Narrow Ca Research Articles

A Non-Stressful Temperature Rise and Greater Food Availability Could Increase Tolerance to Calcium Limitation of Daphnia cf. pulex (Sensu Hebert, 1995) Populations in Cold Soft-Water Lakes.

Simple SummaryClimate warming is evident at many cold sites, including high-altitude and high-latitude lakes. The cladoceran Daphnia pulex, with high calcium (Ca) demands for its heavily calcified exoskeleton, is an ecologically important zooplankton species inhabiting these lakes, many of which are Ca-limited. Other stressors, such as warming and food limitation, may interact with Ca limitation and affect Daphnia populations adapted to these cold environments. In a study of factorial design, a clone of North American Daphnia cf. pulex was exposed to a low-Ca gradient, to temperature rises within its preferred range and expected in these lakes, and to conditions of low and high food quantity. Results suggest that climate warming and higher food availability will make D. pulex populations more tolerant to Ca limitation. Changes in the abundance of Daphnia may be relevant to ecological processes and the functioning of aquatic ecosystems.Calcium (Ca) is an important driver of community structure in freshwaters. We examined the combined effects of increased temperatures and variations in food quantity on the tolerance to low Ca of Daphnia pulex. The aim was to predict the impact of climate warming on this keystone zooplanktonic species in cold-climate lakes. We conducted a factorial life-history experiment in a clone of North American Daphnia cf. pulex to analyse the interaction effects of a temperature increase (17.5 °C–21 °C) within their physiological preferred range and expected by climate warming over the next few decades and a narrow Ca gradient (0.25–1.74 mg Ca L−1) under stressful vs. abundant food conditions. We found a striking positive synergistic effect of Ca and temperature on D. pulex reproduction at high food conditions. Although the increase in temperature to 21 °C greatly reduced survival, high energy allocation to reproduction at high food levels allowed the population to succeed in poor Ca (<0.25 mg Ca L−1). Results suggest that climate warming and higher food availability will make the populations of many cold and Ca-limited lakes more tolerant to low Ca levels with higher growth population rates, thereby altering zooplanktonic community structures and inducing potential cascading effects on the food web.

Wide temporal horns are associated with cognitive dysfunction, as well as impaired gait and incontinence

The association between morphology of the brain and symptoms of suspected idiopathic normal pressure hydrocephalus (iNPH) is largely unknown. We investigated how ventricular expansion (width of the temporal horns [TH], callosal angle [CA], and Evans’ index [EI]) related to symptom severity in suspected iNPH. Participants (n = 168; 74.9 years ± SD 6.7; 55% females) from the general population underwent neurological examination, computed tomography, and neuropsychological testing. Multiple linear regression analysis revealed that wide TH was independently associated with all examined iNPH symptoms (p < 0.01) except for fine-motor performance, whereas a narrow CA only was associated to specific motor and cognitive functions (p < 0.05). TH and EI correlated significantly with incontinence (rs 0.17 and rs 0.16; p < 0.05). In conclusion, wide TH was significantly associated with most iNPH-symptoms. This finding potentially reflects the complex nature of the hippocampus, however further studies are needed to demonstrate functional connectivity.

Facies and sequence stratigraphic architecture of the Mural Limestone (Albian), Arizona: Carbonate response to global and local factors and implications for reservoir characterization

