variance and covariance components were estimated by restricted maximum likelihood fitting a multi-trait animal model. Experiments assessed performance of VIE tags in juvenile GFP of different size classes and individuals tagged with different numbers of tags showed that juvenile GFP at 2 g were of suitable size for VIE tags with no negative effects evident on growth or survival. Tag retention rates were above 97.8% and tag readability rates were 100% with a correct assignment rate of 95% through to mature animal size of up to 170 g. Across generations, estimates of heritability for body traits (body weight, body length, cephalothorax length, abdominal length, cephalothorax width and abdominal width) and carcass weight traits (abdominal weight, skeleton-off weight and telson-off weight) were moderate and ranged from 0.14 to 0.19 and 0.17 to 0.21, respectively. Body trait heritabilities estimated for females were significantly higher than for males whereas carcass weight trait heritabilities estimated for females and males were not significantly different (P > 0.05). Maternal and common environmental effects for body traits accounted for 4 to 5% of the total variance and were greater in females (7 to 10%) than in males (4 to 5%). Genetic correlations among body traits were generally high in both sexes. Genetic correlations between body and carcass weight traits were also high in the mixed sexes. Average selection response (% per generation) for body weight (transformed to square root) estimated as the difference between the Selection and the Control group was 7.4% calculated from least squares means (LSMs), 7.0% from estimated breeding values (EBVs) and 4.4% calculated from EBVs between two consecutive generations. Favourable correlated selection responses (estimated from LSMs) were detected for other body traits (12.1%, 14.5%, 10.4%, 15.5% and 13.3% for body length, cephalothorax length, abdominal length, cephalothorax width and abdominal width, respectively) over three selection generations. Data in the second selection generation showed positive correlated responses for carcass weight traits (8.8%, 8.6% and 8.8% for abdominal weight, skeleton-off weight and telson-off weight, respectively). Data in the third selection generation showed that heritability for body traits were moderate and ranged from 0.06 to 0.11 and 0.11 to 0.22 at weeks 10 and 18, respectively. Body trait heritabilities estimated at week 10 were not significantly lower than at week 18. Genetic correlations between body traits within age and genetic correlations for body traits between ages were generally high. Overall our results suggest that growth rate responds well to the application of family selection and carcass weight traits can also be improved in parallel, using this approach. Moreover, selection for high growth rate in GFP can be undertaken successfully before full market size has been reached. The outcome of this study was production of an improved culture strain of GFP for the Vietnamese culture industry that will be trialed in real farm production environments to confirm the genetic gains identified in the experimental stock improvement program.

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PURPOSE Accurate monitoring of prevalence and trends in population levels of physical activity is fundamental to the planning of health promotion and disease-prevention strategies. Test-retest reliability (repeatability) was assessed for four self-report measures of physical activity commonly used in population surveys: the Active Australia survey (AA, N=356), the short form of the International Physical Activity Questionnaire (IPAQ-S, N=104), the physical activity items in the Behavioral Risk Factor Surveillance System (BRFSS, N=127) and the physical activity items in the Australian National Health Survey (NHS, N=122). METHODS Percent agreement and Kappa statistics were used to assess the reliability of classification of activity status (where active= 150 minutes of activity per week) and sedentariness (where sedentary = reporting no physical activity). Intraclass correlations (ICCs) were used to assess agreement on minutes of activity reported for each item of each survey and on total minutes reported in each survey. RESULTS Percent agreement scores for both activity status and sedentariness were very good on all four instruments. Overall the percent agreement between repeated surveys was between 73% (NHS) and 87% (IPAQ) for the criterion measure of achieving 150 minutes per week, and between 77% (NHS) and 89% (IPAQ) for the criterion of being sedentary. Corresponding Kappa statistics ranged from 0.46 (NHS) to 0.61 (AA) for activity status and from 0.20 (BRFSS) to 0.52 (AA) for sedentariness. For the individual items ICCs were highest for walking (0.45 to 0.56) and vigorous activity (0.22 to 0.64) and lowest for the moderate questions (0.16 to 0.44). CONCLUSION All four measures provide acceptable levels of test-retest reliability for assessing both activity status and sedentariness, and moderate reliability for assessing total minutes of activity. Supported by the Australian Commonwealth Department of Health and Ageing.

