These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Foliar nickel application alleviates detrimental effects of glyphosate drift on yield and seed quality of wheat.  

PubMed

Glyphosate drift to nontarget crops causes growth aberrations and yield losses. This herbicide can also interact with divalent nutrients and form poorly soluble complexes. The possibility of using nickel (Ni), an essential divalent metal, for alleviating glyphosate drift damage to wheat was investigated in this study. Effects of Ni applications on various growth parameters, seed yield, and quality of durum wheat ( Triticum durum ) treated with sublethal glyphosate at different developmental stages were investigated in greenhouse experiments. Nickel concentrations of various plant parts and glyphosate-induced shikimate accumulation were measured. Foliar but not soil Ni applications significantly reduced glyphosate injuries including yield losses, stunting, and excessive tillering. Both shoot and grain Ni concentrations were enhanced by foliar Ni treatment. Seed germination and seedling vigor were impaired by glyphosate and improved by foliar Ni application to parental plants. Foliar Ni application appears to have a great potential to ameliorate glyphosate drift injury to wheat. PMID:23882996

Kutman, Bahar Yildiz; Kutman, Umit Baris; Cakmak, Ismail

2013-09-01

2

IMPACTS OF AN EXOTIC DISEASE AND VEGETATION CHANGE ON FOLIAR CALCIUM CYCLING IN APPALACHIAN FORESTS  

Microsoft Academic Search

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

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

2007-01-01

3

Acidic mist reduces foliar membrane-associated calcium and impairs stomatal responsiveness in red spruce  

Microsoft Academic Search

Summary Acidic deposition can leach essential pools of cal- cium (Ca) directly from plant foliage. Because of the central role of Ca in environmental signal transduction, disruptions of labile foliar Ca pools could impair physiological responses to a variety of environmental stimuli and stressors. We investigated the possibility that acidic mist-induced depletion of mem- brane-associated Ca (mCa), which is one

CATHERINE H. BORER; PAUL G. SCHABERG; DONALD H. DEHAYES

4

Effects of Boron Foliar Applications on Vegetative and Reproductive Growth of Sunflower  

PubMed Central

Foliar application may be used to supply boron (B) to a crop when B demands are higher than can be supplied via the soil. While B foliar sprays have been used to correct B deficiency in sunflower (Helianthus annuus L.) in the field, no studies have determined the amount of B taken up by sunflower plant parts via foliar application. A study was conducted in which sunflower plants were grown at constant B concentration in nutrient solution with adequate B (46 µm) or with limited B supply (0·24, 0·40 and 1·72 µm) using Amberlite IRA?743 resin to control B supply. At the late vegetative stage of growth (25 and 35 d after transplanting), two foliar sprays were applied of soluble sodium tetraborate (20·8 % B) each at 0, 28, 65, 120 and 1200 mm (each spray equivalent to 0, 0·03, 0·07, 0·13 and 1·3 kg B ha–1 in 100 L water ha–1). The highest rate of B foliar fertilization resulted in leaf burn but had no other evident detrimental effect on plant growth. Under B?deficient conditions, B foliar application increased the vegetative and reproductive dry mass of plants. Foliar application of 28–1200 mm B increased the total dry mass of the most B?deficient plants by more than three?fold and that of plants grown initially with 1·72 µm B in solution by 37–49 %. In this latter treatment, the dry mass of the capitulum was similar to that achieved under control conditions, but in no instance was total plant dry mass similar to that of the control. All B foliar spray rates increased the B concentration in various parts of the plant tops, including those that developed after the sprays were applied, but the B concentration in the roots was not increased by B foliar application. The B concentration in the capitulum of the plants sprayed at the highest rate was between 37 and 93 % of that in the control plants. This study showed that B foliar application was of benefit to B?deficient sunflower plants, increasing the B status of plant tops, including that of the capitulum which developed after the B sprays were applied. PMID:12933368

ASAD, A.; BLAMEY, F. P. C.; EDWARDS, D. G.

2003-01-01

5

Physiological Response of Wheat to Foliar Application of Zinc and Inoculation with some Bacterial Fertilizers  

Microsoft Academic Search

In a pot experiment, sterilized sandy soil (irrigated with Long-Ashton nutrient solution containing a half of the recommended dose of ZnSO4 · 7H2O) was used to study the effects of zinc (Zn) foliar-application, and soil biofertilization on some physiological traits of wheat (Triticum aestivum cv. Sakha 155) plant grown for 70 days in greenhouse under controlled conditions. The treatments comprised different levels

Mohsen K. H. Ebrahim; Magda M. Aly

2005-01-01

6

The recovery of citrus from iron chlorosis using different foliar applications. Effects on fruit quality  

Microsoft Academic Search

The response of Encore trees grown on a calcareous soil to different foliar applications to offset iron deficiency. Four treatments\\u000a were tested: distilled water (control); iron (II) sulphate (500 mg Fe.L?1); sulphuric acid (0.5 mM H2SO4) and Fe-EDDHA (120 mg Fe.L?1). The recovery from iron chlorosis was evaluated with the SPAD apparatus and the values converted to total chlorophyll density.

