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1

Impacts of an exotic disease and vegetation change on foliar calcium cycling in Appalachian forests.  

PubMed

Because of the high calcium content of its foliage, Cornus florida (flowering dogwood) has been described as a calcium "pump" that draws calcium from deeper mineral soil and enriches surface soil horizons. However, over the last two decades an exotic fungal disease (dogwood anthracnose, Discula destructiva) has decimated populations of this once-common understory species. Its loss, combined with forest stand development, could alter intra-stand calcium cycling. We used data from long-term vegetation monitoring plots to examine the ecological role of C. florida in calcium cycling and to identify changes in annual foliar calcium cycling over a 20-year period between two sampling intervals, 1977-1979 (preanthracnose) and 1995-2000 (post-anthracnose). Published equations were used to estimate foliar biomass per species for five forest types: alluvial, typic cove, acid cove, oak-hickory, and oak-pine. Calcium concentrations derived from foliage samples were used to estimate annual foliar calcium production per species for understory woody stems (<20 cm dbh) and total foliar calcium production for overstory stems (> or =20 cm dbh). At a given level of soil calcium availability, C. florida foliage contained greater concentrations of calcium than three other dominant understory species (Tsuga canadensis, Acer rubrum, and Rhododendron maximum). Between 1977-1979 and 1995-2000, the annual calcium contributions of understory woody vegetation declined across all forest types, ranging from 26% in oak-pine stands to 49% in acid coves. Loss of C. florida was responsible for only 13% of this decline in oak-pine stands, but accounted for 96% of the decline in typic coves. In oak-hickory and oak-pine stands, we observed large increases in the foliar biomass of T. canadensis, a species whose calcium-poor foliage increases soil acidity. Increases in overstory foliar biomass and calcium offset understory losses in three forest types (alluvial, typic coves, and oak-pine) but not in oak-hickory and acid cove stands. Overall, calcium cycling in oak-hickory stands was more negatively affected by the loss of C. florida than the other forest types. Oak-hickory forests comprise over a third of the total forest cover in the eastern United States, and decreases in annual calcium cycling could have cascading effects on forest biota. PMID:17494403

Jenkins, Michael A; Jose, Shibu; White, Peter S

2007-04-01

2

A NEW STRATEGY TO ENRICH CALCIUM NUTRITION OF FRUIT: SYNERGISTIC EFFECTS OF POSTHARVEST FOLIAR CALCIUM AND BORON SPRAYS  

Microsoft Academic Search

The objective of the study is to investigate the role of calcium (Ca) and boron (B) synergy in higher maintenance of Ca in fruit buds during senescence. To study the hypothesis, an experiment was conducted for two years in two ‘Starking Delicious’ apple (Malus domastica Borkh.) orchards established on seedling rootstocks in Banaz, Usak, Turkey. Treatments composed of postharvest foliar

Fatih Sen; Ismail Karacali; Mehmet Esref Irget; Omer Lutfu Elmaci; Mahmut Tepecik

2010-01-01

3

RESPONSE OF WHEAT TO FOLIAR APPLICATION OF NUTRIENTS  

Microsoft Academic Search

Foliar application can guarantee the availability of nutrients to crops for obtaining higher yield. To study the response of wheat to foliar application of nutrients, an experiment was conducted at Agricultural Research Farm of NWFP Agricultural University Peshawar during winter 2005-06. The treatments consist of control (water spray), spray at tillering (single spray) and\\/or spray at jointing (two sprays) and\\/or

Muhammad Arif; Muhammad Aslam Chohan; Sajid Ali; Rozina Gul; Sajjad Khan

2006-01-01

4

Foliar application of two silica sols reduced cadmium accumulation in rice grains.  

PubMed

In the present study, pot experiments were conducted to investigate the effects of foliar application of two silica (Si) sols on the alleviation of cadmium (Cd) toxicity in contaminated soil to rice. Results showed that the foliar application of Si sols significantly increased the dry weight of grains (without husk) and shoots in rice grown in Cd contaminated soil, whereas the Cd concentration in the grains and shoots decreased obviously. The total accumulation of Cd in rice grains also decreased with the application of both of the Si sols, but no significant effect was found on the Cd accumulation in the shoots. For the optimal effect, Si-sol-B should be foliar applied at the tillering-stage during rice growth. The mechanism of Si foliar application to alleviate the toxicity and accumulation of Cd in grains of rice may be related to the probable Cd sequestration in the shoot cell walls. PMID:18555602

Liu, Chuanping; Li, Fangbai; Luo, Chunling; Liu, Xinming; Wang, Shihua; Liu, Tongxu; Li, Xiangdong

2009-01-30

5

Effects of foliar sprays containing calcium, magnesium and titanium on plum (Prunus domestica L.) fruit quality.  

PubMed

An experiment was performed in which Ti(4+)-ascorbate was sprayed onto plum trees in several combinations with other commercial compounds containing Ca2+ and Mg2+ to study the effects on the commercial quality of fruits, with special focus on improving their resistance against postharvest handling damage. All the treatments containing titanium increased the tree performance (branch elongation, flowering and fruit setting intensities) and fruit size. At harvest fruits from the Ti-treated trees showed improved resistance to compression and penetration, as well as a decrease in weight-loss during postharvest storage. A similar response was obtained for the external colour, though all the treatments seemed to delay somewhat the apparent ripening status. Nevertheless, the fruits from Ti-treated trees showed a better behaviour in the evolution of the colour parameters during storage than did the control fruits. Titanium application significantly increased the calcium, iron, copper and zinc concentrations in peel and flesh. This improvement in the calcium absorption is explained as a consequence of the beneficial effect of titanium on the absorption, translocation and assimilation processes. PMID:14717435

Alcaraz-Lopez, Carlos; Botia, Maria; Alcaraz, Carlos F; Riquelme, Fernando

2003-12-01

6

Control of Potato Tuber Rots Caused by Oomycetes with Foliar Applications of Phosphorous Acid  

Microsoft Academic Search

Johnson, D. A., Inglis, D. A., and Miller, J. S. 2004. Control of potato tuber rots caused by oo- mycetes with foliar applications of phosphorous acid. Plant Dis. 88:1153-1159. Phosphorous acid for control of tuber rots caused by Phytophthora infestans, P. erythroseptica, and Pythium ultimum was applied to foliage of potato cultivars at various application timings and rates under growing

Dennis A. Johnson; Debra A. Inglis; Jeffrey S. Miller

2004-01-01

7

Relationships among Chloroplast Pigments Concentration and Chlorophyllmeter Readings in Soybean under Influence of Foliar Magnesium Application  

Microsoft Academic Search

The influence of foliar magnesium (Mg) application before flowering on chloroplast pigment indices was investigated in a 2?year field experiment with five soybean cultivars. Acetone extraction of pigments (chlorophyll a and b, total chlorophylls, and carotenoids as well as their ratios) was compared to chlorophyll meter (SPAD?502) readings. The untreated plants showed significant influence of cultivar on pigment concentrations, and

Tihana Tekli?; Marija Vratari?; Aleksandra Sudari?; Vlado Kova?evi?; Vladimir Vukadinovi?; Blaženka Berti?

2009-01-01

8

Effect of Foliar Salicylic Acid Applications on Growth, Chlorophyll, and Mineral Content of Cucumber Grown Under Salt Stress  

Microsoft Academic Search

The objective of this study was to determine the effect of foliar salicylic acid (SA) applications on growth, chlorophyll, and mineral content of cucumber grown under salt stress. The study was conducted in pot experiments under greenhouse conditions. Cucumber seedlings were treated with foliar SA applications at different concentrations (0.0, 0.25, 0.50, and 1.00 mM). Salinity treatments were established by

Ertan Yildirim; Metin Turan; Ismail Guvenc

2008-01-01

9

Screening of As-accumulating plants using a foliar application and a native accumulation of As.  

PubMed

The discovery of novel accumulating plants is useful for efficient phytoremediation due to the demands of various conditions of impacted sites such as land use, soil properties, concentration of pollutants, and climate. In the present study, we investigated foliar application or a field with highly bioavailable arsenic (As) to screen As-accumulating plants. Plants grown in the downstream of a hot springs area were analyzed for native As accumulation and As foliar application, and the rhizosphere soils were collected. The water-soluble As in the rhizosphere soils had a high average, 144 microg/kg, whereas total As was similar to normal soil in Japan. Among 34 herbaceous plants and 17 woody plants, Chelidonium majus var. asiaticum accumulated a relatively high As level, 8.07 mg/kg DW (93.6% of As added), that was not revealed by native accumulation. In a further pot experiment, C. majus accumulated a moderately high As level (314 mg/kg DW) in the roots but not in the shoot (30.1 mg/kg DW), and exhibited a low transfer factor (TF = 0.096). Thus, a foliar application would be a simple and high-throughput method to screen plants that accumulate and tolerate As. C. majus would be useful as a tool for phytostabilization of As. PMID:24912222

Zhang, Z; Sugawara, K; Hatayama, M; Huang, Y; Inoue, Chihiro

2014-01-01

10

Application of Calcium Phosphate Materials in Dentistry  

PubMed Central

Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1) application of calcium phosphate into various fields in dentistry; (2) improving mechanical properties of calcium phosphate; (3) biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials such as hydroxyapatite and tricalcium phosphate which are currently used in dental and medical fields.

Al-Sanabani, Jabr S.; Al-Sanabani, Fadhel A.

2013-01-01

11

Application of calcium phosphate materials in dentistry.  

PubMed

Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1) application of calcium phosphate into various fields in dentistry; (2) improving mechanical properties of calcium phosphate; (3) biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials such as hydroxyapatite and tricalcium phosphate which are currently used in dental and medical fields. PMID:23878541

Al-Sanabani, Jabr S; Madfa, Ahmed A; Al-Sanabani, Fadhel A

2013-01-01

12

Foliar Boron Applications Increase the Final Number of Branches and Pods on Branches of Field-Grown Soybeans 1  

PubMed Central

Our previous work demonstrated that boron (B) supplied to soybeans (Glycine max [L.] Merrill cv `Williams 82') by a stem infusion technique increased the number of pods on branches and led to a significant yield increase. Therefore, research was continued to determine whether soil or foliar applications of B could be used to achieve the same results. Field experiments were completed with both soil and foliar applications of B. Only the foliar applications of B resulted in a significant increase in the number of pods/branch. When split foliar treatments were applied twice during flowering, the total application of 0.56 kilograms of B per hectare was the optimal treatment for increasing pods/branch. In a second field experiment in 1987, soybeans were treated weekly from flowering through podfill with six split foliar applications of aqueous H3BO3 solutions so that total applications were either 0, 1.1, or 2.24 kilograms of B per hectare. Foliar applications increased the number of branches/plant at the end of the season and significantly stimulated the formation of pods on branches, with 1.12 kilograms of B per hectare being the optimal treatment for these variables. This rate also tended to increase the number of seeds/plant and seed yield/plant. A duplicate experiment with minor modifications was conducted during the summer of 1988, and again the 1.12 kilograms of B per hectare application rate resulted in significant increases in number of branches at harvest as well as number of pods on branches. The 2.24 kilograms of B per hectare application rate also significantly increased these parameters. Foliar B applications induced increases in leaf B concentration far above the 60 micrograms per gram level that was previously accepted as the upper level of tolerance for soybeans. Since optimal branching and per plant yield parameters were achieved by plants with B leaf concentrations greater than 160 micrograms per gram, the accepted range of soybean tolerance for B must be reconsidered when B is foliarly applied. Images Figure 1

Schon, Mary K.; Blevins, Dale G.

1990-01-01

13

Effect of bio-phosphate and chemical phosphorus fertilizer accompanied with micronutrient foliar application on growth, yield and yield components of maize (Single Cross 704)  

Microsoft Academic Search

The effects of bio-phosphate, chemical phosphorus fertilizer and micronutrient foliar application on growth, yield and yield components of maize (Zea mays L.) were studied in a field experiment at Kerman Agricultural and Natural Resources Research Centre (Iran). A split plot experiment based on randomized complete blocks design (RCBD) with four replications was followed in the study. The micronutrient foliar application

Khatoon Yosefi; Mohammad Galavi; Mahmod Ramrodi; Sayed Roholla Mousavi

2011-01-01

14

Iron and zinc concentrations in grain and flour of winter wheat as affected by foliar application.  

PubMed

Human deficiencies of iron (Fe) and zinc (Zn) are worldwide problems. Biofortification of wheat could reduce Fe and Zn deficiencies in societies that depend on wheat consumption. This study investigated the effects of foliar application of Fe with or without Zn on the concentrations of Fe and Zn in grain and especially in flour of three wheat cultivars. On average, grain Fe concentration was increased significantly from 29.5 mg kg(-1) in the control to 37.8, 35.9, or 34.9 mg kg(-1) by application of FeSO4, ferric citrate plus ZnSO4, or ferric citrate, respectively. As expected, grain Zn concentration was increased from 29.0 mg kg(-1) in the control to 45.7 or 39.6 mg kg(-1) by application of ferric citrate plus ZnSO4 or a complex of micronutrients. Although the Fe and Zn concentrations in flour were inherently lower than in bran and shorts made by experimental mill, the concentrations in flour were simultaneously increased from 10.4 to 12.4 mg kg(-1) for Fe and from 11.8 to 17.4 mg kg(-1) for Zn by application of ferric citrate plus ZnSO4. Importantly, Fe was peripherally localized within grain fractions and strictly limited to transport to endosperm, making it more difficult to increase the quantity of Fe in flour products by foliar Fe application, but the situation with Zn is promising because Zn is more readily transported to the endosperm than Fe. The current study increases the understanding of agronomic biofortification. PMID:21073194

Zhang, Yueqiang; Shi, Rongli; Rezaul, Karim Md; Zhang, Fusuo; Zou, Chunqin

2010-12-01

15

Calcium Hydroxyapatite for Medical Applications  

Microsoft Academic Search

Biocompatible calcium hydroxyapatite, C?10(??4)6(??)2?, is prepared by the alkoxide method. A functional derivative of 1,3-thiazinon (5,6-dihydro-2-methylimino-3-methyl-1,3-thiazine-4-on-6-carboxylic acid-4-chloroanilide) is synthesized, which is expected to combine anti-inflammatory and antiosteoporotic effects. Its pharmacological activity is analyzed using computer simulation. Adsorption of a 1,3-thiazinon solution in acetone on the C?10(??4)6(??)2 surface is studied with the aim of examining the possibility of preparing C?10(??4)6(??)2-based combined

N. A. Zakharov; I. A. Polunina; K. E. Polunin; N. M. Rakitina; E. I. Kochetkova; N. P. Sokolova; V. T. Kalinnikov

2004-01-01

16

Effects of foliar application of some macro- and micro-nutrients on tomato plants in aquaponic and hydroponic systems  

Microsoft Academic Search

An aquaponic system was designed to investigate effects of foliar applications of some micro- and macro-nutrients on tomato growth and yield in comparison with a hydroponic system. Common carp, grass carp and silver carp were stocked in the rearing tanks at 15, 20 and 15fishm?3, respectively. The fish were fed three times daily with a pellet diet containing 46% protein.

Hamid R. Roosta; Mohsen Hamidpour

2011-01-01

17

Foliar boron application affects lint and seed yield and improves seed quality of cotton grown on calcareous soils  

Microsoft Academic Search

Cotton (Gossypium hirsutum L.) is one of the most important fiber crops worldwide because of the good fiber quality, high yield, and high adaptability. Cotton has high requirements for B and many times B is applied to correct B deficiency. Despite the fact that B is important for cotton the effect of foliar applications on seed yield and seed quality

Christos Dordas

2006-01-01

18

Uptake and persistence of pesticides in plants: Measurements and model estimates for imidacloprid after foliar and soil application  

Microsoft Academic Search

The uptake and persistence behaviour of the insecticide imidacloprid in tomato plants treated by (i) foliar spray application and (ii) soil irrigation was studied using two plant uptake models. In addition to a pesticide deposition model, a dynamic root uptake and translocation model was developed, and both models predict residual concentrations of pesticides in or on fruits. The model results

Ronnie Juraske; Francesc Castells; Ashwin Vijay; Pere Muñoz; Assumpció Antón

2009-01-01

19

Effects of Conventional and Reduced-Volume, Charged-Spray Application Techniques on Dislodgeable Foliar Residue of Captan on Strawberries  

Microsoft Academic Search

An air atomization, electrostatic charging spray system was used for reduced-volume (80 L\\/ha) applications of captan onto commercial strawberry plantings. Initial dislodgeable foliar residue from the charged reduced-volume application was higher (7.03 vs 5.33 pg\\/cm2) and the first-order decay time constant was longer (9.07 vs 6.65 days) than from a conventional, high-volume (1870 L\\/ha) application. Comparison of charged vs uncharged

Durham K. Giles; T. Craig Blewett

1991-01-01

20

Effect of Foliar-Applied Humic Acid to Dry Weight and Mineral Nutrient Uptake of Maize under Calcareous Soil Conditions  

Microsoft Academic Search

Greenhouse research was conducted to determine the effects of foliar application of humic acid on dry matter and some nutrient element uptake of maize grown under calcareous soil conditions. Agricultural lime was used to obtain five calcium carbonate (CaCO3) doses (0, 5, 10 20, and 40%) and three foliar application doses of humic acid (0, 0.1, and 0.2%) sprayed at

Hakan Çelik; Ali Vahap Katkat; Bar?? Bülent A??k; Murat Ali Turan

2010-01-01

21

Effect of Foliar Applications of Urea on Accelerated Senescence of Maize Induced by Ear Removal 1  

PubMed Central

Field grown maize (Zea mays L. cv B73 × Mo17) plants, with and without ears, were sprayed with urea solutions to determine whether foliar application of N could prevent or delay the accelerated loss of reduced N from the leaf and leaf senescence induced by ear removal. Urea sprays were applied at 7, 14, and 21 days after anthesis in three separate and equal applications that provided a total of 67 kilograms N per hectare or 1 gram N per plant. Treatments were arranged in a 2 × 2 factorial in a randomized complete block with five replicates. Appropriate plant and leaf samplings and assays were made. In response to spray treatments, net increases of reduced N were detected in the whole shoot and plant parts, especially the stalk of the earless plants and grain of the eared plants. There was no effect of urea spray treatment on the normal loss of N from the leaves or rate of senescence of the eared plants or on the accelerated loss of N from the leaves or rate of senescence induced by ear removal. Grain and stover yields were unaffected by the spray treatment. Apparently the plants were unable to utilize the urea N applied to the vegetation (primarily leaves) after anthesis to enhance or extend the accumulation of dry weight by either eared or earless plants.

Below, Frederick E.; Crafts-Brandner, Steven J.; Hageman, Richard H.

1985-01-01

22

Growth Promotion of Yunnan Pine Early Seedlings in Response to Foliar Application of IAA and IBA  

PubMed Central

A field experiment was conducted using a 3 × 3 orthogonal regression design to explore the growth promotion of one-year-old Yunnan pine seedlings (Pinus yunnanensis Franch.) in response to foliar application of IAA (indole-3-acetic acid) at rates of 0, 200 and 400 mg·L?1 and IBA (indole-3-butyric acid) at rates of 0, 200 and 400 mg·L?1 in order to promote the growth during the seedlings’ early stage. The experiment was conducted at the Lufeng Village Forest Farm of Yiliang County in Kunming, Yunnan, China. The results showed that IAA and IBA were effective in growth promotion of Yunnan pine seedlings. The response of both growth increment and biomass accumulation to the concentration of IAA and IBA can be modeled using a bivariate surface response, and each growth index had a peak value. Growth indexes increased with the increase of the dosage of photohormones before reaching a peak value, and then decreased. The different growth indexes had various responses to the concentrations and ratio of IAA and IBA. The foliar application of IAA in combination with IBA showed the largest improvement on the biomass of the needles, followed by stems and roots. The higher ratio of IAA promoted stem diameter growth, root system development and biomass accumulation in the needles, while a higher ratio of IBA contributed to height growth and biomass accumulation in the stem. Based on the auxin effect equations on the different growth indexes and surface response, the optimum concentrations and the (IAA:IBA) ratios can be obtained. The optimum concentrations of IAA and IBA were 167 and 186, 310 and 217, 193 and 159, 191 and 221, and 206 and 186 mg·L?1, with corresponding ratios of 1:1.11, 1:0.70, 1:0.82, 1:1.15 and 1:0.90, respectively, at the maximum seedling height and collar diameter growth as well as biomass accumulation at the root, stem and needle. The above growth indexes were 22.00%, 79.80%, 48.65%, 82.20% and 107.00% higher than the control treatment.

Xu, Yulan; Zhang, Yuemin; Li, Yunfei; Li, Genqian; Liu, Daiyi; Zhao, Minchong; Cai, Nianhui

2012-01-01

23

Investigating calcium polyphosphate addition to a conventional calcium phosphate cement for bone-interfacing applications  

Microsoft Academic Search

Calcium phosphate cements (CPCs) are of great interest in bone regeneration applications because of their biocompatibility and osteoconductivity, and as delivery vehicles for therapeutics; however, delivery applications have been limited by adverse interactions between therapeutics and the cement setting reaction. Amorphous calcium polyphosphate (CPP) yields a biodegradable material with a demonstrated drug delivery capacity following appropriate processing. The incorporation of

Jennifer Lynn Krausher

2010-01-01

24

Uptake and persistence of pesticides in plants: measurements and model estimates for imidacloprid after foliar and soil application.  

PubMed

The uptake and persistence behaviour of the insecticide imidacloprid in tomato plants treated by (i) foliar spray application and (ii) soil irrigation was studied using two plant uptake models. In addition to a pesticide deposition model, a dynamic root uptake and translocation model was developed, and both models predict residual concentrations of pesticides in or on fruits. The model results were experimentally validated. The fraction of imidacloprid ingested by the human population is on average 10(-2) to 10(-6), depending on the time between pesticide application and ingestion, the processing step, and the application method. Model and experimentally derived intake fractions deviated by less than a factor of 2 for both application techniques. Total imidacloprid residues were up to five times higher in plants treated by foliar spray application than by soil irrigation. However, peeling tomatoes treated by spray application reduces the human intake fraction by up to three orders of magnitude. Model calculations suggest that drip-irrigation in a closed hydroponic system minimizes worker and consumer exposure to pesticides and prevents runoff of pesticide by spray drift and leaching into the environment. PMID:19036517

Juraske, Ronnie; Castells, Francesc; Vijay, Ashwin; Muñoz, Pere; Antón, Assumpció

2009-06-15

25

Effect of sequential applications of foliar nutrients, biofertilizers and sowing dates on the incidence of corn stem borers in Egypt.  

PubMed

In this study either early sown (May 1st) or lately sown (June 2nd) corn plants were treated with Phosphorin & Rhizobactrin as biofertilizers and sprayed with six selected foliar nutrients, i.e. Polymex; Greenzit SP100, Greenzit NPK, Potasin-F, Copper sulphate and Ascorbic acid; in mono-, bi-, and/or tri-sequential applications. Such practices were conducted to show their beneficial effects compared with the chemical treatment in checking the incidence of the stem borers and hence increasing the corn yield. The obtained results could be summarized in the following chief points: (a) the lately sown biofertilized plants showed somewhat higher levels of infestation than the early planted ones., (b) in general, spraying the biofertilized corn plants in both sowing dates with the tested foliar nutrients, significantly decreased the rate of the stem borers infestation than the untreated plants of control., (c) the foliar sprays of Greenzit NPK alone, bi- or tri-sequential applications of Potasin-F, Polymex, Ascorbic acid and Copper sulphate achieved considerable success in reducing larval numbers of the borers species. For example, in case of using the bi-sequential nutrients (Polymex/Ascorbic acid) the numbers were 1.2, 1.5 and 1.2 larvae/5 plants, whereas the numbers were 1.3, 1.0 and 0.7 larvae/5 plants as a result, of the tri-sequential applications (Potasin-F/Ascorbic acid/Polymex) for the pink stem borer, Sesamia cretica, (Led.), the purple lined borer, Chilo agamemnon, (Bels.), and the European corn borer Ostrinia nubilalis (Hb.), in respect, vs. 4.8, 4.5 and 2.9 larvae/5 plants for the same stem borers, respectively, in case of the untreated corn plants. In addition, the other trisequential applications (Polymex/ascorbic acid/Copper sulphate), (Potasin-F/Copper sulphate/ascorbic acid) and (Potasin-F/Copper sulphate/Polymex) reduced the stem borers infestation; (d) from the view point of the interaction effects of sowing dates and the tested foliar nutrients, it was found that the tri-sequential sprayings (Potasin-F/Copper sulphate/Polymex) and/or (Potasin-F/Copper sulphate/Ascorbic acid) have lowered the rate of the stem borers infestation to 3.3 and 3.3 and 5.7 and 4.3 larvae/5 plants for the tri-applications in the 1st and 2nd sowing dates, respectively. Such reductions in the levels of infestation led to an increase in the grain yield up to 6.9 and 7.2 and 5.4 and 5.8 ton/fed, for the early and lately sown corn plants, in respect, and (e) All the foliar nutrients, with no exception, proved to be efficient in managing the stem borers infestation as compared with the insecticide treatment using Polytrin. Although the chemical application had lowered the level of infestation to 2.3 and 5.7 larvae/5 plants in the 1st and 2nd sowing dates as compared with 9.7 and 14.7 larvae/5 untreated plants for the same sowing dates, lesser grain yield of 5.6 and 4.4 ton/fed. was obtained in the first and second dates of planting, successively, in comparison to the grain yield resulted from the tri-applications of Potasin-F/Copper sulphate with either Polymex or Ascorbic acid. The abovementioned results assured the profitable effects of using foliar nutrients as well as the biofertilizers for attaining healthy corn plants, which would be capable of tolerating the injury inflicted by the studied stem borers and compensating for the harmful effects of insects infestation, so high grain yields could be obtained than those of the untreated and/or the insecticide treated plants. PMID:12696416

Mesbah, H A; Mourad, A K; el-Nimr, Hanyiat M; el-Kady, Magda B; Haroun, Nagah S

2002-01-01

26

Multispectral remote sensing of landscape level foliar moisture: techniques and applications for forest ecosystem monitoring  

Microsoft Academic Search

Broad-scale monitoring of varying moisture levels of leaves has ramifications for understanding fire poten- tial, biogeochemistry, and ecosystem dynamics. Five different shortwave infrared (SWIR)-derived spectral indices, prin- cipal components analysis (PCA), and the tasseled cap transformation (TCT), derived from Landsat Thematic Mapper (TM) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite data, were used to quantify landscape-level foliar

Michael Toomey; Lee A. Vierling

2005-01-01

27

Intestinal Calcium Absorption: Mechanisms and Applications  

Microsoft Academic Search

Calcium absorption from the intestine in volves two sets of events. One, a saturable transcellular process is regulated by vitamin D via its molecular product, the calcium-binding protein (CaBP, MW = 8800). This transcellular movement is largely confined to the proximal portion of the intestine. The second process is nonsatur- able, occurs throughout the length of the intestine and is

FELIX BRONNER

28

40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.  

Code of Federal Regulations, 2010 CFR

...false Applicability; description of the calcium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Carbonate Production Subcategory § 415.300 Applicability; description of the calcium carbonate production subcategory....

2009-07-01

29

40 CFR 461.20 - Applicability; description of the calcium subcategory.  

Code of Federal Regulations, 2010 CFR

... Applicability; description of the calcium subcategory. 461.20 Section 461...MANUFACTURING POINT SOURCE CATEGORY Calcium Subcategory § 461.20 Applicability; description of the calcium subcategory. This subpart...

2010-07-01

30

40 CFR 424.50 - Applicability; description of the other calcium carbide furnaces subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the other calcium carbide furnaces subcategory. 424...MANUFACTURING POINT SOURCE CATEGORY Other Calcium Carbide Furnaces Subcategory § 424.50 Applicability; description of the other calcium carbide furnaces subcategory....

2010-07-01

31

40 CFR 415.40 - Applicability; description of the calcium chloride production subcategory.  

Code of Federal Regulations, 2010 CFR

...false Applicability; description of the calcium chloride production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Chloride Production Subcategory § 415.40 Applicability; description of the calcium chloride production subcategory....

2009-07-01

32

40 CFR 415.40 - Applicability; description of the calcium chloride production subcategory.  

Code of Federal Regulations, 2010 CFR

...true Applicability; description of the calcium chloride production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Chloride Production Subcategory § 415.40 Applicability; description of the calcium chloride production subcategory....

2010-07-01

33

40 CFR 415.310 - Applicability; description of the calcium hydroxide production subcategory.  

Code of Federal Regulations, 2010 CFR

...false Applicability; description of the calcium hydroxide production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Hydroxide Production Subcategory § 415.310 Applicability; description of the calcium hydroxide production subcategory....

2009-07-01

34

40 CFR 415.50 - Applicability; description of the calcium oxide production subcategory.  

Code of Federal Regulations, 2010 CFR

...false Applicability; description of the calcium oxide production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Oxide Production Subcategory § 415.50 Applicability; description of the calcium oxide production subcategory....

2009-07-01

35

40 CFR 415.50 - Applicability; description of the calcium oxide production subcategory.  

Code of Federal Regulations, 2010 CFR

...true Applicability; description of the calcium oxide production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Oxide Production Subcategory § 415.50 Applicability; description of the calcium oxide production subcategory....

2010-07-01

36

40 CFR 424.50 - Applicability; description of the other calcium carbide furnaces subcategory.  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the other calcium carbide furnaces subcategory. 424...MANUFACTURING POINT SOURCE CATEGORY Other Calcium Carbide Furnaces Subcategory § 424.50 Applicability; description of the other calcium carbide furnaces subcategory....

2009-07-01

37

40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.  

Code of Federal Regulations, 2010 CFR

...true Applicability; description of the calcium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Carbonate Production Subcategory § 415.300 Applicability; description of the calcium carbonate production subcategory....

2010-07-01

38

40 CFR 415.30 - Applicability; description of the calcium carbide production subcategory.  

Code of Federal Regulations, 2013 CFR

...true Applicability; description of the calcium carbide production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Carbide Production Subcategory § 415.30 Applicability; description of the calcium carbide production subcategory....

2013-07-01

39

40 CFR 461.20 - Applicability; description of the calcium subcategory.  

Code of Federal Regulations, 2013 CFR

... Applicability; description of the calcium subcategory. 461.20 Section 461...MANUFACTURING POINT SOURCE CATEGORY Calcium Subcategory § 461.20 Applicability; description of the calcium subcategory. This subpart...

2013-07-01

40

40 CFR 415.40 - Applicability; description of the calcium chloride production subcategory.  

Code of Federal Regulations, 2013 CFR

...true Applicability; description of the calcium chloride production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Chloride Production Subcategory § 415.40 Applicability; description of the calcium chloride production subcategory....

2013-07-01

41

40 CFR 424.50 - Applicability; description of the other calcium carbide furnaces subcategory.  

Code of Federal Regulations, 2013 CFR

...Applicability; description of the other calcium carbide furnaces subcategory. 424...MANUFACTURING POINT SOURCE CATEGORY Other Calcium Carbide Furnaces Subcategory § 424.50 Applicability; description of the other calcium carbide furnaces subcategory....

2013-07-01

42

40 CFR 415.50 - Applicability; description of the calcium oxide production subcategory.  

Code of Federal Regulations, 2013 CFR

...true Applicability; description of the calcium oxide production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Oxide Production Subcategory § 415.50 Applicability; description of the calcium oxide production subcategory....

2013-07-01

43

40 CFR 415.300 - Applicability; description of the calcium carbonate production subcategory.  

Code of Federal Regulations, 2013 CFR

...true Applicability; description of the calcium carbonate production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Carbonate Production Subcategory § 415.300 Applicability; description of the calcium carbonate production subcategory....

2013-07-01

44

40 CFR 415.310 - Applicability; description of the calcium hydroxide production subcategory.  

Code of Federal Regulations, 2010 CFR

...true Applicability; description of the calcium hydroxide production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Hydroxide Production Subcategory § 415.310 Applicability; description of the calcium hydroxide production subcategory....

2010-07-01

45

40 CFR 415.310 - Applicability; description of the calcium hydroxide production subcategory.  

Code of Federal Regulations, 2013 CFR

...true Applicability; description of the calcium hydroxide production subcategory. 415...CHEMICALS MANUFACTURING POINT SOURCE CATEGORY Calcium Hydroxide Production Subcategory § 415.310 Applicability; description of the calcium hydroxide production subcategory....

2013-07-01

46

Calcium  

MedlinePLUS

... calcium. Veggies. You'll also find calcium in broccoli and dark green, leafy vegetables (especially collard and ... of calcium such as dark green, leafy vegetables, broccoli, chickpeas, and calcium-fortified products, including orange juice, ...

47

Effect of Bio-phosphate and Chemical Phosphorus Fertilizer Accompanied with Foliar Application of Micronutrients on Yield, Quality and Phosphorus and Zinc Concentration of Maize  

Microsoft Academic Search

Field experiment was conducted at Kerman Agricultural and Natural Resources Research Centre (Iran) during 2008-2009 to evaluate the effect of bio-fertilizer, phosphorus and foliar application of micronutrients on dry matter accumulation, yield, and phosphorus and zinc concentration of maize (Zea mays L.). A split plot experiment based on randomized complete blocks design (RCBD) with four replications was followed in the

Mohammad Galavi; Khatoon Yosefi; Mahmod Ramrodi

2011-01-01

48

Foliar application of the exogenous plant hormones at pre-blooming stage improves flowering and fruiting in cashew ( Anacardium occidentale L.)  

Microsoft Academic Search

The problem of declining tree yield has led to an investigation into the effectiveness of foliar application of exogenous\\u000a hormones to improve flowering, fruit set, and fruit retention in cashew. Five exogenous hormones, one Gibberellic Acid (GA3) and four Auxins (IAA, IBA, NAA, and 2,4-D) at seven different rates of application (0 mg L?1, 10 mg L?1, 25 mg L?1,

Olawale Mashood Aliyu; Oluwayemisi Oluwatosin Adeigbe; Joshua Adedokun Awopetu

2011-01-01

49

Root biomass response to foliar application of imazapyr for two imidazolinone tolerant alleles of sunflower (Helianthus annuus L.).  

PubMed

Imisun and CLPlus are two imidazolinone tolerance traits in sunflower (Helianthus annuus L.) determined by the expression of two alleles at the locus Ahasl1. Both traits differed in their tolerance level to imazapyr -a type of imidazolinone herbicide- when aboveground biomass is considered, but the concomitant herbicide effect over the root system has not been reported. The objective of this work was to quantify the root biomass response to increased doses of imazapyr in susceptible (ahasl1/ahasl1), Imisun (Ahasl1-1/Ahasl1-1) and CLPlus (Ahasl1-3/Ahasl1-3) homozygous sunflower genotypes. These materials were sprayed at the V2-V4 stage with increased doses of imazapyr (from 0 to 480 g active ingredient ha(-1)) and 14 days after treatment root biomass of each plant was assessed. Genotype at the Ahasl1 locus, dose of imazapyr and their interaction significantly contributed (P < 0.001) to explain the reduction in root biomass accumulation after herbicide application. Estimated dose of imazapyr required to reduce root biomass accumulation by fifty percent (GR(50)) differed statistically for the three genotypes under study (P < 0.001). CLPlus genotypes showed the highest values of GR(50), 300 times higher on average than the susceptible genotypes, and almost 8 times higher than Imisun materials, demonstrating that both alleles differ in their root biomass response to foliar application of increased doses of imazapyr. PMID:23226083

Sala, Carlos A; Bulos, Mariano; Altieri, Emiliano; Ramos, María Laura

2012-09-01

50

Foliar applications of Lo-Biuret Urea and Potassium Phosphite to Navel Orange trees  

Microsoft Academic Search

This experiment was established in January 2000 in a block of 'Washington' navel orange trees at Verde Growers, Stanfield, AZ. Treatments included: normal grower practice, winter low biuret (LB) urea application, summer LB urea application, winter LB urea application plus winter and spring potassium phosphite, winter LB urea application plus summer potassium phosphite, and normal grower practice plus spring potassium

Glenn Wright; James Walworth

51

Study of the effects of proline, phenylalanine, and urea foliar application to Tempranillo vineyards on grape amino acid content. Comparison with commercial nitrogen fertilisers.  

PubMed

The aim of this work was to study the influence of foliar application of different nitrogen sources on grape amino acid content. The nitrogen sources applied to Tempranillo grapevines were proline, phenylalanine, urea, and two commercial nitrogen fertilisers, both without and with amino acids in their formulations. All treatments were applied at veraison and one week later. Proline treatment did not affect the must nitrogen composition. However, phenylalanine and urea foliar application enhanced the plants' synthesis of most of the amino acids, producing similar effects. In addition, the spray of commercial nitrogen fertilisers over leaves also induced a rise in grape amino acid concentrations regardless of the presence or absence of amino acids in their formulation. The most effective treatments were phenylalanine and urea followed by nitrogen fertilisers. This finding is of oenological interest for improved must nitrogen composition, ensuring better fermentation kinetics and most likely enhancing wine quality. PMID:24912708

Garde-Cerdán, T; López, R; Portu, J; González-Arenzana, L; López-Alfaro, I; Santamaría, P

2014-11-15

52

Comparative movement of labelled nitrogen and zinc in 1-year-old peach (Prunus persica (L.) Batsch) trees following late-season foliar application  

Microsoft Academic Search

SUMMARY Late in the season, a double-labelled solution containing 15N-enriched urea and 68Zn sulphate was painted on the entire leaf area of 15, 1-year-old 'O'Henry\\/Nemaguard' peach trees to quantify N and Zn movement out of leaves following foliar application, and redistribution of these nutrients to new growth in the following Spring. About 47% of the labelled N and only 7%

E. E. SANCHEZ; S. A. WEINBAUM; R. S. JOHNSON

53

Biomineralization of calcium carbonates and their engineered applications: a review  

PubMed Central

Microbially induced calcium carbonate precipitation (MICCP) is a naturally occurring biological process in which microbes produce inorganic materials as part of their basic metabolic activities. This technology has been widely explored and promising with potential in various technical applications. In the present review, the detailed mechanism of production of calcium carbonate biominerals by ureolytic bacteria has been discussed along with role of bacteria and the sectors where these biominerals are being used. The applications of bacterially produced carbonate biominerals for improving the durability of buildings, remediation of environment (water and soil), sequestration of atmospheric CO2 filler material in rubbers and plastics etc. are discussed. The study also sheds light on benefits of bacterial biominerals over traditional agents and also the issues that lie in the path of successful commercialization of the technology of microbially induced calcium carbonate precipitation from lab to field scale.

Dhami, Navdeep K.; Reddy, M. Sudhakara; Mukherjee, Abhijit

2013-01-01

54

Reversible loss of gravitropic sensitivity in maize roots after tip application of calcium chelators  

NASA Technical Reports Server (NTRS)

The application of calcium chelating agents (EDTA or EGTA) to the tips of maize roots caused a loss of gravitropic sensitivity. When the chelator was replaced with calcium chloride, gravitropic sensitivity was restored. Asymmetric application of calcium chloride near the tip of a vertical root caused curvature toward the calcium source. When the calcium was applied to the upper surface of the tip of a root oriented horizontally, the root curved upward even though control roots exhibited strong downward curvature. Application of calcium chloride to the tips of decapped roots, which are known to be gravitropically insensitive, did not restore gravitropic sensitivity. However, asymmetric application of calcium chloride near the tips of decapped roots caused curvature toward the calcium source. Calcium may play a key role in linking gravity detection to gravitropic curvature in roots.

Lee, J. S.; Mulkey, T. J.; Evans, M. L.

1983-01-01

55

Influence of phosphorus application and arbuscular mycorrhizal inoculation on growth, foliar nitrogen mobilization, and phosphorus partitioning in cowpea plants.  

PubMed

The present study was undertaken to evaluate the effects of phosphorus (P) application and arbuscular mycorrhizal (AM) fungi (Funneliformis mosseae) on growth, foliar nitrogen mobilization, and phosphorus partitioning in cowpea (Vigna unguiculata cv. Vita-5) plants. The experiment was conducted in a greenhouse in pots containing a mixture of vermiculite and sterilized quartz sand. Mycorrhizal and non-mycorrhizal cowpea plants were supplied with three levels of soluble P (0.1 (low P), 0.5 (medium P), or 1.0 mM (high P)).Cowpea plants supplied with low P fertilization showed significantly (p?

Taffouo, Victor Désiré; Ngwene, Benard; Akoa, Amougou; Franken, Philipp

2014-07-01

56

Influence of surfactants on potassium uptake and yield response of cotton to foliar potassium nitrate  

Microsoft Academic Search

Foliar potassium (K) applications are intended to supplement soil K uptake, and thereby, increase cotton (Gossypium hirsutum L.) yields. Considerable research has been conducted to evaluate yield response to foliar K, but research evaluating surfactant effects on foliar uptake has been limited. Research was initiated in West Tennessee in 1991 to evaluate effects of foliar applied potassium nitrate (KNO3) with

D. D. Howard; C. O. Gwathmey

1995-01-01

57

40 CFR 424.40 - Applicability; description of the covered calcium carbide furnaces with wet air pollution control...  

Code of Federal Regulations, 2010 CFR

...Applicability; description of the covered calcium carbide furnaces with wet air pollution...MANUFACTURING POINT SOURCE CATEGORY Covered Calcium Carbide Furnaces With Wet Air Pollution...Applicability; description of the covered calcium carbide furnaces with wet air...

2010-07-01

58

Metabolization of Elemental Sulfur in Wheat Leaves Consecutive to Its Foliar Application 1  

PubMed Central

The qualitative and quantitative aspects of elemental sulfur metabolization in wheat leaves and its effect upon photosynthetic metabolism were studied through the application of micronized sulfur upon the third leaf. Energy-dispersive x-ray analysis combined with scanning electron microscopy emphasized the existence of a sulfur peak associated with a strong potassium peak in the spectra of different tissue regions for treated leaves only, supplying an original evidence of sulfur uptake. Experiments with35S-labeled micronized sulfur showed that about 2% of the labeled S was absorbed and metabolized into cystine, methionine, glutathione, and sulfate. The close correlation between the excess of oxygen uptake and oxygen needs for sulfur oxidation in conjunction with the absence of hydrogen sulfide released by treated leaves support direct and fast oxidation of sulfur into sulfate according to a pathway still unclear but independent of photosynthetic CO2 metabolism in treated leaf. The mechanisms involved in the primary metabolism of element sulfur in wheat therefore appear to be different from those in fungi. Images Fig. 2

Legris-Delaporte, Stephanie; Ferron, Francoise; Landry, Jacques; Costes, Claude

1987-01-01

59

Amorphous calcium phosphate and its application in dentistry  

PubMed Central

Amorphous Calcium Phosphate (ACP) is an essential mineral phase formed in mineralized tissues and the first commercial product as artificial hydroxyapatite. ACP is unique among all forms of calcium phosphates in that it lacks long-range, periodic atomic scale order of crystalline calcium phosphates. The X-ray diffraction pattern is broad and diffuse with a maximum at 25 degree 2 theta, and no other different features compared with well-crystallized hydroxyapatite. Under electron microscopy, its morphological form is shown as small spheroidal particles in the scale of tenths nanometer. In aqueous media, ACP is easily transformed into crystalline phases such as octacalcium phosphate and apatite due to the growing of microcrystalline. It has been demonstrated that ACP has better osteoconductivity and biodegradability than tricalcium phosphate and hydroxyapatite in vivo. Moreover, it can increase alkaline phosphatase activities of mesoblasts, enhance cell proliferation and promote cell adhesion. The unique role of ACP during the formation of mineralized tissues makes it a promising candidate material for tissue repair and regeneration. ACP may also be a potential remineralizing agent in dental applications. Recently developed ACP-filled bioactive composites are believed to be effective anti-demineralizing/remineralizing agents for the preservation and repair of tooth structures. This review provides an overview of the development, structure, chemical composition, morphological characterization, phase transformation and biomedical application of ACP in dentistry.

2011-01-01

60

Foliar Mn accumulation in eastern Australian herbarium specimens: prospecting for 'new' Mn hyperaccumulators and potential applications in taxonomy  

PubMed Central

Background and Aims The analysis of herbarium specimens has previously been used to prospect for ‘new’ hyperaccumulators, while the use of foliar manganese (Mn) concentrations as a taxonomic tool has been suggested. On the basis of their geographic and taxonomic affiliations to known Mn hyperaccumulators, six eastern Australian genera from the Queensland Herbarium collection were sampled for leaf tissue analyses. Methods ICP-OES was used to measure Mn and other elemental concentrations in 47 species within the genera Austromyrtus, Lenwebbia, Gossia (Myrtaceae), Macadamia (Proteaceae), Maytenus and Denhamia (Celastraceae). Key Results The resulting data demonstrated (a) up to seven ‘new’ Mn hyperaccumulators, mostly tropical rainforest species; (b) that one of these ‘new’ Mn hyperaccumulators also had notably elevated foliar Ni concentrations; (c) evidence of an interrelationship between foliar Mn and Al uptake among the Macadamias; (d) considerable variability of Mn hyperaccumulation within Gossia; and (e) the possibility that Maytenus cunninghamii may include subspecies. Conclusions Gossia bamagensis, G. fragrantissima, G. sankowsiorum, G. gonoclada and Maytenus cunninghamii were identified as ‘new’ Mn hyperaccumulators, while Gossia lucida and G. shepherdii are possible ‘new’ Mn hyperaccumulators. Of the three Myrtaceae genera examined, Mn hyperaccumulation appears restricted to Gossia, supporting its recent taxonomic revision. In the context of this present investigation and existing information, a reassesment of the general definition of Mn hyperaccumulation may be warranted. Morphological variation of Maytenus cunninghamii at two extremities was consistent with variation in Mn accumulation, indicating two possible ‘new’ subspecies. Although caution should be exercised in interpreting the data, surveying herbarium specimens by chemical analysis has provided an effective means of assessing foliar Mn accumulation. These findings should be followed up by field studies.

Fernando, Denise R.; Guymer, Gordon; Reeves, Roger D.; Woodrow, Ian E.; Baker, Alan J.; Batianoff, George N.

2009-01-01

61

Investigating calcium polyphosphate addition to a conventional calcium phosphate cement for bone-interfacing applications  

NASA Astrophysics Data System (ADS)

Calcium phosphate cements (CPCs) are of great interest in bone regeneration applications because of their biocompatibility and osteoconductivity, and as delivery vehicles for therapeutics; however, delivery applications have been limited by adverse interactions between therapeutics and the cement setting reaction. Amorphous calcium polyphosphate (CPP) yields a biodegradable material with a demonstrated drug delivery capacity following appropriate processing. The incorporation of drug-loaded CPP into a CPC is under consideration as a method of minimizing adverse interactions and extending drug release. This thesis represents the first investigation into the effects of CPP addition on the properties, setting and antibiotic release profile of a conventional apatitic calcium phosphate cement. As-made, gelled and vancomycin-loaded CPP particulate were added to the powder component of a conventional dicalcium phosphate/tetracalcium phosphate CPC. The setting behaviour, set properties and microstructure of the resulting CPP-CPCs were evaluated with setting time testing (Gilmore needle method), pH testing, mechanical testing, SEM imaging, XRD and FTIR analysis. In vitro degradation and elution behaviour were evaluated by monitoring calcium release (atomic absorbance spectroscopy), mechanical strength and vancomycin release (UV-visual spectrophotometry). CPP addition was found to increase the setting time, reduce the mechanical strength and inhibit the conversion of the CPC starting powders to the set apatitic phase. The most likely mechanism for the observed effect of CPP addition was the adsorption of polyphosphate chains on the particle surfaces, which would inhibit the dissolution of the starting powders and the conversion of apatite precursor phases to apatite, leading to reduced mechanical properties. The detrimental effects of CPP were reduced by limiting the CPP fraction to less than a few weight per cent and increasing the size of the CPP particulate. CPP-containing CPCs were found to degrade more rapidly than the CPP-free controls. The ability of drug-loaded CPP to minimize adverse interactions between drug and cement could not be determined because of the adverse effect of CPP itself and the low vancomycin loads studied, but there was evidence that vancomycin release from apatitic CPCs could be extended through the use of loaded CPP.

Krausher, Jennifer Lynn

62

USO DA ADUBAÇÃO FOLIAR NITROGENADA E POTÁSSICA NO ALGODOEIRO  

Microsoft Academic Search

NITROGEN AND POTASSIUM IN FOLIAR APPLICATION ON COTTON CROP The present work was conducted in Selvíria county (MS-Brazil), in the agricultural year of 1998\\/99, for evaluating nitrogen and potassium foliar application to supplement sowing fertilization on cotton (IAC 22) crop. A randomized complete block design with 13 treatments and four replications was used. The treatments were constituted by a control

MARCO ANTONIO CAMILLO DE CARVALHO; HELDER BARBOSA PAULINO; ENES FURLANI-JÚNIOR; SALATIÉR BUZETTI; MARCO EUSTÁQUIO DE SÁ; MANOEL LUIZ FERREIRA DE ATHAYDE

2001-01-01

63

Estimation of leaf wetness duration requirements of foliar fungal pathogens with uncertain data-an application to Mycosphaerella nawae.  

PubMed

Wetness of the host surface is a critical environmental factor for the development of foliar fungal diseases, but it is difficult to estimate the wetness durations required by pathogens for infection when only few experimental data are available. In this paper, we propose a method to estimate wetness duration requirements of foliar fungal pathogens when precise experimental data are not available. The proposed method is based on approximate Bayesian computation. It only requires lower and upper bounds of wetness duration requirements for one or fewer temperatures. We describe the method, show how to apply it to an infection model, and then present a case study on Mycosphaerella nawae, the causal agent of circular leaf spot of persimmon. In this example, the parameters of a simple infection model were estimated using experimental data found in the literature for the pathogen, and the model was applied to assess the risk in a Spanish area recently affected by the disease. The results showed that the probability of successful infection was higher than 0.5 for 32% of the on-site wetness durations recorded in the affected area. Results obtained with simulated data showed that our method was able to improve the estimation of wetness duration requirement. Given the flexibility of the proposed method, we expect it to become adopted for assessing the risk of introduction of exotic fungal plant pathogens. PMID:21864085

Makowski, D; Bancal, R; Vicent, A

2011-11-01

64

Foliar application of calcium and magnesium improves growth, yield, and essential oil yield of oregano ( Origanum vulgare ssp. hirtum)  

Microsoft Academic Search

Oregano is one of the most important spices, is used all over the world, and includes many species. One of the most important commercially grown species is Origanum vulgare ssp. hirtum (Link) Ietsw (syn.: O. heracleoticum.), which is endemic to the Mediterranean area. O. vulgare ssp. hirtum is a crop species which is well adapted to both dry land conditions

Christos Dordas

2009-01-01

65

Biphasic calcium phosphate bioceramics: preparation, properties and applications  

Microsoft Academic Search

Biphasic calcium phosphate (BCP) bioceramics belong to a group of bone substitute biomaterials that consist of an intimate mixture of hydroxyapatite (HA), Ca10(PO4)6(OH)2, and beta-tricalcium phosphate (ß-TCP), Ca3(PO4)2, of varying HA\\/ß-TCP ratios. BCP is obtained when a synthetic or biologic calcium-deficient apatite is sintered at temperatures at and above 700 °C. Calcium deficiency depends on the method of preparation (precipitation,

R. Z. LeGeros; S. Lin; R. Rohanizadeh; D. Mijares; J. P. LeGeros

2003-01-01

66

Doped calcium-aluminium-phosphate cements for biomedical applications.  