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Background: Transthoracic echocardiography (TTE) during extra corporeal membrane oxygenation (ECMO) is important but can be technically challenging. Contrast-specific TTE can improve imaging in suboptimal studies. These contrast microspheres are hydrodynamically labile structures. This study assessed the feasibility of contrast echocardiography (CE) during venovenous (VV) ECMO in a validated ovine model. Method: Twenty-four sheep were commenced on VV ECMO. Parasternal long-axis (Plax) and short-axis (Psax) views were obtained pre- and postcontrast while on VV ECMO. Endocardial definition scores (EDS) per segment were graded: 1 = good, 2 = suboptimal 3 = not seen. Endocardial border definition score index (EBDSI) was calculated for each view. Endocardial length (EL) in the Plax view for the left ventricle (LV) and right ventricle (RV) was measured. Results: Summation EDS data for the LV and RV for unenhanced TTE (UE) versus CE TTE imaging: EDS 1 = 289 versus 346, EDS 2 = 38 versus 10, EDS 3 = 33 versus 4, respectively. Wilcoxon matched-pairs rank-sign tests showed a significant ranking difference (improvement) pre- and postcontrast for the LV (P < 0.0001), RV (P < 0.0001) and combined ventricular data (P < 0.0001). EBDSI for CE TTE was significantly lower than UE TTE for the LV (1.05 0.17 vs. 1.22 0.38, P = 0.0004) and RV (1.06 0.22 vs. 1.42 0.47, P = 0.0.0006) respectively. Visualized EL was significantly longer in CE versus UE for both the LV (58.6 11.0 mm vs. 47.4 11.7 mm, P < 0.0001) and the RV (52.3 8.6 mm vs. 36.0 13.1 mm, P < 0.0001), respectively. Conclusions: Despite exposure to destructive hydrodynamic forces, CE is a feasible technique in an ovine ECMO model. CE results in significantly improved EDS and increased EL.