AbstractThis study documents the detailed facies and sequence stratigraphic architecture of a multi‐cyclic patch‐reef and its associated ramp interior facies that formed during Oceanic Anoxic Event 1b in the Mural Limestone, Arizona, USA. Ramp interior facies are comprised of bedded wackestone/packstone, rudist build‐up and coral–algal patch‐reef facies located north of Bisbee, Arizona, at the Grassy Hill locality. The larger multi‐cyclic patch‐reef that developed coevallyca5 km to the south of Grassy Hill consists of a high‐angle windward margin with a narrowca70 m long reef frame containing vertically zonatedMicrosolena, Actinastrea, diverse branching coral and rudist assemblages, and an 870 m long low‐angle leeward margin comprised of reef debris rudstone and grainstone shoal facies. Similar reef geomorphology and orientation is documented across the Gulf of Mexico and reflects the shelf‐wide north to north‐east‐trending prevailing wind and current energies. Controls affecting reef formation and growth patterns include changes in accommodation space associated with low‐amplitude global sea‐level rise and regional thermotectonic subsidence, local accommodation space and nutrient fluctuations associated with the inner shelf depositional setting within a humid and siliciclastic‐rich environment. Four aggradational to retrogradational high‐frequency sequences are documented in Arizona: High‐frequency sequences 1 and 2 represent the first pulse of patch‐reef development in an overall second‐order marine transgression over the Sonora/Bisbee Shelf. These sequences correlate to δ13C signatures associated with Oceanic Anoxic Event 1b across the Gulf of Mexico and suggest that carbonate reefs persisted on the ramp interior during this time. High‐frequency sequences 3 and 4 record a second brief transgression and backstepping of reef facies followed by the final regression of shallow shelf carbonates that correlates to more robust patch‐reef development in Sonora, Mexico. The patch‐reef at Paul Spur is an excellent outcrop analogue for productive patch‐reefs in the Maverick Basin (Comanche Shelf) of Texas. Detailed facies mapping of this outcrop analogue shows that the greatest reservoir potential is contained within the backreef grainstone shoals where primary porosity of up to 15% is observed.

The interplay of dietary nutrient specification and varying calcium to total phosphorus ratio on efficacy of a bacterial phytase: 1. Growth performance and tibia mineralization

A 14-d experiment was conducted to study the effects of 2 dietary variables on efficacy of a 6-phytase from Citrobacter braakii on broiler growth performance and tibia mineralization. Diets were formulated with or without nutrient matrix values for phytase as negative or positive control (NC or PC, respectively) and with 2 Ca:total P (tP; 2:1 or 2.5:1). The diets were supplemented with 0, 1,000, or 2,000 phytase units (FYT)/kg, thus producing a 2 × 2 × 3 factorial arrangement. Birds and feed were weighed on d 7 and 21, and tibia bones were collected from all the birds on d 21. The main effects of nutrient matrix, Ca:tP, and phytase supplementation were significant (P < 0.05) for all the growth performance responses (except for G:F for which there was no effect of matrix). The Ca:tP × phytase and matrix × phytase interactions were significant (P < 0.05) for weight gain. In the PC diets, phytase increased weight gain (P < 0.05) relative to the control only in diets with 2,000 FYT/kg, whereas in NC diets weight gain increased (P < 0.01) only from 0 to 1,000 FYT/kg levels. Broilers consuming diets with 2.5:1 Ca:tP had lower (P < 0.05) tibia ash, whereas phytase increased (P < 0.01) tibia ash, Ca, P, and Zn but decreased (P < 0.01) tibia K. Phytase supplementation of diets with 2:1 Ca:tP increased (P < 0.05) tibia P in birds receiving 1,000 FYT/kg relative to the control with no further increase at 2,000 FYT/kg, whereas each level of phytase supplementation increased (P < 0.05) tibia P in the diets with 2.5:1 Ca:tP. It was concluded that the best response to lower phytase supplementation (1,000 FYT/kg) was in NC diets with narrow Ca:tP, whereas the best response to higher level of phytase supplementation (2,000 FYT/kg) was achieved in diets in PC diets with wide Ca:tP.

Fast GCaMPs for improved tracking of neuronal activity.