PubMed

Calcium-aluminium-phosphate cements (CAPCs) for biomedical applications, mainly intended for applications in the dental field as non-resorbable fillers, were obtained by reacting Ca-aluminates compounds, i.e. CaO·Al(2)O(3) (CA) and CaO·2 Al(2)O(3) (CA(2)), with Al(H(2)PO(4))(3) aqueous solution. Hydroxyapatite was also introduced as a bioactive dispersed phase. Suitable elements like Sr and La were used to increase the radiopacity of the set yielded pastes towards X-ray wavelength used in clinical diagnostic radiographic equipments. La and Sr doped Ca-aluminates powders have been synthesized by solid state reaction at 1,400°C from a mixture of CaCO(3), Al(2)O(3), La(2)O(3) and SrCO(3). The characteristics of the obtained powders were analyzed and related to the starting compositions and synthesis procedures. The microstructure, setting time, radiopacity and compressive strength of the CAPCs have been investigated and discussed. PMID:21165760

Medri, V; Mazzocchi, M; Bellosi, A

2011-02-01

67

Foliar chemistry and leaf herbivory on mount Bloomfield, Palawan, Philippines  

Microsoft Academic Search

Mount Bloomfield has a range of vegetation types on non-ultramafic and ultramafic soils. We report here foliar chemical analyses for N, P, K, Na, Ca, Mg, AI, B, Co, Cr, Cu, Fe, Mo, Mn, Ni, Si, Zn made on a large number of tree species. The most important results were: the notably high calcium in the ultramafic forest leaves, the

J. Proctor; A. J. M. Baker; L. A. Bruijnzeel; M. M. J. VAN; G. M. Fairweather; D. A. Madulid

2000-01-01

68

Application of 1-methylcyclopropene, calcium chloride and calcium amino acid chelate on fresh-cut cantaloupe muskmelon  

Microsoft Academic Search

The objective of this work was to determine the effects of postharvest application of 1-methylcyclopropene (1-MCP) and two calcium salts, applied individually or combined, on firmness and visual quality of fresh-cut muskmelon stored in air, for 18 days. Two sets of fruits, one of them exposed to 1-MCP at 300 nL L -1 , were cut into cubes, dipped in

Francisca Ligia

2008-01-01

69

The foliar microbiome.  

PubMed

Proficient performance in plants is strongly associated with distinct microbial communities that live in and on their organs. We comment here on the current knowledge of the composition of the foliar microbiome, highlight its importance for plants, ecosystemic functioning, and crop yields, and propose tools and experiments to overcome the current knowledge gap. PMID:24439491

Peñuelas, Josep; Terradas, Jaume

2014-05-01

70

Coronary Artery Calcium Scores: Current Thinking and Clinical Applications  

PubMed Central

Most incident coronary disease occurs in previously asymptomatic individuals who were considered to be at a lower risk by traditional screening methods. There is a definite advantage if these individuals could be reclassified into a higher risk category, thereby impacting disease outcomes favorably. Coronary artery calcium scores have been recognized as an independent marker for adverse prognosis in coronary disease. Multiple population based studies have acknowledged the shortcomings of risk prediction models such as the Framingham risk score or the Procam score. The science behind coronary calcium is discussed briefly followed by a review of current thinking on calcium scores. An attempt has been made to summarize the appropriate indications and use of calcium scores.

George, Anil; Movahed, Assad

2008-01-01

71

Leaf Urea Metabolism in Potato. Urease Activity Profile and Patterns of Recovery and Distribution of 15N after Foliar Urea Application in Wild-Type and Urease-Antisense Transgenics1  

PubMed Central

The influence of urease activity on N distribution and losses after foliar urea application was investigated using wild-type and transgenic potato (Solanum tuberosum cv Désirée) plants in which urease activity was down-regulated. A good correlation between urease activity and 15N urea metabolism (NH3 accumulation) was found. The general accumulation of ammonium in leaves treated with urea indicated that urease activity is not rate limiting, at least initially, for the assimilation of urea N by the plant. It is surprising that there was no effect of urease activity on either N losses or 15N distribution in the plants after foliar urea application. Experiments with wild-type plants in the field using foliar-applied 15N urea demonstrated an initial rapid export of N from urea-treated leaves to the tubers within 48 h, followed by a more gradual redistribution during the subsequent days. Only 10% to 18% of urea N applied was lost (presumably because of NH3 volatilization) in contrast to far greater losses reported in several other studies. The pattern of urease activity in the canopy was investigated during plant development. The activity per unit protein increased up to 10-fold with leaf and plant age, suggesting a correlation with increased N recycling in senescing tissues. Whereas several reports have claimed that plant urease is inducible by urea, no evidence for urease induction could be found in potato.

Witte, Claus-Peter; Tiller, Sarah A.; Taylor, Mark A.; Davies, Howard V.

2002-01-01

72

[Calcium antagonists: current and future applications based on new evidence. Neuroprotective effect of calcium antagonists].  

PubMed

Voltage-dependent Ca(2+) channels have been divided into at least 5 types (L-, N-, T-, P-, and Q-type). L/N-type Ca(2+) channel blocker cilnidipine could reduce the size of cerebral infarction in the rat focal brain ischemia. L-type Ca(2+) channel blocker amlodipine reduced cerebral edema and inhibit neuronal cell death. N-type Ca(2+) channel blocker omega-conotoxin reduce the size of cerebral infarction and inhibit delayed neuronal cell death in hippocampal CA1 area. It is suggested that calcium antagonist has neuroprotective effect. PMID:20048438

Ito, Yasuo; Araki, Nobuo

2010-01-01

73

Rapid Induction of Ion Pulses in Tomato, Cucumber, and Maize Plants following a Foliar Application of L(+)-Adenosine.  

PubMed Central

Application of picomole quantities of (+)-adenosine, a plant growth-regulating second messenger elicited by triacontanol, to tomato (Lycopersicon esculentum Mill.), maize (Zea mays L.), and cucumber (Cucumis sativa L.) foliage, increased Ca2+, Mg2+, and K+ concentrations in the exudate from the stumps of excised plants by 20 to 60% within 5 s after treatment. The change in ionic concentration of the exudate was transitory. When L(+)-adenosine and triacontanol were applied to different tomato plants at the same time, the L(+)-adenosine caused an increase in Ca2+ flux within 3 s, whereas a significant increase from triacontanol was not detectable until 5 min after application. This was expected because triacontanol elicits the formation of L(+)-adenosine. The enantiomer of L(+)-adenosine, D(-)-adenosine, had no effect on the cation concentration in tomato and inhibited the effect of L(+)-adenosine at equimolar or lower concentrations. These observations suggest that L(+)-adenosine acts by eliciting a rapidly propagated signal that increases the concentration of several ions in the apoplast. We postulate that modulations in apoplastic ion concentration, especially increases in Ca2+ concentration, constitute a mechanism by which plants regulate metabolic activity and growth in response to certain stimuli.

Ries, S.; Savithiry, S.; Wert, V.; Widders, I.

1993-01-01

74

Formation, characterization and properties of hydroxyapatite-calcium polycarboxylate and calcium polyvinylphosphonate composites for biomedical applications  

NASA Astrophysics Data System (ADS)

A hot pressing technique was used to prepare composites anticipated to be biocompatible. Composites were formed by reactions between tetracalcium phosphate (Ca4(PO4)2O, TetCP) and a biomedical polymer. Polymers used in this study were poly(acrylic-co-itaconic), and poly(vinyl phosphonic acid) (PVPA). The processing technique is commonly used in metallurgy where powder mixtures are hot pressed at elevated pressures, and temperatures. Powder mixtures of TetCP with both polymers were compacted at temperatures up to 300°C, pressures up to 690 MPa for up to 60 minutes. The effects of varying these conditions as well as the TetCP:polymer weight ratios on the reaction kinetics were studied using X-ray diffraction (XRD), Fourier-transform-infrared (FT-IR), 13C, and 31P nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), scanning electron microscope (SEM) and transmission electron microscope (TEM). Results showed that TetCP was converted to hydroxyapatite (Ca10 (PO4)6(OH)2, HAp) with the formation of a Ca salt of the polymer. The reaction kinetics were found to increase with increasing compaction time, temperature and pressure. Formation of anhydrous calcium phosphate (CaHPO4, DCPA) was also observed when PVPA was used. The reaction appears to start with the softening of the polymer when it was heated at temperatures equal to or greater than its glass transition temperature (Tg). The molten polymer flows and surrounds the TetCP grains, permitting a direct reaction to take place on the interface between them. The Ca polysalt appear to form first followed by formation of HAp in case of the copolymer and DCPA then HAp in case of PVPA. Tensile strengths and elastic moduli of the composites increased when the compaction time and temperature were increased. However, when the applied pressure was increased, these properties increased then reduced at higher pressures. The improvement in mechanical properties was related to the increase in densification of the composites with these conditions. These results were correlated to the microstructure of the composites, where HAp crystals are embedded in a network of the calcium salt of the polymer. The reinforcing of the salt by these HAp crystals is considered the main reason of the improvement in mechanical properties. The effects of bioactive glass (bioglassRTM) and wollastonite fibers additions on the mechanical properties and in vitro behavior of these composites were also studied. Results showed that the mechanical properties were improved by ˜50% in case of bioglassRTM and by ˜100% when wollastonite was used. In vitro studies were conducted by immersing these composites in a simulated body fluid (SBF) for up to 14 days, and measuring the changes in the concentrations of Ca, PO4, and SiO4 ions in these solutions. Concentrations of these ions increased with the time of immersion in SBF due to the formation of apatite nuclei on the surface of the composites, suggesting increased bioactivity of the reinforced composites.

Greish, Yaser Elhanafy

75

RBS and XPS analyses of the composite calcium phosphate coatings for biomedical applications  

NASA Astrophysics Data System (ADS)

The calcium phosphate coatings on metallic implants are widely used for biomedical applications. The calcium phosphate coatings require mechanical strength, strong adhesion to the metallic implants, chemical stability and low dissolution into the human body fluid for stable functioning in the corrosive environment of the human body. In this study, a novel approach for improving the calcium phosphate coatings is utilized by adding trace metallic element into the coatings. We focused on teeth enamel, which is the hardest calcium phosphate tissue in the human body. Zn concentration increases exponentially from the interior to the surface of the enamel. As the Zn concentration increases, so the local hardness increases. Our previous studies suggest that Zn has influence on the hardness and other properties of enamel, calcium phosphate tissue. Calcium phosphate coatings doped with Zn was fabricated and characterized. The atomic composition and chemical state were investigated by using Rutherford backscattering spectroscopy (RBS) and X-ray photoelectron spectrometer (XPS), respectively. Scratch test was also carried out for measuring the adhesion of the coatings.

Ide-Ektessabi, Ari; Yamaguchi, Tetsuro; Tanaka, Yoshikazu

2005-12-01

76

APLICACIÓN DE UREA FOLIAR AL CULTIVO DE TRIGO EN ANTESIS BAJO CONDICIONES DE ESTRÉS HÍDRICO  

Microsoft Academic Search

The foliar nitrogen (N) applications in the period from leaf flag to anthesis enable yield optimization and\\/or to improve grain quality, but can generate phytotoxicity that impacts negatively on both parameters. The aim of this work was to evaluate the effect of N rates, fertilization moments and the use of a urease activity inhibitor in foliar urea applications at anthesis

HERNÁN EDUARDO ECHEVERRÍA; PABLO BARBIERI; HERNÁN SAINZ ROZAS

2008-01-01

77

Application of various electrodes in potentiometric titration of calcium.  

PubMed

In complexometric titrations various indicator electrodes may be employed for monitoring the course of titration and for detection of the end-point. Several of them, including the silver, mercury, bivalent cation membrane, calcium membrane and manganese dioxide electrodes were investigated and compared in their usefulness. As titrant, EDTA was mostly used, but results with similar chelating titrants were also obtained. The practical utility of the electrodes in titrations depends on their selectivity, magnitude of the end-point break and precision in determination of the end-point. For the electrodes studied, in some instances there is good correlation between the theoretical and experimental titration curves, but it is not always possible to predict the electrode response in the low activity range. In other cases poor correlation does not mean that reasonably good analytical results may not be obtained. PMID:18961322

Hulanicki, A; Trojanowicz, M

1973-07-01

78

[Calcium antagonists: current and future applications based on new evidence. Calcium channel blockers and autonomic nervous system].  

PubMed

Calcium channel blockers are widely used for the treatment of hypertension. Although they are effective for their strong vasodilator action, there are concerns regarding related baroreflex-mediated activation of sympathetic nervous system. However, long-acting calcium channel blockers, such as amlodipine, are now known safe for the treatment of hypertension. Furthermore, the new type of calcium channel blockers, such as cilnidipine with N-type calcium channel blocking action, or azelnidipine that has sympatho-inhibitory action with anti-oxidant effect, provide a new insight for the future use of calcium channel blockers. PMID:20048431

Hirooka, Yoshitaka; Sunagawa, Kenji

2010-01-01

79

Synthesis of spherical calcium phosphate particles for dental and orthopedic applications  

PubMed Central

Calcium phosphate materials have been used increasingly in the past 40 years as bone graft substitutes in the dental and orthopedic fields. Accordingly, numerous fabrication methods have been proposed and used. However, the controlled production of spherical calcium phosphate particles remains a challenge. Since such particles are essential for the synthesis of pastes and cements delivered into the host bone by minimally-invasive approaches, the aim of the present document is to review their synthesis and applications. For that purpose, production methods were classified according to the used reagents (solutions, slurries, pastes, powders), dispersion media (gas, liquid, solid), dispersion tools (nozzle, propeller, sieve, mold), particle diameters of the end product (from 10 nm to 10 mm), and calcium phosphate phases. Low-temperature calcium phosphates such as monetite, brushite or octacalcium phosphate, as well as high-temperature calcium phosphates, such as hydroxyapatite, ?-tricalcium phosphate or tetracalcium phosphate, were considered. More than a dozen production methods and over hundred scientific publications were discussed.

Bohner, Marc; Tadier, Solene; van Garderen, Noemie; de Gasparo, Alex; Dobelin, Nicola; Baroud, Gamal

2013-01-01

80

Uptake of Hydrophilic Solutes Through Plant Leaves: Current State of Knowledge and Perspectives of Foliar Fertilization  

Microsoft Academic Search

Foliar fertilization is an agricultural practice of increasing importance in practical terms. Since nutrient sprays are mostly applied as water solutions, the focus of the article was placed on the penetration of ionic, polar solutes through the leaf surface, although the mechanisms of cuticular penetration of lipophilics are also taken into consideration. In theory, application of foliar nutrient sprays may

V. Fernández; T. Eichert

2009-01-01

81

ATP-stabilized amorphous calcium carbonate nanospheres and their application in protein adsorption.  

PubMed

Calcium carbonate is a common substance found in rocks worldwide, and is the main biomineral formed in shells of marine organisms and snails, pearls and eggshells. Amorphous calcium carbonate (ACC) is the least stable polymorph of calcium carbonate, which is so unstable under normal conditions that it is difficult to be prepared in vitro because it rapidly crystallizes to form one of the more stable polymorphs in aqueous solution. Herein, we report the successful synthesis of highly stable ACC nanospheres in vitro using adenosine 5'-triphosphate disodium salt (ATP) as a stabilizer. The effect of ATP on the stability of ACC nanospheres is investigated. Our experiments show that ATP plays an unique role in the stabilization of ACC nanospheres in aqueous solution. Moreover, the as-prepared ACC nanospheres are highly stable in phosphate buffered saline for a relatively long period of time (12 days) even under relatively high concentrations of calcium and phosphate ions. The cytotoxicity tests show that the as-prepared highly stable ACC nanospheres have excellent biocompatibility. The highly stable ACC nanospheres have high protein adsorption capacity, implying that they are promising for applications in biomedical fields such as drug delivery and protein adsorption. PMID:24578276

Qi, Chao; Zhu, Ying-Jie; Lu, Bing-Qiang; Zhao, Xin-Yu; Zhao, Jing; Chen, Feng; Wu, Jin

2014-05-28

82

Three-year growth response of young Douglas-fir to nitrogen, calcium, phosphorus, and blended fertilizers in Oregon and Washington  

USGS Publications Warehouse

Studies of nutrient limitation in Douglas-fir forests of the Pacific Northwest focus predominantly on nitrogen, yet many stands demonstrate negligible or even negative growth response to nitrogen fertilization. To understand what nutrients other than nitrogen may limit forest productivity in this region, we tested six fertilizer treatments for their ability to increase stem volume growth response of dominant and co-dominant trees in young Douglas-fir plantations across a range of foliar and soil chemistry in western Oregon and Washington. We evaluated responses to single applications of urea, lime, calcium chloride, or monosodium phosphate at 16 sites, and to two site-specific nutrients blends at 12 of these sites. Across sites, the average stem volume growth increased marginally with urea, lime, and phosphorus fertilization. Fertilization responses generally aligned with plant and soil indicators of nutrient limitation. Response to nitrogen addition was greatest on soils with low total nitrogen and high exchangeable calcium concentrations. Responses to lime and calcium chloride additions were greatest at sites with low foliar calcium and low soil pH. Response to phosphorus addition was greatest on sites with low foliar phosphorus and high soil pH. Blended fertilizers yielded only marginal growth increases at one site, with no consistent effect across sites. Overall, our results highlight that calcium and phosphorus can be important growth limiting nutrients on specific sites in nitrogen-rich Douglas-fir forests of the Pacific Northwest.

Mainwaring, Douglas B.; Maguire, Douglas A.; Perakis, Steven S.

2014-01-01

83

Preparation and optimization of calcium fluoride particles for dental applications.  

PubMed

Fluorides are used in dental care due to their beneficial effect in tooth enamel de-/remineralization cycles. To achieve a desired constant supply of soluble fluorides in the oral cavity, different approaches have been followed. Here we present results on the preparation of CaF2 particles and their characterization with respect to a potential application as enamel associated fluoride releasing reservoirs. CaF2 particles were synthesized by precipitation from soluble NaF and CaCl2 salt solutions of defined concentrations and their morphology analyzed by scanning electron microscopy. CaF2 particles with defined sizes and shapes could be synthesized by adjusting the concentrations of the precursor salt solutions. Such particles interacted with enamel surfaces when applied at fluoride concentrations correlating to typical dental care products. Fluoride release from the synthesized CaF2 particles was observed to be largely influenced by the concentration of phosphate in the solution. Physiological solutions with phosphate concentration similar to saliva (3.5 mM) reduced the fluoride release from pure CaF2 particles by a factor of 10-20 × as compared to phosphate free buffer solutions. Fluoride release was even lower in human saliva. The fluoride release could be increased by the addition of phosphate in substoichiometric amounts during CaF2 particle synthesis. The presented results demonstrate that the morphology and fluoride release characteristics of CaF2 particles can be tuned and provide evidence of the suitability of synthetic CaF2 particles as enamel associated fluoride reservoirs. PMID:24682907

Koeser, Joachim; Carvalho, Thiago Saads; Pieles, Uwe; Lussi, Adrian

2014-07-01

84

Development and application of a liquid chromatography-mass spectrometry method to evaluate the glyphosate and aminomethylphosphonic acid dissipation in maize plants after foliar treatment.  

PubMed

A simple and fast method has been developed and validated to measure glyphosate (GLYP) and aminomethylphosphonic acid (AMPA), which were previously derivatized with 9-fluorenylmethylchloroformate (FMOC-Cl), in maize plants using liquid chromatography (LC) coupled to fluorescence (FLD) and electrospray ionization mass spectrometry (ESI-MS) detection. The method has shown to be consistent, reliable, precise, and efficient. Moreover, the limits of detection (LOD) and quantification (LOQ) reached with the proposed method for GLYP and AMPA are lower than the established maximum residue levels (MRLs). The validated method was applied to quantify GLYP and AMPA in genetically modified (GM) maize foliar treated with the herbicide. It has been found that the GLYP dissipation was mainly due to the progressive dilution effect after herbicide treatment. Finally, it was also observed that the GLYP residue dissipation trend in maize shoot (leaves and stem) tissue determined by LC-ESI-MS matched that determined by liquid scintillation. PMID:22480367

Bernal, José; Martin, María T; Soto, María E; Nozal, María J; Marotti, Ilaria; Dinelli, Giovanni; Bernal, José L

2012-04-25

85

Influence of calcium ion deposition on apatite-inducing ability of porous titanium for biomedical applications.  

PubMed

In the present study, the influence of calcium ion deposition on the apatite-inducing ability of porous titanium (Ti) was investigated in a modified simulated body fluid (m-SBF). Calcium hydroxide (Ca(OH)(2)) solutions with five degrees of saturation were used to hydrothermally deposit Ca ions on porous Ti with a porosity of 80%. Apatite-inducing ability of the Ca-ion-deposited porous Ti was evaluated by soaking them in m-SBF for up to 14 days. Scanning electron microscopy (SEM) and X-ray diffractometry (XRD) confirmed that a thin layer of calcium titanate (CaTiO(3))/calcium oxide (CaO) mixture with a nanostructured porous network was produced on porous Ti substrates after hydrothermal treatment at 200 degrees C for 8 h. X-ray photoelectron spectroscopy results demonstrated that the content of the Ca ions deposited on Ti and the thickness of the CaTiO(3)/CaO layer increased with increasing saturation degree of the Ca(OH)(2) solution. The thickest (over 10 nm) CaTiO(3)/CaO layer with the highest Ca content was achieved on the Ti treated in an oversaturated Ca(OH)(2) solution (0.2 M). SEM, XRD, transmission electron microscopy and Fourier transformed infrared spectroscopy analysis indicated that the porous Ti samples deposited with the highest content of Ca ions exhibited the best apatite-inducing ability, producing a dense and complete carbonated apatite coating after a 14 day soaking in m-SBF. The present study illustrated the validity of using Ca ion deposition as a pre-treatment to endow desirable apatite-inducing ability of porous Ti for bone tissue engineering applications. PMID:19223253

Chen, Xiao-Bo; Li, Yun-Cang; Du Plessis, Johan; Hodgson, Peter D; Wen, Cui'e

2009-06-01

86

Structural characterization of phosphorylated chitosan and their applications as effective additives of calcium phosphate cements.  

PubMed

Chitosan was phosphorylated by P2O5 in methanesulfonic acid and the product as water-soluble phosphorylated chitosan (P-chitosans) was then characterized by phosphorus elemental analysis, IR and 31P-NMR spectroscopy. Two calcium phosphate cement (CPC) systems, i.e. (1) monocalcium phosphate monohydrate (MCPM) and calcium oxide (CaO) in 1 M phosphate buffer (pH = 7.4) and (2) dicalcium phosphate dihydrate (DCPD) and calcium hydroxide [Ca(OH)2] in 1 M Na2HPO4 solution, were chosen to improve their mechanical properties by the addition of water-soluble P-chitosans with various values for molecular weight, degree of deacetylation (DD) and degree of substitution (DS). The results show that the compressive strength (CS) and Young's modulus of both CPC formulations after setting were obviously increased and setting time was slightly prolonged by adding water-soluble P-chitosan to the liquid phases. When a suitable amount of P-chitosan was used, two improved CPC formulations were obtained with much better mechanical properties while the setting times were not longer than 15 min. The enhancement of compressive strength was due to high Ca2+-binding ability of phosphorylated chitosan, which could tightly bind the newly formed hydroxyapatite (HA) particles together by polymeric chains. It was noted that excessive addition of P-chitosan would lead to slow setting or no setting at all. The hardened CPC samples containing P-chitosan were characterized via X-ray diffraction spectra and scanning electron microscopy. Their leaching experiment was also carried out. The results indicated that P-chitosan-forced calcium phosphate cements have some good characteristics for clinical applications. PMID:11456064

Wang, X; Ma, J; Wang, Y; He, B

2001-08-01

87

Effect of Pre-Harvest Foliar Application of Citric Acid and Malic Acid on Chlorophyll Content and Post-Harvest Vase Life of Lilium cv. Brunello  

PubMed Central

Citric acid is a regular ingredient in many vase solution formulations but pre-harvest use of citric acid is a novel method in vase life extension of cut flowers, which is reported on tuberose earlier. In order to verify previous result, and check for possible substitution of citric acid by malic acid, the current research was designed. Citric acid (0, 0.075, 0.15% w/v) and malic acid (0, 0.075, 0.15% w/v) were used in a factorial design with three replications. Foliar sprays were applied two times during growth period of Lilium plants. The results point out that 0.15% citric acid alone had increased vase life from 11.8 in control treatment to 14?days (??

Darandeh, Nafiseh; Hadavi, Ebrahim

2012-01-01

88

Effect of GA3 and 2,4-D foliar application on the anatomy of date palm (Phoenix dactylifera L.) seedling leaf.  

PubMed

Two concentrations (10-5M and 10-3M) of both GA3 and 2,4-D were used as foliar spray to evaluate the response of date palm (Phoenix dactylifera L.) cv. Khedri seedlings. They affected some of the anatomical characteristics of the first leaf emerging after the beginning of the spray. The high concentration of GA3 increased the size of the midrib and its vascular bundle numbers. Both low and high concentrations of 2,4-D inhibited the formation of the midrib. 2,4-D in both low and high concentrations decreased the number of vessels in both protoxylem and metaxylem and also decreased their diameters, where as GA3 in low and high concentrations have less effect on the number of vessels and its diameters. GA3 in high concentration increased the number of vascular bundles in 1mm long of the leaf blade, while 2,4-D in low and high concentrations decreased their numbers. 10-3M of 2,4-D increased the size and layers of special hypodermal cells. PMID:23961229

Doaigey, Abdullah R; Al-Whaibi, M H; Siddiqui, M H; Al Sahli, A A; El-Zaidy, M E

2013-04-01

89

Effect of Pre-Harvest Foliar Application of Citric Acid and Malic Acid on Chlorophyll Content and Post-Harvest Vase Life of Lilium cv. Brunello.  

PubMed

Citric acid is a regular ingredient in many vase solution formulations but pre-harvest use of citric acid is a novel method in vase life extension of cut flowers, which is reported on tuberose earlier. In order to verify previous result, and check for possible substitution of citric acid by malic acid, the current research was designed. Citric acid (0, 0.075, 0.15% w/v) and malic acid (0, 0.075, 0.15% w/v) were used in a factorial design with three replications. Foliar sprays were applied two times during growth period of Lilium plants. The results point out that 0.15% citric acid alone had increased vase life from 11.8 in control treatment to 14?days (??

Darandeh, Nafiseh; Hadavi, Ebrahim

2011-01-01

90

Quantitative analysis of binary mineral mixtures using Raman microspectroscopy: Calibration curves for silica and calcium carbonate minerals and application to an opaline silica nodule of volcanic origin  

Microsoft Academic Search

Quantitative analysis of binary mineral mixtures using Raman microspectroscopy: Calibration curves for silica and calcium carbonate minerals and application to an opaline silica nodule of volcanic origin

Naoki Noguchi; Keiji Shinoda; Kaori Masuda

2009-01-01

91

Quantitative analysis of binary mineral mixtures using Raman microspectroscopy: Calibration curves for silica and calcium carbonate minerals and application to an opaline silica nodule of volcanic origin  

NASA Astrophysics Data System (ADS)

Quantitative analysis of binary mineral mixtures using Raman microspectroscopy: Calibration curves for silica and calcium carbonate minerals and application to an opaline silica nodule of volcanic origin

Noguchi, Naoki; Shinoda, Keiji; Masuda, Kaori

92

Foliar Absorption and Phloem Translocation  

NSDL National Science Digital Library

Herbicides must be absorbed into plants in order to be effective. Herbicide absorption can occur through leaves, roots or both. The process by which herbicides kill weeds, called mode of action, requires herbicide absorption and may also require herbicide movement or translocation within the plant. Translocation means that the herbicide moves from the site of absorption to some other plant part. Foliar applied herbicides that have the necessary characteristics to move in the phloem will translocate to areas of the plant that are actively growing; however, not all foliar-applied herbicides move from the leaves that intercepted the spray solution. Herbicides that are absorbed but not translocated are calledcontact herbicides, while herbicides that translocate to shoot or root meristems are called systemic herbicides. Absorption and translocation of xylem mobile herbicides will be discussed in another lesson.

93

The effect of milk-based foliar sprays on yield components of field pumpkins with powdery mildew  

Microsoft Academic Search

Previous work has shown that foliar applications of mixtures of cow's milk and water are effective in preventing powdery mildew (Podosphaera xanthii) of zucchini on greenhouse grown plants. Our own work on field-grown pumpkins indicated that the efficacy of such foliar sprays is highly variable. This study is an attempt to measure the effect of milk-based sprays on the yield

Francis J. Ferrandino; Victoria L. Smith

2007-01-01

94

Biomineralization and Size Control of Stable Calcium Phosphate Core Protein Shell Nanoparticles: Potential for Vaccine Applications  

PubMed Central

Calcium phosphate (CaP) polymorphs are nontoxic, biocompatible and hold promise in applications ranging from hard tissue regeneration to drug delivery and vaccine design. Yet, simple and robust routes for the synthesis of protein-coated CaP nanoparticles in the sub-100 nm size range remain elusive. Here, we used cell surface display to identify disulfide-constrained CaP binding peptides that, when inserted within the active site loop of E. coli Thioredoxin 1 (TrxA), readily and reproducibly drive the production of nanoparticles that are 50–70 nm in hydrodynamic diameter and consist of an approximately 25 nm amorphous calcium phosphate (ACP) core stabilized by the protein shell. Like bone and enamel proteins implicated in biological apatite formation, peptides supporting nanoparticle production were acidic. They also required presentation in a loop for high affinity ACP binding since elimination of the disulfide bridge caused a nearly 3-fold increase in hydrodynamic diameters. When compared to a commercial aluminum phosphate adjuvant, the small core-shell assemblies led to a 3-fold increase in mice anti-TrxA titers three weeks post-injection, suggesting that they might be useful vehicles for adjuvanted antigen delivery to dendritic cells.

Chiu, David; Zhou, Weibin; Kitayaporn, Sathana; Schwartz, Daniel T.; Murali-Krishna, Kaja; Kavanagh, Terrance J.; Baneyx, Francois

2012-01-01

95

Ion microprobe measurement of strontium isotopes in calcium carbonate with application to salmon otoliths  

USGS Publications Warehouse

The ion microprobe has the capability to generate high resolution, high precision isotopic measurements, but analysis of the isotopic composition of strontium, as measured by the 87Sr/ 86Sr ratio, has been hindered by isobaric interferences. Here we report the first high precision measurements of 87Sr/ 86Sr by ion microprobe in calcium carbonate samples with moderate Sr concentrations. We use the high mass resolving power (7000 to 9000 M.R.P.) of the SHRIMP-RG ion microprobe in combination with its high transmission to reduce the number of interfering species while maintaining sufficiently high count rates for precise isotopic measurements. The isobaric interferences are characterized by peak modeling and repeated analyses of standards. We demonstrate that by sample-standard bracketing, 87Sr/86Sr ratios can be measured in inorganic and biogenic carbonates with Sr concentrations between 400 and 1500 ppm with ???2??? external precision (2??) for a single analysis, and subpermil external precision with repeated analyses. Explicit correction for isobaric interferences (peak-stripping) is found to be less accurate and precise than sample-standard bracketing. Spatial resolution is ???25 ??m laterally and 2 ??m deep for a single analysis, consuming on the order of 2 ng of material. The method is tested on otoliths from salmon to demonstrate its accuracy and utility. In these growth-banded aragonitic structures, one-week temporal resolution can be achieved. The analytical method should be applicable to other calcium carbonate samples with similar Sr concentrations. Copyright ?? 2005 Elsevier Ltd.

Weber, P. K.; Bacon, C. R.; Hutcheon, I. D.; Ingram, B. L.; Wooden, J. L.

2005-01-01

96

Application of Atomic Absorption Spectro- photometry in the Determination of Calcium in Serum  

Microsoft Academic Search

Atomic absorption spectrophotometry (AAS) was applied to the determination of serum calcium. A specialdiluent was developedto abolishthe effect of absorption depressors.This made possiblemeasurement of calcium in directly diluted serum sampleswithout prior removalof any serum constituents. Values obtained by AAS on calcium oxalate precipitates from serum were identical with those found by the direct dilution technique. THE RECENT appearance of good

Alfred Zettner; David Seligson

97

Growth of calcium phosphates on magnesium substrates for corrosion control in biomedical applications via immersion techniques.  

PubMed

Magnesium (Mg) has been suggested as a revolutionary biodegradable replacement for current permanent metals used in orthopedic applications. Current investigations concentrate on the control of the corrosion rate to match bone healing. Calcium phosphate coatings have been a recent focus of these investigations through various coating protocols. Within this investigation, an in situ crystallization technique was utilized as an inexpensive and relatively simple method to produce a brushite and monetite coating on pure Mg. Coatings were characterized using energy dispersive spectroscopy, glancing angle X-ray diffraction and field emission scanning electron microscopy. Corrosion protection properties of the coatings were assessed in physiological buffers, Earles balanced salt solution, minimum essential media, and minimum essential media containing serum albumin, over a 4-week period. Using this novel coating protocol, our findings indicate brushite and monetite coated Mg to have significant corrosive protective effects when compared with its uncoated counterpart whilst maintaining high coating substrate adhesion, homogeneity, and reproducibility. PMID:23090758

Shadanbaz, Shaylin; Walker, Jemimah; Staiger, Mark P; Dias, George J; Pietak, Alexis

2013-01-01

98

Iron concentration, bioavailability, and nutritional quality of polished rice affected by different forms of foliar iron fertilizer.  

PubMed

The present study compared the effects of four different forms of foliar iron (Fe) fertilizers on Fe concentration, bioavailability and nutritional quality of polished rice. The results showed that foliar fertilisation at the anthesis stage was an effective way to promote Fe concentration and bioavailability of polished rice, especially in case of DTPA-Fe. Compared to the control, foliar application of DTPA-Fe increased sulphur concentration and the nutrition promoter cysteine content, whereas decreased phosphorus concentration and the antinutrient phytic acid content of polished rice, as a result increased 67.2% ferrtin formation in Caco-2 cell. Moreover, foliar DTPA-Fe application could maintain amylase, protein and minerals quality of polished rice. According to the current study, DTPA-Fe is recommended as an excellent foliar Fe form for Fe biofortification program. PMID:23993594

He, Wanling; Shohag, M J I; Wei, Yanyan; Feng, Ying; Yang, Xiaoe

2013-12-15

99

In situ synthesis and magnetic studies of iron oxide nanoparticles in calcium-alginate matrix for biomedical applications  

Microsoft Academic Search

In this work we applied a new route to synthesize magnetic iron oxide nanoparticles into alginate polymer for future application as drug delivery system activated by magnetic external stimuli. Calcium-alginate was used to encapsulate iron oxide nanoparticles, and as scaffold for particle nucleation and its influence on particles size and magnetic properties were studied. The iron oxide mean sizes were

M. A. Morales; P. V. Finotelli; J. A. H. Coaquira; M. H. M. Rocha-Leão; C. Diaz-Aguila; E. M. Baggio-Saitovitch; A. M Rossi

2008-01-01

100

Application of reutilization technology to calcium fluoride sludge from semiconductor manufacturers.  

PubMed

Glass ceramics were prepared from mixtures of wastes generated from refining of waste glass and semiconductor industrial wastewater sludge. The aim is then indeed to study the possible use and effects of integrating calcium fluoride (CaF2) as present in semiconductor wastewater sludge in the silica (glass) melts. CaF2 sludge was blended with a conditioner according to characteristics of the target. Calcium oxide-silicon dioxide-aluminum oxide system glass ceramics have relatively high melting points. Addition of CaF2 sludge to fluxes can significantly reduce the melting point and hence improve the kinetics of the reactions. CaF2 sludge and waste glass were co-melted in various ratios to elucidate their interactions at various heating temperatures. The results indicate that the lowest melting temperature was 1163 degrees C, obtained for the CaF2 sludge-waste glass mixture at a ratio 6:4 (wt:wt), which is significantly lower than that of CaF2 sludge (1378 degrees C). The benefits of using melting to dispose of sludge are the reduction of waste and the fixation of heavy metals. Heat treatment was used to convert the obtained glass into glass ceramics. Heavy metal leaching tests revealed that melting conditions lowered the heavy metal concentrations in the leachate to an order of magnitude lower than that in the sludge. Consequently, industrial sludge can be safely used as a fine aggregate material for a potentially wide range of construction applications. PMID:21305892

Liu, Wei-Ting; Li, Kung-Cheh

2011-01-01

101

Stable calcium adsorbates on carbon nanostructures: Applications for high-capacity hydrogen storage  

NASA Astrophysics Data System (ADS)

We have investigated the stability of calcium adsorbates on carbon nanotubes and defective graphene using first-principles calculations. For ultranarrow carbon nanotubes, we find that the effect of chirality is more important to the adsorption as compared to the diameter (D) . The binding energy for a calcium atom absorbed on the (5,0) tube is about 1.4 eV higher than that on the (3,3) tube. We also find that calcium atoms on the octagon defect of graphene are also stable. The binding energies of calcium adsorbates on narrow tubes (3.2Åcalcium monolayer should be stable without clustering. The results show that every calcium atom can uptake four to five H2 and the hydrogen storage can reach 9wt% .

Yang, Xiaobao; Zhang, R. Q.; Ni, Jun

2009-02-01

102

Secondary Ion Mass Spectrometers (SIMS) for calcium isotope measurements as an application to biological samples  

NASA Astrophysics Data System (ADS)

The potential use of secondary ion mass spectroscopy (SIMS) to analyze biological samples for calcium isotopes is discussed. Comparison of UTI and Extranuclear based quadrupole systems is made on the basis of the analysis of CaO and calcium metal. The Extranuclear quadrupole based system is superior in resolution and sensitivity to the UTI system and is recommended. For determination of calcium isotopes to within an accuracy of a few percent a high resolution quadrupole, such as the Extranuclear, and signal averaging capability are required. Charge neutralization will be mandated for calcium oxide, calcium nitrate, or calcium oxalate. SIMS is not capable of the high precision and high accuracy results possible by thermal ionization methods, but where faster analysis is desirable with an accuracy of a few percent, SIMS is a viable alternative.

Craven, S. M.; Hoenigman, J. R.; Moddeman, W. E.

1981-11-01

103

Application of lime and calcium hypochlorite in the dephenolisation and discolouration of olive mill wastewater.  

PubMed

The application of hypochlorite for the removal of soluble COD, phenolic and polyphenolic like compounds, and other organic compounds responsible for the olive mill wastewater (OOWW) colour has been experimentally studied. After the OOWW filtration on a sand column, the effluent was subjected to a fast liming under optimal conditions. Lime application reduced polyphenols, COD and SS contents to half of their initial values but an important blackening of the treated OOWW was observed, especially when adding high concentrations of lime (10% (W/V) and 15% (W/V)). A second stage of treatment was applied using calcium hypochlorite. In this stage, removal of the studied compounds reached as much as 95% at higher concentrations, and particularly the colouring of OOWW which is generally difficult to eliminate was greatly reduced. The OOWW hypochloration acted through coagulation-flocculation and a rapid oxidation of the organic matter proceeded from the first 5min. The kinetic study of the degradation of the waste polluting compounds from liming showed that Ca(ClO)(2) reacts similarly in the elimination of organic compounds, polyphenols, SS and colouration. The analysis of the organochloride compounds generated by the reaction between hypochlorite and the organic compounds showed that DDD, DDT and the heptachlor contents exceeded the values recommended by the International and European drinking water standards. PMID:19720448

Boukhoubza, F; Jail, A; Korchi, F; Idrissi, L Loukili; Hannache, H; Duarte, J C; Hassani, L; Nejmeddine, A

2009-10-01

104

Development and Field Application of a Novel Non-acid Calcium Naphthenate Inhibitor  

Microsoft Academic Search

Current state of the art for treating calcium naphthenates requires addition of large doses of acid to the production fluids. Although effective in dissolving deposits, acid treatments result in increased corrosion in production equipment, decreased oil quality and increased transport and HSE costs. Consequently, an opportunity exists for the development of non-acid inhibitors to prevent calcium naphthenate formation without the

Justin Debord; Piyush Srivastava

2009-01-01

105

The impact of foliar boron sprays on reproductive biology and seed quality of black gram.  

PubMed

An experiment was conducted under glass house condition to study the effect of foliar application of boron (B) on reproductive biology and seed quality of black gram (Vigna mungo). Black gram (V. mungo L. var. DPU-88-31) was grown under controlled sand culture condition at deficient and sufficient B levels. After 32 days of sowing B deficient plants were sprayed with three concentrations of B (0.05%, 0.1% and 0.2% borax) at three different stages of reproductive development, i.e. prior to flowering, initiation of bud formation and after bud formation. Deficient B supply decreased the anther and pollen size, pollen tube growth, pollen viability as well as stigmatic receptivity which were increased by foliar B application. Foliar spray at all the three concentrations and at all stages increased the yield parameters like number of pods, pod size and number of seeds formed per plant. Foliar B application also improved the seed yield and seed quality in terms of storage seed proteins (albumin, globulin, glutenin and prolamin) and carbohydrates (sugars and starch) in black gram. The foliar application of B in appropriate doses (particularly 0.1%) after bud formation made quantitative and qualitative improvement in seed yield of black gram by supplementing additional/critical B requirements for reproductive development. PMID:22947393

Pandey, Nalini; Gupta, Bhavana

2013-01-01

106

Effect of calcium silicate slag application on radium-226 concentrations in plant tissues  

SciTech Connect

A greenhouse pot experiment was conducted to determine if plants absorb Ra from slag applied to soil. Slag at rates equivalent to 0 and 22 mt/ha was mixed with Mountview silt loam (Typic Paleudults) limed to pH 5.8 and 7.2. Three clippings each of fescue (Festuca arundiancea Schreb.), and Swiss chard (Beta vulgaris L.), and one harvest of wheat (Triticum aestivum L.) for grain and straw were grown on separate series of treated soil, and plant samples were analyzed for radioactivity due to /sup 226/Ra uptake. Samples of sugarcane (Saccharum officinarum L.) forage and extracted juice from field experiments in Florida testing this slage as a Si source also were analyzed for radioactivity. Dry forage yields of fescue and wheat were not affected by slag applications, but those of Swiss chard were somewhat higher on slag-treated soil at pH 5.8. Wheat grain and straw yields were higher on soil at pH 7.2 than at pH 5.8 regardless of slag treatment. Uptake of /sup 226/Ra by fescue forage and wheat grain and straw was not affected by slag application. Concentrations of /sup 226/Ra were similar in forage and extracted juice from untreated sugarcane or that treated with slag at rates up to 5.6 mt/ha. These results suggest that plant uptake of radionuclides is negligible from calcium silicate slag applied at the recommended rates for liming acid soils or as a source of Si for sugarcane.

Mortvedt, J.J.

1986-01-01

107

Effect of preharvest calcium applications on postharvest quality, softening and cell wall degradation of two blueberry ( Vaccinium corymbosum) varieties  

Microsoft Academic Search

Excessive softening is the main factor limiting blueberry storage. We evaluated the effect of preharvest calcium applications on ‘O’Neal’ and ‘Bluecrop’ blueberry quality during refrigerated storage. Blueberry plants were fertilized with CaSO4 (0.06kgm?2). On the following season, fruit was harvested at commercial maturity (100% blue) and stored at 2°C for 23d. During storage, we analyzed firmness, weight loss, surface color,

Pablo Angeletti; Hilda Castagnasso; Elisa Miceli; Laura Terminiello; Analía Concellón; Alicia Chaves; Ariel R. Vicente

2010-01-01

108

Combined effect of CO2 enrichment and foliar application of salicylic acid on the production and antioxidant activities of anthocyanin, flavonoids and isoflavonoids from ginger  

PubMed Central

Background The increase in atmospheric CO2 concentration caused by climate change and agricultural practices is likely to affect biota by producing changes in plant growth, allocation and chemical composition. This study was conducted to evaluate the combined effect of the application of salicylic acid (SA, at two levels: 0 and 10-3 M) and CO2 enrichment (at two levels: 400 and 800 ?mol·mol?1) on the production and antioxidant activities of anthocyanin, flavonoids and isoflavonoids from two Malaysian ginger varieties, namely Halia Bentong and Halia Bara. Methods High-performance liquid chromatography (HPLC) with photodiode array detection and mass spectrometry was employed to identify and quantify the flavonoids and anthocyanins in the ginger extracts. The antioxidant activity of the leaf extracts was determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and thiobarbituric acid (TBA) assays. The substrate specificity of chalcone synthase, the key enzyme for flavonoid biosynthesis, was investigated using the chalcone synthase (CHS) assay. Results CO2 levels of 800 ?mol·mol?1 significantly increased anthocyanin, rutin, naringenin, myricetin, apigenin, fisetin and morin contents in ginger leaves. Meanwhile, the combined effect of SA and CO2 enrichment enhanced anthocyanin and flavonoid production compared with single treatment effects. High anthocyanin content was observed in H Bara leaves treated with elevated CO2 and SA. The highest chalcone synthase (CHS) activity was observed in plants treated with SA and CO2 enrichment. Plants not treated with SA and kept under ambient CO2 conditions showed the lowest CHS activity. The highest free radical scavenging activity corresponded to H Bara treated with SA under high CO2 conditions, while the lowest activity corresponded to H Bentong without SA treatment and under atmospheric CO2 levels. As the level of CO2 increased, the DPPH activity increased. Higher TBA activity was also recorded in the extracts of H Bara treated with SA and grown under high CO2 conditions. Conclusions The biological activities of both ginger varieties were enhanced when the plants were treated with SA and grown under elevated CO2 concentration. The increase in the production of anthocyanin and flavonoids in plants treated with SA could be attributed to the increase in CHS activity under high CO2 levels.

2012-01-01

109

Microstructure of the system calcium aluminate cement-silica fume: application in waste immobilization  

Microsoft Academic Search

The immobilization of wastes in cement suggests that cement compositions can be tailored in terms of pH, Eh and internal chemistry so as to maximize immobilization potential. This work presents some studies concerning the micro structure of calcium aluminate cement (CAC), and silica fume-calcium aluminate cement (SF-CAC) systems, and their resistance to the leaching by natural waters, with a view

A. Hidalgo; S. Petit; J. L. García; C. Alonso; C. Andrade

2007-01-01

110

Influence of calcium ion deposition on apatite-inducing ability of porous titanium for biomedical applications  

Microsoft Academic Search

In the present study, the influence of calcium ion deposition on the apatite-inducing ability of porous titanium(Ti) was investigated in a modified simulated body fluid (m-SBF). Calcium hydroxide (Ca(OH)2) solutions with five degrees of saturation were used to hydrothermally deposit Ca ions on porous Ti with a porosity of 80%. Apatite-inducing ability of the Ca-ion-deposited porous Ti was evaluated by

Xiao-Bo Chen; Yun-Cang Li; Johan Du Plessis; Peter D. Hodgson; Cui’e Wen

2009-01-01

111

PARTITIONING THE RELATIVE INFLUENCE OF SOIL N, MYCORRHIZAE, AND FOLIAR N UPTAKE ON FOLIAR delta15N PATTERNS: CAN WE DETECT FOLIAR UPTAKE OF REACTIVE N?  

Microsoft Academic Search

Vegetation is an important sink for atmospheric reactive N in N-limited systems and may be capable of incorporating reactive N compounds directly into leaves through the foliar uptake pathway. A proxy for atmospheric reactive N entering vegetation would be useful to estimate the impact of direct foliar N uptake on plant metabolism. Natural abundance foliar N isotopic composition (delta15N) is

D. Vallano; J. P. Sparks

2009-01-01

112

Amorphous calcium silicate hydrate/block copolymer hybrid nanoparticles: synthesis and application as drug carriers.  

PubMed

Amorphous calcium silicate hydrate (CSH)/block copolymer monomethoxy(polyethyleneglycol)-block-poly(lactide-co-glycolide) (mPEG-PLGA) (CSHP) hybrid nanoparticles have been prepared in aqueous solution via a facile coprecipitation route at room temperature. The block copolymer mPEG-PLGA micelles in aqueous solution serve as the templates, and the CSH links to the micelles by hydrogen bonding between the silanol groups and the hydrophilic mPEG segments. The obtained core/shell hybrid nanoparticles can be transformed to solid hybrid nanoparticles by washing with water. The drug ibuprofen (IBU) loading capacity of the CSHP hybrid nanoparticles is ultrahigh (~1.9 g drug per g carrier), and the IBU loading efficiency can reach as high as ~100%. The drug release of loaded IBU in the CSHP hybrid nanoparticles has been investigated in simulated body fluid (SBF). The loaded IBU drug in CSHP hybrid nanoparticles can release in SBF for a long period of time (about 300 h), during which the CSHP nanocarrier is completely transformed to hydroxyapatite, exhibiting a good bioactivity. The IBU drug release profile can be interpreted by the Higuchi model. The loading capacity for the anticancer drug docetaxel (DTX) in the CSHP hybrid nanoparticles is about 82 mg g(-1). More importantly, the release of the loaded DTX in phosphate buffer saline (PBS) at pH 5.5 is obviously faster than that at pH 7.4, which is promising for the application in cancer therapy. Human gastric carcinoma (SGC-7901) cells can be effectively killed in the presence of the DTX-loaded CSHP hybrid nanoparticles at appropriate concentrations. Thus, the CSHP hybrid nanoparticles are promising nanocarriers in drug delivery. Furthermore, the hemoglobin (Hb) loading capacity of CSHP hybrid nanoparticles can achieve an utrahigh value of 995 mg g(-1), suggesting that the as-prepared CSHP hybrid nanoparticles are excellent protein adsorbents. PMID:23511873

Wu, Jin; Zhu, Ying-Jie; Chen, Feng; Zhao, Xin-Yu; Zhao, Jing; Qi, Chao

2013-05-21

113

40 CFR 424.40 - Applicability; description of the covered calcium carbide furnaces with wet air pollution control...  

Code of Federal Regulations, 2013 CFR

...calcium carbide furnaces with wet air pollution control devices subcategory. 424...Calcium Carbide Furnaces With Wet Air Pollution Control Devices Subcategory § 424...calcium carbide furnaces with wet air pollution control devices subcategory....

2013-07-01

114

Calcium bioavailability of vegetarian diets in rats: potential application in a bioregenerative life-support system  

NASA Technical Reports Server (NTRS)

Calcium bioavailability of vegetarian diets containing various proportions of candidate crops for a controlled ecological life-support system (CELSS) was determined by femur 45Ca uptake. Three vegetarian diets and a control diet were labeled extrinsically with 45Ca and fed to 5-wk old male rats. A fifth group of rats fed an unlabeled control diet received an intraperitoneal (IP) injection of 45Ca. There was no significant difference in mean calcium absorption of vegetarian diets (90.80 +/- 5.23%) and control diet (87.85 +/- 5.25%) when calculated as the percent of an IP dose. The amounts of phytate, oxalate, and dietary fiber in the diets did not affect calcium absorption.

Nickel, K. P.; Nielsen, S. S.; Smart, D. J.; Mitchell, C. A.; Belury, M. A.

1997-01-01

115

Reinforcement of calcium phosphate cement with multi-walled carbon nanotubes and bovine serum albumin for injectable bone substitute applications.  