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Medium bedding sand which is commonly available in coastal sedimentary deposits, and a marine polychaete-worm species from Moreton Bay recently classified as Perinereis helleri (Nereididae), were deployed in a simple low-maintenance sand filter design that potentially has application at large scale. Previous work had shown that this physical and biological combination can provide a new option for saline wastewater treatment, since the worms help to prevent sand filter blocking with organic debris and offer a profitable by-product. To test the application of this new concept in a commercial environment, six 1.84 m2 Polychaete-assisted sand filters were experimentally tested for their ability to treat wastewater from a semi-intensive prawn culture pond. Polychaetes produced exclusively on the waste nutrients that collected in these gravity-driven sand filters were assessed for their production levels and nutritional contents. Water parameters studied included temperature, salinity, pH, dissolved oxygen (DO), oxidation/ reduction potential (redox), suspended solids, chlorophyll a, biological oxygen demand (BOD), and common forms of nitrogen and phosphorus. Pond water which had percolated through the sand bed had significantly lower pH, DO and redox levels compared with inflow water. Suspended solids and chlorophyll a levels were consistently more than halved by the process. Reductions in BOD appeared dependant on regular subsurface flows. Only marginal reductions in total nitrogen and phosphorus were documented, but their forms were altered in a potentially useful way: dissolved forms (ammonia and orthophosphate) were generated by the process, and this remineralisation also seemed to be accentuated by intermittent flow patterns. Flow rates of approximately 1,500 L m-2 d-1 were achieved suggesting that a 1 ha polychaete bed of this nature could similarly treat the discharge from a 10 ha semi-intensive prawn farm. Sixteen weeks after stocking sand beds with one-month-old P. helleri, over 3.6 kg of polychaete biomass (wet weight) was recovered from the trial. Production on a sand bed area basis was 328 g m-2. Similar (P>0.05) overall biomass production was found for the two stocking densities tested (2000 and 6000 m-2; n = 3), but survival was lower and more worms were graded as small (<0.6 g) when produced at the higher density (28.2 1.5 % and approx. 88 %, respectively) compared with the lower density (46.8 4.4 % and approx. 76 %, respectively). When considered on a weight for weight basis, about half of the worm biomass produced was generally suitable for use as bait. The nutritional contents of the worms harvested were analysed for different stocking densities and graded sizes. These factors did not significantly affect their percentages of dry matter (DM) (18.23 0.57 %), ash (19.77 0.80 % of DM) or gross energy 19.39 0.29 MJ kg-1 DM) (n = 12). Although stocking density did not affect the worms nitrogen and phosphorus contents, small worms had a higher mean proportion of nitrogen and phosphorus (10.57 0.17 % and 0.70 0.01 % of DM, respectively) than large worms (9.99 0.12 % and 0.65 0.01 % of DM, respectively) (n = 6). More lipid was present in large worms grown at the medium density (11.20 0.19 %) compared with the high density (9.50 0.31 %) and less was generally found in small worms (7.1-7.6 % of DM). Mean cholesterol and total phospholipid levels were 5.24 0.15 mg g-1 and 13.66 2.15 mg g-1 DM, respectively (n = 12). Of the specific phospholipids tested, phosphatidyl-serine or sphingomyelin were below detection limits (<0.05 mg g-1), whilst mean levels of phosphatidyl-ethanolamine, phosphatidyl-inositol, phosphatidyl-choline and lysophosphatidyl-choline were 6.89 1.09, 0.89 0.26, 4.04 1.17 and 1.84 0.37 mg g-1, respectively (n = 12). Culture density generally had a more pronounced effect on phospholipid contents than did size of worms. By contrast, worm size had a more pronounced effect on total fatty acid contents, with large worms containing significantly higher (P<0.001) levels on a DM basis (46.88 2.46 mg g-1) than smaller worms (27.76 1.28 mg g-1). A very broad range of fatty acids were detected with palmitic acid being the most heavily represented class (up to 14.23 0.49 mg g-1 DM or 27.28 0.22 % of total fatty acids). Other heavily represented classes included stearic acid (7.4-8.8 %), vaccenic acid (6.8-7.8 %), arachidonic acid (3.5-4.4 %), eicosapentaenoic acid (9.9-13.8 %) and docosenoic acid (5.7-7.0 %). Stocking density did not affect (P>0.05) the levels of amino acids present in polychaete DM, but there was generally less of each amino acid tested on a weight per weight basis in large worms than in small worms. This difference was significant (P<0.05) for the most heavily represented classes being glutamic acid (73-77 mg g-1), aspartic acid (50-54 mg g-1), and glycine (46-53 mg g-1). These results demonstrate how this polychaete species can be planted and sorted at harvest according to various strategies aimed at providing biomass with specific physical and nutritional qualities for different uses.

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Nanocrystalline Ce1-xRuxO2-delta (x = 0.05 and 0.10) of 8-10 nm sizes have been synthesized by hydrothermal method using melamine as complexing agent. Compounds have been characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray analysis (EDX) and their structures have been refined by the Rietveld method.The compounds crystallize in fluorite structure and the composition is Ce1-xRuxO2-x/2 where Ru is in +4 state and Ce is in mixed-valence (+3, +4) state. Substitution of Ru4+ ion in CeO2 activated the lattice oxygen. Ce1-xRuxO2-x/2 reversibly releases 0.22[O] and 0.42[O] for x = 0.05 and 0.10, respectively, which is higher than the maximumpossible OSC of 0.22 [O] observed for Ce0.50Zr0.50O2. Utilization of Higher OSC of Ce1-xRuxO2-delta (x = 0.05 and 0.10) is also reflected in terms of low-temperature CO oxidation with these catalysts, both in the presence and absence of feed oxygen. The Ru4+ ion acts as an active center for reducing molecules (CO, hydrocarbon ``HC'') and oxide ion vacancy acts as an active center for O-2 and NO, leading to low-temperature NO conversion to N-2. Thus due to Ru4+ ion, Ce1-xRuxO2-delta is not just a high oxygen storage material but also shows high activity toward CO, hydrocarbon ``HC'' oxidation, and NO reduction by CO at low temperature with high N-2 selectivity for three-way catalysis.