The use of genetically encodable calcium indicator proteins to monitor neuronal activity is hampered by slow response times and a narrow Ca(2+)-sensitive range. Here we identify three performance-limiting features of GCaMP3, a popular genetically encodable calcium indicator protein. First, we find that affinity is regulated by the calmodulin domain's Ca(2+)-chelating residues. Second, we find that off-responses to Ca(2+) are rate-limited by dissociation of the RS20 domain from calmodulin's hydrophobic pocket. Third, we find that on-responses are limited by fast binding to the N-lobe at high Ca(2+) and by slow binding to the C-lobe at lower Ca(2+). We develop Fast-GCaMPs, which have up to 20-fold accelerated off-responses and show that they have a 200-fold range of K(D), allowing coexpression of multiple variants to span an expanded range of Ca(2+) concentrations. Finally, we show that Fast-GCaMPs track natural song in Drosophila auditory neurons and generate rapid responses in mammalian neurons, supporting the utility of our approach.

Crustacean zooplankton sedimentary remains from calcium-poor lakes: complex responses to threshold concentrations

Declines in lakewater calcium (Ca) concentrations are occurring in many softwater lakes of the Canadian Shield, and likely elsewhere, and there is growing interest regarding the potential impacts that reduced Ca availability may have on aquatic ecosystems. Here, we test the hypotheses that the Ca limitations of Daphnia pulex (reduced growth/survival when Ca <1.5 mg L−1) identified in laboratory analyses and paleolimnological case studies can be observed among cladoceran assemblages from surface sediments along a narrow Ca gradient (1–3 mg L−1), and also whether the impacts of low Ca concentrations can be distinguished from those of low lakewater pH. Significant differences among daphniid communities were observed across the 1.5 mg L−1 Ca threshold; however, these differences did not extend to the broader cladoceran community and considerable variability in Ca tolerance was observed within the D. pulex species complex. Of the measured environmental variables, only pH and lake depth explained a significant amount of variation among the entire cladoceran community, although when enlarging the dataset to extend the Ca and pH ranges, Ca replaced pH as a significant explanatory variable. Our data adds support to our previous observations that, within the cladoceran community, daphniids are the most responsive to Ca decline, however responses differ within daphniid species complexes and Ca thresholds under natural conditions may be higher for some species than their laboratory-identified values.

Elemental Depth Profiling of Fluoridated Hydroxyapatite: Saving Your Dentition by the Skin of Your Teeth?

Structural and chemical changes that arise from fluoridation of hydroxyapatite (Ca(5)(PO(4))(3)OH or "HAp"), as representing the synthetic counterpart of tooth enamel, are investigated by X-ray photoelectron spectroscopy (XPS). Elemental depth profiles with a depth resolution on the nanometer scale were determined to reveal the effect of fluoridation in neutral (pH = 6.2) and acidic agents (pH = 4.2). With respect to the chemical composition and the crystal structure, XPS depth profiling reveals different effects of the two treatments. In both cases, however, the fluoridation affects the surface only on the nanometer scale, which is in contrast to recent literature with respect to XPS analysis on dental fluoridation, where depth profiles of F extending to several micrometers were reported. In addition to the elemental depth profiles, as published in various other studies, we also present quantitative depth profiles of the compounds CaF(2), Ca(OH)(2), and fluorapatite (FAp) that were recently proposed by a three-layer model concerning the fluoridation of HAp in an acidic agent. The analysis of our experimental data exactly reproduces the structural order of this model, however, on a scale that differs by nearly 2 orders of magnitude from previous predictions. The results also reveal that the amount of Ca(OH)(2) and FAp is small compared to that of CaF(2). Therefore, it has to be asked whether such narrow Ca(OH)(2) and FAp layers really can act as protective layers for the enamel.