PubMed

This paper presents the development of novel alternative injectable calcium phosphate cement (CPC) composites for orthopaedic applications. The new CPC composites comprise ?-tri-calcium phosphate (?-TCP) and di-calcium phosphate anhydrous (DCPA) mixed with bovine serum albumin (BSA) and incorporated with multi-walled carbon nanotubes (MWCNTs) or functionalized MWCNTs (MWCNTs-OH and MWCNTs-COOH). Scanning electron microscopy (SEM), compressive strength tests, injectability tests, Fourier transform infrared spectroscopy and X-ray diffraction were used to evaluate the properties of the final products. Compressive strength tests and SEM observations demonstrated particularly that the concomitant admixture of BSA and MWCNT improved the mechanical properties, resulting in stronger CPC composites. The presence of MWCNTs and BSA influenced the morphology of the hydroxyapatite (HA) crystals in the CPC matrix. BSA was found to act as a promoter of HA growth when bounded to the surface of CPC grains. MWCNT-OH-containing composites exhibited the highest compressive strengths (16.3 MPa), being in the range of values for trabecular bone (2-12 MPa). PMID:21316621

Chew, Kean-Khoon; Low, Kah-Ling; Sharif Zein, Sharif Hussein; McPhail, David S; Gerhardt, Lutz-Christian; Roether, Judith A; Boccaccini, Aldo R

2011-04-01

116

Biodegradable calcium polyphosphate/polyvinyl-urethane carbonate composites for osteosynthesis applications  

NASA Astrophysics Data System (ADS)

The formation of biodegradable implants for use in osteosynthesis has been a major goal of biomaterials research for the past two to three decades. Self-reinforced polylactide systems represent the most significant success of this research to date, however with elastic constants of, at most, 12--15 GPa, they fail to provide the necessary initial stiffness required of devices designed for stabilizing fractures of major load-bearing bones. One objective of this study has been the development of a biodegradable composite suitable for fabrication of implants for the repair of fractures of major load-bearing bones. Specifically, this research has focussed on the use of calcium polyphosphate (CPP), an uiorganic polymer in combination with polyvinyl-urethane carbonate (PVUC) organic polymers. Composite samples were formed as interpenetrating phase composites (IPC), particle-reinforced composites (PRC), and fibre-reinforced composites (FRC). Additionally, the IPCs were produced as both monolithic and laminated specimens. PRC samples exhibit too low asmade elastic constant for fracture fixation applications, while the IPC and FRC samples exhibit desired as-made strength and bending stiffness but lose these properties too rapidly when exposed to aqueous-based in vitro aging, simulating in vivo conditions. An investigation to determine the mechanism of the rapid in vitro degradation was undertaken using a model IPC system to study the effect of the interfacial strength on the mechanical properties of the composite. In addition, these studies provided further support for a hypothesis to explain the observed high mechanical properties of the as-made CPP-PVUC interpenetrating phase composites. It was found that strong interfacial strength is very significant in obtaining appropriate mechanical properties in the IPC system. Results support the conclusion that a rapid loss of the CPP-PVUC interface through exposure to an aqueous environment, as well as stresses imposed on the CPP phase due to swelling of the PVUC in an aqueous environment are responsible for the rapid in vitro decrease in mechanical properties of the IPC.

Ramsay, Scott Desmond

117

Application of pulsed spark discharge for calcium carbonate precipitation in hard water.  

PubMed

The effect of underwater pulsed spark discharge on the precipitation of dissolved calcium ions was investigated in the present study. Water samples with different calcium hardness were prepared by continuous evaporation of tap water using a laboratory cooling tower. It was shown that the concentration of calcium ions dropped by 20-26% after 10-min plasma treatment, comparing with no drop for untreated cases. A laser particle counting method demonstrated that the total number of solid particles suspended in water increased by over 100% after the plasma treatment. The morphology and the crystal form of the particles were identified by both scanning electron microscopy and X-ray diffraction. Calcite with rhombohedron morphology was observed for plasma treated cases, comparing with the round structure observed for no-treatment cases. It was hypothesized that the main mechanisms for the plasma-assisted calcium carbonate precipitation might include electrolysis, local heating in the vicinity of plasma channel and a high electric field at the tip of plasma streamers, inducing structural changes in the electric double layer of hydrated ions. PMID:20494397

Yang, Yong; Kim, Hyoungsup; Starikovskiy, Andrey; Fridman, Alexander; Cho, Young I

2010-06-01

118

Effect of coir pith based cyanobacterial basal and foliar biofertilizer on Basella rubra L  

Microsoft Academic Search

The growth promoting effect of basal and foliar application of coir pith based cyanobacterial biofertilizer on Basella rubra L. was determined by analyzing the morphological and biochemical parameters of the control and test plants after treatment. Compared to control plants test plants showed better height, stem circumference, number of branches, number of leaves and number of flowers. Biochemical analysis of

P. ABRAHAM CHRISTOPHER; V. VISWAJITH; S. PRABHA; K. SUNDHAR; P. MALLIGA

2007-01-01

119

Influence of fertilisation with foliar urea on the content of amines in wine  

Microsoft Academic Search

Amines are substances that could cause toxic effects in the consumer. The concentration of amines in wine depends on different factors such as grape variety, vinification conditions and nitrogen fertilisation of the vines. The aim of this work was to study the influence of the application of foliar urea on the concentration of amines in wine. To carry out the

C. Ancín-Azpilicueta; R. Nieto-Rojo; J. Gómez-Cordón

2011-01-01

120

Foliar ?15N is affected by foliar nitrogen uptake, soil nitrogen, and mycorrhizae along a nitrogen deposition gradient.  

PubMed

Foliar nitrogen isotope (?(15)N) composition patterns have been linked to soil N, mycorrhizal fractionation, and within-plant fractionations. However, few studies have examined the potential importance of the direct foliar uptake of gaseous reactive N on foliar ?(15)N. Using an experimental set-up in which the rate of mycorrhizal infection was reduced using a fungicide, we examined the influence of mycorrhizae on foliar ?(15)N in potted red maple (Acer rubrum) seedlings along a regional N deposition gradient in New York State. Mycorrhizal associations altered foliar ?(15)N values in red maple seedlings from 0.06 to 0.74 ‰ across sites. At the same sites, we explored the predictive roles of direct foliar N uptake, soil ?(15)N, and mycorrhizae on foliar ?(15)N in adult stands of A. rubrum, American beech (Fagus grandifolia), black birch (Betula lenta), and red oak (Quercus rubra). Multiple regression analysis indicated that ambient atmospheric nitrogen dioxide (NO2) concentration explained 0, 69, 23, and 45 % of the variation in foliar ?(15)N in American beech, red maple, red oak, and black birch, respectively, after accounting for the influence of soil ?(15)N. There was no correlation between foliar ?(13)C and foliar %N with increasing atmospheric NO2 concentration in most species. Our findings suggest that total canopy uptake, and likely direct foliar N uptake, of pollution-derived atmospheric N deposition may significantly impact foliar ?(15)N in several dominant species occurring in temperate forest ecosystems. PMID:23070141

Vallano, Dena M; Sparks, Jed P

2013-05-01

121

Preparation and characterisation of calcium-phosphate porous microspheres with a uniform size for biomedical applications  

Microsoft Academic Search

In the present work, a novel route for the preparation of porous ceramic microspheres is described. Two ceramic powders, calcium-titanium-phosphate\\u000a (CTP) and hydroxyapatite (HAp), were mixed with a sodium alginate solution that enabled the preparation of spherical particles,\\u000a using the droplet extrusion method combined with ionotropic gelation in the presence of Ca2+. The spherical particles were subsequently sintered, to burn-off

C. C. Ribeiro; C. C. Barrias; M. A. Barbosa

2006-01-01

122

Mg 2+ substituted calcium phosphate nano particles synthesis for non viral gene delivery application  

Microsoft Academic Search

Gene therapy provides a unique approach to medicine as it can be adapted towards the treatment of both inherited and acquired\\u000a diseases. Recently, calcium phosphate vectors as a new generation of the non viral gene delivery nano carriers have been studied\\u000a because of their biocompatibility and DNA condensation and gene transfer ability. Substituting cations, like magnesium, affects\\u000a physical and chemical

A. HanifiM; M. H. Fathi; H. Mir Mohammad Sadeghi; J. Varshosaz

2010-01-01

123

Application of two-photon flash photolysis to measure microscopic diffusion and calcium fluxes  

NASA Astrophysics Data System (ADS)

Two-photon excitation (TPE) via a microscope objective lens produces a spatially confined excitation volume where UV-excited caged molecules may be broken (uncaged) to release active products. We describe an optical system that creates a stationary parfocal TPE uncaging spot on the stage of a conventional confocal microscope. With this system, we have examined the ability of two dyes to track microscopic calcium changes produced by TPE photolysis of DM-nitrophen. We find that, even when EGTA is used with a low affinity indicator, the dye signals are complicated by diffusion of both indicator-Ca complex and CaEGTA to produce a signal that does not simply report the spatial dimensions of the calcium release site. In addition, the time course of calcium release is poorly reported. This suggests that considerable caution must be applied to the interpretation of spatially resolved calcium signals inside cells. We have also used TPE of CMND-caged fluorescein to measure the rate of fluorescein production in test solution (2500 s-1) as well as the diffusion of fluorescein in drops of solution and within and between between eye lens fiber cells. While diffusion of uncaged fluorescein was about an order of magnitude slower inside fiber cells than in aequeous solution, slower diffusion between cells could also be detected and could be explained by the gap junctions joining the cells behaving as a barrier to diffusion. By using a computer model, parameter fits to experimental data gave estimates for both intracellular and intercellular diffusion coefficients. From this analysis, the gap junctions in eye lens fiber cells permit exchange of low molecular weight compounds between cells at about 0.4% of the rate of free diffusion.

Cannell, Mark B.; Jacobs, Marc D.; Donaldson, Paul J.; Soeller, Christian

2005-03-01

124

Application of X-ray computed tomography to characterise the early hydration of calcium aluminate cement  

Microsoft Academic Search

Techniques that monitor in situ the setting and hardening of calcium aluminate cements (CACs) are of interest to the engineering community. This paper focuses on one non-destructive technique, X-ray computed tomography (CT). The early hydration of the cement can be followed from a few minutes to a few hours after mixing. This technique is based on both X-ray absorption measurements

T. J Chotard; M. P Boncoeur-Martel; A Smith; J. P Dupuy; C Gault

2003-01-01

125

Influence of the calcium content on the coal fly ash features in some innovative applications  

Microsoft Academic Search

Despite a low chemical reactivity, recent trends in the innovative uses of coal fly ash based on the chemical properties have been successful. Lots of fly ash showing sharply alkaline reaction (water pH rising to 11–12 upon contact) usually are high-calcium (>3–4%), most of which is present as CaO. These lots are suitable to be used as remotion agents of

Paola Catalfamo; Sebastiana Di Pasquale; Francesco Corigliano; Letterio Mavilia

1997-01-01

126

Preparation and characterisation of calcium-phosphate porous microspheres with a uniform size for biomedical applications.  

PubMed

In the present work, a novel route for the preparation of porous ceramic microspheres is described. Two ceramic powders, calcium-titanium-phosphate (CTP) and hydroxyapatite (HAp), were mixed with a sodium alginate solution that enabled the preparation of spherical particles, using the droplet extrusion method combined with ionotropic gelation in the presence of Ca(2+). The spherical particles were subsequently sintered, to burn-off the polymer and obtain calcium-phosphate microspheres with a uniform size and an interconnected porous network. CTP microspheres with diameters ranging from 513 +/- 24 microm to 792 +/- 35 microm and with pores of approximately 40 microm were obtained. HAp microspheres presented diameters of 429 +/- 46 microm and 632 +/- 40 microm and pores of ca. 2 microm. Depending on the formulations tested, the structure of both calcium phosphates may become altered during the sintering process, suggesting that the ratio between the ceramic phase and the polymer solution is a critical parameter. Porous microspheres prepared using the described methodology are promising candidates as bone defect fillers and scaffolds for bone tissue regeneration. PMID:16688586

Ribeiro, C C; Barrias, C C; Barbosa, M A

2006-05-01

127

Europium-doped amorphous calcium phosphate porous nanospheres: preparation and application as luminescent drug carriers  

PubMed Central

Calcium phosphate is the most important inorganic constituent of biological tissues, and synthetic calcium phosphate has been widely used as biomaterials. In this study, a facile method has been developed for the fabrication of amorphous calcium phosphate (ACP)/polylactide-block-monomethoxy(polyethyleneglycol) hybrid nanoparticles and ACP porous nanospheres. Europium-doping is performed to enable photoluminescence (PL) function of ACP porous nanospheres. A high specific surface area of the europium-doped ACP (Eu3+:ACP) porous nanospheres is achieved (126.7 m2/g). PL properties of Eu3+:ACP porous nanospheres are investigated, and the most intense peak at 612 nm is observed at 5 mol% Eu3+ doping. In vitro cytotoxicity experiments indicate that the as-prepared Eu3+:ACP porous nanospheres are biocompatible. In vitro drug release experiments indicate that the ibuprofen-loaded Eu3+:ACP porous nanospheres show a slow and sustained drug release in simulated body fluid. We have found that the cumulative amount of released drug has a linear relationship with the natural logarithm of release time (ln(t)). The Eu3+:ACP porous nanospheres are bioactive, and can transform to hydroxyapatite during drug release. The PL properties of drug-loaded nanocarriers before and after drug release are also investigated.

2011-01-01

128

Europium-doped amorphous calcium phosphate porous nanospheres: preparation and application as luminescent drug carriers  

NASA Astrophysics Data System (ADS)

Calcium phosphate is the most important inorganic constituent of biological tissues, and synthetic calcium phosphate has been widely used as biomaterials. In this study, a facile method has been developed for the fabrication of amorphous calcium phosphate (ACP)/polylactide-block-monomethoxy(polyethyleneglycol) hybrid nanoparticles and ACP porous nanospheres. Europium-doping is performed to enable photoluminescence (PL) function of ACP porous nanospheres. A high specific surface area of the europium-doped ACP (Eu3+:ACP) porous nanospheres is achieved (126.7 m2/g). PL properties of Eu3+:ACP porous nanospheres are investigated, and the most intense peak at 612 nm is observed at 5 mol% Eu3+ doping. In vitro cytotoxicity experiments indicate that the as-prepared Eu3+:ACP porous nanospheres are biocompatible. In vitro drug release experiments indicate that the ibuprofen-loaded Eu3+:ACP porous nanospheres show a slow and sustained drug release in simulated body fluid. We have found that the cumulative amount of released drug has a linear relationship with the natural logarithm of release time ( ln( t)). The Eu3+:ACP porous nanospheres are bioactive, and can transform to hydroxyapatite during drug release. The PL properties of drug-loaded nanocarriers before and after drug release are also investigated.

Chen, Feng; Zhu, Ying-Jie; Zhang, Kui-Hua; Wu, Jin; Wang, Ke-Wei; Tang, Qi-Li; Mo, Xiu-Mei

2011-12-01

129

Augmentation of Bone Tunnel Healing in Anterior Cruciate Ligament Grafts: Application of Calcium Phosphates and Other Materials  

PubMed Central

Bone tunnel healing is an important consideration after anterior cruciate ligament (ACL) replacement surgery. Recently, a variety of materials have been proposed for improving this healing process, including autologous bone tissue, cells, artificial proteins, and calcium salts. Amongst these materials are calcium phosphates (CaPs), which are known for their biocompatibility and are widely commercially available. As with the majority of the materials investigated, CaPs have been shown to advance the healing of bone tunnel tissue in animal studies. Mechanical testing shows fixation strengths to be improved, particularly by the application of CaP-based cement in the bone tunnel. Significantly, CaP-based cements have been shown to produce improvements comparable to those induced by potentially more complex treatments such as biologics (including fibronectin and chitin) and cultured cells. Further investigation of CaP-based treatment in the bone tunnels during ACL replacement is therefore warranted in order to establish what improvements in healing and resulting clinical benefits may be achieved through its application.

Baxter, F. R.; Bach, J. S.; Detrez, F.; Cantournet, S.; Corte, L.; Cherkaoui, M.; Ku, D. N.

2010-01-01

130

Hyperspectral remote sensing of foliar nitrogen content.  

PubMed

A strong positive correlation between vegetation canopy bidirectional reflectance factor (BRF) in the near infrared (NIR) spectral region and foliar mass-based nitrogen concentration (%N) has been reported in some temperate and boreal forests. This relationship, if true, would indicate an additional role for nitrogen in the climate system via its influence on surface albedo and may offer a simple approach for monitoring foliar nitrogen using satellite data. We report, however, that the previously reported correlation is an artifact--it is a consequence of variations in canopy structure, rather than of %N. The data underlying this relationship were collected at sites with varying proportions of foliar nitrogen-poor needleleaf and nitrogen-rich broadleaf species, whose canopy structure differs considerably. When the BRF data are corrected for canopy-structure effects, the residual reflectance variations are negatively related to %N at all wavelengths in the interval 423-855 nm. This suggests that the observed positive correlation between BRF and %N conveys no information about %N. We find that to infer leaf biochemical constituents, e.g., N content, from remotely sensed data, BRF spectra in the interval 710-790 nm provide critical information for correction of structural influences. Our analysis also suggests that surface characteristics of leaves impact remote sensing of its internal constituents. This further decreases the ability to remotely sense canopy foliar nitrogen. Finally, the analysis presented here is generic to the problem of remote sensing of leaf-tissue constituents and is therefore not a specific critique of articles espousing remote sensing of foliar %N. PMID:23213258

Knyazikhin, Yuri; Schull, Mitchell A; Stenberg, Pauline; Mõttus, Matti; Rautiainen, Miina; Yang, Yan; Marshak, Alexander; Latorre Carmona, Pedro; Kaufmann, Robert K; Lewis, Philip; Disney, Mathias I; Vanderbilt, Vern; Davis, Anthony B; Baret, Frédéric; Jacquemoud, Stéphane; Lyapustin, Alexei; Myneni, Ranga B

2013-01-15

131

Hyperspectral Remote Sensing of Foliar Nitrogen Content  

NASA Technical Reports Server (NTRS)

A strong positive correlation between vegetation canopy bidirectional reflectance factor (BRF) in the near infrared (NIR) spectral region and foliar mass-based nitrogen concentration (%N) has been reported in some temperate and boreal forests. This relationship, if true, would indicate an additional role for nitrogen in the climate system via its influence on surface albedo and may offer a simple approach for monitoring foliar nitrogen using satellite data. We report, however, that the previously reported correlation is an artifact - it is a consequence of variations in canopy structure, rather than of %N. The data underlying this relationship were collected at sites with varying proportions of foliar nitrogen-poor needleleaf and nitrogen-rich broadleaf species, whose canopy structure differs considerably. When the BRF data are corrected for canopy-structure effects, the residual reflectance variations are negatively related to %N at all wavelengths in the interval 423-855 nm. This suggests that the observed positive correlation between BRF and %N conveys no information about %N. We find that to infer leaf biochemical constituents, e.g., N content, from remotely sensed data, BRF spectra in the interval 710-790 nm provide critical information for correction of structural influences. Our analysis also suggests that surface characteristics of leaves impact remote sensing of its internal constituents. This further decreases the ability to remotely sense canopy foliar nitrogen. Finally, the analysis presented here is generic to the problem of remote sensing of leaf-tissue constituents and is therefore not a specific critique of articles espousing remote sensing of foliar %N.

Knyazikhin, Yuri; Schull, Mitchell A.; Stenberg, Pauline; Moettus, Matti; Rautiainen, Miina; Yang, Yan; Marshak, Alexander; Carmona, Pedro Latorre; Kaufmann, Robert K.; Lewis, Philip; Disney, Mathias I.; Vanderbilt, Vern; Davis, Anthony B.; Baret, Frederic; Jacquemoud, Stephane; Lyapustin, Alexei; Myneni, Ranga B.

2013-01-01

132

Foliar spray of validamycin a or validoxylamine a controls tomato fusarium wilt.  

PubMed

ABSTRACT Tomato wilt, caused by the soilborne fungus Fusarium oxysporum f. sp. lycopersici, is effectively controlled by a foliar spray of validamycin A (VMA) or validoxylamine A (VAA) (>/=10 mug/ml); however, neither VMA nor VAA is antifungal in vitro. In pot tests, the effect of a foliar application of VMA or VAA at 100 mug/ml lasted for 64 days. Plants sprayed with VMA or VAA accumulated salicylic acid and had elevated expression of the systemic acquired resistance (SAR) marker genes P4 (PR-1), Tag (PR-2), and NP24 (PR-5). Foliar spray of VMA also controlled late blight and powdery mildew of tomato. The disease control by VMA and VAA lasted up to 64 days after treatment, was broad spectrum, and induced the expression of PR genes, all essential indicators of SAR, suggesting that VMA and VAA are plant activators. The foliar application of plant activators is a novel control method for soilborne diseases and may provide an economically feasible alternative to soil fumigants such as methyl bromide. PMID:18943474

Ishikawa, Ryo; Shirouzu, Kentaro; Nakashita, Hideo; Lee, Han-Young; Motoyama, Takayuki; Yamaguchi, Isamu; Teraoka, Tohru; Arie, Tsutomu

2005-10-01

133

New processing approaches in calcium phosphate cements and their applications in regenerative medicine.  

PubMed

The key feature of calcium phosphate cements (CPCs) lies in the setting reaction triggered by mixing one or more solid calcium phosphate salts with an aqueous solution. Upon mixture, the reaction takes place through a dissolution-precipitation process which is macroscopically observed by a gradual hardening of the cement paste. The precipitation of hydroxyapatite nanocrystals at body or room temperature, and the fact that those materials can be used as self-setting pastes, have for many years been the most attractive features of CPCs. However, the need to develop materials able to sustain bone tissue ingrowth and be capable of delivering drugs and bioactive molecules, together with the continuous requirement from surgeons to develop more easily handling cements, has pushed the development of new processing routes that can accommodate all these requirements, taking advantage of the possibility of manipulating the self-setting CPC paste. It is the goal of this paper to provide a brief overview of the new processing developments in the area of CPCs and to identify the most significant achievements. PMID:20123046

Ginebra, M P; Espanol, M; Montufar, E B; Perez, R A; Mestres, G

2010-08-01

134

Properties and application of immobilized. beta. -D-glucosidase coentrapped with Zymomanas mobilis in calcium alginate  

SciTech Connect

The enzyme ..beta..-D-glucosidase has been immobilized on concanavalin A-Sepharose to give a maximum loading of 2050 units/g dry weight of support material. The immobilized ..beta..-D-glucosidase was also entrapped within calcium alginate gel spheres with apparently only 35% retention of activity when assayed with 10mM cellobiose. However, it was discovered that, unlike the immobilized enzyme, the entrapped immobilized enzyme was not subject to substrate inhibition up to 100mM cellobiose, suggesting that a concentration gradient of cellobiose existed between the bulk solution and the interior of the gel sphere. Thus, the activity of the entrapped immobilized enzyme was almost twice as high as that of the immobilized enzyme when assayed with 100mM cellobiose. Concanavalin A-Sepharose-immobilized ..beta..-D-glucosidase and the bacterium Zymomonas mobilis coimmobilized in calcium alginate gel spheres converted cellobiose to ethanol in both batch and continuous-flow fermentation systems. (Refs. 20).

Lee, J.M.; Woodward, J.

1983-10-01

135

Synthesis and characterization of porous nanocrystalline biphasic calcium phosphate for bio applications  

NASA Astrophysics Data System (ADS)

The nano crystalline biphasic calcium phosphates of hydroxyapatite (HAp)/?-tricalcium phosphate (?-TCp) in the ratio 80:20 and 72:28 with interconnected porosity have successfully been prepared by co-precipitation method using mixed catanionic surfactants as template. The sample was calcinated at various temperatures for 8 h. The samples were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, Field emission scanning electron microscopy (FESEM) and thermal analyser. The samples calcinated at 750°C and 850°C show 75% and 89% of crystallinity respectively. Usually to obtain the biphasic calcium phosphates, either the medium will be set as acidic by altering the pH or the Ca/P ratio can be set below the value of 1.5. However this experiment was neither conducted with low Ca/P ratio (<=1.5) nor at low pH (<=7) to obtain the mixed phase. The combination of surfactants and calcination temperature controls the HAp/?-TCp ratio.

Shanthi, P. Michael S. L.; Ashok, M.; Balasubramanian, T.

2012-10-01

136

Effects of foliar applied benzyladenine on grain yield and grain protein in wheat (Triticum aestivum L.)  

Microsoft Academic Search

The effects of foliar applications of nitrogen and benzyladenine (BA) on grain yield and grain protein of wheat grown under field conditions were studied over 2 years with 5 cultivars at 2 locations. Nitrogen (N) at 20 kg.ha-1, and BA at 100 or 800 mg.l-1 were applied alone or combined at pre and post-anthesis; applications of BA at 8 mg.l-1

Daniel O. Caldiz; Jose Beltrano; Laura V. Fernandez; Santiago J. Sarandon; Carlos Favoretti

1991-01-01

137

Neural field theory of calcium dependent plasticity with applications to transcranial magnetic stimulation.  

PubMed

Calcium dependent plasticity (CaDP), a physiologically realistic plasticity mechanism in the microscopic regime, is incorporated into a neural field theory to explore system-level plasticity. This system-level plasticity model is capable of reproducing the characteristic plasticity window of spike-timing dependent plasticity (STDP) in paired associative stimulation (PAS), where a peripheral electric pulse stimulation is paired to transcranial magnetic stimulation (TMS) in the cortex, and rTMS frequency dependent plasticity, where low and high frequency rTMS trains induce depression and potentiation, respectively. These thus reproduce experimental results for system-level plasticity for the first time. This also bridges the gap between microscopic plasticity theory and system-level plasticity observed experimentally, and addresses long standing problems of stability and adaptability by predicting stable plasticity, a possible seizure state where neurons fire at a high rate, and spike-rate adaptation. PMID:23376643

Fung, P K; Robinson, P A

2013-05-01

138

Size controlled hydroxyapatite and calcium carbonate particles: synthesis and their application as templates for SERS platform.  

PubMed

An elegant route for hydroxyapatite (HA) particle synthesis via ionic exchange reaction is reported. Calcium carbonate particles (CaCO3) were recrystallized into HA beads in water solution with phosphate ions. The size of initial CaCO3 particles was controlled upon the synthesis by varying the amount of ethylene glycol (EG) in aqueous solution. The average size of HA beads ranged from 0.6±0.1 to 4.3±1.1?m. Silver nanoparticles were deposited on the surface of HA and CaCO3 particles via silver mirror reaction. Surface enhanced Raman scattering of silver functionalized beads was demonstrated by detecting Rhodamine B. CaCO3 and HA particles have a great potential for design of carrier which can provide diagnostic and therapeutic functions. PMID:24802965

Parakhonskiy, B V; Svenskaya, Yu I; Yashchenok, A ?; Fattah, H A; Inozemtseva, O A; Tessarolo, F; Antolini, R; Gorin, D A

2014-06-01

139

The effect of increasing application rate of granular calcium ammonium nitrate on net nitrification in a laboratory study of grassland soils  

Microsoft Academic Search

Soil incubation studies were undertaken in controlled environment cabinets at 15°C to investigate the effect of increasing application rates of calcium ammonium nitrate (CAN) on net nitrification in two grassland soils. Granular CAN was applied to the surface of freshly collected, moist soil, at a rate equivalent to 0, 100, 200, 400, 800 and 1600µg NH

C. J. Watson; D. J. Kilpatrick; J. E. Cooper

1994-01-01

140

Methods for the study of calcium oxalate crystallisation and their application to urolithiasis research.  

PubMed

Many methods have been used to study calcium oxalate crystallisation. Most can be characterised by changes in supersaturation during the experiment, which may increase, remain constant or decay. Their ability to quantify various aspects of crystallisation often reflects the extent to which nucleation, growth and aggregation can be measured independently, when two or three of these processes may be occurring simultaneously. The mixed suspension, mixed product removal technique reaches a steady state supersaturation, is a good model for intrarenal crystallisation and allows both growth and nucleation rates to be measured. Using 92% urine and comparing control urines with samples from recurrent stone formers no difference in growth rates was found but the controls had higher nucleation rates (p = 0.003) and lower supersaturations (p = 0.001). In parallel crystallisers running simultaneously, heparin or hyaluronic acid addition to 92% urine was studied. Both macromolecules increased growth rates, decreased nucleation rates and increased supersaturation (p < 0.05). The steady state supersaturation achieved in this system may be an important determinant of stone forming potential. The ability to reach a lower urinary supersaturation by increased nucleation may be a crucial protective factor distinguishing non stone formers from stone formers. PMID:1439665

Kavanagh, J P

1992-09-01

141

Calcium - urine  

MedlinePLUS

... from the kidneys, which causes calcium kidney stones Sarcoidosis Takiong too much calcium Too much production of ... metabolism. In: Goldman L, Ausiello D, eds. Cecil Medicine . 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap ...

142

Improved methods for reducing calcium and magnesium concentrations in tissue culture medium: Application to studies of lymphoblast proliferation in vitro  

Microsoft Academic Search

Summary  We have compared several methods for reducing calcium and magnesium concentrations in tissue culture medium, with the objective\\u000a of producing selective deficiency effects on the growth of mouse (L5178Y) and human (P1R) lymphoblasts. In experiments in\\u000a which calcium- and magnesium-“free” McCoy’s medium was supplemented with 15% horse or fetal calf serum, enough calcium and\\u000a magnesium was provided by serum to

James K. Brennan; James Mansky; Geraldine Roberts; Marshall A. Lichtman

1975-01-01

143

Remote Sensing of Foliar %N across Broad Spatial Scales Using Data from Multiple Platforms  

NASA Astrophysics Data System (ADS)

The concentration of nitrogen (N) in foliage is central to numerous biogeochemical, physiological and ecological processes operating at a wide range of scales, and serves as a useful indicator of ecosystem behavior. Despite growing understanding regarding the role of foliar N in ecosystems, application of this knowledge in regional- to global-scale analyses has lagged, in part because we lack a reliable means of extending N concentration measurements to broad-scale spatial patterns. At relatively fine spatial scales (~100-1000 km2), foliar N estimation has been repeatedly demonstrated using high spectral resolution remote sensing instruments. The potential for extending N estimation to sites that have remote sensing measurements but little or no field measurements has also been demonstrated via a generalized, multi-site equation that incorporates field and imaging spectrometer data to estimate foliar N across a wide range of forest conditions. Still, N detection efforts such as these have been limited to small landscapes because presently available imaging spectrometers have swath widths in the range of 10 km or less. There are at least two potential solutions to this problem. The first is development of a space-based imaging spectrometer capable of providing regional to global coverage. Although planning for such instruments is underway (e.g. HyspIRI), it will be years before data become routinely available. A second possibility is through further investigation of whether some level of foliar N estimation may be possible by integrating foliar chemistry and other important plant traits with spectral features available from existing broad-band sensors. Here, we report progress on examining these potential solutions. First, we present results from refining generalized methods for estimating foliar N by including optically important plant traits—e.g. LMA, LAD, water content—in iterative regression equations with whole canopy spectral reflectance over an expanded range of vegetation conditions. Second, we examine whether these generalizeable methods can be easily translated from imaging spectrometers to broad-band sensor data by quantifying the influence of spectral, spatial and radiometric resolution on foliar N estimation. Our work is based on an integration of a large data set consisting of intensive field measurements from North American forests, imaging spectrometry scenes from AVIRIS, and broad-band sensor data from Landsat and MODIS.

Lepine, L. C.; Ollinger, S. V.; Martin, M.

2012-12-01

144

[Calcium antagonists: current and future applications based on new evidence. The mechanisms on lowering serum uric acid level by calcium channel blockers].  

PubMed

In hypertensive subjects, their serum uric acid levels tend to be higher because of decreasing urinary secretion or overproduction of uric acid. Among calcium channel blockers (CCBs) , long acting nifedipine and cilnidipine reveal serum uric acid lowering action. They decrease the production of uric acid precursor in skeletal muscles under anaerobic condition induced by hypertension or insulin resistance. Hyperuricemia is considered to be a risk factor of not only gout but also renal and cardiovascular diseases, thus, it is important to use CCBs without adverse effect on uric acid metabolisms. PMID:20048433

Mizuta, Einosuke; Hamada, Toshihiro; Igawa, Osamu; Shigemasa, Chiaki; Hisatome, Ichiro

2010-01-01

145

Towards estimation of canopy foliar biomass with spectral reflectance measurements  

Microsoft Academic Search

Canopy foliar biomass, defined as the product of leaf dry matter content and leaf area index, is an important measurement for global biogeochemical cycles. This study explores the potential for retrieving foliar biomass in green canopies using a spectral index, the Normalized Dry Matter Index (NDMI). This narrow-band index is based on absorption at the C–H bond stretch overtone and

Lingli Wang; John J. Qu; Xianjun Hao; Craig S. T. Daughtry

2011-01-01

146

FOLIAR WASHOFF OF PESTICIDES (FWOP) MODEL: DEVELOPMENT AND EVALUATION  

EPA Science Inventory

The Foliar Washoff of Pesticides (FWOP) Model was developed to provide an empirical simulation of pesticide washoff from plant leaf surfaces as influenced by rainfall amount. To evaluate the technique, simulations by the FWOP Model were compared to those by the foliar washoff alg...

147

Design and application of chitosan/biphasic calcium phosphate porous scaffolds for bone tissue engineering  

NASA Astrophysics Data System (ADS)

For the restoration of maxillofacial bone tissue, design of novel tissue engineering scaffolds capable of inducing bone remodeling through the delivery of mesenchymal stem cells (MSCs) and an angiogenic growth factor, directly at the site of the defect was investigated in order to replace autogenous cancellous bone grafts with synthetic materials. Porous, three dimensional scaffolds were fabricated by a freeze drying method. In culture media, biphasic calcium phosphate particles within chitosan produced a surface reprecipitate of a composition similar to natural apatite that led to a uniform distribution of cells and mineralized ECM through chemotaxis. Further, the reprecipitation regulated the differentiation pathway and phenotype commitment of stem cells by altering the initial cell attachment morphology and actin cytoskeleton organization. In order to induce neovascularization after implantation, constructs were designed to be loaded with gelatin microspheres that delivered basic fibroblast growth factor (bFGF), a potent angiogenic factor. In vitro proliferation tests performed on fibroblastic cells showed no detectible loss of bFGF activity when delivered through enzymatic degradation of gelatin. Laser scanning confocal microscopy was used to demonstrate that gelatin microspheres can be injected evenly into cell-scaffold constructs owing to the spongy characteristics of the scaffold. To examine the binding interactions of bFGF with surface bound gelatin, a label free biosensor system, Biomolecular INteraction Detection sensor (BIND) was used. Results confirm that the principal interaction that takes place between bFGF and gelatin is electrostatic. Cell loaded tissue engineered constructs were produced in vitro at clinically relevant sizes and implanted with and without bFGF into a porcine mandibular defect model. Tissue engineered constructs facilitated the healing of mandibular defects only if combined with delivery of bFGF via gelatin microspheres. bFGF release from the constructs improved neovascularization in the defect area and subsequently enhanced new bone formation. Although the rate and extent of bone formation was similar in bFGF group to those in empty defects for the period of the study, existence of woven bone in bFGF group suggests that bone formation is continuing while the lamellar structure in empty defects indicates that bone formation in that group was finalized.

Sendemir-Urkmez, Aylin

148

Characteristics of long afterglow phosphorescent calcium aluminate crystals for fluorescence thermometer application  

Microsoft Academic Search

Temperature dependence of photoluminescence (PL) peaking at wavelength of ?=440nm from FZ grown CaAl2O4; Eu, Dy phosphor crystal is evaluated for a fiber-optic thermometer application. The PL lifetime from the specimens decreases greatly from 11.24 to 1.17ms as the temperature increases from 305 to 458K. The temperature coefficient of PL lifetime, -0.17ms\\/K, in the narrow temperature range from 305 to

H. Kubo; H. Aizawa; T. Katsumata; S. Komuro; T. Morikawa

2005-01-01

149

FOLIAR SPRAYS OF PHOTOSYNTHETIC BACTERIA IMPROVE THE GROWTH AND ANTI-OXIDATIVE CAPABILITY ON CHINESE DWARF CHERRY SEEDLINGS  

Microsoft Academic Search

Recently, there has been increasing attempts for photosynthetic bacteria (PSB) as foliar fertilizer in China. The biomass, net photosynthetic rate (Pn), maximal photochemical efficiency of PS II(Fv\\/Fm) and antioxidant isoenzymes metabolism were examined in Chinese dwarf cherry (Prunus humilis Bunge) seedlings with or without exogenous PSB application in this study. PSB sprays resulted in a significant accumulation of fresh weight

Ze Peng Yin; Zhi Wei Shang; Chao Wei; Jing Ren; Xing Shun Song

2012-01-01

150

Bulk physicochemical, interconnectivity, and mechanical properties of calcium phosphate cements-fibrin glue composites for bone substitute applications.  

PubMed

Calcium phosphate cements (CPCs) and fibrin glue (FG) are used for surgical applications. Their combination is promising to create bone substitutes able to promote cell attachment and bone remodeling. This study proposes a novel approach to create CPC-FG composites by simultaneous CPC setting and FG fibrinogenesis. CPC-FG composites were obtained by mixing CPC powders, i.e. ?-tricalcium phosphate, dicalcium phosphate anhydrous and precipitated hydroxyapatite, with FG powder components, i.e. fibrinogen and thrombin, and a 2% Na(2) HPO(4) solution. To study the effect of FG quantity and fibrinogenesis kinetics, long and fast setting FGs were evaluated in amounts of 0.125, 0.250, and 0.500 mL on CPC-FG composites. Physicochemical, interconnectivity, and mechanical properties were measured. Scanning electron microscopy, Micro-computed tomography (?-CT), X-ray diffraction, and Fourier transform Infrared spectroscopy (FTIR) analyzed morphology, structure, crystallographic, and chemical composition, respectively. FG fibrinogenesis was performed within the CPC. FTIR confirmed this and its interfacial bonding with CPC. ?-CT confirmed a good FG distribution. FG addition affected the CPC when compared with pristine CPC. Adding FG to CPC changed their morphology, density, porosity, setting, cohesion, injectability, interconnectivity, crystallographic and chemical composition and mechanical properties. Moreover, 0.500 mL of long setting FG modified the observed fracture behavior of the CPC-FG. PMID:22927324

Lopez-Heredia, M A; Pattipeilohy, J; Hsu, S; Grykien, M; van der Weijden, B; Leeuwenburgh, S C G; Salmon, P; Wolke, J G C; Jansen, J A

2013-02-01

151

Application of calcium carbonate slows down organic amendments mineralization in reclaimed soils  

NASA Astrophysics Data System (ADS)

A field experiment was set up in Cartagena-La Unión Mining District, SE Spain, aimed at evaluating the short-term effects of pig slurry (PS) amendment alone and together with marble waste (MW) on organic matter mineralization, microbial activity and stabilization of heavy metals in two tailing ponds. These structures pose environmental risk owing to high metals contents, low organic matter and nutrients, and null vegetation. Carbon mineralization, exchangeable metals and microbiological properties were monitored during 67 days. The application of amendments led to a rapid decrease of exchangeable metals concentrations, except for Cu, with decreases up to 98%, 75% and 97% for Cd, Pb and Zn, respectively. The combined addition of MW+PS was the treatment with greater reduction in metals concentrations. The addition of PS caused a significant increase in respiration rates, although in MW+PS plots respiration was lower than in PS plots. The mineralised C from the pig slurry was low, approximately 25-30% and 4-12% for PS and MW+PS treatments, respectively. Soluble carbon (Csol), microbial biomass carbon (MBC) and ?-galactosidase and ?-glucosidase activities increased after the application of the organic amendment. However, after 3 days these parameters started a decreasing trend reaching similar values than control from approximately day 25 for Csol and MBC. The PS treatment promoted highest values in enzyme activities, which remained high upon time. Arylesterase activity increased in the MW+PS treatment. Thus, the remediation techniques used improved soil microbiological status and reduced metal availability. The combined application of PS+MW reduced the degradability of the organic compounds. Keywords: organic wastes, mine soils stabilization, carbon mineralization, microbial activity.

Zornoza, Raúl; Faz, Ángel; Acosta, José A.; Martínez-Martínez, Silvia; Ángeles Muñoz, M.

2014-05-01

152

Preparation of porosity-controlled calcium carbonate by thermal decomposition of volume content-variable calcium carboxylate derivatives.  

PubMed

We demonstrate a novel approach for synthesizing porosity-controlled calcium carbonate by one-step thermal decomposition of various calcium carboxylate derivatives as well as their mixtures with different molar ratios. By varying the volume content of calcium in the calcium compounds or mixtures, the resulting porous calcium carbonate exhibits distinct porosity and structures that are very promising for various applications. PMID:22935875

Yu, Hai-Dong; Tee, Si Yin; Han, Ming-Yong

2013-05-14

153

Active electrochemical dissolution of molybdenum and application for room-temperature synthesis of crystallized luminescent calcium molybdate film  

SciTech Connect

Calcium molybdate (CaMoO{sub 4}) with a scheelite-type structure has been of practical interest for a long time because of its attractive luminescence property. It provides green emission as an available solid-state laser material. Crystallized luminescent calcium molybdate (CaMoO{sub 4}) film has been prepared on a molybdenum substrate in an alkaline solution containing calcium ions by active electrochemical dissolution of molybdenum at room temperature (25 C). The dissolution rate became faster with an increase of pH value. A high concentration of calcium (0.02M) and a high pH value (13) favored the reaction of film formation. The film showed only a single green emission at 536 nm with the excitation of 285 nm at liquid-nitrogen temperature ({minus}196 C), strongly suggesting that it consisted of well-crystallized defect-free crystals.

Cho, W.S.; Yashima, Masatomo; Kakihana, Masato; Kudo, Akihiko; Sakata, Tadayoshi; Yoshimura, Masahiro [Tokyo Inst. of Tech., Yokohama (Japan)

1997-03-01

154

The effect of postharvest calcium application in hydro-cooling water on tissue calcium content, biochemical changes, and quality attributes of sweet cherry fruit.  

PubMed

To improve storage/shipping quality of sweet cherry (Prunus avium L.), the effect of calcium chloride (CaCl2) added to hydro-cooling water on physiological and biochemical processes related to fruit and pedicel quality was investigated on two major cultivars. The fruit tissue Ca content increased up to 29-85% logarithmically for 'Sweetheart' and 39-188% linearly for 'Lapins' as CaCl2 rate increased from 0.2% to 2.0% at 0 °C for 5 min. The increase of fruit tissue Ca content was accompanied by reductions in respiration rate, ascorbic acid degradation, and membrane lipid peroxidation, which enhanced total phenolics content and total antioxidant capacity, and resulted in increases in fruit firmness and pitting resistance and decreases in titratable acidity loss and decay of both cultivars. Pedicel browning was inhibited by CaCl2 at 0.2% and 0.5%, but increased by higher rates at 1.0% and 2.0%, possibly via modifying membrane lipid peroxidation. PMID:24799204

Wang, Yan; Xie, Xingbin; Long, Lynn E

2014-10-01

155

Feasibility of digital image colorimetry--application for water calcium hardness determination.  

PubMed

Interpretation and relevance of basic RGB colors in Digital Image-Based Colorimetry have been treated in this paper. The studies were carried out using the chromogenic model formed by the reaction between Ca(II) ions and glyoxal bis(2-hydroxyanil). It produced orange-red colored solutions in alkaline media. Individual basic color data (RGB) and also the total intensity of colors, I(tot), were the original variables treated by Factorial Analysis. Te evaluation evidenced that the highest variance of the system and the highest analytical sensitivity were associated to the G color. However, after the study by Fourier transform the basic R color was recognized as an important feature in the information. It was manifested as an intrinsic characteristic that appeared differentiated in terms of low frequency in Fourier transform. The Principal Components Analysis study showed that the variance of the system could be mostly retained in the first principal component, but was dependent on all basic colors. The colored complex was also applied and validated as a Digital Image Colorimetric method for the determination of Ca(II) ions. RGB intensities were linearly correlated with Ca(II) in the range 0.2-2.0 mg L(-1). In the best conditions, using green color, a simple and reliable method for Ca determination could be developed. Its detection limit was established (criterion 3s) as 0.07 mg L(-1). And the reproducibility was lower than 6%, for 1.0 mg L(-1) Ca. Other chromatic parameters were evaluated as dependent calibration variables. Their representativeness, variance and sensitivity were discussed in order to select the best analytical variable. The potentiality of the procedure as a field and ready-to-use method, susceptible to be applied 'in situ' with a minimum of experimental needs, was probed. Applications of the analysis of Ca in different real water samples were carried out. Water of the city net, mineral bottled, and natural-river were analyzed and results were compared and evaluated statistically. The validity was assessed by the alternative techniques of flame atomic absorption spectroscopy and titrimetry. Differences were appreciated but they were consistent with the applied methods. PMID:23200383

Lopez-Molinero, Angel; Tejedor Cubero, Valle; Domingo Irigoyen, Rosa; Sipiera Piazuelo, Daniel

2013-01-15

156

Effect of bio-regulator and foliar fertilizers on chemical composition and yield of soybean.  

PubMed

Current study evaluates the effects of bio-regulator associated with foliar fertilizers on the yield components, productivity and chemical composition of soybean. The experimental design was entirely randomized blocks, with four replications. The treatments consisted of: T1-absolute control, T2-application of 0.25 L h(-1) Stimulate in R1 stage of development, T3-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1, T4-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1 and 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R5.1; T5-application of 0.25 L h(-1) Stimulate and 3 L h(-1) Sett in R1 and 2 L h(-1) Mover in R5.1, T6-application of 3 L h(-1) Sett in R1 and 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R5.1 and T7-application of 0.25 L h(-1) Stimulate and 2 L h(-1) Mover in R1. Application of Sett and Mover is a potentially efficient handling as it favors the soybean agronomic performance in R1 stage. Chemical composition of processed grains has influence with applying bio-regulator and foliar fertilizers. PMID:24511692

Piccinin, Gleberson Guillen; Braccini, Alessandro Lucca; da Silva, Luiz Henrique; Mariucci, Giovanna Emanuêlle Gonçalves; Suzukawa, Andréia Kazumi; Dan, Lilian Gomes de Morais; Tonin, Telmo António

2013-11-15

157

Salinity-induced calcium deficiencies in wheat and barley  

Microsoft Academic Search

Salinity-calcium interactions, which have been shown to be important in plants grown in dryland saline soils of the Canadian prairies, were studied in two species differing in salt tolerance. In solution culture, wheat showed a greater reduction in growth and a higher incidence of foliar Ca deficiency symptoms than barley when grown under MgSO4 or Na2SO4 plus MgSO4 salt stress.

D. L. Ehret; R. E. Redmann; B. L. Harvey; A. Cipywnyk

1990-01-01

158

Associations of calcium and aluminum with the growth and health of sugar maple trees in Vermont  

Microsoft Academic Search

We compared tree growth and crown condition with soil and foliar elemental composition in 14 sugar maple (Acer saccharum Marsh.) stands in VT, USA, to evaluate if deficiencies or imbalances in cation nutrition were associated with growth and health reductions in native stands. The Till Source Model (TSM) was used to select study sites potentially high or low in calcium

Paul G. Schaberg; James W. Tilley; Gary J. Hawley; Donald H. DeHayes; Scott W. Bailey

2006-01-01

159

Foliar mercury accumulation and exchange for three tree species.  

PubMed

The goals of this study were to (1) investigate plant mercury (Hg) uptake using different air and soil Hg concentrations near natural background values for three tree species, and (2) test if measured foliar Hg fluxes could explain observed foliar Hg concentrations. Plants were exposed to three soil treatments (<0.01, 0.09 +/- 0.02, and 0.92 +/- 0.27 microg Hg g(-1)), and to three atmospheric exposure concentrations (5.9 +/- 2.3, 14.3 +/- 2.7, and 30.1 +/- 3.5 ng Hg m(-3)). Foliar Hg concentrations were found to be influenced primarily by atmospheric Hg concentrations and to a lesser extent by soil Hg exposures. Data indicated that deciduous species might play a more active role in ecosystem Hg cycling than evergreen trees. Foliar mercury fluxes quantified using a dynamic single-plant gas-exchange chamber for two species were variable and accumulation rates were lower than those predicted based on foliar Hg concentrations. A hypothesis to explain this discrepancy is that the plant gas-exchange chamber measures net flux which includes emission, deposition, adsorption, and reemission of Hg at the leaf surface, while total foliar accumulation represents only deposition and assimilation. PMID:17051791

Millhollen, Allison G; Gustin, Mae S; Obrist, Daniel

2006-10-01

160

LOW CONCENTRATION MERCURY SORPTION MECHANISMS AND CONTROL BY CALCIUM-BASED SORBENTS; APPLICATION IN COAL-FIRED PROCESSES  

EPA Science Inventory

The capture of elemental mercury (Hgo) and mercuric chloride (HgCl2) by three types of calcium (Ca)-based sorbents was examined in this bench-scale study under conditions prevalent in coal fired utilities. Ca-based sorbent performances were compared to that of an activated carbon...

161

Minerals Yearbook 1991: Calcium and Calcium Compounds.  

National Technical Information Service (NTIS)

Calcium, is chemically very active and is found in a host of minerals that occur in nearly every geologic environment. Calcium fluoride is sold as fluorspar; calcium sulfate as gypsum or anhydrite; calcium oxide and hydroxide as lime; calcium phosphate as...

M. M. Miller

1992-01-01

162

Application of impedance spectroscopy to evaluate the effect of different setting accelerators on the developed microstructures of calcium phosphate cements  

Microsoft Academic Search

The main goal of the present study was to evaluate the effect of different setting accelerator agents on the developed microstructures\\u000a of calcium phosphate cements (CPCs) by employing the impedance spectroscopy (IS) technique. Six compositions of CPCs were\\u000a prepared from mixtures of commercial dicalcium phosphate anhydrous (DCPA) and synthesized tetracalcium phosphate (TTCP) as\\u000a the solid phases. Two TTCP\\/DCPA molar ratios

H. E. Romeo; P. R. Bueno; M. A. Fanovich

2009-01-01

163

Calcium oxide as a solid base catalyst for transesterification of soybean oil and its application to biodiesel production  

Microsoft Academic Search

In order to study solid base catalyst for biodiesel production with environmental benignity, transesterification of edible soybean oil with refluxing methanol was carried out in the presence of calcium oxide (CaO), -hydroxide (Ca(OH)2), or -carbonate (CaCO3). At 1h of reaction time, yield of FAME was 93% for CaO, 12% for Ca(OH)2, and 0% for CaCO3. Under the same reacting condition,

Masato Kouzu; Takekazu Kasuno; Masahiko Tajika; Yoshikazu Sugimoto; Shinya Yamanaka; Jusuke Hidaka

2008-01-01

164

Effects of Different Concentrations and Applications of Calcium on Storage Life and Physicochemical Characteristics of Papaya (Carica Papaya L.)  

Microsoft Academic Search

Papaya (Carica Papaya L.) fruits index 2 were treated with 1.5, 2.5 and 3.5% solutions of calcium chloride by dipping and vacuum infiltration (-33 Kpa) or untreated (0%) as control. Effects of these treatments were evaluated on storage life and postharvest quality characteristics of papaya. After 21 days of storage at 13±1°C, the fruits were removed from storage for physicochemical

Mohamed Zaki

2008-01-01

165

Drosophila mushroom body Kenyon cells generate spontaneous calcium transients mediated by PLTX-sensitive calcium channels.  

PubMed

Spontaneous calcium oscillations in mushroom bodies of late stage pupal and adult Drosophila brains have been implicated in memory consolidation during olfactory associative learning. This study explores the cellular mechanisms regulating calcium dynamics in Kenyon cells, principal neurons in mushroom bodies. Fura-2 imaging shows that Kenyon cells cultured from late stage Drosophila pupae generate spontaneous calcium transients in a cell autonomous fashion, at a frequency similar to calcium oscillations in vivo (10-20/h). The expression of calcium transients is up regulated during pupal development. Although the ability to generate transients is a property intrinsic to Kenyon cells, transients can be modulated by bath application of nicotine and GABA. Calcium transients are blocked, and baseline calcium levels reduced, by removal of external calcium, addition of cobalt, or addition of Plectreurys toxin (PLTX), an insect-specific calcium channel antagonist. Transients do not require calcium release from intracellular stores. Whole cell recordings reveal that the majority of voltage-gated calcium channels in Kenyon cells are PLTX-sensitive. Together these data show that influx of calcium through PLTX-sensitive voltage-gated calcium channels mediates spontaneous calcium transients and regulates basal calcium levels in cultured Kenyon cells. The data also suggest that these calcium transients represent cellular events underlying calcium oscillations in the intact mushroom bodies. However, spontaneous calcium transients are not unique to Kenyon cells as they are present in approximately 60% of all cultured central brain neurons. This suggests the calcium transients play a more general role in maturation or function of adult brain neurons. PMID:15772240

Jiang, Shaojuan Amy; Campusano, Jorge M; Su, Hailing; O'Dowd, Diane K

2005-07-01

166

Project Calcium  

SciTech Connect

Fouling problems in utility boilers have been classified into two principal types: high-temperature and low-temperature fouling. A multiclient-sponsored program was initiated at the Energy and Environmental Research Center (EERC) to better understand the causes of low-temperature fouling when burning high-calcium western US coals. The goals of Project Calcium were to define the low-temperature deposition problem, identify the calcium-based components that are responsible for the formation of the deposits, develop ways to predict their formation, and identify possible methods to mitigate the formation of these deposits. To achieve the goals of Project Calcium, detailed sampling of utility boilers and laboratory-scale studies coupled with state-of-the-art methods to determine the inorganic components in coals and coal ash-derived materials were conducted. Boiler Sampling was also performed. The work involved sampling coal, entrained ash, deposits and slags from five full-scale utility boilers combined with detailed advanced characterization of the materials. The results of this work aided in identifying the key phenomena to focus the laboratory studies and in model verification. Field testing was conducted at three utilities.