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Stable carbon isotope ratios of peats dated (by C-14) back to 40 kyr BP from the montane region (> 1800 m asl) of the Nilgiris, southern India, reflect changes in the relative proportions of C3 and C4 plant types, which are influenced by soil moisture (and hence monsoonal precipitation), From prior to 40 kyr BP until 28 kyr BP, a general decline in delta(13)C values from about - 14 per mil to - 19 per mil suggests increased dominance of C3 plants concurrent with increasingly moist conditions, During 28-18 kyr BP there seems relatively little change with delta(13) C of - 19 to - 18 per mil, At about 16 kyr BP a sharp reversal in delta(13)C to a peak of - 14.7 per mil indicates a clear predominance of C4 vegetation associated with arid conditions, possibly during or just after the Last Glacial Maximum, A moist phase at about 9 kyr BP (the Holocene Optimum) with dominance of C3 vegetation type is observed, while arid conditions are re-established during 5-2 kyr BP with an overall dominance of C4 vegetation, New data do not support the occurrence of a moist phase coinciding with the Mediaeval Warm Period (at 0.6 kyr BP) as suggested earlier, Overall, the climate and vegetation in the high altitude regions of the southern Indian tropics seem to have responded to past global climatic changes, and this is consistent with other evidences from India and other tropical regions.

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This thesis consists of an introduction to a topic of optimal use of taxes and government expenditure and three chapters analysing these themes more in depth. Chapter 2 analyses to what extent a given amount of subsidies affects the labour supply of parents. Municipal supplement to the Finnish home care allowance provides exogenous variation to labour supply decision of a parent. This kind of subsidy that is tied to staying at home instead of working is found to have fairly large effect on labour supply decisions of parents. Chapter 3 studies theoretically when it is optimal to provide publicly private goods. In the set up of the model government sets income taxes optimally and provides a private good, if it is beneficial to do so. The analysis results in an optimal provision rule according to which the good should be provided when it lowers the participation threshold into labour force. Chapter 4 investigates what happened to prices and demand when hairdressers value added tax was cut in Finland from 22 per cent to 8 per cent. The pass-through to prices was about half of the full pass-through and no clear indication of increased demand for the services or better employment situation in the sector is found.

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Here we report chromium isotope compositions, expressed as delta Cr-53/ 52 in per mil (&) relative to NIST 979, measured in selected Cr-rich minerals and rocks formed by the primary magmatic as well as the secondary metamorphic and weathering processes. The main objectives of this study were: (i) to further constrain the isotope composition of the Earth's mantle Cr inventory and its possible variation during geological history, based on the analysis of globally distributed and stratigraphically constrained mantle-derived chromites; and (ii) to investigate the magnitude and systematics of Cr isotope fractionation during oxidative weathering and secondary alteration (i. e., hydration, serpentinization) of the magmatic Cr sources. Specifically, we analyzed delta Cr-53/ 52 in a set of globally distributed mantle-derived chromites (FeMgCr2O4, n = 30) collected from various locations in Europe, Asia, Africa and South America, and our results confirm that a chromite-hosted Earth's mantle Cr inventory is uniform at - 0.079 +/- 0.129& (2SD), which we named here as a ` canonical' mantle d 53/ 52 Cr signature. Furthermore our dataset of stratigraphically constrained chromites, whose crystallization ages cover most of the Earth's geological history, indicate that the bulk Cr isotope composition of the chromite-hosted mantle inventory has remained uniform, within about +/- 0.100&, since at least the Early Archean times (similar to 3500 million years ago, Ma). To investigate the systematics of Cr isotope fractionation associated with alteration processes we analyzed a number of secondary Cr-rich minerals and variably altered ultramafic rocks (i. e., serpentinized harzburgites, lherzolites) that revealed large positive delta Cr-53/ 52 anomalies that are systematically shifted to higher values with an increasing degree of alteration and serpentinization. The degree of aqueous alteration and serpentinization was quantified by the abundances of fluid-mobile (Rb, K) elements, and by the Loss On Ignition (LOI) parameter, which determines the amount of structurally bound water (OH/ H2O) present in secondary hydrated minerals like serpentine. Overall, we observed that altered ultramafic rocks that yielded the highest LOI values, and the lowest amounts of fluid mobile elements, also yielded the heaviest delta Cr-53/ 52 signatures. Therefore, we conclude that secondary alteration (i.e., hydration, serpentinization) of ultramafic rocks in near-surface oxidative environments tend to shift the bulk Cr isotope composition of the weathered products to isotopically heavier values, pointing to a dynamic redox cycling of Cr in the Earth's crustal and near-surface environments. Hence, if validated by future