Measurements of mean longitudinal magnetic fields in the Of?p stars HD 108 and HD 191612

AbstractUsing polarimetric spectra obtained with the SOFIN spectrograph installed at the Nordic Optical Telescope, we detect a longitudinal magnetic field 〈Bz〉 = –168±35 G in the Of?p star HD 108. This result is in agreement with the longitudinal magnetic field measurement of the order of –150 G recently reported by the MiMeS team. The measurement of the longitudinal magnetic field in the Of?p star HD 191612 results in 〈Bz〉 = +450±153 G. The only previously published magnetic field measurement for this star showed a negative longitudinal magnetic field 〈Bz〉 = –220±38 G, indicating a change of polarity over ∼100 days. Further, we report the detection of distinct Zeeman features in the narrow Ca II and Na I doublet lines for both Of?p stars, hinting at the possible presence of material around these stars. The origin of these features is not yet clear and more work is needed to investigate how magnetic fields interact with stellar wind dynamics (© 2010 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

The Effect of Cultivation Method on the Macronutrients Content of Shallot Bulbs (Allium Ascalonicum L.)

The Effect of Cultivation Method on the Macronutrients Content of Shallot Bulbs (Allium Ascalonicum L.) A field experiments were carried out in 2005-2007 at the Experimental Station of the University of Warmia and Mazury in Olsztyn. The experiments were set up in a split-plot design, in four replications. Plants were grown in typical black earth soil of quality class IIIb, cereal-fodder strong complex. The first experimental factor was the cultivation method. In the first year of the study, shallot were grown by direct seeding and from seedlings, while small bulbs (Ø 16-20 mm) were additionally introduced in the second year of the experiment. Cultivars were the second experimental factor. The analyzed material consisted of two hybrid shallot cultivars: Bonilla F1 and Matador F1. A total of 100 plants were grown in experimental plots with an area of 3 m2, with 30 × 10 cm spacing. Shallots were harvested when the foliage on approximately 60 to 70% of plants have collapsed. Plant material (bulbs) was assayed for nitrogen, phosphorus, potassium, calcium and magnesium concentrations. The highest total nitrogen levels were determined in shallot bulbs grown from seedlings, while shallots bulbs grown from seeds were most abundant in phosphorus, potassium, calcium and magnesium. Significantly higher nitrogen and phosphorus concentrations were observed in the bulbs of cv. Matador F1, while Bonilla F1 bulbs showed significantly higher levels of potassium, calcium and magnesium. Favorable Ca:Mg ratios, narrow Ca:P ratios and wide K:Mg, K:(Ca+Mg) and K:Ca ratios were noted in all experimental variants.

Linking mean body size of pelagic Cladocera to environmental variables in Precambrian Shield lakes: A paleolimnological approach

Daphnia and Bosmina fragments were identified and measured in the surface sediments of 42 lakes in the Muskoka-Haliburton region of Ontario, Canada, in an attempt to identify environmental factors that may influence cladoceran body size. Specifically, pecten length on Daphnia post-abdominal claws, antennule length on Bosmina headshields, and carapace and mucro lengths of Bosmina carapaces were measured. These measurements were then compared to limnological variables previously identified as possibly influencing cladoceran size, including dissolved organic carbon (DOC), total phosphorus (TP), pH, calcium (Ca), Chaoborus density, and fish presence/absence. Cladoceran size displayed a linear relationship to TP, with larger Bosmina and Daphnia present in lakes with lower nutrient levels. We suspect that, as larger individuals are more efficient grazers, they may competitively exclude smaller individuals when nutrients are limiting in these lakes. Bosmina mucro length and cladoceran community size structure displayed a step response to DOC, with mean size significantly smaller when DOC concentrations were higher than 5.89 mg L-1. Daphnia pecten length displayed a negative linear relationship to DOC above a concentration of 4.90 mg l-1. Reduced predation pressure from gape-limited macroinvertebrate predators, such as Chaoborus, may have influenced these relationships. DOC was also highly correlated to TP in these lakes, and size trends might be responding to the TP gradient rather than the DOC gradient. Mean cladoceran body size in acidic lakes (pH 6.0). There was no relationship between size structure and Ca concentrations, attributed to a narrow Ca gradient in these lakes. Predation effects were examined using limited Chaoborus density and fish presence/absence data. Although there were no significant relationships between cladoceran size and Chaoborus density, some significant relationships between size variables and fish predation were identified. The sensitivity of size variables to certain environmental gradients suggests that size structure has the potential to be an effective paleolimnological tool.