Hurley, J.P.; Benson, S.A.; Erickson, T.A.; Allan, S.E.; Bieber, J.

1992-09-01

167

Characterization of calcium oxide catalysts from natural sources and their application in the transesterification of sunflower oil.  

PubMed

The catalytic activities of calcium oxide obtained from natural sources (crab shell and eggshell) were characterized and evaluated in the transesterification of vegetable oil. These catalysts are mainly composed of calcium carbonate, which is partially converted into CaO after calcination (900°C for 2h). The catalysts have some advantages, such as abundant occurrence, low cost, porous structure, and nontoxic. The materials were characterized by XRD, FTIR, TG/DTG, CO2-TPD, XPS, SEM, and BET methods. The thermal treatment produces small particles of CaCO3 and CaO that are responsible for the catalytic activity. The conversion from triglycerides to methyl ester was not observed in transesterification carried out using natural crab shell and eggshell. Under optimized reaction conditions, the conversions to YFAME using the calcined catalysts were: crab shell (83.10±0.27 wt.%) and eggshell (97.75±0.02 wt.%). These results, showed that these materials have promising viability in transesterification for biodiesel production. PMID:24240148

Correia, Leandro Marques; Saboya, Rosana Maria Alves; Campelo, Natália de Sousa; Cecilia, Juan Antonio; Rodríguez-Castellón, Enrique; Cavalcante, Célio Loureiro; Vieira, Rodrigo Silveira

2014-01-01

168

Screening assays using intramitochondrial calcium  

US Patent & Trademark Office Database

The invention provides methods for screening for agents that modulate mitochondrial function and in particular mitochondrial regulation of intracellular calcium. The methods may be used to detect agents that bind to a mitochondrial calcium uniporter and may also detect inhibitors or uncouplers of mitochondrial respiration. Agents identified using the screens provided herein have application in the prevention and treatment of a variety of diseases associated with abnormal mitochondrial function.

2004-10-26

169

The Mauna Loa environmental matrix: foliar and soil nutrients  

Microsoft Academic Search

The accumulation of total carbon, nitrogen, and phosphorus in soils, available soil nutrients, and foliar nutrients in the native dominant Metrosideros polymorpha were determined across a wide elevational range on 9 lava flows on Mauna Loa, Hawai'i. The flows included a young (2800 y) áá (rough surface texture) and pahoehoe (smooth) flow on the wet east and dry northwest side

Peter M. Vitousek; Gregory Aplet; Douglas Turner; John J. Lockwood

1992-01-01

170

Influence of calcium sources on microbially induced calcium carbonate precipitation by Bacillus sp. CR2.  

PubMed

Stimulation of microbially induced calcium carbonate precipitation (MICCP) is likely to be influenced by calcium sources. In order to study such influences, we performed MICCP using Bacillus sp. CR2 in nutrient broth containing urea, supplemented with different calcium sources (calcium chloride, calcium oxide, calcium acetate and calcium nitrate). The experiment lasted 7 days, during which bacterial growth, urease activity, calcite production and pH were measured. Our results showed that calcium chloride is the better calcium source for MICCP process, since it provides higher urease activity and more calcite production. The influences of calcium sources on MICCP were further studied using Fourier transform-infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. These analyses confirmed that the precipitate formed was CaCO3 and composed of predominantly calcite crystals with a little amount of aragonite and vaterite crystals. The maximum yield of calcite precipitation was achievable with calcium chloride followed by calcium nitrate as a calcium source. The results of present study may be applicable to media preparation during efficient MICCP process. PMID:24643454

Achal, Varenyam; Pan, Xiangliang

2014-05-01

171

Comparison of Rain-Fast Bait Stations Versus Foliar Bait Sprays for Control of Oriental Fruit Fly, Bactrocera dorsalis, in Papaya Orchards in Hawaii  

PubMed Central

Bait stations represent an environmentally friendly attract-and-kill approach to fruit fly population suppression. Recently a novel, visually attractive, rain-fast bait station was developed in Hawaii for potential use against multiple species of pestiferous fruit flies. Here, we compared the efficacy of GF-120 NF Naturalyte Fruit Fly Bait applied either as foliar sprays or onto bait stations in reducing female oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), population density and level of fruit infestation in commercial papaya orchards in Hawaii. Trapping and infestation data were used as indicators of the effectiveness of the two bait application methods. For the first 10 weeks of the study, captures of female B. dorsalis in monitoring traps were significantly greater in control plots than in plots treated with foliar sprays or bait stations. Six weeks after the first bait spray, incidence of infestation (i.e. number of fruit with one or more B. dorsalis larvae) of quarter to half-ripe papaya fruit was reduced by 71.4% and 63.1% for plots with bait stations and foliar sprays, respectively, as compared to control plots. Twelve weeks after first spray, incidence of infestation was reduced by only 54.5% and 45.4% for plots with bait stations and foliar sprays, respectively, as compared to control plots. About 42% less GF-120 was used in orchard plots with bait stations compared to those subject to foliar sprays. The impact of field sanitation on the outcome is also discussed. The results indicate that bait stations can provide a simple, efficient, and economical method of applying insecticidal baits to control fruit flies and a safer alternative to foliar sprays.

Pinero, Jaime C.; Mau, Ronald F. L.; Vargas, Roger I.

2010-01-01

172

Calcium and osteoporosis  

Microsoft Academic Search

Calcium is an essential nutrient that is involved in most metabolic processes and the phosphate salts of which provide mechanical rigidity to the bones and teeth, where 99% of the body's calcium resides. The calcium in the skeleton has the additional role of acting as a reserve supply of calcium to meet the body's metabolic needs in states of calcium

B. E. Christopher Nordin

1997-01-01

173

Novel sulI binary vectors enable an inexpensive foliar selection method in Arabidopsis  

PubMed Central

Background Sulfonamide resistance is conferred by the sulI gene found on many Enterobacteriaceae R plasmids and Tn21 type transposons. The sulI gene encodes a sulfonamide insensitive dihydropteroate synthase enzyme required for folate biosynthesis. Transformation of tobacco, potato or Arabidopsis using sulI as a selectable marker generates sulfadiazine-resistant plants. Typically sulI-based selection of transgenic plants is performed on tissue culture media under sterile conditions. Findings A set of novel binary vectors containing a sulI selectable marker expression cassette were constructed and used to generate transgenic Arabidopsis. We demonstrate that the sulI selectable marker can be utilized for direct selection of plants grown in soil with a simple foliar spray application procedure. A highly effective and inexpensive high throughput screening strategy to identify transgenic Arabidopsis without use of tissue culture was developed. Conclusion Novel sulI-containing Agrobacterium binary vectors designed to over-express a gene of interest or to characterize a test promoter in transgenic plants have been constructed. These new vector tools combined with the various beneficial attributes of sulfonamide selection and the simple foliar screening strategy provide an advantageous alternative for plant biotechnology researchers. The set of binary vectors is freely available upon request.

2011-01-01

174

Complexometric Determination of Calcium  

NASA Astrophysics Data System (ADS)

Ethylenediaminetetraacetate (EDTA) complexes with numerous mineral ions, including calcium and magnesium. This reaction can be used to determine the amount of these minerals in a sample by a complexometric titration. Endpoints in the titration are detected using indicators that change color when they complex with mineral ions. Calmagite and eriochrome black T (EBT) are such indicators that change from blue to pink when they complex with calcium and magnesium. In the titration of a mineral-containing solution with EDTA, the solution turns from pink to blue at the endpoint with either indicator. The pH affects a complexometric EDTA titration in several ways, and must be carefully controlled. A major application of EDTA titration is testing the hardness of water, for which the method described is an official one (Standard Methods for the Examination of Water and Wastewater, Method 2340C; AOAC Method 920.196).

Nielsen, S. Suzanne

175

Meta-analysis of yield response of hybrid field corn to foliar fungicides in the U.S. Corn Belt.  

PubMed

The use of foliar fungicides on field corn has increased greatly over the past 5 years in the United States in an attempt to increase yields, despite limited evidence that use of the fungicides is consistently profitable. To assess the value of using fungicides in grain corn production, random-effects meta-analyses were performed on results from foliar fungicide experiments conducted during 2002 to 2009 in 14 states across the United States to determine the mean yield response to the fungicides azoxystrobin, pyraclostrobin, propiconazole + trifloxystrobin, and propiconazole + azoxystrobin. For all fungicides, the yield difference between treated and nontreated plots was highly variable among studies. All four fungicides resulted in a significant mean yield increase relative to the nontreated plots (P < 0.05). Mean yield difference was highest for propiconazole + trifloxystrobin (390 kg/ha), followed by propiconazole + azoxystrobin (331 kg/ha) and pyraclostrobin (256 kg/ha), and lowest for azoxystrobin (230 kg/ha). Baseline yield (mean yield in the nontreated plots) had a significant effect on yield for propiconazole + azoxystrobin (P < 0.05), whereas baseline foliar disease severity (mean severity in the nontreated plots) significantly affected the yield response to pyraclostrobin, propiconazole + trifloxystrobin, and propiconazole + azoxystrobin but not to azoxystrobin. Mean yield difference was generally higher in the lowest yield and higher disease severity categories than in the highest yield and lower disease categories. The probability of failing to recover the fungicide application cost (p(loss)) also was estimated for a range of grain corn prices and application costs. At the 10-year average corn grain price of $0.12/kg ($2.97/bushel) and application costs of $40 to 95/ha, p(loss) for disease severity <5% was 0.55 to 0.98 for pyraclostrobin, 0.62 to 0.93 for propiconazole + trifloxystrobin, 0.58 to 0.89 for propiconazole + azoxystrobin, and 0.91 to 0.99 for azoxystrobin. When disease severity was >5%, the corresponding probabilities were 0.36 to 95, 0.25 to 0.69, 0.25 to 0.64, and 0.37 to 0.98 for the four fungicides. In conclusion, the high p(loss) values found in most scenarios suggest that the use of these foliar fungicides is unlikely to be profitable when foliar disease severity is low and yield expectation is high. PMID:21554185

Paul, P A; Madden, L V; Bradley, C A; Robertson, A E; Munkvold, G P; Shaner, G; Wise, K A; Malvick, D K; Allen, T W; Grybauskas, A; Vincelli, P; Esker, P

2011-09-01

176

Calcium Collage  

NSDL National Science Digital Library

In this activity (on pages 11-14 of PDF), learners cut out pictures from magazines of foods that help make bones strong and glue the pictures to a paper bone. The lesson plan includes information about various activities - including physical exercise as well as diet - that lead to healthy bones. It also includes a list of foods that provide calcium to strengthen bones, including dairy products, spinach, and tofu. The paper bones can be cut out of construction paper prior to the activity.

Omsi

2004-01-01

177

Preparation of biomorphic porous calcium titanate and its application for preconcentration of nickel in water and food samples.  

PubMed

Biomorphic porous nanocrystalline-calcium titanate (SPCTO) was successfully prepared using the sol-gel method and with sorghum straw as the template. Characterization was conducted through XRD, SEM and FTIR. The ability of SPCTO to adsorb nickel ion in water was assessed. Elution and regeneration conditions, as well as the thermodynamics and kinetics of nickel adsorption, were also investigated. The result showed that the sorbent by the sol-gel template method was porous and has a perovskite structure with an average particle diameter of 26 nm. The nickel ion could be quantitatively retained at a pH value range of 4-8, but the adsorbed nickel ion could be completely eluted using 2 mol L(-1) HNO3. The adsorption capacity of SPCTO for nickel was found to be 51.814 mg g(-1) and the adsorption behavior followed a Langmuir adsorption isotherm and a pseudo-second-order kinetic model. The enthalpy change (?H) of the adsorption process was 33.520 kJ mol(-1). At various temperatures, Gibbs free energy changes (?G) were negative, and entropy changes (?S) were positive. The activation energy (Ea) was 25.291 kJ mol(-1) for the adsorption. These results demonstrate that the adsorption was an endothermic and spontaneous physical process. This same method has been successfully applied in the preconcentration and determination of nickel in water and food samples with good results. PMID:24094175

Zhang, Dong; Wang, Min; Ren, Guang-jun; Song, En-jun

2013-12-01

178

Report on the Study of Radiation Damage in Calcium Fluoride and Magnesium Fluoride Crystals for use in Excimer Laser Applications  

SciTech Connect

A study was performed to investigate the effects of radiation damage in calcium fluoride and magnesium fluoride crystals caused by gamma rays and UV photons from excimer lasers. The purpose was to study and correlate the damage caused by these two different mechanisms in various types of material used for fabricating optical elements in high power excimer lasers and lens systems of lithography tools. These optical systems are easily damaged by the laser itself, and it is necessary to use only the most radiation resistant materials for certain key elements. It was found that a clear correlation exists between the, radiation induced damage caused by high energy gamma rays and that produced by UV photons from the excimer laser. This correlation allows a simple procedure to be developed to select the most radiation resistant material at the ingot level, which would be later used to fabricate various components of the optical system. This avoids incurring the additional cost of fabricating actual optical elements with material that would later be damaged under prolonged use. The result of this screening procedure can result in a considerable savings in the overall cost of the lens and laser system.

none,

1999-10-04

179

Calcium source (image)  

MedlinePLUS

Getting enough calcium to keep bones from thinning throughout a person's life may be made more difficult if that person has ... as a tendency toward kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the ...

180

Coronary Calcium Scan  

MedlinePLUS

... the NHLBI on Twitter. What Is a Coronary Calcium Scan? A coronary calcium scan is a test ... you have calcifications in your coronary arteries. Coronary Calcium Scan Figure A shows the position of the ...

181

Calcium and bones (image)  

MedlinePLUS

Calcium is one of the most important minerals for the growth, maintenance, and reproduction of the human ... body, are continually being re-formed and incorporate calcium into their structure. Calcium is essential for the ...

182

Effects of foliar applied nickel on tomato plants. [Lycopersicon esculentum  

SciTech Connect

Shoot-applied nickel (Ni) treatments produced symptomatology, foliar Ni accumulation, and cytological changes in tomato (Lycopersicon esculentum Mill.) similar to those caused by treatments with root-applied nickel (Ni). Leaf damage resulting from 100 ..mu..g/ml foliar Ni-treatments consisted of interveinal chlorosis and spotting necrosis which appeared histologically as tissue collapse, cell clumping, and chloroplast disintegration. Shoot-treated plants accumulated more Ni in leaves than in roots; whereas the reverse was true in root-treated plants. Interference with root-to-shoot manganese translocation was attributed to attenuated vascular tissue and phloem blockage. Evidence of reduced nutrient transport and inhibited meristem activity due to Ni toxicity presents a potential for crop damage from excessive Ni in the atmosphere as well as in the soil environment.

Cash, R.C.; Leone, I.A.

1987-01-01

183

Minerals Yearbook, 1990. Calcium and Calcium Compounds.  

National Technical Information Service (NTIS)

The U.S. Bureau of Mines publishes reports for a variety of calcium-containing minerals and compounds because of their commercial significance and contribution to the quality of human life. The 'Calcium and Calcium Compounds Annual Report' includes calciu...

M. M. Miller

1991-01-01

184

Minerals Yearbook, 1989. Calcium and Calcium Compounds.  

National Technical Information Service (NTIS)

The Bureau of Mines publishes reports for a variety of calcium-containing minerals and compounds because of their commercial significance and contribution to the quality of human life. Calcium fluoride is sold as fluorspar; calcium sulfate as gypsum or an...

M. M. Miller

1990-01-01

185

Foliar and ecosystem respiration in an old-growth tropical rain forest.  

PubMed

Foliar respiration is a major component of ecosystem respiration, yet extrapolations are often uncertain in tropical forests because of indirect estimates of leaf area index (LAI). A portable tower was used to directly measure LAI and night-time foliar respiration from 52 vertical transects throughout an old-growth tropical rain forest in Costa Rica. In this study, we (1) explored the effects of structural, functional and environmental variables on foliar respiration; (2) extrapolated foliar respiration to the ecosystem; and (3) estimated ecosystem respiration. Foliar respiration temperature response was constant within plant functional group, and foliar morphology drove much of the within-canopy variability in respiration and foliar nutrients. Foliar respiration per unit ground area was 3.5 +/- 0.2 micromol CO2 m(-2) s(-1), and ecosystem respiration was 9.4 +/- 0.5 micromol CO2 m(-2) s(-1)[soil = 41%; foliage = 37%; woody = 14%; coarse woody debris (CWD) = 7%]. When modelled with El Niño Southern Oscillation (ENSO) year temperatures, foliar respiration was 9% greater than when modelled with temperatures from a normal year, which is in the range of carbon sink versus source behaviour for this forest. Our ecosystem respiration estimate from component fluxes was 33% greater than night-time net ecosystem exchange for the same forest, suggesting that studies reporting a large carbon sink for tropical rain forests based solely on eddy flux measurements may be in error. PMID:18182017

Cavaleri, Molly A; Oberbauer, Steven F; Ryan, Michael G

2008-04-01

186

Influence of casein phosphopeptide-amorphous calcium phosphate application, smear layer removal, and storage time on resin-dentin bonding*  

PubMed Central

The aim of this study is to evaluate the influence of Tooth Mousse (TM) application, smear layer removal, and storage time on resin-dentin microtensile bond strength (?TBS). Dentin specimens were divided into two groups: (1) smear layer covered; (2) smear layer removed using 15% EDTA for 90 s. In each group, half the specimens were treated once with TM for 60 min. After bonding procedures using a two-step self-etching adhesive (Clearfil SE Bond (CSE); Kuraray Medical, Tokyo, Japan), an all-in-one adhesive (G-Bond (GB); GC Corp, Tokyo, Japan), and a total-etch adhesive (Adper Single Bond 2 (SB); 3M ESPE, St. Paul, MN, USA), the specimens were stored for 3 d or 6 months in deionized water at 37 °C, and ?TBS was tested and analyzed. With the exception of SB (no TM application) and GB, the ?TBS was significantly increased for CSE and SB using EDTA pre-conditioning and 3 d of storage (P?0.001). Bond strength of GB decreased significantly when using EDTA (3 d storage, P<0.05). TM application only increased the ?TBS of GB (no EDTA) and SB (with EDTA) after 3 d (P?0.02). Comparing the adhesives after 3 d of storage, CSE exhibited the greatest ?TBS values followed by GB and SB (P?0.02). The factors of adhesive, EDTA, and TM did not show any significant impact on ?TBS when specimens were stored for 6 months (P>0.05). The additional application of TM and EDTA for cavity preparation seems only to have a short-term effect, and no influence on ?TBS of dentin bonds after a period of 6 months.

Lin, Jun; Zheng, Wei-ying; Liu, Peng-ruo-feng; Zhang, Ning; Lin, Hui-ping; Fan, Yi-jing; Gu, Xin-hua; Vollrath, Oliver; Mehl, Christian

2014-01-01

187

Application of the specular and diffuse reflection analysis for in vitro diagnostics of dental erosion: correlation with enamel softening, roughness, and calcium release  

NASA Astrophysics Data System (ADS)

We present assembly and application of an optical reflectometer for the analysis of dental erosion. The erosive procedure involved acid-induced softening and initial substance loss phases, which are considered to be difficult for visual diagnosis in a clinic. Change of the specular reflection signal showed the highest sensitivity for the detection of the early softening phase of erosion among tested methods. The exponential decrease of the specular reflection intensity with erosive duration was compared to the increase of enamel roughness. Surface roughness was measured by optical analysis, and the observed tendency was correlated with scanning electron microscopy images of eroded enamel. A high correlation between specular reflection intensity and measurement of enamel softening (r2 >= -0.86) as well as calcium release (r2 >= -0.86) was found during erosion progression. Measurement of diffuse reflection revealed higher tooth-to-tooth deviation in contrast to the analysis of specular reflection intensity and lower correlation with other applied methods (r2 = 0.42-0.48). The proposed optical method allows simple and fast surface analysis and could be used for further optimization and construction of the first noncontact and cost-effective diagnostic tool for early erosion assessment in vivo.

Rakhmatullina, Ekaterina; Bossen, Anke; Höschele, Christoph; Wang, Xiaojie; Beyeler, Barbara; Meier, Christoph; Lussi, Adrian

2011-10-01

188

Highly stable amorphous calcium phosphate porous nanospheres: microwave-assisted rapid synthesis using ATP as phosphorus source and stabilizer, and their application in anticancer drug delivery.  

PubMed

Highly stable amorphous calcium phosphate (ACP) porous nanospheres with a relatively uniform size and an average pore diameter of about 10?nm have been synthesized by using a microwave-assisted hydrothermal method with adenosine 5'-triphosphate disodium salt (ATP) as the phosphorus source and stabilizer. The as-prepared ACP porous nanospheres have a high stability in the phosphate buffer saline (PBS) solution for more than 150?h without phase transformation to hydroxyapatite, and the morphology and size were essentially not changed. The important role of ATP and effects of experimental conditions on the formation of ACP porous nanospheres were also investigated. The ACP porous nanospheres were characterized by X-ray powder diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). This method is facile, rapid, surfactant-free and environmentally friendly. The as-prepared ACP porous nanospheres are efficient for anticancer drug (docetaxel) loading and release. The ACP porous nanosphere drug-delivery system with docetaxel shows a high ability to damage tumor cells, thus, is promising for the application in anticancer treatment. PMID:23180605

Qi, Chao; Zhu, Ying-Jie; Zhao, Xin-Yu; Lu, Bing-Qiang; Tang, Qi-Li; Zhao, Jing; Chen, Feng

2013-01-14

189

Calcium ?-Hydroxy-?-Methylbutyrate  

Microsoft Academic Search

The binding capacity of calcium ?-hydroxy-?-methylbutyrate (calcium HMB), compared to other binders, was investigated in an in vitro study. Fifty milli-equivalents of either calcium HMB, calcium acetate, calcium carbonate, aluminum hydroxide gel or non-gel aluminum hydroxide was added to a phosphate solution, titrated (HC1 or NaOH), shaken and centrifuged to four different pH levels at 37 °C (simulating the gastrointestinal

Mauri F. Sousa; Naji N. Abumrad; Cristina Martins; Steven Nissen; Miguel C. Riella

1996-01-01

190

Comparing the applicability of some geostatistical methods to predict the spatial distribution of topsoil Calcium Carbonate in part of farmland of Zanjan Province  

NASA Astrophysics Data System (ADS)

Most of soils in iran, were located in the arid and semi-arid regions and have high pH (more than 7) and high amount of calcium carbonate and this problem cause to their calcification.In calcareous soils, plant growing and production is difficult. Most part of this problem, in relation to high pH and high concentration of calcium ion that cause to fixation and unavailability of elements which were dependent to pH, especially Phosphorous and some micro nutrients such as Fe, Zn, Mn and Cu. Prediction of soil calcium carbonate in non-sampled areas and mapping the calcium carbonate variability in order to sustainable management of soil fertility is very important.So, this research was done with the aim of evaluation and analyzing spatial variability of topsoil calcium carbonate as an aspect of soil fertility and plant nutrition, comparing geostatistical methods such as kriging and co-kriging and mapping topsoil calcium carbonate. For geostatistical analyzing, sampling was done with stratified random method and soil samples from 0 to 15 cm depth were collected with auger within 23 locations.In co-kriging method, salinity data was used as auxiliary variable. For comparing and evaluation of geostatistical methods, cross validation were used by statistical parameters of RMSE. The results showed that co-kriging method has the highest correlation coefficient and less RMSE and has the higher accuracy than kriging method to prediction of calcium carbonate content in non-sampled areas.

Sarmadian, Fereydoon; Keshavarzi, Ali

2010-05-01

191

Effectiveness of a calcium sodium phosphosilicate containing prophylaxis paste in reducing dentine hypersensitivity immediately and 4 weeks after a single application: a double-blind randomized controlled trial  

PubMed Central

Aims The aim of this single-site, randomized, controlled, double-blind, 3-arm parallel study was to determine the effectiveness of a prophylaxis paste containing 15% calcium sodium phosphosilicate (CSPS; NovaMin®) with and without fluoride in reducing dentine hypersensitivity immediately after a single application and 28 days following dental scaling and root planing. Materials & Methods Overall, 151 subjects were enrolled in this study. All subjects received a scaling and root planing procedure followed by a final prophylaxis step using one of three different prophylaxis pastes: Test-A (15% NovaMin® and NaF), Test-B (15% NovaMin®) and a control. Dentine hypersensitivity was assessed by tactile stimulus (Yeaple Probe®) and by air blast (Schiff scale) at baseline, immediately after and 28 days after a prophylaxis procedure. One hundred and forty-nine subjects completed the study. Results Subjects having received the test prophylaxis pastes showed statistically lower (anova, p < 0.05) dentine hypersensitivity compared with the control group immediately after the prophylaxis procedure (Yeaple Probe®: Test-A = 20.9 ± 12.6, Test-B = 22.7 ± 12.9, Control=11.2 ± 3.1; Schiff score: Test-A = 1.1 ± 0.6, Test-B = 1.1 ± 0.6, Control = 2.0 ± 0.7) and after 28 days (Yeaple probe: Test-A = 21.5 ± 11.9, Test-B = 20.6 ± 11.3, Control = 11.8 ± 6.0; Schiff score: Test-A = 1.0 ± 0.6, Test-B = 1.0 ± 0.6, Control = 2.0 ± 0.7). Conclusions In conclusion, the single application of both fluoridated and non-fluoridated prophylaxis pastes containing 15% CSPS (NovaMin®) provided a significant reduction of dentine hypersensitivity up to at least 28 days.

Neuhaus, Klaus W; Milleman, Jeffery L; Milleman, Kimberly R; Mongiello, Kimberly A; Simonton, Thomas C; Clark, Courtney E; Proskin, Howard M; Seemann, Rainer

2013-01-01

192

Foliar anthocyanin content - Sensitivity of vegetation indices using green reflectance  

NASA Astrophysics Data System (ADS)

The amount and composition of photosynthetic and non-photosynthetic foliar pigments varies primarily as a function of species, developmental and phenological stages, and environmental stresses. Information on the absolute and relative amounts of these pigments thus provides insights onto the physiological conditions of plants and their responses to stress, and has the potential to be used for evaluating plant species composition and diversity across broad geographic regions. Anthocyanins in particular, are non-photosynthetic pigments associated with the resistance of plants to environmental stresses (e.g., drought, low soil nutrients, high radiation, herbivores, and pathogens). As they absorb radiation primarily in the green region of the electromagnetic spectrum (around 540-560 nm), broad-band vegetation indices that use this region in their formulation will respond to their presence. We evaluated the sensitivity of three vegetation indices using reflectance in the green spectral region (the green Normalized Difference Vegetation Index, gNDVI, the green Chlorophyll Index, CIg, and the Visible Atmospherically Resistant Vegetation Index, VARI) to foliar anthocyanins in five different species. For comparison purposes the widely used Normalized Difference Vegetation Index, NDVI was also evaluated. Among the four indices tested, the VARI, which uses only spectral bands in the visible region of the electromagnetic spectrum, was found to be inversely and linearly related to the relative amount of foliar anthocyanins. While this result was obtained at leaf level, it opens new possibilities for analyzing anthocyanin content across multiple scales, by means of currently operational aircraft- and spacecraft-mounted broad-band sensor systems. Further studies that evaluate the sensitivity of the VARI to the relative content of anthocyanins across space (e.g., at canopy and regional scales) and time, and its relationship with plant biodiversity and vegetation stresses, are needed.

Vina, A.; Gitelson, A. A.

2009-12-01

193

Natural foliar variegation without costs? The case of Begonia  

PubMed Central

Background and Aims Foliar variegation is recognized as arising from two major mechanisms: leaf structure and pigment-related variegation. Begonia has species with a variety of natural foliar variegation patterns, providing diverse examples of this phenomenon. The aims of this work are to elucidate the mechanisms underlying different foliar variegation patterns in Begonia and to determine their physiological consequences. Methods Six species and one cultivar of Begonia were investigated. Light and electron microscopy revealed the leaf structure and ultrastructure of chloroplasts in green and light areas of variegated leaves. Maximum quantum yields of photosystem II were measured by chlorophyll fluorescence. Comparison with a cultivar of Ficus revealed key features distinguishing variegation mechanisms. Key Results Intercellular space above the chlorenchyma is the mechanism of variegation in these Begonia. This intercellular space can be located (a) below the adaxial epidermis or (b) below the adaxial water storage tissue (the first report for any taxa), creating light areas on a leaf. In addition, chlorenchyma cell shape and chloroplast distribution within chlorenchyma cells differ between light and green areas. Chloroplasts from both areas showed dense stacking of grana and stroma thylakoid membranes. The maximum quantum yield did not differ significantly between these areas, suggesting minimal loss of function with variegation. However, the absence of chloroplasts in light areas of leaves in the Ficus cultivar led to an extremely low quantum yield. Conclusions Variegation in these Begonia is structural, where light areas are created by internal reflection between air spaces and cells in a leaf. Two forms of air space structural variegation occur, distinguished by the location of the air spaces. Both forms may have a common origin in development where dermal tissue becomes loosely connected to mesophyll. Photosynthetic functioning is retained in light areas, and these areas do not include primary veins, potentially limiting the costs of variegation.

Sheue, Chiou-Rong; Pao, Shang-Horng; Chien, Lee-Feng; Chesson, Peter; Peng, Ching-I

2012-01-01

194

Role of polyhydroxybutyrate in mitochondrial calcium uptake.  

PubMed

Polyhydroxybutyrate (PHB) is a biological polymer which belongs to the class of polyesters and is ubiquitously present in all living organisms. Mammalian mitochondrial membranes contain PHB consisting of up to 120 hydroxybutyrate residues. Roles played by PHB in mammalian mitochondria remain obscure. It was previously demonstrated that PHB of the size similar to one found in mitochondria mediates calcium transport in lipid bilayer membranes. We hypothesized that the presence of PHB in mitochondrial membrane might play a significant role in mitochondrial calcium transport. To test this, we investigated how the induction of PHB hydrolysis affects mitochondrial calcium transport. Mitochondrial PHB was altered enzymatically by targeted expression of bacterial PHB hydrolyzing enzyme (PhaZ7) in mitochondria of mammalian cultured cells. The expression of PhaZ7 induced changes in mitochondrial metabolism resulting in decreased mitochondrial membrane potential in HepG2 but not in U87 and HeLa cells. Furthermore, it significantly inhibited mitochondrial calcium uptake in intact HepG2, U87 and HeLa cells stimulated by the ATP or by the application of increased concentrations of calcium to the digitonin permeabilized cells. Calcium uptake in PhaZ7 expressing cells was restored by mimicking calcium uniporter properties with natural electrogenic calcium ionophore - ferutinin. We propose that PHB is a previously unrecognized important component of the mitochondrial calcium uptake system. PMID:23702223

Smithen, Matthew; Elustondo, Pia A; Winkfein, Robert; Zakharian, Eleonora; Abramov, Andrey Y; Pavlov, Evgeny

2013-08-01

195

Wood and foliar respiration of tropical wet forest environment  

NASA Astrophysics Data System (ADS)

Wood and foliar respiration from tropical forests constitute major components of ecosystem respiration that may control their productivity and carbon storage. However, few estimates on tropical forests vary greatly. Furthermore, the trees in these forests respire great amounts of carbon, but impacts of individual tree species on respiration is not well known. We examined wood and foliar respiration in this environment in relation to individual tree species. The objectives of this study were to: 1) identify how respiration rates relate to scaling variables for wood and foliage, 2) examine the effects of individual tree species on these relationships, 3) extrapolate the rates to the annual fluxes of the whole stands, and 4) determine if tree species differed in these fluxes. Established on an abandoned pasture in 1988 at La Selva Biological Station in Costa Rica, the monodominant stands contained four native species in a complete randomized block design. Respiration rates based on tissue surface area ranged among dominant tree species from 0.6 to 1.0 ?g C m^-2 s^-1 for small diameter wood (<10cm), 1.0 to 1.8 ?g C m^-2 s^-1 for large diameter wood, and 0.7 to 0.8 ?g C m^-2 s^-1 for foliage. Understory species had similar wood respiration rates, but foliage respiration rates were about half of those for canopy leaves. Among surface area, volume, or biomass, respiration rates scaled best with surface area for wood with small diameter, volume or biomass for large diameter wood, and leaf area for foliage. These relationships differed slightly among tree species and between canopy trees and understory species. Foliar respiration rate was generally related to leaf nitrogen content, and this relationship differed among dominant tree species. Temperature response of foliar respiration also differed among tree species and canopy class. However, daily and annual temperature fluctuations had less than 3% effect on annual flux. Annual respiratory fluxes from wood and foliage averaged 11 Mg C hectare^-1. The difference between species with highest and lowest fluxes was about 3 Mg C hectare^-1, with the highest coming from species with the most amount of biomass and the lowest coming from species with the least biomass. Wood and foliage respiratory fluxes of the whole stand partitioned to canopy foliage ranged from a third to a little less than half, while the flux partitioned to dominant tree wood differed very little from about half. Our results suggest strong abiotic control of wood and foliage respiratory fluxes in this environment, while species affect the fluxes through differences in biomass.

Asao, S.; Bedoya Arrieta, R.; Ryan, M. G.

2011-12-01

196

Presynaptic Calcium Signalling in Cerebellar Mossy Fibres  

PubMed Central

Whole-cell recordings were obtained from mossy fibre terminals in adult turtles in order to characterize the basic membrane properties. Calcium imaging of presynaptic calcium signals was carried out in order to analyse calcium dynamics and presynaptic GABA B inhibition. A tetrodotoxin (TTX)-sensitive fast Na+ spike faithfully followed repetitive depolarizing pulses with little change in spike duration or amplitude, while a strong outward rectification dominated responses to long-lasting depolarizations. High-threshold calcium spikes were uncovered following addition of potassium channel blockers. Calcium imaging using Calcium-Green dextran revealed a stimulus-evoked all-or-none TTX-sensitive calcium signal in simple and complex rosettes. All compartments of a complex rosette were activated during electrical activation of the mossy fibre, while individual simple and complex rosettes along an axon appeared to be isolated from one another in terms of calcium signalling. CGP55845 application showed that GABA B receptors mediated presynaptic inhibition of the calcium signal over the entire firing frequency range of mossy fibres. A paired-pulse depression of the calcium signal lasting more than 1?s affected burst firing in mossy fibres; this paired-pulse depression was reduced by GABA B antagonists. While our results indicated that a presynaptic rosette electrophysiologically functioned as a unit, topical GABA application showed that calcium signals in the branches of complex rosettes could be modulated locally, suggesting that cerebellar glomeruli may be dynamically sub-compartmentalized due to ongoing inhibition mediated by Golgi cells. This could provide a fine-grained control of mossy fibre-granule cell information transfer and synaptic plasticity within a mossy fibre rosette.

Thomsen, Louiza B.; Jorntell, Henrik; Midtgaard, Jens

2009-01-01

197

Phytophthora root-rot of container-grown citrus as affected by foliar sprays and soil drenches of phosphorous and acetyl salicylic acids  

Microsoft Academic Search

Mycelial growth ofPhytophthora nicotianae var.parasitica in vitro was inhibited by phosphorous and acetyl salicylic acids at 10 ppm; mycelial growth ofP. citrophthora was inhibited by phosphorous acid at 10 ppm and acetyl salicylic acid at 100 ppm. Foliar sprays and soil drenches with these\\u000a chemicals were compared with soil applications of metalaxyl as treatments for Phytophthora root-rot of container-grown citrus

G. E. Walker

1988-01-01

198

Chitosan/?-1,3-glucan/calcium phosphate ceramics composites-Novel cell scaffolds for bone tissue engineering application.  

PubMed

Bone tissue engineering put emphasis on fabrication three-dimensional biodegradable porous scaffolds that possess ability to enhance adhesion, proliferation and differentiation of osteoblast cells, therefore supporting bone regeneration and functional bone tissue formation. The aim of this work was to fabricate novel tri-component scaffolds composed of chitosan, ?-1,3-glucan, and bioceramics and to evaluate their basic structural, mechanical, and biological properties. It should be noted that we are the first who describe fabrication and characterization of tri-component composites containing ?-1,3-glucan. Microstructure of novel composites was visualized by computed tomography scanning and SEM. Compressive strength and Young's modulus of the composites were evaluated by compression testing. The biocompatibility was assessed in vitro by cytotoxicity, cell attachment and cell proliferation tests using human foetal osteoblast cell line. Our results demonstrated that novel composites possess good compressive strength as the effect of polysaccharide components of scaffolds, are very elastic, are non-toxic, favourable to cell adhesion and promote cell proliferation. However, novel biomaterials revealed relatively low Young's modulus values. Thus, we infer that fabricated novel composites are promising materials for bone tissue engineering application as cell scaffolds to fill small bone losses rather than as massive bone fillers exposed to mechanical load. PMID:24815684

Przekora, Agata; Palka, Krzysztof; Ginalska, Grazyna

2014-07-20

199

Scaling uncertainties in estimating canopy foliar maintenance respiration for black spruce ecosystems in Alaska  

USGS Publications Warehouse

A major challenge confronting the scientific community is to understand both patterns of and controls over spatial and temporal variability of carbon exchange between boreal forest ecosystems and the atmosphere. An understanding of the sources of variability of carbon processes at fine scales and how these contribute to uncertainties in estimating carbon fluxes is relevant to representing these processes at coarse scales. To explore some of the challenges and uncertainties in estimating carbon fluxes at fine to coarse scales, we conducted a modeling analysis of canopy foliar maintenance respiration for black spruce ecosystems of Alaska by scaling empirical hourly models of foliar maintenance respiration (Rm) to estimate canopy foliar Rm for individual stands. We used variation in foliar N concentration among stands to develop hourly stand-specific models and then developed an hourly pooled model. An uncertainty analysis identified that the most important parameter affecting estimates of canopy foliar Rm was one that describes R m at 0??C per g N, which explained more than 55% of variance in annual estimates of canopy foliar Rm. The comparison of simulated annual canopy foliar Rm identified significant differences between stand-specific and pooled models for each stand. This result indicates that control over foliar N concentration should be considered in models that estimate canopy foliar Rm of black spruce stands across the landscape. In this study, we also temporally scaled the hourly stand-level models to estimate canopy foliar Rm of black spruce stands using mean monthly temperature data. Comparisons of monthly Rm between the hourly and monthly versions of the models indicated that there was very little difference between the estimates of hourly and monthly models, suggesting that hourly models can be aggregated to use monthly input data with little loss of precision. We conclude that uncertainties in the use of a coarse-scale model for estimating canopy foliar Rm at regional scales depend on uncertainties in representing needle-level respiration and on uncertainties in representing the spatial variability of canopy foliar N across a region. The development of spatial data sets of canopy foliar N represents a major challenge in estimating canopy foliar maintenance respiration at regional scales. ?? Springer 2006.

Zhang, X.; McGuire, A. D.; Ruess, R. W.

2006-01-01

200

Evidence for calcium regulation of spinal cord motoneuron death in the chick embryo in vivo  

Microsoft Academic Search

We have studied in living chick embryos the effects of an extracellular calcium load on the induction of apoptosis in spinal cord motoneurons. The action of a calcium ionophore, A23187, that does not raise extracellular calcium was also evaluated in order to explore the role of endogenous calcium in determining developmentally-regulated cell death of motoneurons. The application of a single

Dolors Ciutat; Josep E. Esquerda; Jordi Calderó

1995-01-01

201

CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING IN CENTER, CALCIUM CHLORIDE STORAGE BUILDING ON RIGHT WITH SA (SODA ASH) BUILDING IN RIGHT BACKGROUND. - Solvay Process Company, Calcium Chloride Plant, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

202

Foliar sorption of emerging and priority contaminants under controlled conditions.  

PubMed

Agricultural irrigation water contains a variety of contaminants that can be introduced into the food chain through intake by irrigated crops. This paper describes an experiment under controlled conditions designed to simulate sprinkle irrigation with polluted water at two different relative humidities (40 and 90%). Specifically, shed lettuce-heart leaves were spiked with an aqueous solution containing organic microcontaminants, including pharmaceuticals (ibuprofen, diclofenac, clofibric acid, and carbamazepine), fragrances (tonalide), biocides (triclosan), insecticides (lindane), herbicides (atrazine), phenolic estrogen (bisphenol A), and polycyclic aromatic hydrocarbons (phenanthrene and pyrene). Following an incubation period (48 h), the treated leaves were rinsed with water, and both the solution used to rinse them and the leaves themselves were independently analyzed to investigate the foliar sorption and uptake of the spiked organic contaminants through cuticle. The results showed that the foliar sorption of emerging and priority microcontaminants in leaves wetted by irrigation practices is related to their polarity (logD(ow)) and volatility (logk(H)), regardless of their compound class and the relative humidity. The results thus underscore the need to improve the quality of reclaimed water in crop irrigation, particularly when sprinkle irrigation is used. PMID:23747476

Calderón-Preciado, Diana; Matamoros, Víctor; Biel, Carmen; Save, Robert; Bayona, Josep M

2013-09-15

203

The Mauna Loa environmental matrix: foliar and soil nutrients  

USGS Publications Warehouse

The accumulation of total carbon, nitrogen, and phosphorus in soils, available soil nutrients, and foliar nutrients in the native dominant Metrosideros polymorpha were determined across a wide elevational range on 9 lava flows on Mauna Loa, Hawai'i. The flows included a young (2800 y) a??a?? (rough surface texture) and pa??hoehoe (smooth) flow on the wet east and dry northwest side of the mountain. Soil element pools and nutrient availability increased with flow age independent of climate. The dry sites accumulated organic matter and nutrients more slowly than comparable wet sites, but relative nutrient availability to plants (as indicated by soil assays and foliar nutrients) was greater in the dry sites. Accumulation of soil organic matter and nutrients occurred most rapidly in lowerelevation sites on the young flows, but the largest accumulations occurred at higher elevations on old flows. The range of sites sampled represents a complete and largely independent matrix of major factors governing ecosystem structure and function. ?? 1992 Springer-Verlag.

Vitousek, P. M.; Aplet, G.; Turner, D.; Lockwood, J. J.

1992-01-01

204

Foliar pathogenesis and plant water relations: a review.  

PubMed

As the world population grows, there is a pressing need to improve productivity from water use in irrigated and rain-fed agriculture. Foliar diseases have been reported to decrease crop water-use efficiency (WUE) substantially, yet the effects of plant pathogens are seldom considered when methods to improve WUE are debated. We review the effects of foliar pathogens on plant water relations and the consequences for WUE. The effects reported vary between host and pathogen species and between host genotypes. Some general patterns emerge however. Higher fungi and oomycetes cause physical disruption to the cuticle and stomata, and also cause impairment of stomatal closing in the dark. Higher fungi and viruses are associated with impairment of stomatal opening in the light. A number of toxins produced by bacteria and higher fungi have been identified that impair stomatal function. Deleterious effects are not limited to compatible plant-pathogen interactions. Resistant and non-host interactions have been shown to result in stomatal impairment in light and dark conditions. Mitigation of these effects through selection of favourable resistance responses could be an important breeding target in the future. The challenges for researchers are to understand how the effects reported from work under controlled conditions translate to crops in the field, and to elucidate underlying mechanisms. PMID:22664583

Grimmer, Michael K; John Foulkes, M; Paveley, Neil D

2012-07-01

205

Precipitation of solid phase calcium carbonates and their effect on application of seawater SA-T-P models  

NASA Astrophysics Data System (ADS)

At the present time, little is known about how broad salinity and temperature ranges are for seawater thermodynamic models that are functions of absolute salinity (SA), temperature (T) and pressure (P). Such models rely on fixed compositional ratios of the major components (e.g., Na/Cl, Mg/Cl, Ca/Cl, SO4/Cl, etc.). As seawater evaporates or freezes, solid phases [e.g., CaCO3(s) or CaSO42H2O(s)] will eventually precipitate. This will change the compositional ratios, and these salinity models will no longer be applicable. A future complicating factor is the lowering of seawater pH as the atmospheric partial pressures of CO2 increase. A geochemical model (FREZCHEM) was used to quantify the SA-T boundaries at P=0.1 MPa and the range of these boundaries for future atmospheric CO2 increases. An omega supersaturation model for CaCO3 minerals based on pseudo-homogeneous nucleation was extended from 25-40°C to 3°C. CaCO3 minerals were the boundary defining minerals (first to precipitate) between 3°C (at SA=104 g kg-) and 40°C (at SA=66 g kg-). At 2.82°C, calcite(CaCO3) transitioned to ikaite(CaCO36H2O) as the dominant boundary defining mineral for colder temperatures, which culminated in a low temperature boundary of -4.93°C. Increasing atmospheric CO2 from 385 ?atm (390 MPa) (in Year 2008) to 550 ?atm (557 MPa) (in Year 2100) would increase the SA and t boundaries as much as 11 g kg-1 and 0.66°C, respectively. The model-calculated calcite-ikaite transition temperature of 2.82°C is in excellent agreement with ikaite formation in natural environments that occurs at temperatures of 3°C or lower. Furthermore, these results provide a quantitative theoretical explanation (FREZCHEM model calculation) for why ikaite is the solid phase CaCO3 mineral that precipitates during seawater freezing.

Marion, G. M.; Millero, F. J.; Feistel, R.

2009-07-01

206

High-calcium coal combustion by-products: Engineering properties, ettringite formation, and potential application in solidification and stabilization of selenium and boron  

SciTech Connect

Four high-calcium coal combustion by-products (two pulverized coal fly ashes (PCFA), a flue gas desulfurization (FGD) residue, and an atmospheric fluidized bed combustion (AFBC) fly ash), were tested for engineering properties and ability to immobilize boron and selenium. These data are needed to explore high-volume utilization in engineered structure or in solidification/stabilization (S/S) technology. Strengths of cured pastes (91 days), varied from as much as 27 MPa (3,900 psi) for one of the PCFA specimens to 4.6 MPa (670 psi) for the FGD specimen. All of the coal by-product pastes developed more than the 0.34 MPa (50 psi) required for S/S applications. Ettringite formation is important to engineering properties and S/S mechanisms. XRD on plain specimens cured for 91 days indicated that the two PCFA pastes formed 5--6% ettringite, the FGD paste formed 22%, and the AFBC paste formed 32%. The hydrating PCFA pastes showed little expansion, the FGD paste contracted slightly, and the AFBC paste expanded by 2.9% over 91 days. Se and B were spiked into the mixing water as sodium selenite, selenate and borate, and for most pastes this had little effect on strength, workability, and expansion. Leaching of ground specimens (cured for 91 days) showed a generally positive correlation between the amount of ettringite formed and resistance to Se and B leaching. Se spiked as selenate was more readily leached than Se spiked as selenite. B showed a high level of fixation.

Solem-Tishmack, J.K.; McCarthy, G.J. [North Dakota State Univ., Fargo, ND (United States). Dept. of Chemistry] [North Dakota State Univ., Fargo, ND (United States). Dept. of Chemistry; Docktor, B.; Eylands, K.E.; Thompson, J.S.; Hassett, D.J. [Univ. of North Dakota, Grand Forks, ND (United States). Energy and Environmental Research Center] [Univ. of North Dakota, Grand Forks, ND (United States). Energy and Environmental Research Center

1995-04-01

207

Intracellular Ionized Calcium.  

National Technical Information Service (NTIS)

Measurement of intracellular ionized calcium concentration (Ca2+) in living cells is of considerable interest to investigators over a broad range of cell biology. Calcium has an important role in a number of cellular functions and, perhaps most interestin...

C. H. June P. S. Rabinovitch

1994-01-01

208

Calcium absorption and achlorhydria  

Microsoft Academic Search

Defective absorption of calcium has been thought to exist in patients with achlorhydria. The author compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects. Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium

Robert R. Recker

1985-01-01

209

Process for converting magnesium fluoride to calcium fluoride  

DOEpatents

This invention is a process for the conversion of magnesium fluoride to calcium fluoride whereby magnesium fluoride is decomposed by heating in the presence of calcium carbonate, calcium oxide or calcium hydroxide. Magnesium fluoride is a by-product of the reduction of uranium tetrafluoride to form uranium metal and has no known commercial use, thus its production creates a significant storage problem. The advantage of this invention is that the quality of calcium fluoride produced is sufficient to be used in the industrial manufacture of anhydrous hydrogen fluoride, steel mill flux or ceramic applications.

Kreuzmann, A.B.; Palmer, D.A.

1984-12-21

210

Calcium and bones  

MedlinePLUS

... body gets the calcium it needs through the food you eat. If you do not get enough calcium in your diet or if your body does not absorb enough, your bones can get weak or not grow properly. Bone density refers to how much calcium and other types ...

211

Pharmacology of Calcium Antagonists  

Microsoft Academic Search

Although the calcium antagonists verapamil, ni\\\\~{} fedipine, diltiazem and bepridil are structurally diverse, they share, to a variable extent, several pharmacologic properties. These effects are preQ sumably the result of dose-related inhibition of transmembrane calcium ion flux through the slow channel. In diseased tissue, other routes of calcium entry may also be inhibited, and intracellular sites of action also are

Arnold Schwartz; M. Abdul Matus; Joseph Balwierczak; David A. Lathrop

1985-01-01

212

Hyperuricosuric calcium oxalate nephrolithiasis  

Microsoft Academic Search

Many investigators have observed that renal calcium stones may be associated with uric acid disorders. Prien and Prien [1] noted that patients with gout who had stone disease frequently passed stones which contained or were composed of calcium oxalate. Gutman [2] also observed a high frequency of calcium oxalate stones in patients who had gout; and he called attention to

Fredric L Coe

1978-01-01

213

Castable Calcium Aluminate Refractory.  

National Technical Information Service (NTIS)

A castable calcium aluminate refractory having a lower Al2O3 content, which is highly resistant to hot reducing atmospheres, is disclosed. It consists of 15-30% of approximately 85%-325 Tyler mesh calcium aluminate admixed with 85-70% of coarser calcium a...