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<p>The O<sup>18</sup>/O<sup>16</sup>, C<sup>13</sup>/C<sup>12</sup>, and D/H ratios have been determined for rocks and coexisting minerals from several granitic plutons and their contact metamorphic aureoles in northern Nevada, eastern California, central Colorado, and Texas, with emphasis on oxygen isotopes. A consistent order of O<sup>18</sup>/O<sup>16</sup>, C<sup>13</sup>/C<sup>12</sup>, and D/H enrichment in coexisting minerals, and a correlation between isotopic fractionations among coexisting mineral pairs are in general observed, suggesting that mineral assemblages tend to approach isotopic equilibrium during contact metamorphism. In certain cases, a correlation is observed between oxygen isotopic fractionations of a mineral pair and sample distance from intrusive contacts. Isotopic temperatures generally show good agreement with heat flow considerations. Based on the experimentally determined quartz-muscovite O<sup>18</sup>/O<sup>16</sup> fractionation calibration curve, temperatures are estimated to be 525 to 625C at the contacts of the granitic stocks studied.</p> <p>Small-scale oxygen isotope exchange effects between intrusive and country rock are observed over distances of 0.5 to 3 feet on both sides of the contacts; the isotopic gradients are typically 2 to 3 per mil per foot. The degree of oxygen isotopic exchange is essentially identical for different coexisting minerals. This presumably occurred through a diffusion-controlled recrystallization process. The size of the oxygen isotope equilibrium systems in the small-scale exchanged zones vary from about 1.5 cm to 30 cm. A xenolith and a re-entrant of country rock projecting into on intrusive hove both undergone much more extensive isotopic exchange (to hundreds of feet); they also show abnormally high isotopic temperatures. The marginal portions of most plutons have unusually high O<sup>18</sup>/O<sup>16</sup> ratios compared to "normal" igneous rocks, presumably due to large-scale isotopic exchange with meta-sedimentary country rocks when the igneous rocks were essentially in a molten state. The isotopic data suggest that outward horizontal movement of H<sub>2</sub>O into the contact metamorphic aureoles is almost negligible, but upward movement of H<sub>2</sub>O may be important. Also, direct influx and absorption of water from the country rock may be significant in certain intrusive stocks.</p> <p>Except in the exchanged zones, the O<sup>18</sup>/O<sup>16</sup> ratios of pelitic rocks do not change appreciably during contact metamorphism, even in the cordierite and sillimanite grades; this is in contrast to regional metamorphic rocks which commonly decrease in O<sup>18</sup> with increasing grade. Low O<sup>18</sup>/O<sup>16</sup> and C<sup>13</sup>/C<sup>12</sup> ratios of the contact metamorphic marbles generally correlate well with the presence of calc-silicate minerals, indicating that the CO<sub>2</sub> liberated during metamorphic decarbonation reactions is enriched in both O<sup>18</sup> and C<sup>13</sup> relative to the carbonates.</p> <p>The D/H ratios of biotites in the contact metamorphic rocks and their associated intrusions show a geographic correlation that is similar to that shown by the D/H ratios of meteoric surface waters, perhaps indicating that meteoric waters were present in the rocks during crystallization of the biotites.</p>