Effect of low doses of Aspergillus niger phytase on growth performance, bone strength, and nutrient absorption and excretion by growing and finishing swine fed corn-soybean meal diets deficient in available phosphorus and calcium1

Two experiments were conducted to evaluate the efficacy of low doses of Aspergillus niger (AN) phytase for growing and finishing pigs fed corn-soybean meal (SBM) diets with narrow Ca:P ratios that were about 0.9 g/kg deficient in available P and Ca. Experiment 1 utilized 120 pigs with an early finisher period from 51.5 +/- 0.2 to 89.7 +/- 0.9 kg of BW and a late finisher period that ended at 122.5 +/- 2.0 kg of BW. During each period, treatments were the low-P diets with 0, 150, 300, or 450 units (U) of AN phytase added/kg of diet, and a positive control (PC) diet. There were linear increases (P < or = 0.001) in bone strength and ash weight, the absorption of P (g/d and %) and Ca (%), and overall ADG (P = 0.01) with increasing concentration of AN phytase. Pigs fed the diets with 150, 300, or 450 U of AN phytase/kg did not differ from pigs fed the PC diet in growth performance overall, and pigs fed the diets with 300 or 450 U of AN phytase did not differ in P and Ca absorption (g/d) or bone ash weight from pigs fed the PC diet. However, only pigs fed the diet with 450 U of AN phytase/kg had bone strength similar to that of pigs fed the PC diet. Experiment 2 utilized 120 pigs in a grower phase from 25.3 +/- 0.1 to 57.8 +/- 0.8 kg of BW and a finisher phase that ended at 107.6 +/- 1.0 kg of BW. Treatments were the low-P diet with AN phytase added at 300, 500, or 700 U/kg of grower diet, and 150, 250, or 350 U/kg of finisher diet, respectively, resulting in treatments AN300/150, AN500/250, and AN700/350. Growth performance and the absorption (g/d) of P and Ca for the grower and finisher phases were not different for pigs fed the diets containing AN phytase and pigs fed the PC diets. However, pigs fed the PC diets excreted more fecal P (g/d, P < or = 0.01) during the grower and more P and Ca (g/d, P < 0.001) during the finisher phases than the pigs fed the diets with phytase. There were linear increases (P < or = 0.05) in bone strength and bone ash weight with increasing concentration of AN phytase. However, pigs fed the PC diets had a greater bone strength and bone ash weight than pigs fed diets AN300/150, AN500/250 (P < or = 0.02), or AN700/350 (P < or = 0.08). There were no treatment responses for N or DM digestibility in either experiment. Phytase supplementation reduced fecal P excretion from 16 to 38% and fecal Ca excretion from 21 to 42% in these experiments. In conclusion, 450 U of AN phytase/kg was effective in replacing 0.9 g of the inorganic P/kg of corn-SBM diet for finishing swine based on bone strength, whereas 300 or 150 U of AN phytase/kg of diet maintained growth performance of grower or finisher pigs, respectively.