L. Y. Sadler

1977-01-01

214

Calcium addition at the Hubbard Brook Experimental Forest reduced winter injury to red spruce in a high-injury year  

Microsoft Academic Search

Laboratory experiments have verified that acid-deposition-induced calcium (Ca) leaching reduces the foliar cold tolerance of red spruce (Picea rubens Sarg.) current-year foliage, increasing the risk of winter injury and crown deterioration. However, to date no studies have shown that ambient losses in soil Ca have resulted in increased winter injury in the field. In 2003, a year of severe region-wide

Gary J. Hawley; Paul G. Schaberg; Christopher Eagar; Catherine H. Borer

2006-01-01

215

Spectral unmixing techniques for retrieving plant foliar information  

NASA Astrophysics Data System (ADS)

In this study two novel approaches for supervised and semi-supervised hyperspectral unmixing are applied in the unmixing of CHRIS/PROBA data, in order to monitor seasonal land cover changes - in particular plant foliar coverage. Foliar coverage variations are directly linked to seasonal changes of the ecophysiological status of a plant (i.e. growth status, pigment concentrations, LAI etc). The high potential of using hyperspectral satellite data in monitoring plant biochemical and structural characteristics is important in ecophysiological studies. A reliable and efficient method to extract leaf and/or canopy information from a mixed pixel significantly contributes towards this direction. In this study, the development of two efficient algorithms in spectral unmixing enables the detection and mapping of leaf contribution to the overall pixel spectra and its seasonal variations. For this purpose, leaf spectra measured in the field, simultaneously to satellite acquisitions, are included in the endmember data set. The proposed unmixing techniques are performed on ground reflectances, assuming knowledge of the number and spectral signatures of the objects present in the images. An efficient estimation for their corresponding fractions in the pixels of the image is developed, based on a recently proposed maximum a posteriori probability (MAP) method. By exploiting the constraints naturally imposed to the problem, closed form expressions are derived for the statistical parameters required by the MAP estimator. In the semi-supervised scenario, we assume that a spectral library is given, containing spectral signatures of multiple endmembers. The objective in the latter case, is (a) to determine how many and which endmembers are present in the mixed pixel under study and (b) to use the selected endmembers to estimate the corresponding abundance fractions - especially the abundance of foliar coverage. The approach is based on a properly modified weighted l1-regularized least squares algorithm. The motivation of using the sparsity promoting l1 norm is that in practice, only a small number of the available endmembers are present in each pixel. Based on this observation, a weighted version of the well-known least absolute shrinkage and selection operator (lasso) criterion is utilized, where weights are used for penalizing different coefficients in the l1-regularization scheme. To efficiently solve the l1 minimization problem, the Least Angle Regression (LARS) algorithm is used. The performance of the proposed methods is compared to the performance of existing unmixing algorithms, such as standard convex programming procedures and ENVI software unmixing routines.

Themelis, Kostas; Sykioti, Olga; Rontogiannis, Athanasios; Koutroumbas, Konstantinos; Kyparissis, Aris

2010-05-01

216

[Relationship between antophyte foliar morphology and abiotic factors in the main rainforests of Eastern Cuba].  

PubMed

Relationship between antophyte foliar morphology and abiotic factors in the main rainforests of Eastern Cuba. The foliar morphology of representative antophytes in four rainforest types of Eastern Cuba was studied in relation to the main abiotic factors. Although there are several leaf types in these forests, the microphyll type is the most important among endemic species in the ophiolites complex and the Montane rainforest. At the Lowland rainforest (metamorphic complex) the mesophyll leaf was the most important. Most foliar epidermis had structures normally found in mesomorphic plants, but xeromorphic and higromorphic morphologies were also present. PMID:19637704

Quesada, Eddy Martínez

2009-01-01

217

Calcium phosphate-mediated transfection of primary cultured brain neurons using GFP expression as a marker: application for single neuron electrophysiology  

Microsoft Academic Search

We investigated the efficiency of transfecting primary cultured rat postnatal brain neurons (substantia nigra pars compacta neurons and locus coeruleus neurons) with cDNA encoding GFP (jellyfish green fluorescent protein) using a calcium phosphate method. The proportion of transfected neurons (transfection efficiency) was ?5%, when cultures from the substantia nigra pars compacta were transfected 3 days after plating. The transfection efficiency

Shinju Y Watanabe; Abla M Albsoul-Younes; Takeharu Kawano; Hiroshi Itoh; Yoshito Kaziro; Shigehiro Nakajima; Yasuko Nakajima

1999-01-01

218

Preliminary investigations into the significance of floral applications of calcium, boron and polyphenols for increased seed set in confection sunflowers ( Helianthus annuus L.)  

Microsoft Academic Search

One of the major problems of confection sunflowers is low seed set. We studied the relationship between seed set and the origin of pollen, either self or cross, and the effects of stigmatic sprays of calcium nitrate, boric acid and polyphenols on seed set. In a screen-house experiment, seed set was analyzed for three predetermined regions in the sunflower capitulum:

Y. Vaknin; N. Barr; Y. Saranga

2008-01-01

219

Foliar Spray with Vermiwash Modifies the Arbuscular Mycorrhizal Dependency and Nutrient Stoichiometry of Bhut Jolokia (Capsicum assamicum)  

PubMed Central

Vermiwash (VW), a liquid extract obtained from vermicomposting beds, is used as an organic fertilizer for crop plants. The current study investigated the effect of a vermiwash foliar spray on the response of bhut jolokia (Capsicum assamicum) exposed to two different arbuscular mycorrhizal fungi (AMF: Rhizophagus irregularis, RI and G. mosseae, GM) in acidic soil under naturally ventilated greenhouse conditions. The VW spray significantly influenced the growth of plants receiving the dual treatment of AMF+VW. Plant growth was more prominent in the GM+VW treatment group than that in the RI+VW treatment group. The plant-AMF interactions in relation to growth and nutrient requirements were also significantly influenced by the application of VW. Interestingly, the VW treatment appeared to contribute more N to plants when compared to that under the AMF treatment, which led to changes in the C:N:P stoichiometry in plant shoots. Furthermore, the increased potassium dependency, as observed in the case of the dual treatments, suggests the significance of such treatments for improving crop conditions under salt stress. Overall, our study shows that the VW foliar spray modifies the response of a crop to inoculations of different AMF with regard to growth and nutrient utilization, which has implications for the selection of an efficient combination of nutrient source for improving crop growth.

Gupta, Rajeev; Veer, Vijay; Singh, Lokendra; Kalita, Mohan C.

2014-01-01

220

Retention of zinc and calcium from the human colon  

SciTech Connect

Colonic retention of zinc and calcium was studied after installation during colonoscopy of 30 mumol of zinc and 6.4 mmol of calcium labeled with /sup 65/Zn and /sup 47/Ca, and measurement of the whole-body retention of the radionuclides. After cecal installation in nine patients, retention (day 13) of zinc was 3.5 +/- 2.1% (mean +/- SD) and of calcium 3.5 +/- 2.7%. The calculated mean absorption was 4.1% for zinc and 14.1% for calcium. Application at the hepatic flexure in four patients resulted in a mean retention (day 13) of 1.2% for zinc and 0.6% for calcium. Under prevailing conditions, colonic absorption of zinc is relatively small, compared to the uptake after oral administration. Colonic absorption of calcium could, however, account for a substantial part of the total calcium uptake.

Sandstroem, B.C.; Cederblad, A.; Kivistoe, B.S.; Stenquist, B.; Andersson, H.

1986-10-01

221

Stretch-activated calcium channels relay fast calcium waves propagated by calcium-induced calcium influx.  

PubMed

For nearly 30 years, fast calcium waves have been attributed to a regenerative process propagated by CICR (calcium-induced calcium release) from the endoplasmic reticulum. Here, I propose a model containing a new subclass of fast calcium waves which is propagated by CICI (calcium-induced calcium influx) through the plasma membrane. They are called fast CICI waves. These move at the order of 100 to 1000 microm/s (at 20 degrees C), rather than the order of 3 to 30 microm/s found for CICR. Moreover, in this proposed subclass, the calcium influx which drives calcium waves is relayed by stretch-activated calcium channels. This model is based upon reports from approx. 60 various systems. In seven of these reports, calcium waves were imaged, and, in five of these, evidence was presented that these waves were regenerated by CICI. Much of this model involves waves that move along functioning flagella and cilia. In these systems, waves of local calcium influx are thought to cause waves of local contraction by inducing the sliding of dynein or of kinesin past tubulin microtubules. Other cells which are reported to exhibit waves, which move at speeds in the fast CICI range, include ones from a dozen protozoa, three polychaete worms, three molluscs, a bryozoan, two sea urchins, one arthropod, four insects, Amphioxus, frogs, two fish and a vascular plant (Equisetum), together with numerous healthy, as well as cancerous, mammalian cells, including ones from human. In two of these systems, very gentle local mechanical stimulation is reported to initiate waves. In these non-flagellar systems, the calcium influxes are thought to speed the sliding of actinomyosin filaments past each other. Finally, I propose that this mechanochemical model could be tested by seeing if gentle mechanical stimulation induces waves in more of these systems and, more importantly, by imaging the predicted calcium waves in more of them. PMID:17302561

Jaffe, Lionel F

2007-03-01

222

Metabolism of High Concentrations of the Organophosphorus Insecticide Phorate Applied Foliarly to Selected Plant Species.  

National Technical Information Service (NTIS)

Gas chromatographic and enzymatic analysis (cholinesterase-inhibition method) were used to monitor the metabolism of the organophosphorus insecticide 0,0-diethyl S-((ethylthio)methyl) phosphorodithioate (phorate) applied foliarly to three economically imp...

B. C. Wolverton E. E. Boothe G. S. Kotchmar S. M. Lefstad

1971-01-01

223

Exploring the remote sensing of foliar biochemical concentrations with AVIRIS data  

NASA Technical Reports Server (NTRS)

Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data shows promise for the estimation of foliar biochemical concentrations at the scale of the canopy. There are, however, several problems associated with the use of AVIRIS data in this way and these are detailed in recent Plant Biochemical Workshop Report. The research reported was concentrated upon three of these problems: field sampling of forest canopies, wet laboratory assay of foliar chemicals, and the visualization of AVIRIS data.

Smith, Geoffrey M.; Curran, Paul J.

1992-01-01

224

Managing Foliar Blights on Carrot Using Copper, Azoxystrobin, and Chlorothalonil Applied According to TOM-CAST  

Microsoft Academic Search

Dorman, E. A., Webster, B. J., and Hausbeck, M. K. 2009. Managing foliar blights on carrot using copper, azoxystrobin, and chlorothalonil applied according to TOM-CAST. Plant Dis. 93:402-407. Alternaria dauci and Cercospora carotae cause foliar blight on carrot, causing yield reductions in severely blighted fields. Currently, fungicides are used on either a 7-day schedule or according to the TOM-CAST disease

E. A. Dorman; B. J. Webster; M. K. Hausbeck

2009-01-01

225

Foliar Nitrogen Uptake from Wet Deposition and the Relation with Leaf Wettability and Water Storage Capacity  

Microsoft Academic Search

This study assessed the foliar uptake of 15N-labelled nitrogen (N) originating from wet deposition along with leaf surface conditions, measured by wettability and water\\u000a storage capacity. Foliar 15N uptake was measured on saplings of silver birch, European beech, pedunculate oak and Scots pine and the effect of nitrogen\\u000a form (NH4+ or NO3?), NH4+ to NO3? ratio and leaf phenology on

Sandy Adriaenssens; Jeroen Staelens; Karen Wuyts; An de Schrijver; Shari Van Wittenberghe; Tatiana Wuytack; Fatemeh Kardel; Kris Verheyen; Roeland Samson; Pascal Boeckx

2011-01-01

226

Genotypic and phenotypic correlations for reaction to five foliar pathogens in alfalfa  

Microsoft Academic Search

Genotypic and phenotypic correlations for reaction to five foliar pathogens were estimated from analyses of variance and covariance in eight, five-parent diallel crosses each in Saranac, MSA-C4, and MSB-C4 alfalfa (Medicago sativa L.). The foliar pathogens wereUromyces striatus, Schroet. var.medicaginis (Pass.) Arth.,Stemphylium botryosum Wallr.,Pseudopeziza medicaginis (Lib.) Sacc.,Phoma herbarum West var.medicaginis Fckl., andLeptosphaerulina briosiana (Poll.) Graham and Luttrell.

R. R. Hill; K. T. Leath

1975-01-01

227

Field evaluation of in situ remediation of Cd-contaminated soil using four additives, two foliar fertilisers and two varieties of pakchoi.  

PubMed

This study was conducted to determine the optimal planting mode for pakchoi (Brassica rapa chinensis) in Cd-contaminated soil to reduce the accumulation of Cd in the edible parts while maintaining yields. Four additives (red mud (RM), silicon calcium fertiliser (SC), spodium (SP) and calcium magnesium phosphate (CMP)), two foliar fertilisers (Ca and Zn) and two varieties of pakchoi (Aijiaohuang (AJ) and Baixuegongzhu (BX)) were used in this study. The results show that the addition of SC and RM had an effect, but the other additives did not appear to increase the biomasses of AJ and BX. In some cases, the growth responses of AJ and BX to the same treatment were different. Extra additions of Ca or Zn to additive-treated pakchoi did not help the additives stimulate the growth of AJ and BX, except for SC-treated AJ and BX and SP-treated AJ. The SC and CMP additives significantly reduced the available Cd concentration in both the AJ soil and the BX soil; however, they did not significantly decrease the Cd concentration in the aboveground parts of AJ and BX. The RM treatments (for both levels) and some treatments containing SP reduced the available Cd concentration in the soils and reduced the accumulation of Cd in the two pakchoi varieties. Additions of Ca or Zn fertiliser significantly reduced the Cd concentration in the aboveground parts of AJ and BX. However, when Ca or Zn was sprayed on the additive-treated AJ and BX, they did not help the additives reduce the Cd accumulation in the aboveground parts of AJ and BX, except for the additive CMP. This study shows that RM may be an optimal amendment to reduce the accumulation of Cd in the edible part of pakchoi while simultaneously maintaining yields. The utilisation of Ca or Zn as a foliar fertiliser to additive-treated pakchoi showed positive effects only under some conditions. PMID:23603772

Feng, Renwei; Qiu, Weiwen; Lian, Fei; Yu, Zhihong; Yang, YiXin; Song, Zhengguo

2013-07-30

228

Foliar Water Uptake of Tamarix ramosissima from an Atmosphere of High Humidity  

PubMed Central

Many species have been found to be capable of foliar water uptake, but little research has focused on this in desert plants. Tamarix ramosissima was investigated to determine whether its leaves can directly absorb water from high humidity atmosphere and, if they can, to understand the magnitude and importance of foliar water uptake. Various techniques were adopted to demonstrate foliar water uptake under submergence or high atmospheric humidity. The mean increase in leaf water content after submergence was 29.38% and 20.93% for mature and tender leaves, respectively. In the chamber experiment, obvious reverse sap flow occurred when relative humidity (RH) was persistently above 90%. Reverse flow was recorded first in twigs, then in branches and stems. For the stem, the percentage of negative sap flow rate accounting for the maximum value of sap flow reached 10.71%, and its amount accounted for 7.54% of diurnal sap flow. Small rainfall can not only compensate water loss of plant by foliar uptake, but also suppress transpiration. Foliar uptake can appear in the daytime under certain rainfall events. High atmospheric humidity is beneficial for enhancing the water status of plants. Foliar uptake should be an important strategy of water acquisition for desert plants.

Li, Shuang; Xiao, Hong-lang; Zhao, Liang; Zhou, Mao-Xian; Wang, Fang

2014-01-01

229

Self-Setting Calcium Orthophosphate Formulations  

PubMed Central

In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are bioactive and biodegradable grafting bioceramics in the form of a powder and a liquid. After mixing, both phases form pastes, which set and harden forming either a non-stoichiometric calcium deficient hydroxyapatite or brushite. Since both of them are remarkably biocompartible, bioresorbable and osteoconductive, self-setting calcium orthophosphate formulations appear to be promising bioceramics for bone grafting. Furthermore, such formulations possess excellent molding capabilities, easy manipulation and nearly perfect adaptation to the complex shapes of bone defects, followed by gradual bioresorption and new bone formation. In addition, reinforced formulations have been introduced, which might be described as calcium orthophosphate concretes. The discovery of self-setting properties opened up a new era in the medical application of calcium orthophosphates and many commercial trademarks have been introduced as a result. Currently such formulations are widely used as synthetic bone grafts, with several advantages, such as pourability and injectability. Moreover, their low-temperature setting reactions and intrinsic porosity allow loading by drugs, biomolecules and even cells for tissue engineering purposes. In this review, an insight into the self-setting calcium orthophosphate formulations, as excellent bioceramics suitable for both dental and bone grafting applications, has been provided.

Dorozhkin, Sergey V.

2013-01-01

230

High-calcium coal combustion by-products: Engineering properties, ettringite formation, and potential application in solidification and stabilization of selenium and boron  

Microsoft Academic Search

Four high-calcium coal combustion by-products (two pulverized coal fly ashes (PCFA), a flue gas desulfurization (FGD) residue, and an atmospheric fluidized bed combustion (AFBC) fly ash), were tested for engineering properties and ability to immobilize boron and selenium. These data are needed to explore high-volume utilization in engineered structures or in solidification\\/stabilization (S\\/S) technology. Strengths of cured pastes (91 days),

B. Docktor; K. E. Eylands; J. S. Thompson; D. J. Hassett

1995-01-01

231

Voltage-dependent calcium currents and cytosolic calcium in equine airway myocytes.  

PubMed Central

1. The relationship between voltage-dependent calcium channel current (I(Ca)) and cytosolic free calcium concentration ([Ca2+]i) was studied in fura-2 AM-loaded equine tracheal myocytes at 35 degrees C and 1.8 mM Ca2+ using the nystatin patch clamp method. The average cytosolic calcium buffering constant was 77 +/- 3 (n = 14), and the endogenous calcium buffering constant component is likely to be between 15 and 50. 2. I(Ca) did not evoke significant calcium-induced calcium release (CICR) since (i)[Ca2+]i scaled with the integrated I(Ca) over the full voltage range of evoked calcium currents, (ii) increases in [Ca2+]i associated with I(Ca) were consistent with cytoplasmic buffering of calcium ions entering through voltage-dependent calcium channels (VDCCs) only, (iii) there was a fixed instantaneous relationship between transmembrane calcium flux (J(Ca)) and the change in cytosolic free calcium concentration (delta [Ca2+]i) during I(Ca), (iv) caffeine (8 mM) triggered 8-fold higher calcium transients than I(Ca), and (v) I(Ca) evoked following release of intracellular calcium by caffeine resulted in an equivalent delta[Ca2+]i-J(Ca) relationship. 3. The time constant (T) for the decay in [Ca2+]i was 8.6 +/- 1.5 s (n = 8) for single steps and 8.6 +/- 1.1 s (n = 13) following multiple steps that increased [Ca2+]i to much higher levels. Following application of caffeine (8 mM), however, [Ca2+]i decay was enhanced (T = 2.0 +/- 0.2 s, n = 3). The rate of [Ca2+]i decay was not voltage dependent, was not decreased in the absence of extracellular Na+ ions, and no pump current was detected. 4. We conclude that under near physiological conditions, neither CICR nor Na(+)-Ca2+ exchange play a substantial role in the regulation of I(Ca)-induced increases in [Ca2+]i, and that, even following release of intracellular calcium by caffeine, Na(+)-Ca2+ exchange does not play an appreciable role in the removal of calcium ions from the cytosol.

Fleischmann, B K; Wang, Y X; Pring, M; Kotlikoff, M I

1996-01-01

232

Foliar Uptake of Atmospheric Reactive Nitrogen Pollution Along an Urban-Rural Gradient in New York State  

NASA Astrophysics Data System (ADS)

Vegetation is an important sink for atmospheric reactive nitrogen (N) pollution in terrestrial ecosystems, and when soil N is limiting, foliar N uptake can be a source of plant-available N. A proxy for pollution derived N, and in particular foliar assimilated N, would be useful to quantify the impact of the foliar uptake pathway on plant metabolism. Nitrogen stable isotope ratios (15N/14N) are practical for this purpose because forms of plant-available N often have varying isotopic compositions. However, the mechanisms driving differences in foliar N isotopic composition (?15N) are still unresolved. Current understanding of foliar ? 15N suggests these values primarily represent the integration of the soil water solution ?15N, direct foliar uptake of atmospheric reactive N, within-plant fractionations, and fractionation due to the fungus to root transfer in mycorrhizae. In this study, we investigated the influence of direct foliar uptake, soil solution ? 15N, and mycorrhizae on foliar ?15N in seedlings of two dominant Northeastern tree species, red maple (Acer rubrum) and red oak (Quercus rubra), along an N deposition gradient in New York State. Using a potted plant mesocosm system, we compared foliar ?15N values directly to soil solution ?15N values while controlling for mycorrhizal associations. Both species showed higher foliar ?15N when exposed to fractionation by mycorrhizal associations. Overall, A. rubrum showed higher foliar ?15N than Q. rubra across all sites. In both species, patterns of foliar ?15N values were coupled with soil solution ?15N values across the N deposition gradient. Additionally, increasing atmospheric N deposition was correlated with higher foliar ?15N values in Q. rubra, but not in A. rubrum. Using a mixing model, we estimated that Q. rubra seedlings incorporated up to 7% of their assimilated N via direct foliar uptake of atmospheric N pollution. However, foliar uptake was not detectable in A. rubrum seedlings. Results suggest that the use of foliar ?15N values may be an effective tool to estimate the magnitude of foliar uptake of pollutant N compounds under some circumstances.

Vallano, D.; Sparks, J. P.

2008-12-01

233

Evaluation of Herbicides and Application Timing for Control of Japanese Knotweed.  

National Technical Information Service (NTIS)

Testing was conducted from fall 2001 through spring 2003 to evaluate the efficacy of several herbicides, timing of application (foliar vs. dormant), and an alternative application method (Burch Wet Blade) for control of Japanese knotweed along highway rig...

S. H. Kay Z. E. Murrell

2003-01-01

234

Application of Low-Frequency Alternating Current Electric Fields Via Interdigitated Electrodes: Effects on Cellular Viability, Cytoplasmic Calcium, and Osteogenic Differentiation of Human Adipose-Derived Stem Cells  

PubMed Central

Electric stimulation is known to initiate signaling pathways and provides a technique to enhance osteogenic differentiation of stem and/or progenitor cells. There are a variety of in vitro stimulation devices to apply electric fields to such cells. Herein, we describe and highlight the use of interdigitated electrodes to characterize signaling pathways and the effect of electric fields on the proliferation and osteogenic differentiation of human adipose-derived stem cells (hASCs). The advantage of the interdigitated electrode configuration is that cells can be easily imaged during short-term (acute) stimulation, and this identical configuration can be utilized for long-term (chronic) studies. Acute exposure of hASCs to alternating current (AC) sinusoidal electric fields of 1?Hz induced a dose-dependent increase in cytoplasmic calcium in response to electric field magnitude, as observed by fluorescence microscopy. hASCs that were chronically exposed to AC electric field treatment of 1?V/cm (4?h/day for 14 days, cultured in the osteogenic differentiation medium containing dexamethasone, ascorbic acid, and ?-glycerol phosphate) displayed a significant increase in mineral deposition relative to unstimulated controls. This is the first study to evaluate the effects of sinusoidal AC electric fields on hASCs and to demonstrate that acute and chronic electric field exposure can significantly increase intracellular calcium signaling and the deposition of accreted calcium under osteogenic stimulation, respectively.

McCullen, Seth D.; McQuilling, John P.; Grossfeld, Robert M.; Lubischer, Jane L.; Clarke, Laura I.

2010-01-01

235

Effect of Exogenously Supplied Foliar Potassium on Phloem Loading in Beta vulgaris L. 1  

PubMed Central

The effect of foliar application of K+ on processes associated with phloem loading was investigated in source leaves of sugar beet (Beta vulgaris L.). KCI was supplied exogenously at concentrations of up to 100 millimolar in the solution bathing the abraded upper epidermis of source leaves. K+ added at concentrations below 30 millimolar generally promoted the rate of export of material derived from 14CO2 but not from exogenously applied [14C]sucrose. Paralleling promotion of export, the level of material derived from photosynthesis, which was released into the bathing solution, also increased in response to addition of K+ to the free space. Net photosynthetic rate was not affected. K+ at 5 and 15 millimolar concentrations did not stimulate uptake of [14C]sucrose into source leaf discs. The data suggest that the promotion of export rate by K+ results primarily from an effect on the site regulating efflux of sucrose into the apoplast prior to loading into the minor veins, rather than on the loading site itself. A change in the level of sucrose in the free space appears to precede a change in export rate. Images

Doman, Diane C.; Geiger, Donald R.

1979-01-01

236

Calcium carbonate phase transformations during the carbonation reaction of calcium heavy alkylbenzene sulfonate overbased nanodetergents preparation.  

PubMed

The preparation and application of overbased nanodetergents with excess alkaline calcium carbonate is a good example of nanotechnology in practice. The phase transformation of calcium carbonate is of extensive concern since CaCO(3) serves both as an important industrial filling material and as the most abundant biomineral in nature. Industrially valuable overbased nanodetergents have been prepared based on calcium salts of heavy alkylbenzene sulfonate by a one-step process under ambient pressure, the carbonation reaction has been monitored by the instantaneous temperature changes and total base number (TBN). A number of analytical techniques such as TGA, DLS, SLS, TEM, FTIR, and XRD have been utilized to explore the carbonation reaction process and phase transformation mechanism of calcium carbonate. An enhanced understanding on the phase transformation of calcium carbonate involved in calcium sulfonate nanodetergents has been achieved and it has been unambiguously demonstrated that amorphous calcium carbonate (ACC) transforms into the vaterite polymorph rather than calcite, which would be of crucial importance for the preparation and quality control of lubricant additives and greases. Our results also show that a certain amount of residual Ca(OH)(2) prevents the phase transformation from ACC to crystalline polymorphs. Moreover, a vaterite nanodetergent has been prepared for the first time with low viscosity, high base number, and uniform particle size, nevertheless a notable improvement on its thermal stability is required for potential applications. PMID:21507412

Chen, Zhaocong; Xiao, Shan; Chen, Feng; Chen, Dongzhong; Fang, Jianglin; Zhao, Min

2011-07-01

237

Stoichiometric patterns in foliar nutrient resorption across multiple scales  

USGS Publications Warehouse

*Nutrient resorption is a fundamental process through which plants withdraw nutrients from leaves before abscission. Nutrient resorption patterns have the potential to reflect gradients in plant nutrient limitation and to affect a suite of terrestrial ecosystem functions. *Here, we used a stoichiometric approach to assess patterns in foliar resorption at a variety of scales, specifically exploring how N : P resorption ratios relate to presumed variation in N and/or P limitation and possible relationships between N : P resorption ratios and soil nutrient availability. *N : P resorption ratios varied significantly at the global scale, increasing with latitude and decreasing with mean annual temperature and precipitation. In general, tropical sites (absolute latitudes < 23°26?) had N : P resorption ratios of < 1, and plants growing on highly weathered tropical soils maintained the lowest N : P resorption ratios. Resorption ratios also varied with forest age along an Amazonian forest regeneration chronosequence and among species in a diverse Costa Rican rain forest. *These results suggest that variations in N : P resorption stoichiometry offer insight into nutrient cycling and limitation at a variety of spatial scales, complementing other metrics of plant nutrient biogeochemistry. The extent to which the stoichiometric flexibility of resorption will help regulate terrestrial responses to global change merits further investigation.

Reed, Sasha C.; Townsend, Alan R.; Davidson, Eric A.; Cleveland, Cory C.

2012-01-01

238

Use of laser fluorescence and scanning electron microscope to evaluate remineralization of incipient enamel lesions remineralized by topical application of casein phospho peptide amorphous calcium phosphate (CPP-aCP) containing cream.  

PubMed

The aim of this in vitro study was to evaluate the remineralization of incipient enamel lesions by the topical application of Casein PhosphoPeptide-Amorphous Calcium Phosphate (CPP-ACP) using laser fluorescence and scanning electron microscope. Sixty caries free extracted teeth were used in the study. Forty teeth were used as test samples, ten as positive and ten as negative controls. The samples were demineralized and then remineralized by the topical application of CPP-ACP for a period of 14 days. The remineralization was evaluated with the use of laser fluorescence and scanning electron microscope (SEM). The results of this study showed that the laser fluorescent readings of test samples after remineralization were highly significant (p < 0.001). A significant number of test samples observed under SEM showed high scores of remineralization. PMID:18524269

Pai, Deepika; Bhat, Sham S; Taranath, Abhay; Sargod, Sharan; Pai, Vinita M

2008-01-01

239

Mapa bioclimático para las Travesías de Mendoza (Argentina) basado en la fenología foliar Bioclimatic map for the Travesías (vast plains) of Mendoza province (Argentina) based on foliar phenology  

Microsoft Academic Search

The aim was to propose a bioclimatic map of the plain of Mendoza province reflec- ting the climatic differences expressed by vegetation activity (foliar phenology) at regio- nal scale. The digital image of the bioclimatic aridity index P\\/ETP, resulting from a previous research on time series of NDVI images, was recoded into bioclimatic classes. Each class was analysed, assessing whether

Massimo Menenti; Ángela M. Diblasi

2009-01-01

240

Calcium fluoride window mounting  

SciTech Connect

A technique has been developed for joining a large calcium fluoride crystal to a stainless-steel flange by means of a silver transition ring. The process involves both vacuum brazing using a copper-silver alloy and air brazing using silver chloride. This paper describes the procedure used in fabricating a high-vacuum leak-tight calcium fluoride window assembly.

Berger, D.D.

1982-10-01

241

Calcium Nutrition in Adolescence  

Microsoft Academic Search

Adolescence is an important period of nutritional vulnerability due to increased dietary requirements for growth and development and special dietary habits. Calcium needs are elevated as a result of the intensive bone and muscular development and thus adequate calcium intake during growth is extremely important to reach the optimum peak bone mass and to protect against osteoporosis in the adult

Marta Mesías; Isabel Seiquer; M. Pilar Navarro

2011-01-01

242

Calcium signaling in neurodegeneration  

PubMed Central

Calcium is a key signaling ion involved in many different intracellular and extracellular processes ranging from synaptic activity to cell-cell communication and adhesion. The exact definition at the molecular level of the versatility of this ion has made overwhelming progress in the past several years and has been extensively reviewed. In the brain, calcium is fundamental in the control of synaptic activity and memory formation, a process that leads to the activation of specific calcium-dependent signal transduction pathways and implicates key protein effectors, such as CaMKs, MAPK/ERKs, and CREB. Properly controlled homeostasis of calcium signaling not only supports normal brain physiology but also maintains neuronal integrity and long-term cell survival. Emerging knowledge indicates that calcium homeostasis is not only critical for cell physiology and health, but also, when deregulated, can lead to neurodegeneration via complex and diverse mechanisms involved in selective neuronal impairments and death. The identification of several modulators of calcium homeostasis, such as presenilins and CALHM1, as potential factors involved in the pathogenesis of Alzheimer's disease, provides strong support for a role of calcium in neurodegeneration. These observations represent an important step towards understanding the molecular mechanisms of calcium signaling disturbances observed in different brain diseases such as Alzheimer's, Parkinson's, and Huntington's diseases.

Marambaud, Philippe; Dreses-Werringloer, Ute; Vingtdeux, Valerie

2009-01-01

243

Calcium hydroxyapatite fillers.  

PubMed

Calcium hydroxyapatite fillers have unique advantages over other fillers in regards to duration of action and volume of product required for augmentation, especially in the midface and lower face. In this article, we describe our experience with calcium hydroxyapatite fillers and compare them with other available filler products. PMID:22205523

Tansavatdi, Kristina; Mangat, Devinder S

2011-12-01

244

High Blood Calcium (Hypercalcemia)  

MedlinePLUS

... glands in your neck) secrete a hormone called parathyroid hormone (Pth). Pth helps your bones release calcium into ... together, Pth and vitamin D, along with other hormones and minerals, help move calcium in or ... or more of the parathyroid glands produces too much Pth. this, in turn, ...

245

EVALUATION OF CALCIUM SENSORS IN FRESH AND SALTWATER  

EPA Science Inventory

The Orion Calcium Ion Electrode No. 93-20 was evaluated for suitability as a calcium ion sensor for monitoring or in-situ marine applications by testing for the following parameters: accuracy, precision, temperature dependence, short- and long-term stability, durability, sensitiv...

246

Calcium stone disease: a multiform reality  

Microsoft Academic Search

In calcium renal stones, calcium oxalate and calcium phosphate in various crystal forms and states of hydration can be identified. Calcium oxalate monohydrate (COM) or whewellite and calcium oxalate dihydrate (COD) or weddellite are the commonest constituents of calcium stones. Calcium oxalate stones may be pure or mixed, usually with calcium phosphate or sometimes with uric acid or ammonium urate.

Alberto Trinchieri; Chiara Castelnuovo; Renata Lizzano; Giampaolo Zanetti

2005-01-01

247

21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.  

Code of Federal Regulations, 2012 CFR

...Calcium pantothenate, calcium chloride double salt. 172.330 Section 172.330 Food and...Calcium pantothenate, calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may be safely...

2012-04-01

248

21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.  

Code of Federal Regulations, 2011 CFR

...Calcium pantothenate, calcium chloride double salt. 172.330 Section 172.330 Food and...Calcium pantothenate, calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may be safely...

2011-04-01

249

21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.  

Code of Federal Regulations, 2010 CFR

...Calcium pantothenate, calcium chloride double salt. 172.330 Section 172.330 Food and...Calcium pantothenate, calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may be safely...

2010-01-01

250

Calcium-41 concentration in terrestrial materials: prospects for dating of pleistocene samples  

SciTech Connect

Calcium-41 bas been suggested as a new tool for radiometric dating in the range of 10/sup 5/ to 10/sup 6/ years. The concentration of cosmogenic calcium-41 in natural samples of terrestrial origin has now been determined by high-sensitivity accelerator mass spectrometry after pre-enrichment in calcium-41 with an isotope separator. Ratios of calcium-41 to total calcium between 2 x 10/sup -14/ and 3 x 10/sup -15/ were measured for samples of contemporary bovine bone and from limestone deposits. Some prospects for the use of calcium-41 for dating Middle and Late Pleistocene bone and for other geophysical applications are discussed.

Henning, W.; Bell, W.A.; Billquist, P.J.; Glagola, B.G.; Kutschera, W.; Liu, Z.; Lucas, H.F.; Paul, M.; Rehm, K.E.; Yntema, J.L.

1987-05-08

251

CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING ON LEFT, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CALCIUM CHLORIDE PLANT LOOKING EAST. CALCIUM CHLORIDE BUILDING ON LEFT, CALCIUM CHLORIDE STORAGE BUILDING ON RIGHT OF CENTER WITH TOP OF SA (SODA ASH) BUILDING IN RIGHT BACKGROUND. - Solvay Process Company, Calcium Chloride Plant, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

252

Host Genotype Shapes the Foliar Fungal Microbiome of Balsam Poplar (Populus balsamifera)  

PubMed Central

Foliar fungal communities of plants are diverse and ubiquitous. In grasses endophytes may increase host fitness; in trees, their ecological roles are poorly understood. We investigated whether the genotype of the host tree influences community structure of foliar fungi. We sampled leaves from genotyped balsam poplars from across the species' range, and applied 454 amplicon sequencing to characterize foliar fungal communities. At the time of the sampling the poplars had been growing in a common garden for two years. We found diverse fungal communities associated with the poplar leaves. Linear discriminant analysis and generalized linear models showed that host genotypes had a structuring effect on the composition of foliar fungal communities. The observed patterns may be explained by a filtering mechanism which allows the trees to selectively recruit fungal strains from the environment. Alternatively, host genotype-specific fungal communities may be present in the tree systemically, and persist in the host even after two clonal reproductions. Both scenarios are consistent with host tree adaptation to specific foliar fungal communities and suggest that there is a functional basis for the strong biotic interaction.

Balint, Miklos; Tiffin, Peter; Hallstrom, Bjorn; O'Hara, Robert B.; Olson, Matthew S.; Fankhauser, Johnathon D.; Piepenbring, Meike; Schmitt, Imke

2013-01-01

253

Identification of Genes in Thuja plicata Foliar Terpenoid Defenses1[C][W][OA  

PubMed Central

Thuja plicata (western redcedar) is a long-lived conifer species whose foliage is rarely affected by disease or insect pests, but can be severely damaged by ungulate browsing. Deterrence to browsing correlates with high foliar levels of terpenoids, in particular the monoterpenoid ?-thujone. Here, we set out to identify genes whose products may be involved in the production of ?-thujone and other terpenoids in this species. First, we generated a foliar transcriptome database from which to draw candidate genes. Second, we mapped the storage of thujones and other terpenoids to foliar glands. Third, we used global expression profiling to identify more than 600 genes that are expressed at high levels in foliage with glands, but can either not be detected or are expressed at low levels in a natural variant lacking foliar glands. Fourth, we used in situ RNA hybridization to map the expression of a putative monoterpene synthase to the epithelium of glands and used enzyme assays with recombinant protein of the same gene to show that it produces sabinene, the monoterpene precursor of ?-thujone. Finally, we identified candidate genes with predicted enzymatic functions for the conversion of sabinene to ?-thujone. Taken together, this approach generated both general resources and detailed functional characterization in the identification of genes of foliar terpenoid biosynthesis in T. plicata.

Foster, Adam J.; Hall, Dawn E.; Mortimer, Leanne; Abercromby, Shelley; Gries, Regine; Gries, Gerhard; Bohlmann, Jorg; Russell, John; Mattsson, Jim

2013-01-01

254

Application of the molecular interaction volume model (MIVM) to calcium-based liquid alloys of systems forming high-melting intermetallics.  

PubMed

The thermodynamic properties of multiple liquid alloys with strong negative deviation from ideality were successfully modeled by the molecular interaction volume model (MIVM). The modeled partial Gibbs free energy of calcium in Ca-Ag, Ca-In, Ca-Pb, Ca-Sn, Ca-Tl, and Ca-Zn at 800 °C was within 1.5 kJ/mol of the existing experimental data. The partial Gibbs free energy of calcium in Ca-Bi liquid alloys at 600 °C was predicted within 1.6 kJ/mol (or 1%) by the MIVM from experimental data at 800 °C. For the first time, the MIVM was applied to a ternary system far from ideality, Ca-Sb-Pb. The partial Gibbs free energy of Ca in six Ca-Pb-Sb alloys was determined by emf measurements in a cell configured as Ca(s)|CaF2(s)|Ca-Sb-Pb, over the temperature range of 500-830 °C. These values were 2% (or 5 kJ/mol) more negative than those predicted by the MIVM using experimental data for the Ca-Pb, Ca-Sb, and Pb-Sb binary alloys. This difference was attributed to the inability of the MIVM to account for interactions between the first nearest neighbors of Ca, Pb and Sb in the ternary Ca-Sb-Pb alloy. PMID:23621449

Poizeau, Sophie; Sadoway, Donald R

2013-06-01

255

Calcium Imaging Perspectives in Plants  

PubMed Central

The calcium ion (Ca2+) is a versatile intracellular messenger. It provides dynamic regulation of a vast array of gene transcriptions, protein kinases, transcription factors and other complex downstream signaling cascades. For the past six decades, intracellular Ca2+ concentration has been significantly studied and still many studies are under way. Our understanding of Ca2+ signaling and the corresponding physiological phenomenon is growing exponentially. Here we focus on the improvements made in the development of probes used for Ca2+ imaging and expanding the application of Ca2+ imaging in plant science research.

Kanchiswamy, Chidananda Nagamangala; Malnoy, Mickael; Occhipinti, Andrea; Maffei, Massimo E.

2014-01-01

256

Foliar Treatments of 2,4-Dichlorophenoxyacetic Acid for Control of Common Scab in Potato Have Beneficial Effects on Powdery Scab Control  

PubMed Central

Prior studies have shown that applications of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) to the foliage of potato plants can reduce common scab. Here field and glasshouse trials suggest that 2,4-D foliar treatments may also reduce the biologically distinct tuber disease, powdery scab. Significant correlations between suppression of common and powdery scab from the field trials suggested an interaction between the two diseases or possible additional broad spectrum mechanisms of enhanced defence against pathogen invasion provided by 2,4-D treatment.

Thompson, Hannah Katherine; Tegg, Robert Stephen; Corkrey, Ross; Wilson, Calum Rae

2014-01-01

257

Teaching calcium-induced calcium release in cardiomyocytes using a classic paper by Fabiato  

NSDL National Science Digital Library

This teaching paper utilizes the materials presented by Dr. Fabiato in his review article entitled "Calcium-induced release of calcium from the cardiac sarcoplasmic reticulum." In the review, supporting evidence of calcium-induced calcium release (CICR) is presented. Data concerning potential objections to the CICR theory are discussed as well. In closing, technical issues associated with the skinned cell model are mentioned. Based on this review article, teaching and learning points are put forth in this article to highlight two concepts: 1) the regulatory mechanisms of CICR in cardiomyocytes and 2) the recognition of contradicting hypotheses and limitations in experimental design. The first concept is certainly an important one for physiology students. The second concept is universally applicable to researchers in all fields of science. It is thus the aim of this article to cultivate a rewarding teaching and learning experience for both instructors and students.

Willmann Liang (Nanyang Technological University Biological Sciences)

2007-11-09

258

Teaching calcium-induced calcium release in cardiomyocytes using a classic paper by Fabiato.  

PubMed

This teaching paper utilizes the materials presented by Dr. Fabiato in his review article entitled "Calcium-induced release of calcium from the cardiac sarcoplasmic reticulum." In the review, supporting evidence of calcium-induced calcium release (CICR) is presented. Data concerning potential objections to the CICR theory are discussed as well. In closing, technical issues associated with the skinned cell model are mentioned. Based on this review article, teaching and learning points are put forth in this article to highlight two concepts: 1) the regulatory mechanisms of CICR in cardiomyocytes and 2) the recognition of contradicting hypotheses and limitations in experimental design. The first concept is certainly an important one for physiology students. The second concept is universally applicable to researchers in all fields of science. It is thus the aim of this article to cultivate a rewarding teaching and learning experience for both instructors and students. PMID:18334561

Liang, Willmann

2008-03-01

259

Effects of ozone on the foliar histology of the mastic plant (Pistacia lentiscus L.).  

PubMed

An open-top chamber study was conducted to investigate the tissue and cellular-level foliar effects of ozone (O3) on a Mediterranean evergreen species, the mastic plant (Pistacia lentiscus L.). Plants were exposed at three different O3 levels, and leaf samples were collected periodically from the beginning of the exposure. Although no visible foliar injury was evident, alterations of the plastids and vacuoles in the mesophyll were observed. Senescence processes were accelerated with an anomalous stacking of tannin vacuoles, and a reduction in the size and number of the chloroplasts. Overall, most of the modifications induced by O3 were consistent with previously reported observations on deciduous broadleaf species, with the exception of alterations in the cells covering the secretory channels, reported here as a new finding. Comments on the feasibility of using microscopy to validate O3 related field observations and subtle foliar injury are also given. PMID:15312944

Reig-Armiñana, J; Calatayud, V; Cerveró, J; García-Breijo, F J; Ibars, A; Sanz, M J

2004-11-01

260

Purple Phototrophic Bacterium Enhances Stevioside Yield by Stevia rebaudiana Bertoni via Foliar Spray and Rhizosphere Irrigation  

PubMed Central

This study was conducted to compare the effects of foliar spray and rhizosphere irrigation with purple phototrophic bacteria (PPB) on growth and stevioside (ST) yield of Stevia. rebaudiana. The S. rebaudiana plants were treated by foliar spray, rhizosphere irrigation, and spray plus irrigation with PPB for 10 days, respectively. All treatments enhanced growth of S. rebaudiana, and the foliar method was more efficient than irrigation. Spraying combined with irrigation increased the ST yield plant -1 by 69.2% as compared to the control. The soil dehydrogenase activity, S. rebaudiana shoot biomass, chlorophyll content in new leaves, and soluble sugar in old leaves were affected significantly by S+I treatment, too. The PPB probably works in the rhizosphere by activating the metabolic activity of soil bacteria, and on leaves by excreting phytohormones or enhancing the activity of phyllosphere microorganisms.

Wu, Jing; Wang, Yiming; Lin, Xiangui

2013-01-01

261

Purple phototrophic bacterium enhances stevioside yield by Stevia rebaudiana Bertoni via foliar spray and rhizosphere irrigation.  

PubMed

This study was conducted to compare the effects of foliar spray and rhizosphere irrigation with purple phototrophic bacteria (PPB) on growth and stevioside (ST) yield of Stevia. rebaudiana. The S. rebaudiana plants were treated by foliar spray, rhizosphere irrigation, and spray plus irrigation with PPB for 10 days, respectively. All treatments enhanced growth of S. rebaudiana, and the foliar method was more efficient than irrigation. Spraying combined with irrigation increased the ST yield plant (-1) by 69.2% as compared to the control. The soil dehydrogenase activity, S. rebaudiana shoot biomass, chlorophyll content in new leaves, and soluble sugar in old leaves were affected significantly by S+I treatment, too. The PPB probably works in the rhizosphere by activating the metabolic activity of soil bacteria, and on leaves by excreting phytohormones or enhancing the activity of phyllosphere microorganisms. PMID:23825677

Wu, Jing; Wang, Yiming; Lin, Xiangui

2013-01-01

262

Stoichiometry of Calcium Medicines  

ERIC Educational Resources Information Center

The topic of calcium supplement and its effects on human lives is presented in the way of questions to the students. It enables the students to realize the relevance of chemistry outside the classroom surrounding.

Pinto, Gabriel

2005-01-01

263

Eleven-year response of foliar chemistry to chronic nitrogen and sulfur additions at the Bear Brooks Watershed in Maine  

SciTech Connect

The foliar chemistry of sugar maple (Acer saccharum Marsh.), American beech (Fagus grandifolia Ehrh.), and red spruce (Picea rubens Sarg.) was studied from 1993 to 2003 at the Bear Brook Watershed in Maine (BBWM). The BBWM is a paired-watershed forest ecosystem study, with one watershed treated bimonthly since 1989 with ammonium sulfate ((NH4)2SO4) at a rate of 25.2 kg N·ha–1·year–1. Foliar N concentrations were higher in all tree species within the treated watershed compared with trees within the reference watershed. Foliar Ca and Mg concentrations were lower in American beech and red spruce within the treated watershed. There were no significant differences in foliar K concentrations between watersheds. Foliar P and Mn concentration differences between watersheds were inconsistent among years. Differences in foliar N concentrations between watersheds declined over time in sugar maple but not in red spruce or American beech. Differences in foliar Ca and Mg concentrations between the treated and reference watersheds increased over time for American beech and red spruce, primarily because of a consistent decline in concentrations of these nutrients in trees within the treated watershed. No temporal trends in foliar Ca and Mg concentration differences between watersheds were observed for sugar maple.

Jose Alexander Elvir; Gregory J. White

2005-06-01

264

Variation in Foliar delta13C of Desert Plant Reaumuria soongorica (Pall.) Maxim. among Different Environments in Northwestern China  

Microsoft Academic Search

Reaumuria soongorica is a dominant desert shrub species in arid regions of northwest China, it playing an important role in the maintenance of the stability and continuity of desert ecosystem. The objectives of this study were to investigate the distribution characteristics of foliar delta13C value in R. soongorica, establish the correlations between foliar characteristics and environmental factors, and identify the

J. Ma; E. Pendall; F. Chen

2008-01-01

265

Calcium Determination in Bone by Proton Activation Analysis.  

National Technical Information Service (NTIS)

The incidence of post-menopausal osteoporosis in almost epidemic proportions makes the early diagnosis and development of effective therapy a matter of considerable concern. Current status of the project is reviewed and new applications of calcium determi...

R. Wilson S. Adelstein

1974-01-01

266

A grid of non-local thermodynamic equilibrium corrections for magnesium and calcium in late-type giant and supergiant stars: application to Gaia  

NASA Astrophysics Data System (ADS)

We investigate non-local thermodynamic equilibrium (NLTE) effects for magnesium and calcium in the atmospheres of late-type giant and supergiant stars. The aim of this paper is to provide a grid of NLTE/LTE equivalent width ratios W/W* of Mg and Ca lines for the following range of stellar parameters: Teff? [3500, 5250] K, log g? [0.5, 2.0] dex and [Fe/H] ? [- 4.0, 0.5] dex. We use realistic model atoms with the best physics available and taking into account the fine structure. The Mg and Ca lines of interest are in optical and near-IR ranges. A special interest concerns the lines in the Gaia spectrograph [Radial Velocity Spectrometer (RVS)] wavelength domain [8470, 8740] Å. The NLTE corrections are provided as a function of stellar parameters in an electronic table as well as in a polynomial form for the Gaia/RVS lines.

Merle, T.; Thévenin, F.; Pichon, B.; Bigot, L.

2011-12-01

267

Adenosine Triphosphate-Dependent Calcium  

Microsoft Academic Search

Microsomes from rat submaxillary glands are able to take up calcium from the suspension media. Calcium uptake is greatly increased by the presence of ATP. This effect of ATP is not detected at 0°C. ADP cannot replace ATP to potentiate calcium uptake. ATP-dependent calcium uptake is not observed in the absence of magnesium. ATP-dependent calcium uptake is enhanced by oxalate

G. L. ALONSO; P. M. BAZERQUE; M. ARRIG; R. TUMILASCI

268

Persistence of soil and foliar azadirachtin treatments to control sweetpotato whitefly Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) on tomatoes under controlled (laboratory) and field (netted greenhouse) conditions in the humid tropics  

Microsoft Academic Search

Persistence of neem-based products against sweetpotato whitefly Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) was tested in air conditioned rearing rooms and tropical netted greenhouses (GHs). Two commercial neem products, NeemAzal®-T\\/S (1% azadirachtin) and NeemAzal®-U (17% azadirachtin), were used. Foliar application, under room conditions at dose-rates of 7 and 10 ml NeemAzal®-T\\/S, induced an immature mortality of 32 and 44%, respectively, whereas 7 days

Prabhat Kumar; H.-M. Poehling

2006-01-01

269

Calcium Bioavailability and Kinetics of Calcium Ascorbate and Calcium Acetate in Rats  

Microsoft Academic Search

The objective was to investigate the bioavailability and mech- anism of calcium absorption of calcium ascorbate (ASC) and calcium acetate (AC). A series of studies was performed in adult Sprague-Dawley male rats. In the first study, each group of rats (n = 10\\/group) was assigned to one of the five test meals labeled with 45Ca: (i) 25 mg calcium as

JIANWEI CAI; QINMIN ZHANG; MERYL E. WASTNEY; CONNIE M. WEAVER

270

Coal Gasification and Tar-Conversion Reactions over Calcium Oxide. Quarterly Progress Report, August 1, 1981-October 31, 1981.  

National Technical Information Service (NTIS)

The present research was undertaken to investigate the role and potential application of calcium oxide chemistry in gasification and pyrolysis of coal. Specific objectives are to study: (1) the relative selectivity of thermal reactions over calcium oxide,...

J. P. Longwell C. S. Chang W. A. Peters

1982-01-01

271

Portable fluorescence photometer for monitoring free calcium  

NASA Astrophysics Data System (ADS)

We introduce a compact and portable photometric system for measurements of the calcium dynamics in cells. The photometer is designed for applications in centrifuges or in zero gravity environment and thus extremely compact and reliable. It operates with the calcium-sensitive dye Indo-1. The excitation wavelength of 345 nm is generated by frequency doubling of a laser diode. Two compact photomultiplier tubes detect the fluorescent emission. The electronics provide the sensitivity of photon counting combined with simultaneous measurement of the temperature, of air pressure, and of gravitational force. Internal data storage during the experiment is possible. A newly developed cell chamber stabilizes the cell temperature to 37.0+/-0.1 °C and includes a perfusion system to supply the cells with medium. The system has a modular setup providing the possibility of changing the light source and detectors for investigation of ions other than calcium. Measurements of the intracellular calcium concentration are based on a comprehensive calibration of our system. First experiments show that the calcium dynamics of osteosarcoma cells stimulated by parathyroid hormone is observable.

Struckmeier, Jens; Klopp, Erk; Born, Matthias; Hofmann, Martin; Tenbosch, Jochen; Jones, David B.