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<p>Detailed oxygen, hydrogen and carbon isotope studies have been carried out on igneous and metamorphic rocks of the Stony Mountain complex, Colorado, and the Isle of Skye, Scotland, in order to better understand the problems of hydrothermal meteoric water-rock interaction.</p> <p>The Tertiary Stony Mountain stock (~1.3 km in diameter), is composed of an outer diorite, a main mass of biotite gabbro, and an inner diorite. The entire complex and most of the surrounding country rocks have experienced various degrees of <sup>18</sup>O depletion (up to 10 per mil) due to interaction with heated meteoric waters. The inner diorite apparently formed from a low-<sup>18</sup>O magma with <sup>18</sup>O +2.5, but most of the isotopic effects are a result of exchange between H<sub>2</sub>O and solidified igneous rocks. The low-<sup>18</sup>O inner diorite magma was probably produced by massive assimilation and/or melting of hydrothermally altered country rocks. The <sup>18</sup>O values of the rocks generally increase with increasing grain size, except that quartz typically has <sup>18</sup>O = +6 to +8, and is more resistant to hydrothermal exchange than any other mineral studied. Based on atom % oxygen, the outer diorites, gabbros, and volcanic rocks exhibit integrated water/rock ratios of 0.3 0.2, 0.15 0.1, and 0.2 0.1, respectively. Locally, water/rock ratios attain values greater than 1.0. Hydrogen isotopic analyses of sericites, chlorites, biotites, and amphiboles range from -117 to -150. D in biotites varies inversely with Fe/Fe+Mg, as predicted by Suzuoki and Epstein (1974), and positively with elevation, over a range of 600 m. The calculated D of the mid-to-late-Tertiary meteoric waters is about -100. Carbonate <sup>13</sup>C values average -5.5 (PDB), within the generally accepted range for deep-seated carbon.</p> <p>Almost all the rocks within 4 km of the central Tertiary intrusive complex of Skye are depleted in <sup>18</sup>O. Whole-rock <sup>18</sup>O values of basalts (-7. 1 to +8.4), Mesozoic shales (-0.6 to + 12.4), and Precambrian sandstones (-6.2 to + 10.8) systematically decrease inward towards the center of the complex. The Cuillin gabbro may have formed from a <sup>18</sup>O-depleted magma (depleted by about 2 per mil); <sup>18</sup>O of plagioclase (-7.1 to + 2.5) and pyroxene (-0.5 to + 3.2) decrease outward toward the margins of the pluton. The Red Hills epigranite plutons have <sup>18</sup>O quartz (-2.7 to + 7.6) and feldspar (-6.7 to + 6.0) that suggest about 3/4 of the exchange took place at subsolidus temperatures; profound disequilibrium quartz-feldspar fractionations (up to 12) are characteristic. The early epigranites were intruded as low-<sup>18</sup>O melts (depletions of up to 3 per mil) with <sup>18</sup>O of the primary, igneous quartz decreasing progressively with time. The Southern Porphyritic Epigranite was apparently intruded as a low-<sup>18</sup>O magma with <sup>18</sup>O -2.6. A good correlation exists between grain size and <sup>18</sup>O for the unique, high-<sup>18</sup>O Beinn an Dubhaich granite which intrudes limestone having a <sup>18</sup>O range of +0.5 to +20.8, and <sup>13</sup>C of -4.9 to -1.0. The D values of sericites (-104 to -107), and amphiboles, chlorites, and biotites (-105 to -128) from the igneous rocks , indicate that Eocene surface waters at Skye had D -90. The average water/rock ratio for the Skye hydrothermal system is approximately one; at least 2000 km<sup>3</sup> of heated meteoric waters were cycled through these rocks.</p> <p>Thus these detailed isotopic studies of two widely separated areas indicate that (1) <sup>18</sup>O-depleted magmas are commonly produced in volcanic terranes invaded by epizonal intrusions; (2) most of the <sup>18</sup>O-depletion in such areas are a result of subsolidus exchange (particularly of feldspars); however correlation of <sup>18</sup>O with grain size is generally preserved only for systems that have undergone relatively minor meteoric hydrothermal exchange; (3) feldspar and calcite are the minerals mos t susceptible to oxygen isotopic exchange, whereas quartz is very resistant to oxygen isotope exchange; biotite, magnetite, and pyroxene have intermediate susceptibilities; and (4) basaltic country rocks are much more permeable to the hydrothermal convective system than shale, sandstone, or the crystalline basement complex.</p>