Low-column density gas clumps in the halo of the Milky Way

We report on the detection of low-column density neutral hydrogen clumps in the halo of the Milky Way. Using high-resolution (FWHM ∼ 7 km s -1 ) optical spectra obtained with the VLT/UVES spectrograph we detect narrow interstellar absorption by Ca II and Na I at high radial velocities near u LSR -150 km s -1 toward the quasar PKS 1448-232 (/ = 335.4, b = +31.7). Follow-up Hi 21 cm observations with the VIA unveil the presence of a complex of small neutral hydrogen clumps with H 1 column densities <8 × 10 18 cm -2 . The measured H line widths imply that the gas is relatively cold with temperatures T ≤ 900 K. Although the line of sight towards PKS 1448-232 does not pass immediately through a known large high-velocity cloud (HVC). the sky position and the measured radial velocities suggest that these clumps arc associated with HVC cloud complex L. An inspection of other UVES quasar spectra shows that weak. narrow Ca II absorption at high velocities is a common phenomenon, even in directions where high-velocity H 1 21 cm emission is not detected. This suggests that the Milky Way halo contains a large number of high-velocity neutral gas clumps with low H I column densities. If such clumps are typical for halos of spiral galaxies, they should contribute significantly to the population of strong Mg II absorbers and Lyman-Limit Systems (LLS) seen in the circumgalactic environment of other galaxies.

Ultra–High‐Resolution Spectroscopy of a Nearby High‐Latitude Filament

We report new observations of Na I and Ca II interstellar absorption in a nearby (230 ^ 30 pc) southern high-latitude —lament obtained at a spectroscopic resolution of D0.32 km s~1 using HD 22252 as the background probe. Complex absorption is present for both species with total column densities of N(Ca II) D 1.3 ) 1012 cm~2 and N(Na I) ( 7 ) 1012 cm~2. Over a velocity range of 25 km s~1 we —nd 11 Ca II velocity components loosely grouped into three velocity aggregates. Unusually narrow Ca II absorption is present with b-values in the range 0.25¨0.5 km s~1; such small values are rarely dis- covered. Each of these narrow Ca II components has an associated broader component at a slightly shifted velocity. Finally, there are two Ca II clouds with large b-values (D 5k m s~1) but no detectable Na I that —ank the three aggregates. At our particular intercept we may be observing the —lament edge-on and seeing cold interior condensations each with a warm outer shellall contained within a further exterior envelope of ionized gas. We estimate that a typical interior condensation will have a linear dimension d in the range 104 d 6 ) 104 AU and a pressure nT of 1.5 nT 9 ) 104 cm~3 K, but with large uncertainties. This result is consistent with the picture of small and relatively dense cloud cores expanding into the local bubble. Subject headings: ISM: kinematics and dynamicsline: pro—lesstars: individual (HD 22252)

Defect and Electronic Structures of Calcium‐Doped Lanthanum Cuprate

Quenched calcium‐doped lanthanum cuprate (La2CuO4) samples were examined at room temperature using extended X‐ray absorption fine structure (EXAFS) analysis and X‐ray absorption near‐edge spectroscopy (XANES) near the CaK edge, and via atomic‐ and electronic‐structure modeling. Calculations and experiments show that the Ca atom, in a manner similar to that of Sr and Ba atoms, replaces the La atom and maintains its nine‐fold coordination above the center of a CuO4 square, which is the nominal position of the La atom. In contrast to the Sr and Ba atoms, the distances from Ca to its nearest neighbors are similar to the size of the La3+ cation. The distances that are obtained from the simulation are in reasonable agreement with the experimental results for calcium, as well as previous studies that involved strontium and barium. The binding of a calcium dopant to vacancies on the O(1) sites is stable, but only slightly; therefore, there are probably many different types of such clusters. This calculated binding also is supported by the EXAFS data. The overall electronic structure is similar to that observed in calculations for pure La2CuO4: the LaO planes remain ionic, even with the presence of the calcium dopant, and the Cu‐O(1) bond is covalent. The calcium is ionic in character, with a net charge of 1.6, and the narrow Ca 3d band lies ∼6 eV above the Fermi energy level.