2000-12-01

272

Determination of Sr isotopes in calcium phosphates using laser ablation inductively coupled plasma mass spectrometry and their application to archaeological tooth enamel  

NASA Astrophysics Data System (ADS)

The determination of accurate Sr isotope ratios in calcium phosphate matrices by laser ablation multi-collector ICP-MS is demonstrated as possible even with low Sr concentration archaeological material. Multiple on-line interference correction routines for doubly-charged REE, Ca dimers and Rb with additional calibration against TIMS-characterised materials are required to achieve this. The calibration strategy proposed uses both inorganic and biogenic apatite matrices to monitor and correct for a 40Ca- 31P- 16O polyatomic present at levels of 0.3-1% of the non-oxide peak, which interferes on 87Sr causing inaccuracies of 0.03-0.4% in the 87Sr/ 86Sr isotope ratio. The possibility also exists for synthetic materials to be used in this calibration. After correction for interferences total combined uncertainties of 0.04-0.15% (2SD) are achieved for analyses of 13-24 ?g of archaeological tooth enamel with Sr concentrations of ca. 100-500 ppm using MC-ICP-MS. In particular, for samples containing >300 ppm Sr, total uncertainties of ˜0.05% are possible utilising 7-12 ng Sr. Data quality is monitored by determination of 84Sr/ 86Sr ratios. When applied to an archaeological cattle tooth this approach shows Sr-isotope variations along the length of the tooth in agreement with independent TIMS data. The 40Ca- 31P- 16O polyatomic interference is the root cause of the bias at mass 87 during laser ablation ICP-MS analysis of inorganic and biogenic calcium phosphate (apatite) matrices. This results in inaccurate 87Sr/ 86Sr ratios even after correction of Ca dimers and doubly charged rare earth elements. This interference is essentially constant at specific ablation conditions and therefore the effect on 87Sr/ 86Sr data varies in proportion to changes in the Sr concentration of the ablated material. Complete elimination of this interference is unlikely through normal analytical mechanisms and therefore represents a limitation on the achievable accuracy of LA-(MC-)ICP-MS 87Sr/ 86Sr data without rigorous calibration to known reference materials.

Horstwood, M. S. A.; Evans, J. A.; Montgomery, J.

2008-12-01

273

Relationships between C3 Plant Foliar Carbon Isotope Composition and Element Contents of Grassland Species at High Altitudes on the Qinghai-Tibet Plateau, China  

PubMed Central

Relationships of foliar carbon isotope composition (?13C) with foliar C, N, P, K, Ca, Mg contents and their ratios of 219 C3 species leaf samples, obtained in August in 2004 to 2007 from 82 high altitude grassland sites on the Qinghai-Tibet Plateau China, were examined. This was done with reference to the proposition that foliar ?13C increases with altitude and separately for the life-form groups of graminoids, forbs and shrubs and for the genera Stipa and Kobresia. For all samples, foliar ?13C was negatively related to foliar K, P and ?K+ Ca+ Mg, and positively correlated to foliar C, C/N and C/P. The significance of these correlations differed for the taxonomic and life-form groups. Lack of a relationship of foliar ?13C with foliar N was inconsistent with the majority of studies that have shown foliar ?13C to be positively related to foliar N due to a decrease of Ci/Ca (the ratio between intercellular and atmospheric concentration of CO2) and explained as a result of greater photosynthetic capacity at higher foliar N concentration. However this inconsistency relates to other high altitude studies that have found that photosynthetic capacity remains constant as foliar N increases. After accounting for the altitudinal relationship with foliar ?13C, of the elements only the K effect was significant and was most strongly expressed for Kobresia. It is concluded that factors critical to plant survival and growth at very high altitudes, such as low atmospheric pressure and low temperatures, may preclude expression of relationships between foliar ?13C and foliar elements that have been observed at lower altitudes.

Zhou, Yong-Chun; Fan, Jiang-Wen; Harris, Warwick; Zhong, Hua-Ping; Zhang, Wen-Yan; Cheng, Xi-Lei

2013-01-01

274

Calcium tartrate gel.  

PubMed

A method for preparation of a gel for chromatography has been developed. The adsorbent is calcium tartrate treated with potassium phosphate. By changing the temperature of synthesis (10-65 degrees C) and concentration of the salts (calcium chloride and sodium potassium tartrate) from 0.3 to 3.0 M, we have been able to prepare adsorbent crystals of definite sizes in the range 35-200 microns. In all cases, for synthesis of adsorbent, the Ca2+/K+Na+ ratio was greater than 1. After treatment of calcium tartrate crystals with 0.075-1.5 M potassium phosphate at 80-100 degrees C and pH 8.5-9.0, an appropriate chromatographic adsorbent was prepared. The chromatographic properties of calcium tartrate gel have been studied. The adsorbent permits flow rates of 25-150 ml/h, depending on the particle size. The capacity of calcium tartrate gel for binding BSA, RNA, and DNA was similar to that of Tiselius' hydroxyapatite (A. Tiselius, S. Hjerten, O. Levin (1956) Arch. Biochem. Biophys. 65, 132-155). The spheric shape of gel particles permits uniform and compact packing of adsorbent under the conditions of column chromatography. PMID:2757203

Akhrem, A A; Drozhdenyuk, A P

1989-05-15

275

Application of the Monte-Carlo refractive index matching (MCRIM) technique to the determination of the absolute light yield of a calcium molybdate scintillator  

NASA Astrophysics Data System (ADS)

The use of 40Ca100MoO in experimental searches for neutrinoless double beta decay (0?DBD) relies on knowledge of fundamental scintillation properties of the material. In this work we determine the absolute light yield of calcium molybdate using Monte-Carlo refractive index matching technique (MCRIM). The MCRIM technique is a combination of experiment and simulations that allows the absolute light yield of scintillators to be determined by taking into account effects of refraction, scattering and absorption in the material. The light collection efficiency of the scintillator-detector assembly was simulated using the ZEMAX ray-tracing software. By tuning the optical parameters of the scintillation crystal, a model was derived that gives good agreement with the experimental results. It is shown that the light collection efficiency of scintillators increases with transmittance and scattering due to an enhanced probability for photons to escape the crystal volume. Using MCRIM, the absolute light yield for the 40Ca100MoO4 scintillator was found to be 7.5±1.2 ph/keV at room temperature. Comparative measurements using a CaWO4 scintillator as a reference show good agreement with this result. In that way, the study demonstrated the potential of the MCRIM technique as a tool for quantitative characterization of scintillation materials.

Alenkov, V.; Buzanov, O. A.; Khanbekov, N.; Kornoukhov, V. N.; Kraus, H.; Mikhailik, V. B.; Shuvaeva, V. A.

2013-06-01

276

Enhancing Interfacial Bonding of a Biodegradable Calcium Polyphosphate/ Polyvinyl-urethane Carbonate Interpenetrating Phase Composite for Load Bearing Fracture Fixation Applications  

NASA Astrophysics Data System (ADS)

This thesis describe methods to improve the interfacial stability of an interpenetrating phase composite (IPC) (comprised of porous calcium polyphosphate and polyvinylurethanecarbonate), and to increase the hydrophobicity of the polymer phase. The current IPCs introduce covalent bonding between the two phases via silanizing agents to enhance the interfacial stability. Incorporation of the silanizing agents was also intended to reduce the IPC's sensitivity to interfacial hydration, thereby further enhancing the IPC's resistance to rapid degradation during aqueous solution aging. Lysine diisocyanate was used to increase the hydrophobic character in the polyvinylurethanecarbonate infiltrating resin. The polymer resins were infiltrated into porous CPP blocks with 25 volume % interconnected porosity and polymerized to produce the IPCs. After mechanical testing following a 28-day aging study it was found that the silanizing agents contributed to long-term stability of the mechanical properties under aqueous conditions. It was concluded that the mechanical properties and long-term stability were comparable to available nonmetallic and biodegradable composites, as well as being biocompatible to a preosteoblast model cell line.

Guo, Yi

277

Sintering of calcium phosphate bioceramics.  

PubMed

Calcium phosphate ceramics have become of prime importance for biological applications in the field of bone tissue engineering. This paper reviews the sintering behaviour of these bioceramics. Conventional pressureless sintering of hydroxyapatite, Ca10(PO4)6(OH)2, a reference compound, has been extensively studied. Its physico-chemistry is detailed. It can be seen as a competition between two thermally activated phenomena that proceed by solid-state diffusion of matter: densification and grain growth. Usually, the objective is to promote the first and prevent the second. Literature data are analysed from sintering maps (i.e. grain growth vs. densification). Sintering trajectories of hydroxyapatite produced by conventional pressureless sintering and non-conventional techniques, including two-step sintering, liquid phase sintering, hot pressing, hot isostatic pressing, ultrahigh pressure, microwave and spark plasma sintering, are presented. Whatever the sintering technique may be, grain growth occurs mainly during the last step of sintering, when the relative bulk density reaches 95% of the maximum value. Though often considered very advantageous, most assisted sintering techniques do not appear very superior to conventional pressureless sintering. Sintering of tricalcium phosphate or biphasic calcium phosphates is also discussed. The chemical composition of calcium phosphate influences the behaviour. Similarly, ionic substitutions in hydroxyapatite or in tricalcium phosphate create lattice defects that modify the sintering rate. Depending on their nature, they can either accelerate or slow down the sintering rate. The thermal stability of compounds at the sintering temperature must also be taken into account. Controlled atmospheres may be required to prevent thermal decomposition, and flash sintering techniques, which allow consolidation at low temperature, can be helpful. PMID:23212081

Champion, E

2013-04-01

278

Effects of Crown Position and Initial Spacing on Foliar Nutrient Composition of Seven Bottomland Hardwoods  

Microsoft Academic Search

SUMMARY Seven plantation-grown bottomland hardwoods, sweetgum (Liquidambar stryaciflua L.), green ash (Fraxinus pennsylvanica Marsh.), American sycamore (Platanus occidentalis L.), water oak (Quercus nigra L.), Nuttall oak (Q. nuttallii Palmer), cherrybark oak (Q. fal- cafa var. pagodifolia Ell.), and swamp chestnut oak (Q. michauxii Nutt.), were sampled after the seventh grow- ing season to determine foliar nutrient concentrations. Foliage samples were

Harvey E. Kennedy

279

SPECIATION OF GAS-PHASE AND FINE PARTICLE EMISSIONS FROM BURNING OF FOLIAR FUELS: JOURNAL ARTICLE  

EPA Science Inventory

NRMRL-RTP-P- 620 Hays**, M.D., Geron*, C.D., Linna**, K.J., Smith*, N.D., and Schauer, J.J. Speciation of Gas-Phase and Fine Particle Emissions from Burning of Foliar Fuels. Submitted to: Environmental Science & Technology EPA/600/J-02/234, http://pubs.acs.org/journals/esthag/...

280

Foliar and soil uptake of 134Cs and 85Sr by grape vines  

Microsoft Academic Search

The foliar and soil uptake of 134Cs and 85Sr by grape vines and their subsequent translocation to fruits and to the other plant compartments is described. Grape vine plants growing in pots and kept in an open field were contaminated with 134Cs and 85Sr in ionic form by sprinkling on the aerial part, or by addition to the soil. Sprinkling

F. Carini; E. Lombi

1997-01-01

281

Contribution of foliar leaching and dry deposition to sulfate in net throughfall below deciduous trees  

SciTech Connect

Experiments were conducted at Walker Branch Watershed, TN, in 1986 with radioactive {sup 35}S (87 day half-life) to quantify the contribution of foliar leaching and dry deposition to sulfate (SO{sub 4}{sup 2-}) in net throughfall (NTF). Two red maple (Acer rubrum) and two yellow poplar (Liriodendron tulipifera) trees (12-15 m tall) were radiolabeled by stem well injection. Total S and {sup 35}S were measured in leaves; {sup 35}S and SO{sub 4}{sup 2-} were measured in throughfall (THF). The contribution of foliar leaching to SO{sub 4}{sup 2-} in NTF, THF minus incident precipitation, was estimated by isotope dilution of {sup 35}S in NTF arising from nonradioactive S in dry deposition. The per cent contribution of foliar leaching to SO{sub 4}{sup 2-} in NTF was greatest during the week following isotope labeling and during the period of autumn leaf fall. During the growing season, foliar leaching accounted for < 20% and dry deposition accounted for > 80% of the SO{sub 4}{sup 2-} in NTF beneath the study trees. Dry deposition of S to these tree species can be reasonably approximated during summer from the measurement of SO{sub 4}{sup 2-} flux in NTF.

Garten Jr, Charles T [ORNL; Bondietti, E. A. [Oak Ridge National Laboratory (ORNL); Lomax, Ronny D [ORNL

1988-07-01

282

The effects of foliar pubescence and nutrient enrichment on arthropod communities of Metrosideros polymorpha (Myrtaceae)  

Microsoft Academic Search

Nutrient resource availability and host-plant foliar pubescence both influence arthropod food webs, but multifactor studies are needed to under- stand their interdependence and relative importance. Arthropods were sampled by clipping foliage from Metrosideros polymorpha (Myrtaceae) trees of pubescent, glabrous, and intermediate leaf forms on fertilised and unfertilised plots. 2. Fertilisation decreased leaf mass per area (LMA) but did not change

DANIEL S. G RUNER; A NDREW; D. T AYLOR; E. F ORKNER

2005-01-01

283

Foliar elemental composition of spruce-fir in the southern blue ridge province  

Microsoft Academic Search

Data are presented for what we believe to be the first assessment of the elemental foliar status of red spruce (Picea rubens Sarg.) and Fraser fir [Abies fraseri (Pursh.) Poir.] trees in the high elevation forests of the southern Appalachian mountans.

W. P. Robarge; J. M. Pye; R. I. Bruck

1989-01-01

284

Trends in Pinus ponderosa foliar pigment concentration due to chronic exposure of ozone and acid rain  

Microsoft Academic Search

To determine the effects of ozone and acid rain on mature Ponderosa pine trees, Lawrence Livermore National Lab. has collaborated with University of California Berkeley, University of California Davis, California State University Chico, and the US Forest Service at the latter's Chico Tree Improvement Center. Foliar tissue from mature grafted scions of Pinus ponderosa were exposed to two times ambient

L. Neuman; J. Houpis; P. Anderson

1991-01-01

285

Effect of simulated acid rain on physiology, growth and foliar nutrient concentrations of sugar maple  

Microsoft Academic Search

The effect of simulated acid rain (SAR) on sugar maple (Acer saccharum L.) growth and physiology following exposure to 12 weeks of controlled SAR treatment was investigated. SAR induced visible foliar injury in treatments more acidic than pH 3.5. Growth and gas exchange paramenters were not significantly altered by SAR treatment nor were goliar concentrations of K, Mg, Ca, Mn,

Gary D. Hogan

1998-01-01

286

RESPONSE OF SALT STRESSED STRAWBERRY PLANTS TO FOLIAR SALICYLIC ACID PRE-TREATMENTS  

Microsoft Academic Search

Salinity has deleterious effects on plant growth and development through membrane stability, photosynthetic activity, protein content, and ionic composition; however, salicylic acid (SA) could restore these properties in plants. The objective of this study was to determine the ameliorative effects of SA as foliar pre-treatments on membrane permeability, proline and protein contents, chlorophyll a, b and total chlorophyll and ionic

Omer Tohma; Ahmet Esitken

2011-01-01

287

Plant Foliar Response to Soil Nutrient Availability Across Contrasting Geologic Settings  

Microsoft Academic Search

Rock derived mineral nutrients such as P, Ca, Mg, Mn, and K play a significant, but poorly understood role in the structure and function of temperate forest ecosystems. Though these nutrients are not necessarily limiting to plant growth, they are essential to plant physiological functioning. In this study, we test the hypothesis that foliar nutrients are a proxy for soil

S. C. Castle; J. C. Neff

2007-01-01

288

CORRELATION BETWEEN OZONE EXPOSURE AND VISIBLE FOLIAR INJURY IN PONDEROSA AND JEFFREY PINES. (R825433)  

EPA Science Inventory

Ozone exposure was related to ozone-induced visible foliar injury in ponderosa and Jeffrey pines growing on the western slopes of the Sierra Nevada Mountains of California. Measurements of ozone exposure, chlorotic mottle and fascicle retention were collected during the years ...

289

The effect of propiconazole on foliar fungal diseases, herbage yield and quality of perennial ryegrass  

Microsoft Academic Search

The fungicide propiconazole, applied as a foliar spray to swards of perennial ryegrass (Lolium perenne) at four sites in England from 1990 to 1992, reduced the incidence of powdery mildew (Blumeria graminis), Drechslera leaf spot (Drechslera spp.) and Rhynchosporium leaf blotch (Rhynchosporium spp.), increased the number of leaves per tiller and reduced the proportion of dead leaves. Propiconazole increased yield,

G. C. Lewis; R. H. Lavender; T. M. Martyn

1996-01-01

290

Calcium pyrophosphate and pseudogout.  

PubMed

Calcium pyrophosphate deposition disease (CPDD) is a condition in which calcium pyrophosphate dihydrate crystals are deposited in joint articular cartilage, menisci, and synovium. The main clinical presentations of CPDD are chondrocalcinosis--calcification of cartilage, pseudogout--acute joint inflammation due to crystal-induced synovitis, and pyrophosphate arthropathy--degenerative joint disease similar to osteoarthritis associated with calcium pyrophosphate crystal deposition. The clinical importance of CPDD for the arthroscopist is the ability to recognize the condition so that appropriate treatment can be instituted. Arthroscopy is valuable for diagnosis as well as lavage and intraarticular debridement or meniscectomy. Tissue removed for microscopic examination should be sent to the laboratory in saline, since formalin dissolves the crystals. Postarthroscopy treatment of CPDD should include oral antiinflammatory medication. Asymptomatic chondrocalcinosis does not require treatment. PMID:3004529

Zarins, B; McInerney, V K

1985-01-01

291

Calcium absorption from a new calcium delivery system (CCM)  

Microsoft Academic Search

Absorption of calcium from a highly soluble form of calcium, a mixed calcium citrate-malate* salt (CCM), was tested against calcium carbonate and milk in both rats and humans. The rat method estimated absorption from\\u000a the 6-day retention of an oral tracer, and the human method employed the standard double-isotope procedure. CCM was given\\u000a both as a dry powder and in

Kenneth T. Smith; Robert P. Heaney; Lawrence Flora; Sharilyn M. Hinders

1987-01-01

292

Foliar response of black cherry (Prunus serotina) clones to ambient ozone exposure in central Pennsylvania.  

PubMed

During late summer of 1996 and 1997 we examined ozone-induced foliar injury in a plantation of 111 black cherry trees (ramets) comprising 15 clones originating from wild ortets growing in the Allegheny National Forest, Pennsylvania, and the Monongahela National Forest, West Virginia. The experimental plantation was a clonal seed orchard in Centre County, Pennsylvania, started in 1971 using ortet buds grafted onto seedling rootstocks of mixed origin. Clones differed significantly in severity of foliar injury symptoms (F=31.83, p<0.001). One clone (R-12) had significantly more foliar injury with >50% leaf area affected than other clones during both years. In contrast, clone R-14, which is from the same area in northcentral Pennsylvania as R-12, exhibited significantly less injury (LAA<6%). Although ambient O(3) concentrations were similar in both years, foliar injury was significantly greater (15.7%) in 1996 than in 1997 (9.9%). This is probably explained by lower stomatal conductance in 1997 caused by drier and hotter weather patterns in June and July of that year. Despite very different weather patterns and overall levels of injury in 1996 and 1997, mean clonal injury was significantly correlated between both years of assessment (r=0.92, p<0.001). Within tree crowns, foliage in lower and inner crown positions was significantly more injured than foliage in upper and exterior crown positions. There was no evidence of geographically based population differences in sensitivity to foliar O(3) injury. On the contrary, results demonstrate that wild genotypes of proximal geographic origin may differ greatly in sensitivity. PMID:15093074

Lee, J C; Skelly, J M; Steiner, K C; Zhang, J W; Savage, J E

1999-06-01

293

Habitat-specific differences in plasticity of foliar ?13C in temperate steppe grasses  

PubMed Central

A decrease in foliar ?13C with increasing precipitation is a common tendency in steppe plants. However, the rate of decrease has been reported to differ between different species or populations. We here hypothesized that plant populations in the same habitat of temperate steppes may not differ in foliar ?13C response patterns to precipitation, but could differ in the levels of plasticity of foliar ?13C across different habitats. In order to test this hypothesis, we conducted controlled watering experiments in northeast China at five sites along a west–east transect at latitude 44°N, which show substantial interannual fluctuations and intra-annual changes in precipitation among them. In 2001, watering treatment (six levels, three replicates) was assigned to 18 plots at each site. The responses of foliar ?13C to precipitation (i.e., the sum of watering and rainfall) were determined in populations of several grass species that were common across all sites. Although similar linear regression slopes were observed for populations of different species growing at the same site, significantly different slopes were obtained for populations of the same species growing at different sites. Further, the slope of the line progressively decreased from Site I to Site V for all species in this study. These results suggest habitat-specific differences in plasticity of foliar ?13C in temperate steppe grasses. This indicates that species' ?13C response to precipitation is conservative at the same site due to their long-term acclimation, but the mechanism responsible behind this needs further investigations.

Liu, Yanjie; Zhang, Lirong; Niu, Haishan; Sun, Yue; Xu, Xingliang

2014-01-01

294

Habitat-specific differences in plasticity of foliar ? (13)C in temperate steppe grasses.  

PubMed

A decrease in foliar ? (13)C with increasing precipitation is a common tendency in steppe plants. However, the rate of decrease has been reported to differ between different species or populations. We here hypothesized that plant populations in the same habitat of temperate steppes may not differ in foliar ? (13)C response patterns to precipitation, but could differ in the levels of plasticity of foliar ? (13)C across different habitats. In order to test this hypothesis, we conducted controlled watering experiments in northeast China at five sites along a west-east transect at latitude 44°N, which show substantial interannual fluctuations and intra-annual changes in precipitation among them. In 2001, watering treatment (six levels, three replicates) was assigned to 18 plots at each site. The responses of foliar ? (13)C to precipitation (i.e., the sum of watering and rainfall) were determined in populations of several grass species that were common across all sites. Although similar linear regression slopes were observed for populations of different species growing at the same site, significantly different slopes were obtained for populations of the same species growing at different sites. Further, the slope of the line progressively decreased from Site I to Site V for all species in this study. These results suggest habitat-specific differences in plasticity of foliar ? (13)C in temperate steppe grasses. This indicates that species' ? (13)C response to precipitation is conservative at the same site due to their long-term acclimation, but the mechanism responsible behind this needs further investigations. PMID:25035804

Liu, Yanjie; Zhang, Lirong; Niu, Haishan; Sun, Yue; Xu, Xingliang

2014-03-01

295

Calcium and mitosis.  

PubMed

Calcium is thought to be involved in regulating mitotic transitions. The basis for this view is set out. Recent data from experiments on sea urchin embryos is discussed. The relative simplicity of the embryonic cell cycle and the relative ease with which cell physiology can be done in sea urchin embryos has allowed the clear demonstration that the phosphoinositide-calcium-calmodulin signalling pathway is required for and regulates mitosis entry and anaphase onset. The relevance of the sea urchin work to mitosis in other cell types is briefly discussed. PMID:11162747

Whitaker, M; Larman, M G

2001-02-01

296

21 CFR 172.410 - Calcium silicate.  

Code of Federal Regulations, 2013 CFR

...Drugs 3 2013-04-01 2013-04-01 false Calcium silicate. 172.410 Section 172.410 Food...HUMAN CONSUMPTION Anticaking Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium...

2013-04-01

297

21 CFR 573.260 - Calcium silicate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Calcium silicate. 573.260 Section 573.260 Food and Drugs... Food Additive Listing § 573.260 Calcium silicate. Calcium silicate, including synthetic calcium silicate,...

2013-04-01

298

21 CFR 573.260 - Calcium silicate.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Calcium silicate. 573.260 Section 573.260 Food and Drugs... Food Additive Listing § 573.260 Calcium silicate. Calcium silicate, including synthetic calcium silicate,...

2009-04-01

299

21 CFR 172.410 - Calcium silicate.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Calcium silicate. 172.410 Section 172.410 Food and Drugs...CONSUMPTION Anticaking Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium silicate,...

2009-04-01

300

21 CFR 573.260 - Calcium silicate.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Calcium silicate. 573.260 Section 573.260 Food and Drugs... Food Additive Listing § 573.260 Calcium silicate. Calcium silicate, including synthetic calcium silicate,...

2010-04-01

301

21 CFR 573.240 - Calcium periodate.  

Code of Federal Regulations, 2013 CFR

...following prescribed conditions: (a) The additive is produced by reacting calcium iodate with calcium hydroxide or calcium oxide to form a substance consisting of not less than 60 percent by weight of penta calcium orthoperiodate containing...

2013-04-01

302

Electrolytic Production of Calcium Metal.  

National Technical Information Service (NTIS)

The Bureau of Mines developed an alternative electrochemical process for the production of calcium metal. The current industrial practice is costly, complex, and inefficient. The Bureau method involves electrowinning of a calcium-tin alloy followed by ele...

J. J. Lukasko J. E. Murphy

1990-01-01

303

Calcium carbonate with magnesium overdose  

MedlinePLUS

The combination of calcium carbonate and magnesium is commonly found in antacids, which are medicines that provide heartburn relief. Calcium carbonate with magnesium overdose occurs when someone accidentally or ...

304

Dietary calcium intake and obesity.  

PubMed

Obesity is increasing in the United States in epidemic proportions. Epidemiologic data suggest that people with high calcium intake have a lower prevalence of overweight, obesity, and insulin resistance syndrome. Studies in transgenic mice have demonstrated that calcium influences adipocyte metabolism. High calcium intake depresses levels of parathyroid hormone and 1,25-hydroxy vitamin D. These decreased hormone levels cause decreases in intracellular calcium, thereby inhibiting lipogenesis and stimulating lipolysis. High dietary calcium intakes also increases excretion of fecal fat and may increase core body temperature. Calcium from dairy products seems to have more of an impact than calcium from dietary supplements. Primary care providers should include recommendations about adequate calcium intake in standard dietary counseling about weight management. PMID:15879568

Schrager, Sarina

2005-01-01

305

The ER and Cell Calcium  

Microsoft Academic Search

Calcium is one of the most versatile messengers in biological systems, translating developmental and\\u000a environmental cues into cellular responses. The endoplasmic reticulum (ER) constitutes one of the\\u000a most important calcium holding organelles in higher eukaryotes. Upon stimulation, calcium is released from\\u000a the ER into the cytosol where it may trigger downstream effectors. However, the release of calcium\\u000a may also affect internal ER functions,

Staffan Persson; Jeff Harper

306

Ways of looking at calcium.  

PubMed

What we understand about signalling pathways depends very much on the ways we can measure them. I review ways of measuring calcium and explore how changes in methods have led to new ways of thinking about calcium signals. I also suggest how the ways we have of looking at calcium will influence the analysis of other signalling pathways that, until now, have not been studied with the spatiotemporal precision available to those studying calcium signalling. PMID:10504211

Whitaker, M

1999-09-15

307

The plasma membrane calcium pump  

NASA Technical Reports Server (NTRS)

Three aspect of cellular calcium metabolism in animal cells was discussed including the importance of the plasma membrane in calcium homeostasis, experiments dealing with the actual mechanism of the calcium pump, and the function of the pump in relationship to the mitochondria and to the function of calmodulin in the intact cell.

Rasmussen, H.

1983-01-01

308

Mass of Calcium-39.  

National Technical Information Service (NTIS)

The ground-state threshold for the reaction Potassium-39(p,n)Calcium-39 has been measured to be 7.492 plus or minus 0.006 MeV. The absolute value of the total reaction cross section has been determined from threshold to 10.5-MeV bombarding energy. From th...

C. M. McKenna J. W. Nelson K. W. Kemper

1970-01-01

309

Antagonist effects of calcium on borosilicate glass alteration  

NASA Astrophysics Data System (ADS)

Numerous studies have been conducted on glass and cement durability in contact with water, but very little work to date has focused directly on interactions between the two materials. These interactions are mostly controlled by silicon-calcium reactivity. However, the physical and chemical processes involved remain insufficiently understood to predict the evolution of coupled glass-cement systems used in several industrial applications. Results are reported from borosilicate glass alteration in calcium-rich solutions. Our data show that four distinct behaviors can be expected according to the relative importance of three key parameters: the pH, the reaction progress (short- or long-term alteration) and the calcium concentration. Glass alteration is thus controlled by specific mechanisms depending on the solution chemistry: calcium complexation at the glass surface, precipitation of calcium silicate hydrates (C-S-H) or calcium incorporation in the altered layer. These findings highlight the impact of silicon-calcium interactions on glass durability and open the way for a better understanding of glass-cement mixing in civil engineering applications as well as in nuclear waste storage.

Mercado-Depierre, S.; Angeli, F.; Frizon, F.; Gin, S.

2013-10-01

310

Toxicity, absorption, and translocation of soil and foliar applied imazaquin in yellow (Cyperus esculentus) and purple (C. rotundus) nutsedge  

SciTech Connect

Studies were conducted to investigate the toxicity of soil and foliar applied imazaquin in yellow and purple nutsedge. Soil incorporated imazaquin rates from 0.1 to 0.5 ppmw reduced plant dry weight of yellow nutsedge by 92 to 99%, and that of purple nutsedge by 82 to 99%. Imazaquin placement above the tuber was significantly more toxic than placement either around or below the tuber. This suggests that a shallow incorporation of imazaquin at 1 to 2 inch depth should provide effective nutsedge control. Incrementing imazaquin rate significantly increased the number of sprouts when the herbicide was placed above the tuber. This apparent release of apical dominance may be a result of herbicide absorption and translocation from the sprouts to the lateral buds of the tuber at growth regulatory level or a result of the death of the current sprout at lethal concentrations. Three-day old nutsedge propagules absorbed significantly greater amounts of /sup 14/C-imazaquin from shoot application than from root application. The emerging shoot appeared to be the major site of imazaquin uptake at early stages of nutsedge plant development.

Nandihalli, U.B.

1986-01-01

311

Calcium isotope analytical technique for mafic rocks and its applications on constraining the source of Cenozoic ultra-potassic rocks in the Tibetan Plateau  

NASA Astrophysics Data System (ADS)

Ca isotope analytical technique for mafic rocks has been recently developed and set up at our lab. About mg level of a mafic rock sample was digested, and then a sub portion of the solution contains about 100ug Ca was spiked with a 42Ca-43Ca double spike and went through the column chemistry. Generally the Ca recovery is almost 100% and the procedure blank is about 50-150ng. Finally, about 5-10ug of the collected Ca cut was measured on our Triton TIMS. The precision of the data was around 0.1 per mil and the data we collected for standards are consistent with those reported by previous studies. There are two groups of Cenozoic ultra-potassic rocks that are widespread in Tibetan Plateau: a northern group in Songpan-Ganzi and Qiangtang Terranes and a southern group in Lhasa Terrane. Previous petrology evidence, such as a relative enrichment in large ion lithophile element (LILE); negative Ta,Nb and Ti anomalies and high LREE/HREE ratio, support that those rocks are both derived from sub-continental lithospheric mantle (SCLM). However, differences between these two groups of rocks do exist: the southern group has higher K2O, Rb, Zr, Th, contents and a higher Rb/Ba, coupled with lower Al2O3, CaO, Na2O, Sr; the southern 87Sr/86Sr ratios are higher while the 143Nd/144Nd ratios are lower, etc. These suggest that the rocks could be derived from different mantle sources or produced by different geological processes. Ca isotope is chosen in this study to better understand the source of the ultra-potassic rocks because Ca isotope has been a great tracer of different geological reservoirs and the isotopic compositions of Ca may represent different genesic processes. We propose that the ultra-potassic rocks in the Tibet should have significant 40Ca enrichments due to the decay from 40K to 40Ca, therefore the variation of Ca isotopic compositions among these ultra-potassic rocks could be obvious. We believe that based on our calcium data together with earlier Sr, Nd, Pb data, and evidence from petrology, geochronology and geochemistry, there is a good possibility to identify the petrogenesis of those rocks and/or provide important constrains of their sources.

Liu, Y.; Zhang, Z.; Xu, J.

2013-12-01

312

About Calcium Phosphate Cements (CPC)  

NASA Astrophysics Data System (ADS)

Calcium phosphate cements (CPC) are used in orthopaedic surgery as bone substitution and fixation of metallic implants, showing advantages with respect to other materials like polymeric cements or ceramic blocks also used for bone repair. For example, they are easy to shape and fill bone defects, react at low temperature and their setting product is hydroxyapatite, mineral from it's composed the inorganic part of the bone, resulting a bioabsorbable material that can be replaced by new bone. Nevertheless there are still some complications like their low absorption rate, inyectability, setting times and their low strength that limits their use to only non load bearing applications. In this work we present a brief resume of some investigations that has been proposed to solve some of these problems, like the addition of phosphates solutions or seeds to increase the reaction rate, or fibers and hard particles to produce a composite material.

Piñera, Silvia; Piña, Cristina

2006-09-01

313

Reporting neural activity with genetically encoded calcium indicators  

PubMed Central

Genetically encoded calcium indicators (GECIs), based on recombinant fluorescent proteins, have been engineered to observe calcium transients in living cells and organisms. Through observation of calcium, these indicators also report neural activity. We review progress in GECI construction and application, particularly toward in vivo monitoring of sparse action potentials (APs). We summarize the extrinsic and intrinsic factors that influence GECI performance. A simple model of GECI response to AP firing demonstrates the relative significance of these factors. We recommend a standardized protocol for evaluating GECIs in a physiologically relevant context. A potential method of simultaneous optical control and recording of neuronal circuits is presented.

Hires, S. Andrew; Tian, Lin; Looger, Loren L.

2009-01-01

314

Nutrient Requirements and Interactions Bone Repair in Calcium-Deficient Rats: Comparison of Xylitol + Calcium Carbonate with Calcium Carbonate, Calcium Lactate and Calcium Citrate on the Repletion of Calcium1'2'3 i  

Microsoft Academic Search

The potential value of xylitol in calcium therapy was evaluated by comparing the effect of dietary xylitol (50 g\\/kg diet) + calcium carbonate with the ef fects of calcium carbonate, calcium lactate and calcium citrate on bone repair of young male rats after the rats consumed for 3 wk a calcium-deficient diet (0.2 g Ça\\/kg diet). After this calcium-depletion period,

MAURI M. HÃ

315

Coupled nitrogen and calcium cycles in forests of the Oregon Coast Range  

USGS Publications Warehouse

Nitrogen (N) is a critical limiting nutrient that regulates plant productivity and the cycling of other essential elements in forests. We measured foliar and soil nutrients in 22 young Douglas-fir stands in the Oregon Coast Range to examine patterns of nutrient availability across a gradient of N-poor to N-rich soils. N in surface mineral soil ranged from 0.15 to 1.05% N, and was positively related to a doubling of foliar N across sites. Foliar N in half of the sites exceeded 1.4% N, which is considered above the threshold of N-limitation in coastal Oregon Douglas-fir. Available nitrate increased five-fold across this gradient, whereas exchangeable magnesium (Mg) and calcium (Ca) in soils declined, suggesting that nitrate leaching influences base cation availability more than soil parent material across our sites. Natural abundance strontium isotopes (87Sr/86Sr) of a single site indicated that 97% of available base cations can originate from atmospheric inputs of marine aerosols, with negligible contributions from weathering. Low annual inputs of Ca relative to Douglas-fir growth requirements may explain why foliar Ca concentrations are highly sensitive to variations in soil Ca across our sites. Natural abundance calcium isotopes (??44Ca) in exchangeable and acid leachable pools of surface soil measured at a single site showed 1 per mil depletion relative to deep soil, suggesting strong Ca recycling to meet tree demands. Overall, the biogeochemical response of these Douglas-fir forests to gradients in soil N is similar to changes associated with chronic N deposition in more polluted temperate regions, and raises the possibility that Ca may be deficient on excessively N-rich sites. We conclude that wide gradients in soil N can drive non-linear changes in base-cation biogeochemistry, particularly as forests cross a threshold from N-limitation to N-saturation. The most acute changes may occur in forests where base cations are derived principally from atmospheric inputs. ?? 2006 Springer Science+Business Media, Inc.

Perakis, S. S.; Maguire, D. A.; Bullen, T. D.; Cromack, K.; Waring, R. H.; Boyle, J. R.

2006-01-01

316

Coupled nitrogen and calcium cycling in forests of the Oregon Coast Range  

USGS Publications Warehouse

Nitrogen (N) is a critical limiting nutrient that regulates plant productivity and the cycling of other essential elements in forests. We measured foliar and soil nutrients in 22 young Douglas-fir stands in the Oregon Coast Range to examine patterns of nutrient availability across a gradient of N-poor to N-rich soils. N in surface mineral soil ranged from 0.15 to 1.05% N, and was positively related to a doubling of foliar N across sites. Foliar N in half of the sites exceeded 1.4% N, which is considered above the threshold of N-limitation in coastal Oregon Douglas-fir. Available nitrate increased five-fold across this gradient, whereas exchangeable magnesium (Mg) and calcium (Ca) in soils declined, suggesting that nitrate leaching influences base cation availability more than soil parent material across our sites. Natural abundance strontium isotopes (87Sr/86Sr) of a single site indicated that 97% of available base cations can originate from atmospheric inputs of marine aerosols, with negligible contributions from weathering. Low annual inputs of Ca relative to Douglas-fir growth requirements may explain why foliar Ca concentrations are highly sensitive to variations in soil Ca across our sites. Natural abundance calcium isotopes (I'44Ca) in exchangeable and acid leachable pools of surface soil measured at a single site showed 1 per mil depletion relative to deep soil, suggesting strong Ca recycling to meet tree demands. Overall, the biogeochemical response of these Douglas-fir forests to gradients in soil N is similar to changes associated with chronic N deposition in more polluted temperate regions, and raises the possibility that Ca may be deficient on excessively N-rich sites. We conclude that wide gradients in soil N can drive non-linear changes in base-cation biogeochemistry, particularly as forests cross a threshold from N-limitation to N-saturation. The most acute changes may occur in forests where base cations are derived principally from atmospheric inputs.

Perakis, Steven S.; Maguire, Douglas A.; Bullen, Thomas D.; Cromack, Kermit; Waring, Richard H.; Boyle, James R.

2006-01-01

317

Calcium regulation of keratinocyte differentiation  

PubMed Central

Calcium is the major regulator of keratinocyte differentiation in vivo and in vitro. A calcium gradient within the epidermis promotes the sequential differentiation of keratinocytes as they traverse the different layers of the epidermis to form the permeability barrier of the stratum corneum. Calcium promotes differentiation by both outside–in and inside–out signaling. A number of signaling pathways involved with differentiation are regulated by calcium, including the formation of desmosomes, adherens junctions and tight junctions, which maintain cell–cell adhesion and play an important intracellular signaling role through their activation of various kinases and phospholipases that produce second messengers that regulate intracellular free calcium and PKC activity, critical for the differentiation process. The calcium receptor plays a central role by initiating the intracellular signaling events that drive differentiation in response to extracellular calcium. This review will discuss these mechanisms.

Bikle, Daniel D; Xie, Zhongjian; Tu, Chia-Ling

2012-01-01

318

Calcium dynamics in vascular smooth muscle  

PubMed Central

Smooth muscle cells are ultimately responsible for determining vascular luminal diameter and blood flow. Dynamic changes in intracellular calcium are a critical mechanism regulating vascular smooth muscle contractility. Processes influencing intracellular calcium are therefore important regulators of vascular function with physiological and pathophysiological consequences. In this review we discuss the major dynamic calcium signals identified and characterized in vascular smooth muscle cells. These signals vary with respect to their mechanisms of generation, temporal properties, and spatial distributions. The calcium signals discussed include calcium waves, junctional calcium transients, calcium sparks, calcium puffs, and L-type calcium channel sparklets. For each calcium signal we address underlying mechanisms, general properties, physiological importance, and regulation.

Amberg, Gregory C.; Navedo, Manuel F.

2013-01-01

319

Spatial patterns of foliar stable carbon isotope compositions of C 3 plant species in the Loess Plateau of China  

Microsoft Academic Search

The spatial pattern of foliar stable carbon isotope compositions (?13C) of dominant species and their relationships with environmental factors in seven sites, Yangling, Yongshou, Tongchuan, Fuxian,\\u000a Ansai, Mizhi and Shenmu, standing from south to north in the Loess Plateau of China, was studied. The results showed that\\u000a in the 121 C3 plant samples collected from the Loess Plateau, the foliar

Shuxia Zheng; Zhouping Shangguan

2007-01-01

320

Custom-made modification of a commercial confocal microscope to photolyze caged compounds using the conventional illumination module and its application to the observation of Inositol 1,4,5-trisphosphate-mediated calcium signals  

NASA Astrophysics Data System (ADS)

The flash photolysis of ``caged'' compounds is a powerful experimental technique for producing rapid changes in concentrations of bioactive signaling molecules. These caged compounds are inactive and become active when illuminated with ultraviolet light. This paper describes an inexpensive adaptation of an Olympus confocal microscope that uses as source of ultraviolet light the mercury lamp that comes with the microscope for conventional fluorescence microscopy. The ultraviolet illumination from the lamp (350 - 400 nm) enters through an optical fiber that is coupled to a nonconventional port of the microscope. The modification allows to perform the photolysis of caged compounds over wide areas (~200 ?m) and obtain confocal fluorescence images simultaneously. By controlling the ultraviolet illumination exposure time and intensity it is possible to regulate the amount of photolyzed compounds. In the paper we characterize the properties of the system and show its capabilities with experiments done in aqueous solution and in Xenopus Laevis oocytes. The latter demonstrate its applicability for the study of Inositol 1,4,5-trisphosphate-mediated intracellular calcium signals.

Sigaut, Lorena; Barella, Mariano; Espada, Rocío; Ponce, María Laura; Dawson, Silvina Ponce

2011-06-01

321

Stochastic calcium mechanisms cause dendritic calcium spike variability.  

PubMed

Bursts of dendritic calcium spikes play an important role in excitability and synaptic plasticity in many types of neurons. In single Purkinje cells, spontaneous and synaptically evoked dendritic calcium bursts come in a variety of shapes with a variable number of spikes. The mechanisms causing this variability have never been investigated thoroughly. In this study, a detailed computational model using novel simulation routines is applied to identify the roles that stochastic ion channels, spatial arrangements of ion channels, and stochastic intracellular calcium have toward producing calcium burst variability. Consistent with experimental recordings from rats, strong variability in the burst shape is observed in simulations. This variability persists in large model sizes in contrast to models containing only voltage-gated channels, where variability reduces quickly with increase of system size. Phase plane analysis of Hodgkin-Huxley spikes and of calcium bursts identifies fluctuation in phase space around probabilistic phase boundaries as the mechanism determining the dependence of variability on model size. Stochastic calcium dynamics are the main cause of calcium burst fluctuations, specifically the calcium activation of mslo/BK-type and SK2 channels. Local variability of calcium concentration has a significant effect at larger model sizes. Simulations of both spontaneous and synaptically evoked calcium bursts in a reconstructed dendrite show, in addition, strong spatial and temporal variability of voltage and calcium, depending on morphological properties of the dendrite. Our findings suggest that stochastic intracellular calcium mechanisms play a crucial role in dendritic calcium spike generation and are therefore an essential consideration in studies of neuronal excitability and plasticity. PMID:24089492

Anwar, Haroon; Hepburn, Iain; Nedelescu, Hermina; Chen, Weiliang; De Schutter, Erik

2013-10-01

322

Role of Stomata in Plant Innate Immunity and Foliar Bacterial Diseases  

PubMed Central

Pathogen entry into host tissue is a critical first step in causing infection. For foliar bacterial plant pathogens, natural surface openings, such as stomata, are important entry sites. Historically, these surface openings have been considered as passive portals of entry for plant pathogenic bacteria. However, recent studies have shown that stomata can play an active role in limiting bacterial invasion as part of the plant innate immune system. As counter-defense, the plant pathogen Pseudomonas syringae pv. tomato DC3000 uses the virulence factor coronatine to actively open stomata. In nature, many foliar bacterial disease outbreaks require high humidity, rain, or storms, which could promote stomatal opening and/or bypass stomatal defense by creating wounds as alternative entry sites. Further studies on microbial and environmental regulation of stomatal closure and opening could fill gaps in our understanding of bacterial pathogenesis, disease epidemiology, and microbiology of the phyllosphere.

Melotto, Maeli; Underwood, William; He, Sheng Yang

2008-01-01

323

Polystichum munitum (Dryopteridaceae) varies geographically in its capacity to absorb fog water by foliar uptake within the redwood forest ecosystem.  

PubMed

• Premise of the study: Fog provides a critical water resource to plants around the world. In the redwood forest ecosystem of northern California, plants depend on fog absorbed through foliar uptake to stay hydrated during the rainless summer. In this study, we identified regions within the redwood ecosystem where the fern Polystichum munitum canopy most effectively absorbs fog drip that reaches the forest floor. • Methods: We measured the foliar uptake capacity of P. munitum fronds at seven sites along 700 km of the redwood forest ecosystem. We quantified the canopy cover of P. munitum at each site and estimated how much water the fern canopy can acquire aboveground through fog interception and absorption. • Key results: Throughout the ecosystem, nocturnal foliar uptake increased the leaf water content of P. munitum by 7.2%, and we estimated that the P. munitum canopy can absorb 5 ± 3% (mean ± SE) of intercepted fog precipitation. Strikingly, P. munitum had the highest foliar uptake capacity in the center of the ecosystem and may absorb 10% more of the fog its canopy intercepts in this region relative to other regions studied. Conversely, P. munitum had no foliar uptake capacity in the southern end of the ecosystem. • Conclusions: This study shows the first evidence that foliar uptake varies within species at the landscape scale. Our findings suggest that the P. munitum at the southern tip of the redwood ecosystem may suffer most from low summertime water availability because it had no potential to acquire fog as an aboveground water subsidy. PMID:21616864

Limm, Emily B; Dawson, Todd E

2010-07-01

324

Nutrition in calcium nephrolithiasis  

PubMed Central

Idiopathic calcium nephrolithiasis is a multifactorial disease with a complex pathogenesis due to genetic and environmental factors. The importance of social and health effects of nephrolithiasis is further highlighted by the strong tendency to relapse of the disease. Long-term prospective studies show a peak of disease recurrence within 2–3 years since onset, 40-50% of patients have a recurrence after 5 years and more than 50-60% after 10 years. International nutritional studies demonstrated that nutritional habits are relevant in therapy and prevention approaches of nephrolithiasis. Water, right intake of calcium, low intake of sodium, high levels of urinary citrate are certainly important for the primary and secondary prevention of nephrolithiasis. In this review is discussed how the correction of nutritional mistakes can reduce the incidence of recurrent nephrolithiasis.

2013-01-01

325

[Calcium oxalate urolithiasis].  

PubMed

Calcium oxalate is now the main form of nephrolithiasis in most countries. It may result from unfrequent genetic or acquired diseases, the diagnosis of which being of a major importance for an effective treatment to protect against stone recurrence and renal failure. A more common cause of calcium oxalate nephrolithiasis is the conjonction of inappropriate dietary habits and/or low diuresis in subjects who are particularly susceptible to these factors because of an inherited trait. In such cases, an identification of biological factors involved in the crystallization risk related to the dietary factors is required in order to advise efficient preventive measures against stone recurrence. The use of drugs should be limited to nephrolithiasis that cannot be controlled by diuresis and dietary advices. PMID:21563420

Daudon, Michel; Knebelmann, Bertrand

2011-03-01

326

Synthesis of calcium superoxide  

NASA Technical Reports Server (NTRS)

Efforts to prepare Ca(O2) sub 2 from reactions of calcium compounds with 100% O3 and with O(D-1) atoms generated by photolysis of O3 at 2537 A are described. Samples of Ca(OH) sub 2, CaO, CaO2, Ca metal, and mixtures containing suspected impurities to promote reaction have been treated with excess O3 under static and flow conditions in the presence and absence of UV irradiation. Studies with KO2 suggest that the superoxide anion is stable to radiation at 2537 A but reacts with oxygen atoms generated by the photolysis of O3 to form KO3. Calcium superoxide is expected to behave in an analogous.

Rewick, R. T.; Blucher, W. G.; Estacio, P. L.

1972-01-01

327

Effects of ozone on morphogenesis of the foliar embryos of bryophyllum calycinum Salisb  

SciTech Connect

Explants from three different ages, including the foliar embryo of ozonated and non-ozonated marginal leaf tissue from Bryophyllum calycinum were cultured on modified formulations of Murashige and Skoog's medium. Kinetin 2,4-D and IAA were added to the media individually or in combination. The development of the embryos was affected by tissue age, media composition and prior exposure to ozone. The production of callus, shoots, roots and anthocyanin were all in response to different sets of culture conditions.

Rier, J.P.; Phillips, G. (Howard Univ., Washington, DC (USA))

1990-01-01

328

Histochemistry of simple hairs from the foliar cavities of Azolla filiculoides  

Microsoft Academic Search

The foliar cavities of the water fern Azolla filiculoides have as many as 20 – 25 simple hairs (SH) protruding from the epidermal cells that delimit the cavity. These SH have a transfer-like ultrastructure normally associated with secretion of metabolites. The aim of this study was the chemical characterization of the compounds that accumulated in the SH of the zones F1-12 (from

A. L. Pereira; F. Carrapiço

2007-01-01

329

Costs of defense: correlated responses to divergent selection for foliar glucosinolate content in Brassica rapa  

Microsoft Academic Search

The evolutionary response of plant populations to herbivore imposed selection for defense may theoretically be constrained\\u000a by the costs of defense, yet few studies convincingly demonstrate such costs. We investigated possible constraints on the\\u000a evolution of defense in rapid cycling Brassica rapa by divergently selecting lines for investment in foliar glucosinolate content, a chemical defense in this species. Costs\\u000a would

Kirk A. StoweRobert; Robert J. Marquis

2011-01-01

330

Regulation of Nitrogen Assimilation in Foliar Fed Legume Plants at Insufficient Molybdenum Supply  

Microsoft Academic Search

\\u000a Formation and function of N2-fixing systems between bacteria from Rhizobiaceae family and legume plants from Fabaceae family are especially sensitive to molybdenum (Mo) deficiency. The hypothesis of the present work was that nitrogen fixation\\u000a and assimilation in Mo deficient pea and alfalfa plants are enhanced when the nutrients were supplied through the foliage.\\u000a It was established that foliar fertilization resulted

Marieta Hristozkova; Maria Geneva; Ira Stancheva

331

Patterns of Carbon, Nitrogen and Phosphorus Dynamics in Decomposing Foliar Litter in Canadian Forests  

Microsoft Academic Search

We examined the patterns of nitrogen (N) and phosphorus (P) gain, retention or loss in ten foliar tissues in a litterbag experiment\\u000a over 6 years at 18 upland forest sites in Canada, ranging from subarctic to cool temperate. N was usually retained in the\\u000a decomposing litter until about 50% of the original C remained. The peak N content in the

T. R. Moore; J. A. Trofymow; C. E. Prescott; J. Fyles; B. D. Titus

2006-01-01

332

Effects of glyphosate and foliar amendments on activity of microorganisms in the soybean rhizosphere  

Microsoft Academic Search

A field study was conducted to determine the effects of glyphosate on microbial activity in the rhizosphere of glyphosate-resistant (GR) soybean and to evaluate interactions with foliar amendments. Glyphosate at 0.84 kg ae ha was applied GR soybean at the V4–V5 development stages. Check treatments included a conventional herbicide tank mix (2003 study only) and no herbicides (hand-weeded). Ten days

Nathan E. Means; Robert J. Kremer; Clifford Ramsier

2007-01-01

333

Stoichiometry of Calcium Medicines  

NASA Astrophysics Data System (ADS)

Students have a greater appreciation of the principles of chemistry if they can see the relevance to their lives. Calcium supplements provide an excellent context in which to review most of the core content of general chemistry, namely, stoichiometry, concentration units, hydration of salts, inorganic and organic salts, physiological importance of elements, resonance in ions, geometry of polyatomic ions, and isomerism. A set of questions covering the cited topics and the corresponding answers are presented to encourage the critical thinking by students.

Pinto, Gabriel

2005-10-01

334

Tobermorite\\/jennite and tobermorite\\/calcium hydroxide-based models for the structure of CSH: applicability to hardened pastes of tricalcium silicate, ?-dicalcium silicate, Portland cement, and blends of Portland cement with blast-furnace slag, metakaolin, or silica fume  

Microsoft Academic Search

The purpose of this article is to discuss the applicability of the tobermorite–jennite (T\\/J) and tobermorite–‘solid-solution’ calcium hydroxide (T\\/CH) viewpoints for the nanostructure of C-S-H present in real cement pastes. The discussion is facilitated by a consideration of the author's 1992 model, which includes formulations for both structural viewpoints; its relationship to other recent models is outlined. The structural details

I. G. Richardson

2004-01-01

335

Calcium bioavailability and kinetics of calcium ascorbate and calcium acetate in rats.  