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<p>Part I.</p> <p>In recent years, backscattering spectrometry has become an important tool for the analysis of thin films. An inherent limitation, though, is the loss of depth resolution due to energy straggling of the beam. To investigate this, energy straggling of <sup>4</sup>He has been measured in thin films of Ni, Al, Au and Pt. Straggling is roughly proportional to square root of thickness, appears to have a slight energy dependence and generally decreases with decreasing atomic number of the adsorber. The results are compared with predictions of theory and with previous measurements. While Ni measurements are in fair agreement with Bohr's theory, Al measurements are 30% above and Au measurements are 40% below predicted values. The Au and Pt measurements give straggling values which are close to one another.</p> <p>Part II.</p> <p>MeV backscattering spectrometry and X-ray diffraction are used to investigate the behavior of sputter-deposited Ti-W mixed films on Si substrates. During vacuum anneals at temperatures near 700C for several hours, the metallization layer reacts with the substrate. Backscattering analysis shows that the resulting compound layer is uniform in composition and contains Ti, Wand Si. The Ti:W ratio in the compound corresponds to that of the deposited metal film. X-ray analyses with Reed and Guinier cameras reveal the presence of the ternary Ti<sub>x</sub>W<sub>(1-x)</sub>Si<sub>2</sub> compound. Its composition is unaffected by oxygen contamination during annealing, but the reaction rate is affected. The rate measured on samples with about 15% oxygen contamination after annealing is linear, of the order of 0.5 per second at 725C, and depends on the crystallographic orientation of the substrate and the dc bias during sputter-deposition of the Ti-W film.</p> <p>Au layers of about 1000 thickness were deposited onto unreacted Ti-W films on Si. When annealed at 400C these samples underwent a color change,and SEM micrographs of the samples showed that an intricate pattern of fissures which were typically 3m wide had evolved. Analysis by electron microprobe revealed that Au had segregated preferentially into the fissures. This result suggests that Ti-W is not a barrier to Au-Si intermixing at 400C.</p>

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DHDH2-5%DHDNADHDNA * DHDNADHRFLP 1MDHADHGDHSKDH4GOT21DH7PER40.22ESTDHAMY 2SDS-PAGEDH4719243000DNA 3500100DNARFLP809DHRFLP 4DNARFLPMR64DH18DH15;MR724DHDNADNADH 5MR13MR50DHMR13DH18MR64DNADH4.3kb40kb15kb2.5kb2.0kbDNADNADNADNApTa71 6MP64695bpA+T58%GENEBANKDNA RFLP1-3CCGGC5600MR64 7MR64;MR72DHDNADNA 8DNAMR4DNAGENEBANKDNAMR68DNA 9DNADNADH

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The Dhir Beel, one of the major live beels of the Brahmaputra Basin, Assam, has an area of 689 ha and situated in Dhubri district of Assam. The dominance of freshwater shark, Wallago attu (8.10%) in the beel is a striking feature. Restricted breeding of W. attu once a year from June to September was observed. The mean observed length was 37.5, 65.0, 84.5 and 99.0 cm in the 6th, 12th, 18th and 24th months of age respectively. The length growth coefficient (K), the asymptotic length (L infinity ), and the arbitrary origin of the growth curve (t omicron ), for W. attu were estimated to be 0.054484 per month, 136.16 cm and 0.0355 month respectively. The calculated life span (T infinity ) of the fish is 123.86 months (about 10 years). The weight growth parameters were estimated where the monthly growth coefficient (K), the asymptotic weight (W infinity) and the arbitrary origin of the growth curve (t omicron) were found to be 0.0743 per month, 7636.92 gram and 0.431908 month respectively. The length-weight relationship follows the cube law.

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East African sun-dried fish dipped for 4 seconds in different solutions of pyrethrum and piperonyl butoxide were analysed for insecticide residue limits. All analyses showed residues above the FAO/WHO MRL; exceeding factors of between 7.6 (22.9 ppm) and 1.6 (5.3 ppm) were found for pyrethrum while exceeding factors between 5.1 (102 ppm) and 1.7 (33.1 ppm) were common for piperonyl butoxide after 6 months storage at ambient temperature. All insecticide treated fish, regardless of dip concentration, were observed to be less susceptible to infestation by Dermestes maculatus than samples of untreated fish. No dry weight losses due to insect infestation were recorded, however moisture evaporation caused weight losses between 6 and 8% during the period. Further investigations showed that careful handling and a dip concentration more in accordance with FAO/WHO MRL than the commercial practice will reduce the cost of insecticides from K.sh. 0.72 to K.sh. 0.23 per kg pyrethrum treated fish.