Spatially resolved optical spectroscopy of the Herbig Ae/Vega-like binary star HD 35187

We report on observations of the young binary system HD 35187 (SAO 77144). For the first time, we have obtained spatially resolved optical spectra of the individual stars. Analysis of their effective temperatures indicates that the stars have spectral types of A2 (HD 35187B) and A7 (HD 35187A). Analysis of the Hγ Balmer line indicates a luminosity class V for both stars. At the time of these observations, net Hα emission was present only towards HD 35187B. However, there is evidence that the photospheric Hα line in HD 35187A has been ‘filled in’ relative to its expected strength in an A7 star, so this star may also be associated with some process leading to Hα emission. Moreover, both stars exhibit absorption in the He iλ5876 line well in excess of that expected for their spectral types. Comparison with earlier observations reveals that both the Hα and He i lines are variable, so both stars are ‘active’ in some sense. We suggest that the variable He i absorption detected towards both stars is a result of chromospheric activity, and is not necessarily related to the circumstellar environment. We find tentative evidence for a narrow Ca K circumstellar absorption line and excess redshifted absorption of the Na D line profiles in the spectrum of HD 35187B, both of which are absent in the spectrum of HD 35187A. The heliocentric radial velocity of the presumed circumstellar Ca K line (+54.5 km s−1) is similar to that of redshifted circumstellar absorption lines previously identified in IUE spectra of this star, and the velocity range of the Na D absorption precisely matches that of the UV circumstellar components. Moreover, by placing the stars on the HR diagram (with the aid of the reliable Hipparcos distances) we find evidence that HD 35187B is dimmed by about 0.4 mag of grey circumstellar extinction. The detection of net Hα emission, circumstellar absorption lines, and significant circumstellar extinction for HD 35187B suggests that it has far more mass in its circumstellar environment than its companion, and that the observed IR excess of this system originates from a disc surrounding HD 35187B alone.

Ultra–High‐Resolution Observations of Interstellar Naiand CaiiK toward the High Galactic Latitude Star HD 28497

We present very high resolution (0.32 km s-1) spectra of interstellar Na I D1, D2, and Ca II K absorption toward HD 28497 obtained with the Ultra-High-Resolution Facility at the 3.9 m Anglo-Australian Telescope. The star is located in projection in a highly disturbed interstellar region close to a number of identified features including the high galactic latitude molecular cloud MBM 20, the large Orion-Eridanus shell, seen in Hα and H I 21 cm maps, and a filamentary loop structure between vLSR = -12 and -4 km s-1 in the Berkeley H I 21 cm survey and visible on the IRAS 100 μm map. Toward HD 28497 we detect 13 absorption components in the Na I spectra, to a column density limit of 2 × 1010 cm-2, and 10 in Ca II K over a velocity range of ~70 km s-1. Four absorption components in the Na I spectra show s-resolved hyperfine structure with b-values from 0.31 to 0.40 km s-1 and column densities from 4.0 to 14 × 1010 cm-2. If we assume the clouds represented by these components have no internal turbulent velocities, their temperatures would range between 134 and 227 K. One of these hyperfine split (hfs) components, at vLSR = -11.1 km s-1, shows significant temporal variation in equivalent width compared to earlier (1977) observations, making this the first interstellar sight line outside the Vela supernova remnant to show a time-varying component. The feature may be associated with the filamentary loop structure seen in this region. There is poor correspondence between the Na I and Ca II profiles: we do not detect narrow Ca II profiles to the four hfs Na I components, and only three of the well-resolved components have the same Ca II and Na I radial velocities and consistent b-values. One of these components, at vLSR = -30.0 km s-1, has a low Na I/Ca II ratio and arises in a region where turbulent motions dominate—properties consistent with the hypothesis that the cloud lies close to HD 28497. In general, however, the Na I and Ca II occupy different gaseous phases in the ISM. We have compared our data with 21 cm emission profiles obtained from the recent Leiden/Dwingeloo H I survey. Based on agreement in the velocities, the Na I/Ca II ratio, and the kinetic temperatures, we conclude that the component at vLSR = -7.5 km s-1 is associated with the front side of the large, expanding Orion-Eridanus shell. Unexpectedly, the molecular cloud MBM 20 is not detected either in our absorption spectra or in the H I profiles, indicating that HD 28497 lies away from the core of MBM 20. Apart from the two features at -11 and -7.5 km s-1 there is almost no agreement between the H I profiles and the optical spectra. Although we cannot rule out the possibility that most of the H I lies behind the star, this explanation seems unlikely because many of the H I features have previously been attributed to foreground phenomena. The beam sizes of the H I and the optical studies are quite different and this suggests a different explanation, namely that the physical sizes of the interstellar structures we detect in Na I and Ca II are not extensive enough to be detected in H I. If so, this raises questions about the usefulness in general of combining results obtained from H I 21 cm studies with results obtained from optical (or ultraviolet) studies of the interstellar gas.