PubMed

The objective was to investigate the bioavailability and mechanism of calcium absorption of calcium ascorbate (ASC) and calcium acetate (AC). A series of studies was performed in adult Sprague-Dawley male rats. In the first study, each group of rats (n = 10/group) was assigned to one of the five test meals labeled with (45)Ca: (i) 25 mg calcium as heated ASC or (ii) unheated ASC, (iii) 25 mg calcium as unheated AC, (iv) 3.6 mg Ca as unheated ASC, or (v) unheated AC. Femur uptake indicated better calcium bioavailability from ASC than AC at both calcium loads. A 5-min heat treatment partly reduced bioavailability of ASC. Kinetic studies were performed to further investigate the mechanism of superior calcium bioavailability from ASC. Two groups of rats (n = 10/group) received oral doses of 25 mg Ca as ASC or AC. Each dose contained 20 micro Ci (45)Ca. Two additional groups of rats (n = 10/group) received an intravenous injection (iv) of 10 micro Ci (45)Ca after receiving an unlabeled oral dose of 25 mg calcium as ASC or AC. Sequential blood samples were collected over 48 hrs. Urine and fecal samples were collected every 12 hrs for 48 hrs and were analyzed for total calcium and (45)Ca content. Total calcium and (45)Ca from serum, urine, and feces were fitted by a compartment kinetics model with saturable and nonsaturable absorption pathways by WinSAAM (Windows-based Simulation Analysis and Modeling). The difference in calcium bioavailability between the two salts was due to differences in saturable rather than passive intestinal absorption and not to endogenous secretion or calcium deposition rate. The higher bioavailability of calcium ascorbate was due to a longer transit time in the small intestine compared with ASC. PMID:14709775

Cai, Jianwei; Zhang, Qinmin; Wastney, Meryl E; Weaver, Connie M

2004-01-01

336

Characteristics of foliar fungal endophyte assemblages and host effective components in Salvia miltiorrhiza Bunge.  

PubMed

Salvia miltiorrhiza Bunge, a well-known medicinal plant, has more than 20 effective components. The aim of this study was to comprehensively investigate foliar fungal endophyte communities of S. miltiorrhiza and explore the inside relationship between host-specific fungal endophytes and effective components accumulation. Five plant samples were collected from four geological different provinces in China. Foliar fungal endophyte communities were determined by terminal restriction fragment length polymorphism (T-RFLP) of the ITS region. Effective components were analyzed with high-performance liquid chromatography. The results showed that S. miltiorrhiza foliage harbored a large diversity of fungal endophytes. Principal component analysis revealed similar T-RFLP profiles and the characteristics of the 24 effective components among the five samples, which could be clustered into three groups. In foliar T-RFLP profiles derived from the restriction digestion by CfoI, HaeIII, MspI, or TaqI, there were identical 45, 42, 38, and 34 terminal restriction fragments (T-RFs) from the five samples. We consider these T-RFs as host-specific fungal endophytes. Correlation analysis of these T-RFs' area and 24 effective components contents revealed a significant correlationship between some host-specific fungal endophytes and foliage or root effective components accumulation. PMID:24146079

Sun, Jianjun; Xia, Fei; Cui, Langjun; Liang, Jian; Wang, Zhezhi; Wei, Yukun

2014-04-01

337

The contribution of foliar endophytes to quantitative resistance to Melampsora rust.  

PubMed

Foliar endophytes of Populus do not induce the hypersensitive response associated with major genes for resistance to Melampsora leaf rust. But they could contribute to the quantitative resistance that represents a second line of defense. Quantitative resistance is thought to be determined by suites of minor genes in both host and pathogen that are influenced by the abiotic environment. Here, we determined the relative importance to quantitative resistance of foliar endophytes, one element of the biotic environment. Leaves of six host genotypes differing in genetic resistance to Melampsora × columbiana were inoculated first with one of four foliar endophytes (Stachybotrys sp., Trichoderma atroviride, Ulocladium atrum or Truncatella angustata), and then with Melampsora. These endophytes greatly reduced rust severity within inoculated leaves (i.e. local effects), but they had no systemic effect on rust of leaves not inoculated with endophytes. Differences among endophytes and their controls explained 54% of the total variation in quantitative resistance (i.e. rust severity); the six host/pathogen genotypes explained just 5%. In terms of magnitude of effect on rust severity, Stachybotrys, Trichoderma, Ulocladium and Truncatella were ranked in this order on all host/pathogen genotypes. Endophytes may contribute significantly to quantitative resistance to Melampsora in leaves of Populus. PMID:23228058

Raghavendra, Anil K H; Newcombe, George

2013-02-01

338

Effects of elevated CO2 on foliar quality and herbivore damage in a scrub oak ecosystem.  

PubMed

Atmospheric CO2 concentrations have increased exponentially over the last century and continuing increases are expected to have significant effects on ecosystems. We investigated the interactions among atmospheric CO2, foliar quality, and herbivory within a scrub oak community at the Kennedy Space Center, Florida. Sixteen plots of open-top chambers were followed; eight of which were exposed to ambient levels of CO2 (350 ppm), and eight of which were exposed to elevated levels of CO2 (700 ppm). We focused on three oak species, Quercus geminata, Quercus myrtifolia, Quercus chapmanii, and one nitrogen fixing legume, Galactia elliottii. There were declines in overall nitrogen and increases in C:N ratios under elevated CO2. Total carbon, phenolics (condensed tannins, hydrolyzable tannins, total phenolics) and fiber (cellulose, hemicellulose, lignin) did not change under elevated CO2 across plant species. Plant species differed in their relative foliar chemistries over time, however, the only consistent differences were higher nitrogen concentrations and lower C:N ratios in the nitrogen fixer when compared to the oak species. Under elevated CO2, damage by herbivores decreased for four of the six insect groups investigated. The overall declines in both foliar quality and herbivory under elevated CO2 treatments suggest that damage to plants may decline as atmospheric CO2 levels continue to rise. PMID:15856783

Hall, Myra C; Stiling, Peter; Moon, Daniel C; Drake, Bert G; Hunter, Mark D

2005-02-01

339

Evaluation of cucurbitacin-based gustatory stimulant to facilitate cucumber beetle (Coleoptera: Chrysomelidae) management with foliar insecticides in melons.  

PubMed

The bitter plant-derived compounds cucurbitacins are known to stimulate feeding of adult cucumber beetles (Coleoptera: Chrysomelidae). A cucurbitacin-based gustatory stimulant applied as a flowable bait combined with either spinosad or carbaryl was compared with foliar sprays of spinosad and carbaryl for controlling two cucumber beetle species (Diabrotica undecimpunctata undecimpunctata Mannerheim and Acalymma trivittatum Mannerheim) in honeydew melons (Cucumis melo L.). Field studies were conducted on the University of California-Davis plant pathology farm in 2008 and 2009. Beetle densities after applications and fruit damage from beetle feeding were compared among treatments. In addition, beetle survival was compared within field cages placed over the treated foliage infested with beetles. Using all three measures of efficacy, we determined that the addition of cucurbitacin bait had no effect on the level of cucumber beetle control with carbaryl in either 2008 or 2009. In both years, spinosad did not significantly reduce cucumber beetle densities in either field cages or field plots and did not reduce fruit damage relative to the untreated control. The addition of the bait to spinosad did not improve its efficacy. A laboratory bioassay of the spinosad formulation used in the field showed it had significant lethal effects on adults of both cucumber beetle species. Results indicated that the bait formulation used did not improve cucumber beetle control but may benefit from the addition of floral attractants or using a different type of cucurbitacin. PMID:21882695

Pedersen, Andrew B; Godfrey, Larry D

2011-08-01

340

Effects of simulated acid rain and ozone on foliar chemistry of field-grown Pinus ponderosa seedlings and mature trees.  

PubMed

We investigated the additive and interactive effects of simulated acid rain and elevated ozone on C and N contents, and the C:N ratio of one-year-old and current-year foliage of field-grown mature trees and their half-sib seedlings of a stress tolerant genotype of ponderosa pine. Acid rain levels (pH 5.1 and 3.0) were applied weekly to foliage only (no soil acidification or N addition), from January to April, 1992. Plants were exposed to two ozone levels (ambient and twice-ambient) during the day from September 1991 to November 1992. The sequential application of acid rain and elevated ozone mimicked the natural conditions. Twice-ambient ozone significantly decreased foliar N content (by 12-14%) and increased the C:N ratio of both one-year-old and current-year foliage of seedlings. Although similar ozone effects were also observed on one-year-old foliage of mature trees, the only statistically significant effect was an increased C:N ratio when twice-ambient ozone combined with pH 3.0 rain (acid rain by ozone interaction). Enhancing the effect of twice-ambient ozone in increasing the C:N ratio of one-year-old foliage of mature trees in June was the only significant effect of acid rain. PMID:15091457

Momen, B; Helms, J A

1996-01-01

341

Cameleon calcium indicator reports cytoplasmic calcium dynamics in Arabidopsis guard cells  

NASA Technical Reports Server (NTRS)

Cytoplasmic free calcium ([Ca2+]cyt) acts as a stimulus-induced second messenger in plant cells and multiple signal transduction pathways regulate [Ca2+]cyt in stomatal guard cells. Measuring [Ca2+]cyt in guard cells has previously required loading of calcium-sensitive dyes using invasive and technically difficult micro-injection techniques. To circumvent these problems, we have constitutively expressed the pH-independent, green fluorescent protein-based calcium indicator yellow cameleon 2.1 in Arabidopsis thaliana (Miyawaki et al. 1999; Proc. Natl. Acad. Sci. USA 96, 2135-2140). This yellow cameleon calcium indicator was expressed in guard cells and accumulated predominantly in the cytoplasm. Fluorescence ratio imaging of yellow cameleon 2.1 allowed time-dependent measurements of [Ca2+]cyt in Arabidopsis guard cells. Application of extracellular calcium or the hormone abscisic acid (ABA) induced repetitive [Ca2+]cyt transients in guard cells. [Ca2+]cyt changes could be semi-quantitatively determined following correction of the calibration procedure for chloroplast autofluorescence. Extracellular calcium induced repetitive [Ca2+]cyt transients with peak values of up to approximately 1.5 microM, whereas ABA-induced [Ca2+]cyt transients had peak values up to approximately 0.6 microM. These values are similar to stimulus-induced [Ca2+]cyt changes previously reported in plant cells using ratiometric dyes or aequorin. In some guard cells perfused with low extracellular KCl concentrations, spontaneous calcium transients were observed. As yellow cameleon 2.1 was expressed in all guard cells, [Ca2+]cyt was measured independently in the two guard cells of single stomates for the first time. ABA-induced, calcium-induced or spontaneous [Ca2+]cyt increases were not necessarily synchronized in the two guard cells. Overall, these data demonstrate that that GFP-based cameleon calcium indicators are suitable to measure [Ca2+]cyt changes in guard cells and enable the pattern of [Ca2+]cyt dynamics to be measured with a high level of reproducibility in Arabidopsis cells. This technical advance in combination with cell biological and molecular genetic approaches will become an invaluable tool in the dissection of plant cell signal transduction pathways.

Allen, G. J.; Kwak, J. M.; Chu, S. P.; Llopis, J.; Tsien, R. Y.; Harper, J. F.; Schroeder, J. I.; Evans, M. L. (Principal Investigator)

1999-01-01

342

Quantifying Foliar Pigment Concentrations of Temperate Forest Species Using Digital Photography and Hyperspectral Reflectance Indices  

NASA Astrophysics Data System (ADS)

Determination of leaf chlorophyll content is a common and important procedure for plant scientists. There are many multispectral techniques for non destructive in-vivo, estimation of chlorophyll in foliage. Although much has been done to explore the estimation of foliar pigments using remote sensing, very little work has been done exploring the potential that basic, affordable, digital cameras may have for such analysis. This study utilizes a combination of digital photography, hyperspectral laboratory remote sensing, and chlorophyll extractions to determine if digital photographs can be used to accurately predict foliar chlorophyll concentrations as well to compare this digital approach with several common spectral indices used for estimating foliar chlorophyll content. Foliar materials for this study come from three sources. A large collection of samples were collected (60) from 9 common temperate forest species in July and late September over a 1 kilometer area at the Bartlett Experimental Forest in northern New Hampshire. Secondly, 15 trees were selected in a forested setting near the University of New Hampshire for more intensive phenological analysis. These samples consist of 5 white pine (Pinus strobus), 5 black oak (Quercus velutina) and 5 sugar maple (Acer saccharum). Finally, dozens of samples of white pine utilized in Forest Watch, a successful K-12 science outreach which assesses the impact of tropospheric ozone on forest health in New England, were also analyzed for this study. For all samples in this study, chlorophyll extractions were conducted to determine chlorophyll a, chlorophyll b, and total chlorophyll concentrations. Laboratory spectral analysis was performed using a GER 2600 Spectroradiometer to determine hyperspectral estimates of chlorophyll content using a Red Edge Inflection Point (REIP) approach, as well as a Transformed Chlorophyll Absorption Reflectance Index/Optimized Soil Adjusted Vegetation Index (TCARI/OSAVI) approach. These measures of chlorophyll estimation were utilized to determine whether red, green and blue spectral data from digital images taken with a Kodak C713 model camera could be used to estimate foliar chlorophyll concentrations in forest foliage. Preliminary results of this study will be presented.

Gagnon, M. T.; Rock, B. N.; Jahnke, L. S.; Lee, T. D.

2008-12-01

343

Calcium Orthophosphates as Bioceramics: State of the Art  

PubMed Central

In the late 1960s, much interest was raised in regard to biomedical applications of various ceramic materials. A little bit later, such materials were named bioceramics. This review is limited to bioceramics prepared from calcium orthophosphates only, which belong to the categories of bioactive and bioresorbable compounds. There have been a number of important advances in this field during the past 30–40 years. Namely, by structural and compositional control, it became possible to choose whether calcium orthophosphate bioceramics were biologically stable once incorporated within the skeletal structure or whether they were resorbed over time. At the turn of the millennium, a new concept of calcium orthophosphate bioceramics—which is able to promote regeneration of bones—was developed. Presently, calcium orthophosphate bioceramics are available in the form of particulates, blocks, cements, coatings, customized designs for specific applications and as injectable composites in a polymer carrier. Current biomedical applications include artificial replacements for hips, knees, teeth, tendons and ligaments, as well as repair for periodontal disease, maxillofacial reconstruction, augmentation and stabilization of the jawbone, spinal fusion and bone fillers after tumor surgery. Exploratory studies demonstrate potential applications of calcium orthophosphate bioceramics as scaffolds, drug delivery systems, as well as carriers of growth factors, bioactive peptides and/or various types of cells for tissue engineering purposes.

Dorozhkin, Sergey V.

2010-01-01

344

Calcium-activated potassium channels  

Microsoft Academic Search

Calcium-activated potassium channels are fundamental regulators of neuronal excitability, participating in interspike interval and spike-frequency adaptation. For large-conductance calcium-activated potassium (BK) channels, recent experiments have illuminated the fundamental biophysical mechanisms of gating, demonstrating that BK channels are voltage gated and calcium modulated. Structurally, BK channels have been shown to possess an extracellular amino-terminal domain, different from other potassium channels. Domains

Cecilia Vergara; Ramon Latorre; Neil V Marrion; John P Adelman

1998-01-01

345

Calcium Kinetics During Space Flight  

NASA Technical Reports Server (NTRS)

Bone loss is one of the most detrimental effects of space flight, threatening to limit the duration of human space missions. The ability to understand and counteract this loss will be critical for crew health and safety during and after extended-duration missions. The hypotheses to be tested in this project are that space flight alters calcium homeostasis and bone mineral metabolism, and that calcium homeostasis and bone mineral metabolism will return to baseline within days to weeks of return to Earth. These hypotheses will be evidenced by elevated rates of bone mineral resorption and decreased bone mineral deposition, decreased absorption of dietary calcium, altered calcitropic endocrine profiles, elevated excretion of calcium in urine and feces, and elevated excretion of markers of bone resorption. The second hypothesis will be evidenced by return of indices of calcium homeostasis and bone metabolism to preflight levels within days to weeks of return to Earth. Studies will be conducted on International Space Station astronauts before, during, and after extended-duration flights. Measurements of calcium kinetics, bone mass, and endocrine/biochemical markers of bone and calcium homeostasis will be conducted. Kinetic studies utilizing dual isotope tracer kinetic studies and mathematical modeling techniques will allow for determination of bone calcium deposition, bone calcium resorption, dietary calcium absorption and calcium excretion (both urinary and endogenous fecal excretion). These studies will build upon preliminary work conducted on the Russian Mir space station. The results from this project will be critical for clarifying how microgravity affects bone and calcium homeostasis, and will provide an important control point for assessment of countermeasure efficacy. These results are expected to aid in developing countermeasures for bone loss, both for space crews and for individuals on Earth who have metabolic bone diseases.

Smith, Scott M.; Wastney, Meryl E.; OBrien, Kimberly O.; Lane, Helen W.

1999-01-01

346

Calcium channel antagonism by pizotifen.  

PubMed Central

Pizotifen is a clinically effective anti-migraine agent with potent anti-serotonin and anti-histamine properties. Pizotifen is equipotent in blocking contractions of the canine basilar artery induced by serotonin, norepinephrine or calcium chloride. As a result, the primary action of pizotifen in the canine basilar artery system appears to be calcium channel blockade and not selective antagonism of serotonin or norepinephrine. Calcium channel blocking ability may be related to the clinical efficacy of pizotifen in the treatment of migraine.

Peroutka, S J; Banghart, S B; Allen, G S

1985-01-01

347

INTEGUMENTARY LOSS OF CALCIUM.: 839  

Microsoft Academic Search

Integumentary calcium loss was studied in 16 healthy young men. The daily loss by the 16 ambulatory but relatively sedentary young men in 52 determinations of 6-day periods each was 8.7 ± 1.9 mgJm2 per day (average 15.8 mg\\/man per day). The amount lost was not influenced by calcium intake (0. 1 to 2.3 g\\/day). In contrast to urinary calcium

Jen-Yih Chu; Sheldon Margen; Doris Calloway; Francoise Costa; James A. Monteleone

1978-01-01

348

Combustion of calcium treated coals  

Microsoft Academic Search

The combustion of calcium-exchanged coals was studied in laminar flow and fluid bed reactors uder strongly fuel-lean conditions. The purpose of the study was to understand the nature of release and capture of sulfur oxides in the presence of finely dispersed calcium oxide and explore the effectiveness of calcium-exchange pretreatment for sulfur emission control in coal combustion. The experimental variables

K. Chang; R. C. Flagan; G. P. Gavalas

1985-01-01

349

Combustion of calcium treated coals  

Microsoft Academic Search

The combustion of calcium-exchanged coals was studied in laminar flow and fluid bed reactors under strongly fuel-lean conditions. The purpose of the study was to understand the nature of release and capture of sulfur oxides in the presence of finely dispersed calcium oxide and explore the effectiveness of calcium-exchange pretreatment for sulfur emission control in coal combustion. The experimental variables

K. K. Chang; R. C. Flagan; G. R. Gavalas; P. K. Sharma

1984-01-01

350

Development of Magnesium-Doped Biphasic Calcium Phosphatethrough Sol-Gel Method  

Microsoft Academic Search

Calcium phosphate is an interesting material for bone implant applications, as it shows biocompatibility and bioactivity to\\u000a tissue bone. Among calcium phosphate-based materials, biphasic calcium phosphate (BCP), a mixture of non-resorbable hydroxyapatite\\u000a (HA) and resorbable tricalcium phosphate (TCP), has shown to possess unique characteristics appropriate for bone replacement.\\u000a Doping of magnesium ions into BCP will bring biological improvement. Magnesium ion

A. R. Toibah; Iis Sopyan; M. Hamdi; S. Ramesh

351

Calcium channel blockers and dementia  

PubMed Central

Degenerative dementia is mainly caused by Alzheimer's disease and/or cerebrovascular abnormalities. Disturbance of the intracellular calcium homeostasis is central to the pathophysiology of neurodegeneration. In Alzheimer's disease, enhanced calcium load may be brought about by extracellular accumulation of amyloid-?. Recent studies suggest that soluble forms facilitate influx through calcium-conducting ion channels in the plasma membrane, leading to excitotoxic neurodegeneration. Calcium channel blockade attenuates amyloid-?-induced neuronal decline in vitro and is neuroprotective in animal models. Vascular dementia, on the other hand, is caused by cerebral hypoperfusion and may benefit from calcium channel blockade due to relaxation of the cerebral vasculature. Several calcium channel blockers have been tested in clinical trials of dementia and the outcome is heterogeneous. Nimodipine as well as nilvadipine prevent cognitive decline in some trials, whereas other calcium channel blockers failed. In trials with a positive outcome, BP reduction did not seem to play a role in preventing dementia, indicating a direct protecting effect on neurons. An optimization of calcium channel blockers for the treatment of dementia may involve an increase of selectivity for presynaptic calcium channels and an improvement of the affinity to the inactivated state. Novel low molecular weight compounds suitable for proof-of-concept studies are now available.

Nimmrich, V; Eckert, A

2013-01-01

352

Can the foliar nitrogen concentration of upland vegetation be used for predicting atmospheric nitrogen deposition? Evidence from field surveys.  

PubMed

The deposition of atmospheric nitrogen can be enhanced at high altitude sites as a consequence of cloud droplet deposition and orographic enhancement of wet deposition on hills. The degree to which the increased deposition of nitrogen influences foliar nitrogen concentration in a range of upland plant species was studied in a series of field surveys in northern Britain. A range of upland plant species sampled along altitudinal transects at sites of known atmospheric nitrogen deposition showed marked increases in foliar nitrogen concentration with increasing nitrogen deposition and altitude (and hence with decreasing temperature). For Nardus stricta L., Deschampsia flexuosa (L.) Trin., Calluna vulgaris (L.) Hull, Erica cinerea L. and Hylocomium splendens (Hedw.) Br. Eur. on an unpolluted hill, foliar nitrogen increased by 0.07, 0.12, 0.15, 0.08 and 0.04% dry weight respectively for each 1 kg ha(-1) year(-1) increase in nitrogen deposition. Most species showed an approximately linear relationship between foliar nitrogen concentration and altitude but no trend with altitude for foliar phosphorus concentration. This provided evidence that the tissue nutrient status of upland plants reflects nutrient availability rather than the direct effects of climate on growth. However, differences in the relationship between foliar nitrogen concentration and atmospheric nitrogen deposition for N. stricta sampled on hills in contrasting pollution climates show that the possibility of temperature-mediated growth effects on foliar nitrogen concentration should not be ignored. Thus, there is potential to use upland plant species as biomonitors of nitrogen deposition, but the response of different species to nitrogen addition, in combination with climatic effects on growth, must be well characterised. PMID:15092983

Hicks, W K; Leith, I D; Woodin, S J; Fowler, D

2000-03-01

353

Detection and quantification of some plant growth regulators in a seaweed-based foliar spray employing a mass spectrometric technique sans chromatographic separation.  

PubMed

The sap expelled from the fresh harvest of Kappaphycus alvarezii , a red seaweed growing in tropical waters, has been reported to be a potent foliar spray. Tandem mass spectrometry of various organic extracts of the sap confirmed the presence of the plant growth regulators (PGRs) indole 3-acetic acid, gibberellin GA(3), kinetin, and zeatin. These PGRs were quantified in fresh state and after 1 year of storage by ESI-MS without recourse to chromatographic separation. Quantification was validated against HPLC data. The results may be useful in correlating with the efficacy of the sap. The methodology was extended to two other seaweeds. The method developed is convenient and precise and may find application in other agricultural formulations containing these growth hormones. PMID:20355716

Prasad, Kamalesh; Das, Arun Kumar; Oza, Mihir Deepak; Brahmbhatt, Harshad; Siddhanta, Arup Kumar; Meena, Ramavatar; Eswaran, Karuppanan; Rajyaguru, Mahesh Rameshchandra; Ghosh, Pushpito Kumar

2010-04-28

354

Effect of lowering dietary calcium intake on fractional whole body calcium retention  

Microsoft Academic Search

Although fractional calcium absorption is known to vary inversely with calcium intake, the extent and timing of individual hormonal and calcium absorption responses to altered calcium intake have not been defined. We measured fractional whole body retention of orally ingested ⁴⁷Ca, an index of calcium absorption, in nine normal women after they had eaten a 2000-mg calcium diet for 8

B. Dawson-Hughes; D. T. Stern; C. C. Shipp; H. M. Rasmussen

1988-01-01

355

Calcium-Rich Spirulina: A Potential Immunopotentiator and Calcium Supplement  

Microsoft Academic Search

Spirulina is considered to be a good food and medicinal resource. However, its calcium content is relatively low compared with the other nutritional components. Therefore, to improve the calcim content of Spirulina, a new kind of Spirulina, calcium-rich Spirulina was developed by the bioaccumulating ability of Spirulina. To assess the influence of the Spirulina on the health of animal, the

Jiang Zheng; Ya-hui Gao

2008-01-01

356

Caffeine, urinary Calcium, Calcium Metabolism and Bone1'2  

Microsoft Academic Search

Oral doses of caffeine increase the urinary excretion of calcium, magnesium, sodium and chloride for at least 3 h after consumption. The hypercalciuric effect can be blocked by adenosine receptor agonists. The effect is proportional to dose per lean body mass and no adaptation to the urinary losses occurs with continuing consumption of caffeine. Uncompensated losses of calcium would be

LINDA K. MASSEY; ANDSUSAN J. WHITING

357

Calcium-deficiency assessment and biomarker identification by an integrated urinary metabonomics analysis  

PubMed Central

Background Calcium deficiency is a global public-health problem. Although the initial stage of calcium deficiency can lead to metabolic alterations or potential pathological changes, calcium deficiency is difficult to diagnose accurately. Moreover, the details of the molecular mechanism of calcium deficiency remain somewhat elusive. To accurately assess and provide appropriate nutritional intervention, we carried out a global analysis of metabolic alterations in response to calcium deficiency. Methods The metabolic alterations associated with calcium deficiency were first investigated in a rat model, using urinary metabonomics based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry and multivariate statistical analysis. Correlations between dietary calcium intake and the biomarkers identified from the rat model were further analyzed to confirm the potential application of these biomarkers in humans. Results Urinary metabolic-profiling analysis could preliminarily distinguish between calcium-deficient and non-deficient rats after a 2-week low-calcium diet. We established an integrated metabonomics strategy for identifying reliable biomarkers of calcium deficiency using a time-course analysis of discriminating metabolites in a low-calcium diet experiment, repeating the low-calcium diet experiment and performing a calcium-supplement experiment. In total, 27 biomarkers were identified, including glycine, oxoglutaric acid, pyrophosphoric acid, sebacic acid, pseudouridine, indoxyl sulfate, taurine, and phenylacetylglycine. The integrated urinary metabonomics analysis, which combined biomarkers with regular trends of change (types A, B, and C), could accurately assess calcium-deficient rats at different stages and clarify the dynamic pathophysiological changes and molecular mechanism of calcium deficiency in detail. Significant correlations between calcium intake and two biomarkers, pseudouridine (Pearson correlation, r = 0.53, P = 0.0001) and citrate (Pearson correlation, r = -0.43, P = 0.001), were further confirmed in 70 women. Conclusions To our knowledge, this is the first report of reliable biomarkers of calcium deficiency, which were identified using an integrated strategy. The identified biomarkers give new insights into the pathophysiological changes and molecular mechanisms of calcium deficiency. The correlations between calcium intake and two of the biomarkers provide a rationale or potential for further assessment and elucidation of the metabolic responses of calcium deficiency in humans.

2013-01-01

358

Natural variations in calcium isotope composition as a monitor of bone mineral balance in humans.  

NASA Astrophysics Data System (ADS)

The skeleton is the largest reservoir of calcium in the human body and is responsible for the short term control of blood levels of this element. Accurate measurement of changes in bone calcium balance is critical to understanding how calcium metabolism responds to physiological and environmental changes and, more specifically, to diagnosing and evaluating the effectiveness of treatments for osteoporosis and other serious calcium-related disorders. It is very difficult to measure bone calcium balance using current techniques, however, because these techniques rely either on separate estimates of bone resorption and formation that are not quantitatively comparable, or on complex and expensive studies of calcium kinetics using administered isotopic tracers. This difficulty is even more apparent and more severe for measurements of short-term changes in bone calcium balance that do not produce detectable changes in bone mineral density. Calcium isotopes may provide a novel means of addressing this problem. The foundation of this isotope application is the ca. 1.3 per mil fractionation of calcium during bone formation, favoring light calcium in the bone. This fractionation results in a steady-state isotopic offset between calcium in bone and calcium in soft tissues, blood and urine. Perturbations to this steady state due to changes in the net formation or resorption of bone should be reflected in changes in the isotopic composition of soft tissues and fluids. Here we present evidence that easily detectable shifts in the natural calcium isotope composition of human urine rapidly reflect changes in bone calcium balance. Urine from subjects in a 17-week bed rest study was analyzed for calcium isotopic composition. Bed rest promotes net resorption of bone, shifting calcium from bone to soft tissues, blood and urine. The calcium isotope composition of patients in this study shifted toward lighter values during bed rest, consistent with net resorption of isotopically-light bone calcium. In contrast, little shift was seen in patients who exercised during bed rest, consistent with the expectation that exercise should inhibit bone resorption. Most intriguingly, an opposite-sense shift was seen in patients who were administered aledronate, a drug which inhibits bone resorption. We hypothesize that these patients entered a state of positive bone mineral balance despite initiation of bed rest. Comparison of isotopic data with measurements of bone mineral density and metabolic markers of bone metabolism confirms that the calcium isotope composition of urine reflects changes in bone mineral balance. Calcium isotope analysis of urine and soft tissues may provide information on bone mineral balance that is in important respects better than that available from other techniques, and illustrates the usefulness of applying geochemical techniques to biomedical problems.

Skulan, J.; Anbar, A.; Thomas, B.; Smith, S.

2004-12-01

359

Measurement of calcium transients and slow calcium current in myotubes  

PubMed Central

The purpose of this study was to characterize excitation-contraction (e- c) coupling in myotubes for comparison with e-c coupling of adult skeletal muscle. The whole cell configuration of the patch clamp technique was used in conjunction with the calcium indicator dye Fluo-3 to study the calcium transients and slow calcium currents elicited by voltage clamp pulses in cultured myotubes obtained from neonatal mice. Cells were held at -80 mV and stimulated with 15-20 ms test depolarizations preceded and followed by voltage steps designed to isolate the slow calcium current. The slow calcium current had a threshold for activation of about 0 mV; the peak amplitude of the current reached a maximum at 30 to 40 mV a and then declined for still stronger depolarizations. The calcium transient had a threshold of about -10 mV, and its amplitude increased as a sigmoidal function of test potential and did not decrease again even for test depolarizations sufficiently strong (> or = 50 mV) that the amplitude of the slow calcium current became very small. Thus, the slow calcium current in myotubes appears to have a negligible role in the process of depolarization-induced release of intracellular calcium and this process in myotubes is essentially like that in adult skeletal muscle. After repolarization, however, the decay of the calcium transient in myotubes was very slow (hundreds of ms) compared to adult muscle, particularly after strong depolarizations that triggered larger calcium transients. Moreover, when cells were repolarized after strong depolarizations, the transient typically continued to increase slowly for up to several tens of ms before the onset of decay. This continued increase after repolarization was abolished by the addition of 5 mM BAPTA to the patch pipette although the rapid depolarization-induced release was not, suggesting that the slow increase might be a regenerative response triggered by the depolarization-induced release of calcium. The addition of either 0.5 mM Cd2+ + 0.1 mM La3+ or the dihydropyridine (+)-PN 200-110 (1 microM) reduced the amplitude of the calcium transient by mechanisms that appeared to be unrelated to the block of current that these agents produce. In the majority of cells, the decay of the transient was accelerated by the addition of the heavy metals or the dihydropyridine, consistent with the idea that the removal system becomes saturated for large calcium releases and becomes more efficient when the size of the release is reduced.

1994-01-01

360

Adult-type hypolactasia and calcium availability: decreased calcium intake or impaired calcium absorption?  

Microsoft Academic Search

Summary  Adult-type hypolactasia, as mediated by a widespread genetic predisposition, not only reduces calcium intake but also calcium\\u000a absorption in the presence of high amounts of lactose and may, therefore, promote osteoporosis. A lactose-reduced diet and\\u000a lactose-free calcium supplements may reverse this imbalance.\\u000a \\u000a \\u000a \\u000a Introduction and hypothesis  Adult-type hypolactasia (HL) defined by the LCT(?13910) polymorphism may reduce calcium intake by reducing dairy consumption

B. M. Obermayer-Pietsch; M. Gugatschka; S. Reitter; W. Plank; A. Strele; D. Walter; C. Bonelli; W. Goessler; H. Dobnig; C. Högenauer; W. Renner; A. Fahrleitner-Pammer

2007-01-01

361

21 CFR 182.6197 - Calcium diacetate.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 2013-04-01 false Calcium diacetate. 182.6197 Section 182.6197...RECOGNIZED AS SAFE Sequestrants 1 § 182.6197 Calcium diacetate. (a) Product. Calcium diacetate. (b) Conditions of use....

2013-04-01

362

21 CFR 582.6197 - Calcium diacetate.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 2013-04-01 false Calcium diacetate. 582.6197 Section 582.6197...RECOGNIZED AS SAFE Sequestrants 2 § 582.6197 Calcium diacetate. (a) Product. Calcium diacetate. (b) Conditions of use....

2013-04-01

363

21 CFR 172.720 - Calcium lactobionate.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 2013-04-01 false Calcium lactobionate. 172.720 Section 172...Other Specific Usage Additives § 172.720 Calcium lactobionate. The food additive calcium lactobionate may be safely used in food...

2013-04-01

364

21 CFR 582.6199 - Calcium gluconate.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 2013-04-01 false Calcium gluconate. 582.6199 Section 582.6199...RECOGNIZED AS SAFE Sequestrants 2 § 582.6199 Calcium gluconate. (a) Product. Calcium gluconate. (b) Conditions of use....

2013-04-01

365

21 CFR 184.1187 - Calcium alginate.  

Code of Federal Regulations, 2010 CFR

...RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1187 Calcium alginate. (a) Calcium alginate (CAS Reg. No. 9005-35-0) is the calcium salt of alginic acid, a natural polyuronide constituent of certain brown...

2010-01-01

366

Astrocyte Calcium Waves  

PubMed Central

Several lines of evidence indicate that the elaborated calcium signals and the occurrence of calcium waves in astrocytes provide these cells with a specific form of excitability. The identification of the cellular and molecular steps involved in the triggering and transmission of Ca2+ waves between astrocytes resulted in the identification of two pathways mediating this form of intercellular communication. One of them involves the direct communication between the cytosols of two adjoining cells through gap junction channels, while the other depends upon the release of “gliotransmitters” that activates membrane receptors on neighboring cells. In this review we summarize evidence in favor of these two mechanisms of Ca2+ wave transmission and we discuss that they may not be mutually exclusive, but are likely to work in conjunction to coordinate the activity of a group of cells. To address a key question regarding the functional consequences following the passage of a Ca2+ wave, we list, in this review, some of the potential intracellular targets of these Ca2+ transients in astrocytes, and discuss the functional consequences of the activation of these targets for the interactions that astrocytes maintain with themselves and with other cellular partners, including those at the glial/vasculature interface and at perisynaptic sites where astrocytic processes tightly interact with neurons.

SCEMES, ELIANA; GIAUME, CHRISTIAN

2008-01-01

367

Stabilized Calcium Acetate Oil Dispersions.  

National Technical Information Service (NTIS)

A lubricating composition is imparted with improved load-carrying ability and anti-wear properties by incorporation of calcium acetate. The composition consists of a base lubricant, 0.1 to 50 percent by weight calcium acetate and 0.01 to 20 percent by wei...

R. H. Davis

1965-01-01

368

[Formulation of calcium acetate tablets].  

PubMed

The results of the testing of calcium acetate tablets, produced by direct compression and by wet granulation (Ph. Jug. IV) are presented. Tablet hardness, friability and disintegration were determined. The best properties were observed in the tablets produced with maize starch. This procedure is fast and simple, and compound tablets of calcium acetate fulfill the current requirements for this type of preparation. PMID:11521467

Obrenovic, D; Gazikalovic, E; Ognjanovic, J; Nidzovic Z, Z

2000-01-01

369

Molecular Structure of Calcium Sulfide  

NSDL National Science Digital Library

Calcium sulfide in pure form is white and shaped like cubic crystals, and is slightly soluble in water. This is used as a base for luminescent materials. Calcium sulfide is also known as hepar calcies; sulfurated lime. This substance is used in phosphors and as a direct fungicide on powdery mildews and insecticides.

2003-06-03

370

Calcium Intake: A Lifelong Proposition.  

ERIC Educational Resources Information Center

This article reviews the current problem of low calcium intake in the United States among all age groups, the role of calcium in the formation and maintenance of bone mass, and major factors influencing absorption. Osteoporosis is discussed, and current recommendations for Recommended Dietary allowance are provided. (Author/MT)

Amschler, Denise H.

1985-01-01

371

An Improved Calcium Flame Test.  

ERIC Educational Resources Information Center

Indicates that the true red color of calcium can be obtained (using the procedure described by Sorm and Logowski) if the calcium ion solution is mixed with an equal volume of saturated ammonium bromide solution. Suggestions for flame tests of other elements are also noted. (JN)

Pearson, Robert S.

1985-01-01

372

Calcium Requirements of Bovanes Hens  

Microsoft Academic Search

Calcium requirements of laying hens have been widely studied yet keep challenging nutritionists as a result of new genetic make-ups of commercial strains, farm management techniques, environmental concerns, and economics considerations. The present research was conducted to determine the calcium requirement of \\

2003-01-01

373

Calcium Flickers Steer Cell Migration  

PubMed Central

Directional movement is a property common to all cell types during development and is critical to tissue remodelling and regeneration after damage1–3. In migrating cells, calcium plays a multifunctional role in directional sensing, cytoskeleton redistribution, traction force generation, and relocation of focal adhesions1, 4–7. Here we visualise, for the first time, high-calcium microdomains (“calcium flickers”), and their patterned activation in migrating fibroblasts. Calcium flicker activity is dually coupled to membrane tension (via TRPM7, a stretch-activated Ca2+-permeant channel of the transient receptor potential superfamily8) and chemoattractant signal transduction (via type 2 inositol 1,4,5-trisphosphate receptors). Interestingly, calcium flickers are most active at the leading lamella of migrating cells, displaying a 4:1 front-to-rear polarisation opposite to the global calcium gradient6. When exposed to a PDGF gradient perpendicular to cell movement, asymmetric calcium flicker activity develops across the lamella and promotes the turning of migrating fibroblasts. These findings illustrate how the exquisite spatiotemporal organisation of calcium microdomains can orchestrate complex cellular processes such as cell migration.

Wei, Chaoliang; Wang, Xianhua; Chen, Min; Ouyang, Kunfu; Song, Long-Sheng; Cheng, Heping

2012-01-01

374

Effects of acid deposition on calcium nutrition and health of Southern Appalachian spruce fir forests  

SciTech Connect

The role of acid deposition in the health of spruce fir forests in the Southern Appalachian Mountains has been investigated by a wide variety of experimental approaches during the past 10 years. These studies have proceeded from initial dendroecological documentation of altered growth patterns of mature trees to increasingly more focused ecophysiological research on the causes and characteristics of changes in system function associated with increased acidic deposition. Field studies across gradients in deposition and soil chemistry have been located on four mountains spanning 85 km of latitude within the Southern Appalachians. The conclusion that calcium nutrition is an important component regulating health of red spruce in the Southern Appalachians and that acid deposition significantly reduces calcium availability in several ways has emerged as a consistent result from multiple lines or research. These have included analysis of trends in wood chemistry, soil solution chemistry, foliar nutrition, gas exchange physiology, root histochemistry, and controlled laboratory and field studies in which acid deposition and/or calcium nutrition has been manipulated and growth and nutritional status of saplings or mature red spruce trees measured. This earlier research has led us to investigate the broader implications and consequences of calcium deficiency for changing resistance of spruce-fir forests to natural stresses. Current research is exploring possible relationships between altered calcium nutrition and shifts in response of Fraser fir to insect attack by the balsam wooly adelgid. In addition, changes in wood ultrastructural properties in relation to altered wood chemistry is being examined to evaluate its possible role in canopy deterioration, under wind and ice stresses typical of high elevation forests.

McLaughlin, S.B.; Wullschleger, S. [Oak Ridge National Lab., TN (United States); Stone, A. [Univ. of Tennessee, Knoxville, TN (United States); Wimmer, R. [Austrian Agricultural Univ., Vienna (Austria); Joslin, J.D.

1995-02-01

375

Native environment modulates leaf size and response to simulated foliar shade across wild tomato species.  

PubMed

The laminae of leaves optimize photosynthetic rates by serving as a platform for both light capture and gas exchange, while minimizing water losses associated with thermoregulation and transpiration. Many have speculated that plants maximize photosynthetic output and minimize associated costs through leaf size, complexity, and shape, but a unifying theory linking the plethora of observed leaf forms with the environment remains elusive. Additionally, the leaf itself is a plastic structure, responsive to its surroundings, further complicating the relationship. Despite extensive knowledge of the genetic mechanisms underlying angiosperm leaf development, little is known about how phenotypic plasticity and selective pressures converge to create the diversity of leaf shapes and sizes across lineages. Here, we use wild tomato accessions, collected from locales with diverse levels of foliar shade, temperature, and precipitation, as a model to assay the extent of shade avoidance in leaf traits and the degree to which these leaf traits correlate with environmental factors. We find that leaf size is correlated with measures of foliar shade across the wild tomato species sampled and that leaf size and serration correlate in a species-dependent fashion with temperature and precipitation. We use far-red induced changes in leaf length as a proxy measure of the shade avoidance response, and find that shade avoidance in leaves negatively correlates with the level of foliar shade recorded at the point of origin of an accession. The direction and magnitude of these correlations varies across the leaf series, suggesting that heterochronic and/or ontogenic programs are a mechanism by which selective pressures can alter leaf size and form. This study highlights the value of wild tomato accessions for studies of both morphological and light-regulated development of compound leaves, and promises to be useful in the future identification of genes regulating potentially adaptive plastic leaf traits. PMID:22253737

Chitwood, Daniel H; Headland, Lauren R; Filiault, Daniele L; Kumar, Ravi; Jiménez-Gómez, José M; Schrager, Amanda V; Park, Daniel S; Peng, Jie; Sinha, Neelima R; Maloof, Julin N

2012-01-01

376

The activity of calcium in calcium-metal-fluoride fluxes  

NASA Astrophysics Data System (ADS)

The standard Gibbs energy of reaction Ca (1) + O (mass pct, in Zr) = CaO (s) has been determined as follows by equilibrating molten calcium with solid zirconium in a CaO crucible: ? G° = -64,300(±700) + 19.8(±3.5) T J/mol (1373 to 1623 K) The activities of calcium in the CaOsatd-Ca- MF2 ( M: Ca, Ba, Mg) and CaOsatd-Ca-NaF systems were measured as a function of calcium composition at high calcium contents at 1473 K on the basis of the standard Gibbs energy. The activities of calcium increase in the order of CaF2, BaF2, and MgF2 at the same calcium fraction of these fluxes. The observed activities are compared with those estimated by using the Temkin model for ionic solutions. Furthermore, the possibility of the removal of tramp elements such as tin, arsenic, antimony, bismuth, and lead from carbon-saturated iron by using calcium-metal-fluoride fluxes is discussed.

Ochifuji, Yuichiro; Tsukihashi, Fumitaka; Sano, Nobuo

1995-08-01

377

Diffusion in calcium oxide/calcium sulfate pellets  

SciTech Connect

Diffusion rates in calcium oxide pellets after partial conversion to calcium sulfate were measured. A Wicke-Kallenbach type diffusion cell operated in the pulse-response mode was used to measure effective diffusivity. Cylindrical calcium oxide pellets were formed from the powder using pelletizing pressures of 10,000, 20,000 and 30,000 psi. The pellets were reacted at 325, 500 and 600/sup 0/C with sulfur dioxide and oxygen to form calcium sulfate. The volume of calcium sulfate is 2.7 times that of calcium oxide, so partial pore closure occurs. The diffusivity was measured in the original pellet and in pellets partially reacted to several different conversion levels. The effective diffusivity decreases as conversion decreases and is roughly inversely proportional to pellet porosity squared for low conversions. However, the porosity and diffusion rate do not become zero when the reaction rate approaches zero. Pore closure is, therefore, not the mechanism which limits the ultimate conversion. A large diffusion resistance through the calcium sulfate product layer probably causes the reaction to stop before total conversion. The final conversion obtainable increases as reaction temperature increases and decreases as pelletizing pressure increases.

Chang, K.L.

1981-10-01

378

The activity of calcium in calcium-metal-fluoride fluxes  

SciTech Connect

The standard Gibbs energy of reaction Ca (1) + {und O} (mass pct, in Zr) = CaO (s) has been determined as follows by equilibrating molten calcium with solid zirconium in a CaO crucible: {Delta}G{degree} = {minus}64,300({+-}700) + 19.8({+-}3.5)T J/mol (1,373 to 1,623 K). The activities of calcium in the CaO{sub satd.}-Ca-MF{sub 2} (M: Ca, Ba, Mg) and CaO{sub satd.}-Ca-NaF systems were measured as a function of calcium composition at high calcium contents at 1,473 K on the basis of the standard Gibbs energy. The activities of calcium increase in the order of CaF{sub 2}, BaF{sub 2}, and MgF{sub 2} at the same calcium fraction of these fluxes. The observed activities are compared with those estimated by using the Temkin model for ionic solutions. Furthermore, the possibility of the removal of tramp elements such as tin, arsenic, antimony, bismuth, and lead from carbon-saturated iron by using calcium-metal-fluoride fluxes is discussed.

Ochifuji, Yuichiro; Tsukihashi, Fumitaka; Sano, Nobuo [Univ. of Tokyo (Japan). Dept. of Metallurgy

1995-08-01

379

Foliar and soil uptake of 134Cs and 85Sr by grape vines.  

PubMed

The foliar and soil uptake of 134Cs and 85Sr by grape vines and their subsequent translocation to fruits and to the other plant compartments is described. Grape vine plants growing in pots and kept in an open field were contaminated with 134Cs and 85Sr in ionic form by sprinkling on the aerial part, or by addition to the soil. Sprinkling was effected at the stage of ripening of the grapes. Interception, determined by analysing all the leaves picked from three plants after the sprinkling, was approx. 50% of the sprayed activity. Soil contamination was effected after the fruit setting, 1 month earlier than sprinkling. At ripening, the whole plant was picked. Berries, leaves, shoots, stems, roots and soil were analysed by gamma spectrometry. Activities of the different parts of the plant were expressed as: (a) translocation factors of intercepted activity for foliar treatment; (b) transfer factors of activity applied to the soil for soil treatment. Both factors were calculated per unit of fresh weight, or referred to the total biomass of the plant compartment. Leaf-to-fruit translocation factors per unit of weight are of the order of magnitude of 10(-1) for 134Cs and of 10(-2) for 85Sr. One/two order of magnitude lower are soil-to-fruit transfer factors: 10(-3) both for 134Cs and for 85Sr. Radiocesium behaves quite differently from radiostrontium, but the behaviour of both radionuclides within the grape vine is independent of the path of absorption, by leaves or by roots. 134Cs is absorbed more easily than 85Sr by plant foliage, but is absorbed with more difficulty than 85Sr by roots. After absorption by either route, radiocesium concentrates mainly in the fruit compartment of the plant, whereas radiostrontium concentrates in the foliar compartment. Loss from the aerial part of the plant is higher for 85Sr than for 134Cs. 85Sr remains more available in soil than 134Cs, is more absorbed by roots and is more leached downward. After foliar contamination, the dominant pathway of radionuclides to reach the soil is by dislodging of non-absorbed radionuclides or senescent cells from the aerial part of the plant by action of wind and rain. PMID:9447745

Carini, F; Lombi, E

1997-11-27

380

Sulfuric acid rain effects on crop yield and foliar injury. Final report  

SciTech Connect

A study was undertaken to determine the relative sensitivity of major U.S. crops to sulfuric acid rain. Plants were grown under controlled environmental conditions and exposed to simulated acid rain of three sulfuric acid concentrations (pH 3.0, 3.5, 4.0) or to a control rain (pH 5.7). Injury to foliage and effects on yield were common responses to acid rain. However, foliar injury was not a good indicator of effects on yield.

Lee, J.J.; Neely, G.E.; Perrigan, S.C.

1980-01-01

381

Foliar application of potassium silicate reduces the intensity of soybean rust  

Microsoft Academic Search

This study aimed to determine if potassium silicate (KSi) sprays could reduce the intensity of soybean rust. In the field\\u000a experiment 1, soybean plants were sprayed with KSi (pH 10.5) at rates of 8, 20, 40 and 60 g\\/L. In the field experiment 2,\\u000a with the same treatments, the pH of the KSi solutions was 5.5. In experiment 3, the

F. A. Rodrigues; H. S. S. Duarte; G. P. Domiciano; C. A. Souza; G. H. Korndörfer; L. Zambolim

2009-01-01

382

Responses of Vigna radiata to Foliar Application of 28-Homobrassinolide and Kinetin  

Microsoft Academic Search

Effects of 28-homobrassinolide (HBR) and kinetin (KIN) on photosynthesis, nitrogen metabolism, and the seed yield were studied. The leaves of 25-d-old plants of Vigna radiata (L.) Wilczek were sprayed with 0.01, 1.0 or 100 µM aqueous solution of KIN, or 0.0001, 0.01 or 1.0 µM that of HBR. KIN and especially HBR increased the activities of nitrate reductase and carbonic

Q. Fariduddin; A. Ahmad; S. Hayat

2004-01-01

383

Influence of BioFertilizer Foliar Application on Growth and Anatomical Changes of Tagetes  

Microsoft Academic Search

The paper presents the behaviour of plants from Tagetes patula specie at the treatments with Bionat bio-fertilizer, applied in different doses (0.2%, 0.4% and 0.6%). There were effectuated bio-metric observations and determinations, correlated with morph-anatomic analyses at stem, sprout and leave level. The recorded results put in light the favourable effect of the treatments with Bionat, in the way of

Lucia DRAGHIA; Elena-Liliana CHELARIU; Violeta DELINSCHI

384

Foliar application of Azatobactor chroococcum increases leaf yield under saline conditions in mulberry ( Morus spp.)  

Microsoft Academic Search

In this study, the effect of two nitrogenous fertilizers such as urea and the bacterial bio-fertilizer ‘Azatobactor chroococcum’ on growth and development along with leaf quality was studied under various levels of NaCl in mulberry. Performance of four mulberry varieties, two tolerant and two susceptible to salt, were studied in pot culture. NaCl at different concentrations (0.0%, 0.25%, 0.50%, 0.75%

K. Vijayan; S. P. Chakraborti; P. D. Ghosh

2007-01-01

385

Response of Faba Bean to Bio, Mineral Phosphorus Fertilizers and Foliar Application with Zinc  

Microsoft Academic Search

Faba bean (Vicia faba L.) is one of the major leguminous crops grown in the world. It is important source of protein for humans and animals. A 2-yr field study was carried out in the Research and Experimental Center of Faculty of Agriculture at Moshtohor, Benha University, Egypt, during 2006\\/2007 and 2007\\/2008 seasons. The aim of this study was to

N. Kh; B. El-Gizawy; S. A. S. Mehasen

386

Alternative technique for calcium phosphate coating on titanium alloy implants.  