Solonetzic soil properties and yields of wheat, oats and barley as affected by deep plowing and ripping

Deep tillage using two new implements, a three moldboard topsoil saving plow and a soil ripper was compared with classical single moldboard deep plowing and with shallow tilled check areas on four sites on Solonetzic soils in the Brown soil zone of the Province of Alberta, Canada. The study included the determination of several physical and chemical soil properties, crop yields in the field, two greenhouse experiments, and some plant analysis. Each field treatment was applied at two different locations. The single deep plowing gave, in general, more desirable results in soil changes and crop yields than the topsoil saving plow. The ripper was beneficial at one site and detrimental at the other. It was concluded that the resulting Ca:Na ratio was the main factor determining the success of deep plowing; that the topsoil saving plow did not function properly; and that soil deterioration and crop yield reduction after ripping at one site was probably caused by the relatively greater depth of the Bnt horizon, the high clay content and a very narrow Ca:Na ratio.

Influences of Calcium Intake and Vitamin D Supplementation on the Composition of Lactating Cows’ Blood

Two rations with Ca:P ratios averaging 1.1 :1 and 2.3 :1, each with and without 300,000 IU supplemental vitamin D3 weekly by capsule, were fed to study the effects on concentrations of calcium and several phosphorus fractions in blood of 46 Holstein cows, each for 1 to 3 lactations. High energy rations (alfalfa hay-sorghum grain-soybean oil meal), supplemented to furnish more than adequate phosphorus with calcium in the indicated ratios, were group fed to satiety. During the first year, following only 45-day pretrial treatment, serum calcium, inorganic phosphorus and magnesium were not influenced significantly by imposed treatments. During two succeeding years, preceded by at least 5-month pretreatment for all cows, plasma calcium was greater in blood from cows fed the lower calcium ration (432 observations). Vitamin D supplementation did not influence measured blood constituents but interacted with Ca :P ratios so the larger packed cell volume and greater phosphorus content of blood cells were associated with vitamin D supplement in the narrow Ca:P treatment and with no vitamin D supplement in the wider Ca :P treatment. Plasma phosphorus and plasma inorganic phosphorus were not influenced significantly by treatment. All measures, except blood cell phosphorus concentrations in cells and in blood, varied significantly with stage of lactation.

Geologisch‐archäologische Untersuchungen zu den Entstehungsbedingungen der Marschen in Nordfriesland

Geological and archaeological investigation of the mode of origin of the marshes in Nordfriesland (Germany)In the bogs between marine sediments and Pleistocene uplands on the mainland of Nordfriesland, saltbearing peat for salt production was dug before, as well as while, the bogs were covered by sediments with high clay content. Additionally, there is not much fresh‐water coming from the Pleistocene uplands and carbonate is only preserved in the “Klei” deposited in the resulting holes. These facts show, that the “Klei” was originally calcareous and that it was deposited in water with a high salt content. Therefore one cannot conclude that adsorbed cations and narrow Ca:Mgratio (0.5–1.5) indicate sedimentation in brackish water and deposition of sediments with a low, or indeed, no carbonate content. Hence adsorbed cations and the Ca:Mgratio do not allow the separation of marsh soils from soils of a marine or brackish origin.