PubMed

As an alternative technique for calcium phosphate coating on titanium alloys, we propose to functionalize the metal surface with anionic bath containing chlorides of palladium or silver as activators. This new deposition route has several advantages such as controlled conditions, applicability to complex shapes, no adverse effect of heating, and cost effectiveness. A mixture of hydroxyapatite and calcium phosphate hydrate is deposited on the surface of Ti-6Al-4V. Calcium phosphate coating is built faster compared with the one by Simulated Body Fluid. Cell morphology and density are comparable to the control one; and the results prove no toxic compound is released into the medium during the previous seven days of immersion. Moreover, the cell viability is comparable with cells cultivated with the virgin medium. These experimental treatments allowed producing cytocompatible materials potentially applicable to manufacture implantable devices for orthopedic and oral surgeries. PMID:24646569

Le, Van Quang; Pourroy, Geneviève; Cochis, Andrea; Rimondini, Lia; Abdel-Fattah, Wafa I; Mohammed, Hadeer I; Carradò, Adele

2014-01-01

387

Matrix-matched quantitative analysis of trace-elements in calcium carbonate shells by laser-ablation ICP-MS: application to the determination of daily scale profiles in scallop shell (Pecten maximus).  

PubMed

A micro-scale method has been developed for analysis of trace-element concentration profiles in the calcium carbonate shell of the Great Scallop (Pecten maximus). UV laser ablation at 266-nm coupled with ICP-MS detection was used to analyse daily calcite striae of shell samples to obtain high temporal resolution of trace element incorporation. Analysis of scallop shells was carefully examined to determine the quality of calcium carbonate ablation and calibration. An accurate external calibration method based on matrix matching was developed. Twelve sodium-free enriched calcium carbonate standards containing up to twenty-four elements were prepared, by co-precipitation with aqueous ammonia and NH(4)HCO(3), and subsequently back-calibrated in the laboratory. These CaCO(3) standards were found to be homogenous and their use enabled sensitive quantitative analysis (detection limits of a few ng g(-1)) over a wide range of concentrations (0.1 to 500 microg g(-1)). Use of these CaCO(3) standards was also evaluated by analysis of three calcium-rich certified reference materials. Because calibration was consistent with the certified results, this analytical method is a sensitive tool for analysis of environmental calcium carbonate matrices. Repeated analysis of scallop shell samples collected simultaneously at the same location showed that the trace elements are homogeneously distributed along a stria. The reliability of such in-situ records of biogenic calcium carbonate (scallop shells) is apparent from the inter-individual and inter-annual reproducibility of the trace element profiles. PMID:17200850

Barats, A; Pécheyran, C; Amouroux, D; Dubascoux, S; Chauvaud, L; Donard, O F X

2007-02-01

388

Comparison of Foliar Spray Efficacy of Electrolytically Ozonated Water and Acidic Electrolyzed Oxidizing Water for Controlling Powdery Mildew Infection on Cucumber Leaves  

Microsoft Academic Search

We investigated and compared the effects of foliar sprays of electrolytically ozonated water (OW) and acidic electrolyzed oxidizing water (AEOW) on severity of powdery mildew infection (PMI) and occurrence of visible physiological disorder on cucumber leaves. Foliar spray of OW contained severity of PMI to almost the same level as the initial value, without any visible physiological disorder. Although severity

Kazuhiro Fujiwara; Takuya Fujii; Jong-Seok Park

2009-01-01

389

Urticaria due to calcium pidolate.  

PubMed

Calcium salts are often prescribed in the prevention and treatment of osteoporosis. Adverse reactions have been described, mostly concerning to the gastrointestinal tract, parathyroid glands and bone resorption. We report the case of a 52-year-old woman who started treatment with 500 mg per day of calcium-pidolate. 90 minutes after the intake of the second dose, she experienced an itchy maculopapular eruption. Skin Prick Tests were carried out with the implicated drug and calcium-carbonate and they both were negatives. An oral-challenge-test with 500 mg of calcium-pidolate was ruled out. 60 minutes later, the patient responded positively when she experienced a similar reaction with erythematous and itchy papulae on the trunk and the neck. Finally, an oral-challenge-test with 500 mg calcium-carbonate was performed with good tolerance. To the best of our knowledge, this is the first documented case of allergy to calcium-pidolate with tolerance to other calcium salt. PMID:17338902

Domínguez-Ortega, J; Abad-Schilling, C; Kindelan, C

2007-01-01

390

Maternal-perinatal calcium relationships.  

PubMed

Serum concentrations of total and ionic calcium, magnesium, phosphorus, and albumin were measureed in maternal and cord blood of 115 near-term deliveries. The same measurements (except for ionic calcium) were made in blood obtained from corresponding newborns at 24 hours of age. Cord levels of all components exceeded maternal values, and maternal and cord levels correlated significantly with each other. In the case of calcium, the cord-maternal difference involved both ionic and protein-bound forms. Significant umbilical arterio-venous differences were found only in the case of total calcium, and this difference reflected variation in the protein-bound form only. During the first 24 hours postpartum, total calcium concentration fell (by an average of 0.75 mEq/liter), phosphorus levels rose (by an average of 0.63 mg/dl), and magnesium and albumin did not change significantly. Cord levels of all agents correlated significantly with corresponding neonatal values. In view of the significant positive relationships demonstrated between maternal and cord levels and between cord and neonatal levels, these results substantiate the importance of the maternal serum ionic calcium concentration in normal perinatal calcium homeostasis. PMID:760023

Schauberger, C W; Pitkin, R M

1979-01-01

391

Preparation of acute subventricular zone slices for calcium imaging.  

PubMed

The subventricular zone (SVZ) is one of the two neurogenic zones in the postnatal brain. The SVZ contains densely packed cells, including neural progenitor cells with astrocytic features (called SVZ astrocytes), neuroblasts, and intermediate progenitor cells. Neuroblasts born in the SVZ tangentially migrate a great distance to the olfactory bulb, where they differentiate into interneurons. Intercellular signaling through adhesion molecules and diffusible signals play important roles in controlling neurogenesis. Many of these signals trigger intercellular calcium activity that transmits information inside and between cells. Calcium activity is thus reflective of the activity of extracellular signals and is an optimal way to understand functional intercellular signaling among SVZ cells. Calcium activity has been studied in many other regions and cell types, including mature astrocytes and neurons. However, the traditional method to load cells with calcium indicator dye (i.e. bath loading) was not efficient at loading all SVZ cell types. Indeed, the cellular density in the SVZ precludes dye diffusion inside the tissue. In addition, preparing sagittal slices will better preserve the three-dimensional arrangement of SVZ cells, particularly the stream of neuroblast migration on the rostral-caudal axis. Here, we describe methods to prepare sagittal sections containing the SVZ, the loading of SVZ cells with calcium indicator dye, and the acquisition of calcium activity with time-lapse movies. We used Fluo-4 AM dye for loading SVZ astrocytes using pressure application inside the tissue. Calcium activity was recorded using a scanning confocal microscope allowing a precise resolution for distinguishing individual cells. Our approach is applicable to other neurogenic zones including the adult hippocampal subgranular zone and embryonic neurogenic zones. In addition, other types of dyes can be applied using the described method. PMID:23023088

Lacar, Benjamin; Young, Stephanie Z; Platel, Jean-Claude; Bordey, Angélique

2012-01-01

392

Calcium phosphate ceramics in drug delivery  

NASA Astrophysics Data System (ADS)

Calcium phosphate (CaP) particulates, cements and scaffolds have attracted significant interest as drug delivery vehicles. CaP systems, including both hydroxyapaptite and tricalcium phosphates, possess variable stoichiometry, functionality and dissolution properties which make them suitable for cellular delivery. Their chemical similarity to bone and thus biocompatibility, as well as variable surface charge density contribute to their controlled release properties. Among specific research areas, nanoparticle size, morphology, surface area due to porosity, and chemistry controlled release kinetics are the most active. This article discusses CaP systems in their particulate, cements, and scaffold forms for drug, protein, and growth factor delivery toward orthopedic and dental applications.

Bose, Susmita; Tarafder, Solaiman; Edgington, Joe; Bandyopadhyay, Amit

2011-04-01

393

Calcium stone disease: a multiform reality.  

PubMed

In calcium renal stones, calcium oxalate and calcium phosphate in various crystal forms and states of hydration can be identified. Calcium oxalate monohydrate (COM) or whewellite and calcium oxalate dihydrate (COD) or weddellite are the commonest constituents of calcium stones. Calcium oxalate stones may be pure or mixed, usually with calcium phosphate or sometimes with uric acid or ammonium urate. The aim of this study was to compare the clinical and urinary patterns of patients forming calcium stones of different composition according to infrared spectroscopic analysis in order to obtain an insight into their etiology. The stones of 84 consecutive calcium renal stone formers were examined by infrared spectroscopy. In each patient, a blood sample was drawn and analysed for serum biochemistry and a 24-h urine sample was collected and analysed for calcium, phosphate, oxalate, citrate and other electrolytes. We classified 49 patients as calcium oxalate monohydrate (COM) stone formers, 32 as calcium oxalate dihydrate (COD) stone formers and three as apatite stone formers according to the main component of their stones. Patients with COM stones were significantly older than patients with COD stones (P < 0.002). Mean daily urinary calcium and urinary saturation with respect to calcium oxalate were significantly lower in patients with COM than in those with COD stones (P < 0.000). Patients with calcium oxalate stones containing a urate component (< or = 10%) presented with higher saturation (P < 0.012) with respect to uric acid in their urine (and lower with respect to calcium oxalate and calcium phosphate, respectively P < 0.024 and P < 0.003) in comparison with patients without a urate component in the stone. Patients with calcium oxalate stones with a calcium phosphate component (> or = 15%) showed higher (P < 0.0016) urinary saturation levels with respect to calcium phosphate (and lower with respect to uric acid (P < 0.009), compared with patients forming stones without calcium phosphate or with a low calcium phosphate component. Patients with calcium stones mixed with urate had a significantly lower urinary pH (P < 0.002) and urinary calcium (P < 0.000), and patients with calcium phosphate >15%, higher urinary pH (P < 0.004) and urinary calcium (P < 0.000). In conclusion, in the evaluation of the individual stone patient, an accurate analysis of the stone showing its exact composition and the eventual presence of minor components of the stone is mandatory in order to plan the correct prophylactic treatment. Patients with "calcium stones" could require various approaches dependent on the form and hydration of the calcium crystals in their stones, and on the presence of "minor" crystalline components that could have acted as epitaxial factors. PMID:15714335

Trinchieri, Alberto; Castelnuovo, Chiara; Lizzano, Renata; Zanetti, Giampaolo

2005-06-01

394

Calcium and vitamin D controversies.  

PubMed

Controversies regarding appropriate use of vitamin D and calcium are predominately related to the extraskeletal effects. Calcium and vitamin D are essential for bone health. The concerns regarding calcium and cardiovascular complications are inconclusive at best, and do not warrant a change in our approach to supplementation at this time. A growing body of literature exists suggesting that additional vitamin D may have numerous benefits, although more study needs to be done. Further prospective trials would provide insight into the potential advantages that increased vitamin D supplementation could provide. PMID:22023896

Silver, David S

2011-08-01

395

A Novel Botrytis Species Is Associated with a Newly Emergent Foliar Disease in Cultivated Hemerocallis  

PubMed Central

Foliar tissue samples of cultivated daylilies (Hemerocallis hybrids) showing the symptoms of a newly emergent foliar disease known as ‘spring sickness’ were investigated for associated fungi. The cause(s) of this disease remain obscure. We isolated repeatedly a fungal species which proved to be member of the genus Botrytis, based on immunological tests. DNA sequence analysis of these isolates, using several different phyogenetically informative genes, indicated that they represent a new Botrytis species, most closely related to B. elliptica (lily blight, fire blight) which is a major pathogen of cultivated Lilium. The distinction of the isolates was confirmed by morphological analysis of asexual sporulating cultures. Pathogenicity tests on Hemerocallis tissues in vitro demonstrated that this new species was able to induce lesions and rapid tissue necrosis. Based on this data, we infer that this new species, described here as B. deweyae, is likely to be an important contributor to the development of ‘spring sickness’ symptoms. Pathogenesis may be promoted by developmental and environmental factors that favour assault by this necrotrophic pathogen. The emergence of this disease is suggested to have been triggered by breeding-related changes in cultivated hybrids, particularly the erosion of genetic diversity. Our investigation confirms that emergent plant diseases are important and deserve close monitoring, especially in intensively in-bred plants.

Grant-Downton, Robert T.; Terhem, Razak B.; Kapralov, Maxim V.; Mehdi, Saher; Rodriguez-Enriquez, M. Josefina; Gurr, Sarah J.; van Kan, Jan A. L.; Dewey, Frances M.

2014-01-01

396

Biosynthesis of Gold Nanoparticles by Foliar Broths: Roles of Biocompounds and Other Attributes of the Extracts  

NASA Astrophysics Data System (ADS)

Biosynthesis of nanoparticles has arisen as a promising alternative to conventional synthetic methodologies owing to its eco-friendly advantages, and the involved bioprotocol still needs further clarification. This research, for the first time from the standpoint of statistics, confirmed an electrostatic force or ionic bond-based interaction between the chloroauric ions and the involved bioconstituents and manifested that reducing sugars and flavonoids were both important reductants responsible for conversion of Au(III) to Au(0). The result also demonstrated that the proteins were not the reducing agents, yet they might be protection agents in biosynthesis of gold nanoparticles (GNPs). Besides, a significant linear relationship was found between the anti-oxidant ability of the foliar broths and their capability to reduce Au(III) into Au(0). Furthermore, the preliminary investigation based on the boxplot on the size/shape distribution of the biosynthesized GNPs revealed that gold nanospheres with higher degree of homogeneity in size tended to be promoted by foliar broths containing higher content of reducing sugars/flavonoids and proteins. Otherwise, i.e., for those broths with lower content of the above biocompounds, sphere GNPs of wider size distribution or even gold nanotriangles tended to be fabricated.

Zhou, Yao; Lin, Wenshuang; Huang, Jiale; Wang, Wenta; Gao, Yixian; Lin, Liqin; Li, Qingbiao; Lin, Ling; Du, Mingming

2010-08-01

397

Comparison of calculated and measured foliar O3 flux in crop and forest species.  

PubMed

We designed a new gas exchange system that concurrently measures foliar H2O, O3, and CO2 flux (HOC flux system) while delivering known O3 concentrations. Stomatal responses of three species were tested: snapbean, and seedlings of California black oak (deciduous broadleaf) and blue oak (evergreen broadleaf). Acute O3 exposure (120-250 ppb over an hour) was applied under moderate light and low vapor pressure deficits during near steady state conditions. The rate of stomatal closure was measured when the whole plant was placed in the dark. An adjacent leaf on each plant was also concurrently measured in an O3-free cuvette. Under some conditions, direct measurements and calculated foliar O3 flux were within the same order of magnitude; however, endogenously low gs or O3 exposure-induced depression of gs resulted in an overestimation of calculated O3 fluxes compared with measured O3 fluxes. Sluggish stomata in response to light extinction with concurrent O3 exposure, and incomplete stomatal closure likewise underestimated measured O3 flux. PMID:16777298

Grulke, N E; Paoletti, E; Heath, R L

2007-04-01

398

Effects of simulated sulfuric acid rain on yield, growth, and foliar injury of several crops  

SciTech Connect

This study was designed to reveal patterns of response of major United States crops to sulfuric acid rain. Potted plants were grown in field chambers and exposed to simulated sulfuric acid rain (pH 3.0, 3.5 or 4.0) or to a control rain (pH 5.6). At harvest, the weights of the marketable portion, total aboveground portion and roots were determined for 28 crops. Of these, marketable yield production was inhibited for 5 crops (radish, beet, carrot, mustard greens, broccoli), stimulated for 6 crops (tomato, green pepper, strawberry, alfalfa, orchardgrass, timothy), and ambiguously affected for 1 crop (potato). In addition, stem and leaf production of sweet corn was stimulated. Visible injury of tomatoes might have decreased their marketability. No statistically significant effects on yield were observed for the other 15 crops. The results suggest that the likelihood of yield being affected by acid rain depends on the part of the plant utilized, as well as on species. Effects on the aboveground portions of crops and on roots are also presented. Plants were regularly examined for foliar injury associated with acid rain. Of the 35 cultivars examined, the foliage of 31 was injured at pH 3.0, 28 at pH 3.5, and 5 at pH 4.0. Foliar injury was not generally related to effects on yield. However, foilar injury of swiss chard, mustard greens and spinach was severe enough to adversely affect marketability.

Lee, J.J.; Neely, G.E.; Perrigan, S.C.; Grothaus, L.C.

1980-10-01

399

Biosynthesis of Gold Nanoparticles by Foliar Broths: Roles of Biocompounds and Other Attributes of the Extracts  

PubMed Central

Biosynthesis of nanoparticles has arisen as a promising alternative to conventional synthetic methodologies owing to its eco-friendly advantages, and the involved bioprotocol still needs further clarification. This research, for the first time from the standpoint of statistics, confirmed an electrostatic force or ionic bond-based interaction between the chloroauric ions and the involved bioconstituents and manifested that reducing sugars and flavonoids were both important reductants responsible for conversion of Au(III) to Au(0). The result also demonstrated that the proteins were not the reducing agents, yet they might be protection agents in biosynthesis of gold nanoparticles (GNPs). Besides, a significant linear relationship was found between the anti-oxidant ability of the foliar broths and their capability to reduce Au(III) into Au(0). Furthermore, the preliminary investigation based on the boxplot on the size/shape distribution of the biosynthesized GNPs revealed that gold nanospheres with higher degree of homogeneity in size tended to be promoted by foliar broths containing higher content of reducing sugars/flavonoids and proteins. Otherwise, i.e., for those broths with lower content of the above biocompounds, sphere GNPs of wider size distribution or even gold nanotriangles tended to be fabricated. (See supplementary material 1)

2010-01-01

400

EDU and ozone protection: Foliar glycerolipids and steryl lipids in snapbean exposed to O sub 3  

SciTech Connect

Effects of ethylene diurea (EDU) on foliar lipids in snapbeans before and after a single, acute ozone exposure were assessed. Systemic treatment with EDU slightly reduced membrane lipid content in the first trifoliate leaf. EDU conferred protection against ozone-induced necrosis. Leaves of untreated controls had lost ca 50% of both galacto- (GL) and phospholipids (PL) after a 3 hr exposure to 0.4 ppm O{sub 3}, whereas EDU-treated plants showed no significant loss of foliar GL and PL. A decline in the ratio of mono- to digalactosyl-diacylglycerol (MGDG/DGDG) was associated with the loss of GL, and a decline in the ratio of linoleic to linolenic acid (18:2/18:3) associated with the loss of PL, in untreated controls. The MGDG/DGDG ratio declined only slightly and the 18:2/18:3 ratio in PL increased during O{sub 3} exposure of EDU-treated seedlings. The level of total membrane sterols, including free sterols (FS), acylated steryl glycosides (ASG) and steryl glycosides (SG), did not change during O{sub 3} exposure of either treated or untreated plants. ASG and SG increased at the expense of FS, and the ratio of stigmasterol/sitosterol increased in ASG and SG in controls. In EDU-treated plants, a small increase in SG was offset by a decrease in FS, and there was no change in the stigmasterol/sitosterol ratio in ASG, SG or FS.

Whitaker, B.D.; Lee, E.H.; Rowland, R.A. (USDA/Agricultural Research Service, Beltsville, MD (USA))

1990-05-01

401

Endohyphal Bacterium Enhances Production of Indole-3-Acetic Acid by a Foliar Fungal Endophyte  

PubMed Central

Numerous plant pathogens, rhizosphere symbionts, and endophytic bacteria and yeasts produce the important phytohormone indole-3-acetic acid (IAA), often with profound effects on host plants. However, to date IAA production has not been documented among foliar endophytes -- the diverse guild of primarily filamentous Ascomycota that live within healthy, above-ground tissues of all plant species studied thus far. Recently bacteria that live within hyphae of endophytes (endohyphal bacteria) have been detected, but their effects have not been studied previously. Here we show not only that IAA is produced in vitro by a foliar endophyte (here identified as Pestalotiopsis aff. neglecta, Xylariales), but that IAA production is enhanced significantly when the endophyte hosts an endohyphal bacterium (here identified as Luteibacter sp., Xanthomonadales). Both the endophyte and the endophyte/bacterium complex appear to rely on an L-tryptophan dependent pathway for IAA synthesis. The bacterium can be isolated from the fungus when the symbiotic complex is cultivated at 36°C. In pure culture the bacterium does not produce IAA. Culture filtrate from the endophyte-bacterium complex significantly enhances growth of tomato in vitro relative to controls and to filtrate from the endophyte alone. Together these results speak to a facultative symbiosis between an endophyte and endohyphal bacterium that strongly influences IAA production, providing a new framework in which to explore endophyte-plant interactions.

Hoffman, Michele T.; Gunatilaka, Malkanthi K.; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A. Elizabeth

2013-01-01

402

Calcium apatite prepared from calcium hydroxide and orthophosphoric acid  

Microsoft Academic Search

Calcium hydroxyapatite has been prepared due to a direct precipitation reaction between 0.3m orthophosphoric acid solution and 0.1 mol calcium hydroxide dispersed in 200 ml water. The effect of the addition rate of the acid solution, reaction temperature and mixing molar Ca\\/P ratio is examined on the thermal stability and stoichiometry of the precipitates. Optimum conditions for HAp suitable for

A. Osaka; Y. Miura; K. Takeuchi; M. Asada; K. Takahashi

1991-01-01

403

Biocomposites and hybrid biomaterials based on calcium orthophosphates  

PubMed Central

The state-of-the-art of biocomposites and hybrid biomaterials based on calcium orthophosphates that are suitable for biomedical applications is presented in this review. Since these types of biomaterials offer many significant and exciting possibilities for hard tissue regeneration, this subject belongs to a rapidly expanding area of biomedical research. Through successful combinations of the desired properties of matrix materials with those of fillers (in such systems, calcium orthophosphates might play either role), innovative bone graft biomaterials can be designed. Various types of biocomposites and hybrid biomaterials based on calcium orthophosphates, either those already in use or being investigated for biomedical applications, are extensively discussed. Many different formulations, in terms of the material constituents, fabrication technologies, structural and bioactive properties as well as both in vitro and in vivo characteristics, have already been proposed. Among the others, the nanostructurally controlled biocomposites, those containing nanodimensional compounds, biomimetically fabricated formulations with collagen, chitin and/or gelatin as well as various functionally graded structures seem to be the most promising candidates for clinical applications. The specific advantages of using biocomposites and hybrid biomaterials based on calcium orthophosphates in the selected applications are highlighted. As the way from the laboratory to the hospital is a long one, and the prospective biomedical candidates have to meet many different necessities, this review also examines the critical issues and scientific challenges that require further research and development.

Dorozhkin, Sergey V.

2011-01-01

404

Micropatterned TiO 2 effects on calcium phosphate mineralization  

Microsoft Academic Search

The effects of implant surface topography and chemistry on biomineralization have been a research focus because of their potential importance in orthopedic and bone replacement applications. While a vast amount of research is focusing on chemical modified surfaces and rough surfaces, little attention has been paid to the well-defined micropatterned surface effects on calcium phosphate mineralization process due to the

Lili Jiang; Xiong Lu; Yang Leng; Shuxin Qu; Bo Feng; Jie Weng

2009-01-01

405

High-performance concretes from calcium aluminate cements  

Microsoft Academic Search

Calcium aluminate cements have a radically different chemistry to Portland cements. Due principally to their higher cost, they do not compete directly with Portland cements. Nevertheless, concretes based on these cements have very high performance in specific applications. Two of these are discussed in this article: resistance to acid attack and particularly biogenic corrosion and abrasion resistance in hydraulic structures.

Karen L. Scrivener; Jean-Louis Cabiron; Roger Letourneux

1999-01-01

406

Biocomposites and hybrid biomaterials based on calcium orthophosphates.  

PubMed

The state-of-the-art of biocomposites and hybrid biomaterials based on calcium orthophosphates that are suitable for biomedical applications is presented in this review. Since these types of biomaterials offer many significant and exciting possibilities for hard tissue regeneration, this subject belongs to a rapidly expanding area of biomedical research. Through successful combinations of the desired properties of matrix materials with those of fillers (in such systems, calcium orthophosphates might play either role), innovative bone graft biomaterials can be designed. Various types of biocomposites and hybrid biomaterials based on calcium orthophosphates, either those already in use or being investigated for biomedical applications, are extensively discussed. Many different formulations, in terms of the material constituents, fabrication technologies, structural and bioactive properties as well as both in vitro and in vivo characteristics, have already been proposed. Among the others, the nanostructurally controlled biocomposites, those containing nanodimensional compounds, biomimetically fabricated formulations with collagen, chitin and/or gelatin as well as various functionally graded structures seem to be the most promising candidates for clinical applications. The specific advantages of using biocomposites and hybrid biomaterials based on calcium orthophosphates in the selected applications are highlighted. As the way from the laboratory to the hospital is a long one, and the prospective biomedical candidates have to meet many different necessities, this review also examines the critical issues and scientific challenges that require further research and development. PMID:23507726

Dorozhkin, Sergey V

2011-01-01

407

Bone regeneration: molecular and cellular interactions with calcium phosphate ceramics  

PubMed Central

Calcium phosphate bioceramics are widely used in orthopedic and dental applications and porous scaffolds made of them are serious candidates in the field of bone tissue engineering. They have superior properties for the stimulation of bone formation and bone bonding, both related to the specific interactions of their surface with the extracellular fluids and cells, ie, ionic exchanges, superficial molecular rearrangement and cellular activity.

Barrere, Florence; van Blitterswijk, Clemens A; de Groot, Klaas

2006-01-01

408

Metabolic changes associated with calcium deficiency in potato sprouts  

Microsoft Academic Search

Changes in the major elements and in citric, malic and chlorogenic acids have been studied in relation to sub-apical necrosis of potato sprouts. Both citric and chlorogenic acids accumulated in the necrotic sprout; application of calcium decreased these acids but increased malic acid.

P. C. Dekock; P. W. Dyson; A. Hall; Flora B. Grabowska

1975-01-01

409

Extracellular and intracellular regulation of calcium homeostasis.  

PubMed

An organism with an internal skeleton must accumulate calcium while maintaining body fluids at a well-regulated, constant calcium concentration. Neither calcium absorption nor excretion plays a significant regulatory role. Instead, isoionic calcium uptake and release by bone surfaces causes plasma calcium to be well regulated. Very rapid shape changes of osteoblasts and osteoclasts, in response to hormonal signals, modulate the available bone surfaces so that plasma calcium can increase when more low-affinity bone calcium binding sites are made available and can decrease when more high-affinity binding sites are exposed. The intracellular free calcium concentration of body cells is also regulated, but because cells are bathed by fluids with vastly higher calcium concentration, their major regulatory mechanism is severe entry restriction. All cells have a calcium-sensing receptor that modulates cell function via its response to extracellular calcium. In duodenal cells, the apical calcium entry structure functions as both transporter and a vitamin D--responsive channel. The channel upregulates calcium entry, with intracellular transport mediated by the mobile, vitamin D-dependent buffer, calbindin D9K, which binds and transports more than 90% of the transcellular calcium flux. Fixed intracellular calcium binding sites can, like the body's skeleton, take up and release calcium that has entered the cell, but the principal regulatory tool of the cell is restricted entry. PMID:12805727

Bronner, F

2001-12-22

410

21 CFR 184.1193 - Calcium chloride.  

Code of Federal Regulations, 2010 CFR

... Calcium chloride. (a) Calcium chloride (CaCl2 ·2H2 O...10035-04-8) or anhydrous calcium chloride (CaCl2 , CAS...substitution reactions with other calcium and chloride salts...defined in § 170.3(n)(35) of this chapter;...

2010-01-01

411

21 CFR 184.1193 - Calcium chloride.  

Code of Federal Regulations, 2010 CFR

... Calcium chloride. (a) Calcium chloride (CaCl2 ·2H2 O...10035-04-8) or anhydrous calcium chloride (CaCl2 , CAS...substitution reactions with other calcium and chloride salts...defined in § 170.3(n)(35) of this chapter;...

2009-04-01

412

In vitro release modulation from crosslinked pellets for site-specific drug delivery to the gastrointestinal tract. II. Physicochemical characterization of calcium-alginate, calcium-pectinate and calcium-alginate-pectinate pellets.  

PubMed

Pellets of calcium-alginate, calcium-pectinate and calcium-alginate-pectinate were produced via crosslinking in an aqueous medium for site-specific drug delivery in the gastrointestinal tract. A comparative study of their physicochemical characteristics by means of texture analysis, modulated temperature differential scanning calorimetry (MTDSC), scanning electron microscopy and swelling dynamics under different pH conditions was undertaken. It was found that the incorporation of low methoxylated pectin (i.e., degree of methoxylation approximately 35%) together with alginate appears to influence the degree of crosslinking and subsequently the physical, mechanical and resilience behavior. In general, texture analysis of various pellets indicated that both strength and resilience profiles were in the order of calcium-alginate>/=calcium-alginate-pectinate>calcium-pectinate. Calcium-alginate pellets were found to be viscoelastic, while calcium-pectinate was highly brittle. Through the application of MTDSC, depolymerization transitions, reversing and non-reversing heat flow were determined and interpreted for each formulation. Scanning electron microscopy and micro-thermal analysis revealed distinct morphological differences in each case. The influence of and nature of crosslinking, and textural properties of such pellets on drug release rate modulation is discussed. PMID:10332058

Pillay, V; Fassihi, R

1999-05-20

413

The structural consequences of calcium crystal deposition.  

PubMed

Calcium pyrophosphate dihydrate and basic calcium phosphate (BCP) crystals are the most common calcium-containing crystals associated with rheumatic disease. Clinical manifestations of calcium crystal deposition include acute or chronic inflammatory and degenerative arthritides and certain forms of periarthritis. The intra-articular presence of BCP crystals correlates with the degree of radiographic degeneration. Calcium crystal deposition contributes directly to joint degeneration. Vascular calcification is caused by the deposition of calcium hydroxyapatite crystals in the arterial intima. These deposits may contribute to local inflammation and promote further calcification, thus aggravating the atherosclerotic process. Calcium crystal deposition results in substantial structural consequence in humans. PMID:24703349

Durcan, Laura; Bolster, Ferdia; Kavanagh, Eoin C; McCarthy, Geraldine M

2014-05-01

414

CRESCIMENTO, NUTRIÇÃO MINERAL E NÍVEL CRÍTICO FOLIAR DE K EM MUDAS DE UMBUZEIRO, EM FUNÇÃO DA ADUBAÇÃO POTÁSSICA 1 Growth, mineral nutrition and foliar critical level of K in umbuzeiro seedlings, in function of the potassium fertilization  

Microsoft Academic Search

-3 ). A adubação potássica foi realizada parceladamente, em quatro aplicações, tendo como fontes o sulfato de potássio e o cloreto de potássio. Enquanto para atingir a máxima produção de folhas a dose de potássio foi de 137 mg dm -3 , a máxima produção de raízes só aconteceu na dose de 229 mg dm -3 . Os teores foliares

Orlando Sílvio; Caires Neves; Janice Guedes de Carvalho; Eric Victor de Oliveira Ferreira; Natália Victor Pereira

415

Regeneration of Calcium-Based SO2 Sorbents for Fluidized-Bed Combustion: Engineering Evaluation.  

National Technical Information Service (NTIS)

The report gives results of an engineering evaluation of regeneration of calcium-based SO2 sorbents (limestone and dolomite) for application in both atmospheric and pressurized fluidized-bed combustion (FBC) processes. Economics of FBC power plants, opera...

R. A. Newby S. Katta D. L. Keairns

1978-01-01

416

Calcium, vitamin D and cancer.  

PubMed

A low vitamin D status and inadequate calcium intake are important risk factors for various types of cancer. Ecological studies using solar UV-B exposure as an index of vitamin D3 photoproduction in the skin found a highly significant inverse association between UV-B and mortality in fifteen types of cancer. Of these, colon, rectal, breast, gastric, endometrial, renal and ovarian cancer exhibit a significant inverse relationship between incidence and oral intake of calcium. In addition, lung and endometrial cancer as well as multiple myeloma are considered calcium and vitamin D sensitive. Studies on tissue-specific expression of the CYP27B1-encoded 25-hdroxyvitamin D-1alpha-hydroxylase and of the extracellular calcium-sensing receptor (CaR) have led to an understanding how locally produced 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and extracellular Ca2+ act jointly as key regulators of cellular proliferation, differentiation and function. Thus, impairment of antimitogenic, proapoptotic and prodifferentiating signaling from the 1,25(OH)2D3-activated vitamin D receptor (VDR) and from the CaR in vitamin D and calcium insufficiency has been implicated in the pathogenesis of the aforementioned types of cancer. 1,25(OH)2D3 and calcium interact in modulating cell growth in different ways: (i) Signaling pathways from the VDR and the CaR converge on the same downstream elements, e.g. of the canonical Wnt pathway; (ii) high extracellular calcium modulates extrarenal vitamin D metabolism in favor of higher local steady-state concentrations of 1,25(OH)2D3; (iii) 1,25(OH)2D3 may up-regulate expression of the CaR and thus augment CaR-mediated antiproliferative responses to high extracellular Ca2+. This can explain why combined supplementation is required for optimal chemoprevention of cancer by calcium and vitamin D. PMID:19667166

Peterlik, Meinrad; Grant, William B; Cross, Heide S

2009-09-01

417

Medical therapy, calcium oxalate urolithiasis  

NASA Technical Reports Server (NTRS)

The development of diagnostic protocols that identify specific risk factors for calcium oxalate nephrolithiasis has led to the formulation of directed medical regimens that are aimed at correcting the underlying metabolic disturbances. Initiation of these treatment programs has reduced markedly the rate of stone formation in the majority of patients who form stones. This article discusses the rationale that underlies the choice of medical therapy for the various pathophysiologic causes of calcium oxalate nephrolithiasis and the appropriate use of available medications.

Ruml, L. A.; Pearle, M. S.; Pak, C. Y.

1997-01-01

418

IP3 Receptor-Operated Calcium Entry  

NSDL National Science Digital Library

This Perspective by Mikoshiba and Hattori is the third in a series on cellular calcium release mechanisms. The authors describe the regulated release of calcium from intracellular stores by the inositol 1,4,5 trisphosphate receptor (IP3R) and the relationship of this release mechanism to calcium influx from the extracellular milieu through store-operated calcium channels. They discuss a model proposing that intracellular and plasma membrane calcium channels are functionally and physically coupled.

Katsuhiko Mikoshiba (Japan;University of Tokyo and the Laboratory for Developmental Neurobiology REV); Mitsuharu Hattori (Japan;University of Tokyo and the Laboratory for Developmental Neurobiology REV)

2000-09-26

419

Calcium channel function in hypertension.  

PubMed

Calcium channel function is fundamental to membrane excitation in vascular muscle, and imparts the notable voltage sensitivity to small blood vessels. The actions of the electrogenic sodium pump on membrane potential, and thus calcium channels, can explain perturbations that could alternately be conceived as acting on other mechanisms. Evidence for altered calcium channel function in hypertension suggests that deficiencies in function of the calcium channel per se lie at the root of altered membrane function. In this respect the disease may be similar to at least one form of skeletal muscle dysgenesis. Proportional increases in BP and Ca2+ current in vascular muscle of stroke-prone genetically hypertensive rats further strengthen this hypothesis of altered Ca2+ channel function in hypertension. Increased calcium in the subsarcolemmal space and several recently discovered substances that may endogenously modulate Ca2+ channels are additional evidence for abnormal Ca2+ channel function in BP regulation. From several kinds of evidence and multiple investigators, it is reasonable to conclude that calcium channel malfunction plays an important role in the vascular muscle contribution to hypertension. PMID:8389872

Hermsmeyer, K

1993-04-01

420

Effect of Microgravity on Bone Tissue and Calcium Metabolism  

NASA Technical Reports Server (NTRS)

Session TA4 includes short reports concerning: (1) Human Bone Tissue Changes after Long-Term Space Flight: Phenomenology and Possible Mechanics; (2) Prediction of Femoral Neck Bone Mineral Density Change in Space; (3) Dietary Calcium in Space; (4) Calcium Metabolism During Extended-Duration Space Flight; (5) External Impact Loads on the Lower Extremity During Jumping in Simulated Microgravity and the Relationship to Internal Bone Strain; and (6) Bone Loss During Long Term Space Flight is Prevented by the Application of a Short Term Impulsive Mechanical Stimulus.

1997-01-01

421

Calcium metabolism and cardiovascular function after spaceflight  

NASA Technical Reports Server (NTRS)

To determine the influence of dietary calcium on spaceflight-induced alterations in calcium metabolism and blood pressure (BP), 9-wk-old spontaneously hypertensive rats, fed either high- (2%) or low-calcium (0.02%) diets, were flown on an 18-day shuttle flight. On landing, flight animals had increased ionized calcium (P < 0.001), elevated parathyroid hormone levels (P < 0.001), reduced calcitonin levels (P < 0.05), unchanged 1,25(OH)(2)D(3) levels, and elevated skull (P < 0.01) and reduced femur bone mineral density. Basal and thrombin-stimulated platelet free calcium (intracellular calcium concentration) were also reduced (P < 0.05). There was a tendency for indirect systolic BP to be reduced in conscious flight animals (P = 0.057). However, mean arterial pressure was elevated (P < 0.001) after anesthesia. Dietary calcium altered all aspects of calcium metabolism (P < 0.001), as well as BP (P < 0.001), but the only interaction with flight was a relatively greater increase in ionized calcium in flight animals fed low- compared with high-calcium diets (P < 0.05). The results indicate that 1) flight-induced disruptions of calcium metabolism are relatively impervious to dietary calcium in the short term, 2) increased ionized calcium did not normalize low-calcium-induced elevations of BP, and 3) parathyroid hormone was paradoxically increased in the high-calcium-fed flight animals after landing.

Hatton, Daniel C.; Yue, Qi; Dierickx, Jacqueline; Roullet, Chantal; Otsuka, Keiichi; Watanabe, Mitsuaki; Coste, Sarah; Roullet, Jean Baptiste; Phanouvang, Thongchan; Orwoll, Eric; Orwoll, Shiela; McCarron, David A.

2002-01-01

422

The effects of foliar fertilization with iron sulfate in chlorotic leaves are limited to the treated area. A study with peach trees (Prunus persica L. Batsch) grown in the field and sugar beet (Beta vulgaris L.) grown in hydroponics  

PubMed Central

Crop Fe deficiency is a worldwide problem. The aim of this study was to assess the effects of foliar Fe applications in two species grown in different environments: peach (Prunus persica L. Batsch) trees grown in the field and sugar beet (Beta vulgaris L. cv. “Orbis”) grown in hydroponics. The distal half of Fe-deficient, chlorotic leaves was treated with Fe sulfate by dipping and using a brush in peach trees and sugar beet plants, respectively. The re-greening of the distal (Fe-treated) and basal (untreated) leaf areas was monitored, and the nutrient and photosynthetic pigment composition of the two areas were also determined. Leaves were also studied using chlorophyll fluorescence imaging, low temperature-scanning electron microscopy microanalysis, scanning transmission ion microscopy-particle induced X-ray emission and Perls Fe staining. The distal, Fe-treated leaf parts of both species showed a significant increase in Fe concentrations (across the whole leaf volume) and marked re-greening, with significant increases in the concentrations of all photosynthetic pigments, as well as decreases in de-epoxidation of xanthophyll cycle carotenoids and increases in photochemical efficiency. In the basal, untreated leaf parts, Fe concentrations increased slightly, but little re-greening occurred. No changes in the concentrations of other nutrients were found. Foliar Fe fertilization was effective in re-greening treated leaf areas both in peach trees and sugar beet plants. Results indicate that the effects of foliar Fe-sulfate fertilization in Fe-deficient, chlorotic leaves were minor outside the leaf surface treated, indicating that Fe mobility within the leaf is a major constraint for full fertilizer effectiveness in crops where Fe-deficiency is established and leaf chlorosis occurs.

El-Jendoubi, Hamdi; Vazquez, Saul; Calatayud, Angeles; Vavpetic, Primoz; Vogel-Mikus, Katarina; Pelicon, Primoz; Abadia, Javier; Abadia, Anunciacion; Morales, Fermin

2014-01-01

423

The effects of foliar fertilization with iron sulfate in chlorotic leaves are limited to the treated area. A study with peach trees (Prunus persica L. Batsch) grown in the field and sugar beet (Beta vulgaris L.) grown in hydroponics.  

PubMed

Crop Fe deficiency is a worldwide problem. The aim of this study was to assess the effects of foliar Fe applications in two species grown in different environments: peach (Prunus persica L. Batsch) trees grown in the field and sugar beet (Beta vulgaris L. cv. "Orbis") grown in hydroponics. The distal half of Fe-deficient, chlorotic leaves was treated with Fe sulfate by dipping and using a brush in peach trees and sugar beet plants, respectively. The re-greening of the distal (Fe-treated) and basal (untreated) leaf areas was monitored, and the nutrient and photosynthetic pigment composition of the two areas were also determined. Leaves were also studied using chlorophyll fluorescence imaging, low temperature-scanning electron microscopy microanalysis, scanning transmission ion microscopy-particle induced X-ray emission and Perls Fe staining. The distal, Fe-treated leaf parts of both species showed a significant increase in Fe concentrations (across the whole leaf volume) and marked re-greening, with significant increases in the concentrations of all photosynthetic pigments, as well as decreases in de-epoxidation of xanthophyll cycle carotenoids and increases in photochemical efficiency. In the basal, untreated leaf parts, Fe concentrations increased slightly, but little re-greening occurred. No changes in the concentrations of other nutrients were found. Foliar Fe fertilization was effective in re-greening treated leaf areas both in peach trees and sugar beet plants. Results indicate that the effects of foliar Fe-sulfate fertilization in Fe-deficient, chlorotic leaves were minor outside the leaf surface treated, indicating that Fe mobility within the leaf is a major constraint for full fertilizer effectiveness in crops where Fe-deficiency is established and leaf chlorosis occurs. PMID:24478782

El-Jendoubi, Hamdi; Vázquez, Saúl; Calatayud, Angeles; Vavpeti?, Primož; Vogel-Mikuš, Katarina; Pelicon, Primož; Abadía, Javier; Abadía, Anunciación; Morales, Fermín

2014-01-01

424

FOLIAR LEACHING AND ROOT UPTAKE OF CA, MG, AND K IN RELATION TO ACID FOG EFFECTS ON DOUGLAS-FIR  

EPA Science Inventory

The impact of acid fog on foliar leaching and root uptake of Ca, Mg, and K by Douglas-fir (Pseudotsuga menziesii) seedlings was examined. n a factorial experiment, 1-year old seedlings were grown in solution culture at two levels of nutrient availability (low and moderate) and ex...

425

Foliar Leaching and Root Uptake of Ca, Mg and K in Relation to Acid Fog Effects on Douglas-Fir.  

National Technical Information Service (NTIS)

The impact of acid fog on foliar leaching and root uptake of Ca, Mg, and K by Douglas-fir (Pseudotsuga menziesii) seedlings was examined. In a factorial experiment, 1-year old seedlings were grown in a solution culture at two levels of nutrient availabili...

D. P. Turner D. T. Tingey

1990-01-01

426

[Characteristics of foliar delta13C values of common shrub species in various microhabitats with different karst rocky desertification degrees].  

PubMed

By measuring the foliar delta13C values of 5 common shrub species (Rhamnus davurica, Pyracantha fortuneana, Rubus biflorus, Zanthoxylum planispinum, and Viburnum utile) growing in various microhabitats in Wangjiazhai catchment, a typical karst desertification area in Guizhou Province, this paper studied the spatial heterogeneity of plant water use at niche scale and the response of the heterogeneity to different karst rocky desertification degrees. The foliar delta13C values of the shrub species in the microhabitats followed the order of stony surface > stony gully > stony crevice > soil surface, and those of the majority of the species were more negative in the microhabitat soil surface than in the others. The foliar delta13C values decreased in the sequence of V. utile > R. biflorus > Z. planispinum > P. fortuneana > R. davurica, and the mean foliar delta13C value of the shrubs and that of typical species in various microhabitats all increased with increasing karst rocky desertification degree, differed significantly among different microhabitats. It was suggested that with the increasing degree of karst rocky desertification, the structure and functions of karst habitats were impaired, microhabitats differentiated gradually, and drought degree increased. PMID:22384573

Du, Xue-Lian; Wang, Shi-Jie; Rong, Li

2011-12-01

427

Isolation and characterization of a Fusarium virguliforme toxin that induces foliar sudden death syndrome in soybean [Glycine max (L.) Merr.  

Microsoft Academic Search

Fusarium virguliforme (Fv) is the causal organism of the sudden death syndrome (SDS) in soybean (Glycine max [L.] Merr). The estimated average annual soybean yield loss from this disease is valued at about 300 million dollars. F. virguliforme is a soil borne fungus, which attacks soybean roots and causes root rot as well as chlorosis and necrosis in foliar tissues.

Hargeet Kaur Brar

2010-01-01

428

Modulation of Intercellular Calcium Signaling by Melatonin, in Avian and Mammalian Astrocytes, is Brain Region Specific  

PubMed Central

Calcium waves among glial cells impact many central nervous system functions, including neural integration and brain metabolism. Here, we have characterized the modulatory effects of melatonin, a pineal neurohormone that mediates circadian and seasonal processes, on glial calcium waves derived from different brain regions and species. Diencephalic and telencephalic astrocytes, from both chick and mouse brains, expressed melatonin receptor proteins. Further, using the calcium-sensitive dye Fluo-4, we conducted real-time imaging analyses of calcium waves propagated among mammalian and avian astrocytes. Mouse diencephalic astrocytic calcium waves spread to an area 2-5 fold larger than waves among avian astrocytes and application of 10 nM melatonin caused a 32% increase in the spread of these mammalian calcium waves, similar to the 23% increase observed in chick diencephalic astrocytes. In contrast, melatonin had no effect on calcium waves in either avian or mammalian telencephalic astrocytes. Mouse telencephalic calcium waves radially spread from their initiation site among untreated astrocytes. However, waves meandered among mouse diencephalic astrocytes, taking heterogeneous paths at variable rates of propagation. Brain regional differences in wave propagation were abolished by melatonin, as diencephalic astrocytes acquired more telencephalon-like wave characteristics. Astrocytes cultured from different brain regions, therefore, possess fundamentally disparate mechanisms of calcium wave propagation and responses to melatonin. These results suggest multiple roles for melatonin receptors in the regulation of astroglial function, impacting specific brain regions differentially.

Peters, Jennifer L.; Earnest, Barbara J.; Tjalkens, Ronald B.; Cassone, Vincent M.; Zoran, Mark J.

2008-01-01

429

Foliar retention of 15N tracers: implications for net canopy exchange in low- and high-elevation forest ecosystems  

SciTech Connect

Nitrogen-15 ({sup 15}N) labelled ammonium and nitrate were applied to understory saplings in a low-elevation deciduous forest and a high-elevation coniferous forest during the 1993 growing season to estimate the minimum retention of inorganic N from wet deposition. Tissue samples were collected at both sites before and after the tracer applications to determine the initial and the final {sup 15}N content. The fraction of the tracer application retained by deciduous leaves or by current-year leaves and stems on conifers was calculated from measurements of {sup 15}N and total N content. At both study sites, tracer applications significantly increased the {sup 15}N content of sapling tissues, although there was no significant difference between the fractional retention of ammonium and nitrate. The results support earlier studies indicating that the foliar retention of {sup 15}N applied in simulated wet deposition is small. Our estimates of annual N uptake from wet deposition by the forest canopy at the low- and high-elevation study sites were only 14 and 7%, respectively. This study, along with prior studies of the different chemical forms of N deposition, indicates that canopy uptake of dry N deposition is a major contributor to the net canopy exchange of N in both forests.

Garten Jr, Charles T [ORNL; Schwab, Alison [ORNL; Shirshac, Terri [ORNL

1998-04-01

430

Localised calcium release events in cells from the muscle of guinea-pig gastric fundus  

PubMed Central

After enzymatic dispersion of the muscle of the guinea-pig gastric fundus, single elongated cells were observed which differed from archetypal smooth muscle cells due to their knurled, tuberose or otherwise irregular surface morphology. These, but not archetypal smooth muscle cells, consistently displayed spontaneous localized (i.e. non-propagating) intracellular calcium ([Ca2+]i) release events. Such calcium events were novel in their magnitude and kinetic profiles. They included short transient events, plateau events and events which coalesced spatially or temporally (compound events). Quantitative analysis of the events with an automatic detection programme showed that their spatio-temporal characteristics (full width and full duration at half-maximum amplitude) were approximately exponentially distributed. Their amplitude distribution suggested the presence of two release modes. Carbachol application caused an initial cell-wide calcium transient followed by an increase in localized calcium release events. Pharmacological analysis suggested that localized calcium release was largely dependent on external calcium entry acting on both inositol trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs) to release stored calcium. Nominally calcium-free external solution immediately and reversibly abolished all localized calcium release without blocking the initial transient calcium release response to carbachol. This was inhibited by 2-APB (100 ?m), ryanodine (10 or 50 ?m) or U-73122 (1 ?m). 2-APB (100 ?m), xestospongin C (XeC, 10 ?m) or U-73122 (1 ?m) blocked both spontaneous localized calcium release and localized release stimulated by 10 ?m carbachol. Ryanodine (50 ?m) also inhibited spontaneous release, but enhanced localized release in response to carbachol. This study represents the first characterization of localized calcium release events in cells from the gastric fundus.

Parsons, S P; Bolton, T B

2004-01-01

431

Localised calcium release events in cells from the muscle of guinea-pig gastric fundus.  

PubMed

After enzymatic dispersion of the muscle of the guinea-pig gastric fundus, single elongated cells were observed which differed from archetypal smooth muscle cells due to their knurled, tuberose or otherwise irregular surface morphology. These, but not archetypal smooth muscle cells, consistently displayed spontaneous localized (i.e. non-propagating) intracellular calcium ([Ca(2+)](i)) release events. Such calcium events were novel in their magnitude and kinetic profiles. They included short transient events, plateau events and events which coalesced spatially or temporally (compound events). Quantitative analysis of the events with an automatic detection programme showed that their spatio-temporal characteristics (full width and full duration at half-maximum amplitude) were approximately exponentially distributed. Their amplitude distribution suggested the presence of two release modes. Carbachol application caused an initial cell-wide calcium transient followed by an increase in localized calcium release events. Pharmacological analysis suggested that localized calcium release was largely dependent on external calcium entry acting on both inositol trisphosphate receptors (IP(3)Rs) and ryanodine receptors (RyRs) to release stored calcium. Nominally calcium-free external solution immediately and reversibly abolished all localized calcium release without blocking the initial transient calcium release response to carbachol. This was inhibited by 2-APB (100 microm), ryanodine (10 or 50 microm) or U-73122 (1 microm). 2-APB (100 microm), xestospongin C (XeC, 10 microm) or U-73122 (1 microm) blocked both spontaneous localized calcium release and localized release stimulated by 10 microm carbachol. Ryanodine (50 microm) also inhibited spontaneous release, but enhanced localized release in response to carbachol. This study represents the first characterization of localized calcium release events in cells from the gastric fundus. PMID:14608011

Parsons, S P; Bolton, T B

2004-02-01

432

Calcium carbonate binding mechanisms in the setting of calcium and calcium–magnesium putty-limes  

Microsoft Academic Search

Calcium and calcium magnesium putty-limes (C-L and C-M-L) were characterized, through SEM, Porosimeter and Chemical Analysis, to obtain information on the microstructure of their solid-phases. Irregular agglomerates of portlandite grains and large acicular crystallites of brucite are differently interconnected to form a cellular solid matrix dispersed into the saturated aqueous solution of the hydroxides. The setting of these putty-limes was

Dario T. Beruto; Fabrizio Barberis; Rodolfo Botter

2005-01-01

433