M. Pestana; D. A. Gonçalves; A. Varennes; E. A. Faria

7

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

8

Premixed calcium silicate cement for endodontic applications  

PubMed Central

Calcium silicate-based materials (also called MTA) are increasingly being used in endodontic applications. However, the handling properties of MTA are not optimal when it comes to injectability and cohesion. Premixing the cements using glycerol avoids these issues. However, there is a lack of data on the effect of common cement variables on important properties of premixed cements for endodontic applications. In this study, the effects of liquid-to-powder ratio, amount of radiopacifier and amount of calcium sulfate (added to control the setting time) were screened using a statistical model. In the second part of the study, the liquid-to-powder ratio was optimized for cements containing three different amounts of radiopacifier. Finally, the effect of using glycerol rather than water was evaluated in terms of radiopacity. The setting time was found to increase with the amount of radiopacifier when the liquid-to-powder ratio was fixed. This was likely due to the higher density of the radiopacifier in comparison to the calcium silicate, which gave a higher liquid-to-powder ratio in terms of volume. Using glycerol rather than water to mix the cements led to a decrease in radiopacity of the cement. In conclusion, we were able to produce premixed calcium silicate cements with acceptable properties for use in endodontic applications. PMID:23507729

Persson, Cecilia; Engqvist, Hakan

2011-01-01

9

Foliar potassium nitrate application improves the tolerance of Citrus macrophylla L. seedlings to drought conditions.  

PubMed

Scarcity of water is a severe limitation in citrus tree productivity. There are few studies that consider how to manage nitrogen (N) nutrition in crops suffering water deficit. A pot experiment under controlled-environment chambers was conducted to explore if additional N supply via foliar application could improve the drought tolerance of Citrus macrophylla L. seedlings under dry conditions. Two-month-old seedlings were subjected to a completely random design with two water treatments (drought stress and 100% water/field capacity). Plants under drought stress (DS) received three different N supplies via foliar application (DS: 0, DS + NH4NO3: 2% NH4NO3, DS + KNO3: 2% KNO3). KNO3-spraying increased leaf and stem DW as compared with DS + NH4NO3 and DS treatments. Leaf water potential (?w) was decreased by drought stress in all the treatments. However, in plants from DS + NH4NO and DS + KNO3, this was due to a decrease in the leaf osmotic potential, whereas the decrease in those from the DS treatment was due to a decrease in the leaf turgor potential. These responses were correlated with the leaf proline and K concentrations. DS + KNO3-treated plants had a higher leaf proline and K concentration than DS-treated plants. In terms of leaf gas exchange parameters, it was observed that net assimilation of CO2 [Formula: see text] was decreased by drought stress, but this reduction was much lower in DS + KNO3-treated plants. Thus, when all results are taken into account, it can be concluded that a 2% foliar-KNO3 application can enhance the tolerance of citrus plants to water stress by increasing the osmotic adjustment process. PMID:25218731

Gimeno, V; Díaz-López, L; Simón-Grao, S; Martínez, V; Martínez-Nicolás, J J; García-Sánchez, F

2014-10-01

10

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

11

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

12

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

13

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

14

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 PMID:16667322

Schon, Mary K.; Blevins, Dale G.

1990-01-01

15

Inhibition of powdery mildew development and activation of antioxidant enzymes by induction of oxidative stress with foliar application of a mixture of riboflavin and methionine in cucumber  

Microsoft Academic Search

Powdery mildew (Sphaerotheca fuliginea Pollacci) infection in cucumber was significantly reduced by foliar application of a mixture of riboflavin and methionine (RM). The effects of fungicidal activity on leaves applied with RM were detected through restriction of progress of colonies and disease severity compared with control plants. The initial response to foliar application of RM was abrupt generation of hydrogen

Nam Jun Kang

2008-01-01

16

Effect of foliar salicylic acid and methyl jasmonate applications on protection against pill-bugs in lettuce plants ( Lactuca sativa )  

Microsoft Academic Search

The effects were examined of plant-response signaling compounds, salicylic acid (SA) and methyl jasmonate (MeJA), on resistance\\u000a to pill-bugs (Armadillidium vulgare) attack in lettuce plants. Foliar SA and MeJA applications were made at weekly intervals from the emergence of the plant until\\u000a one week before harvesting. SA and MeJA induced detectable levels of hydrogen peroxide (H2O2) at least during 5 days

Nancy Tierranegra-García; Patricia Salinas-Soto; Irineo Torres-Pacheco; Rosalia V. Ocampo-Velázquez; Enrique Rico-García; Sandra O. Mendoza-Diaz; Ana A. Feregrino-Pérez; Adán Mercado-Luna; Marcela Vargas-Hernandez; Genaro M. Soto-Zarazúa; Ramón G. Guevara-González

2011-01-01

17

Effect of pre-harvest calcium chloride applications on fruit calcium level and post-harvest anthracnose disease of papaya  

E-print Network

deficiency could be reduced by calcium spraying (Kader, 2002). However, there are few re- ports about effectsEffect of pre-harvest calcium chloride applications on fruit calcium level and post October 2013 Keywords: Papaya Anthracnose Calcium Disease incidence Disease severity a b s t r a c

Biggs, Alan R.

18

Calcium  

MedlinePLUS

... when taken with food. Some over-the-counter antacid products, such as Tums® and Rolaids®, contain calcium ... calcium excretion and thereby lower blood calcium levels. Antacids containing aluminum or magnesium increase calcium loss in ...

19

Calcium  

MedlinePLUS

... lead levels. Calcium carbonate is used as an antacid for “heartburn.” Calcium carbonate and calcium acetate are ... when given intravenously (by IV). Use as an antacid as calcium carbonate. Reducing phosphate levels in people ...

20

Agricultural and Forest Meteorology 107 (2001) 167175 Reduction of transpiration through foliar application of chitosan  

E-print Network

Agricultural and Forest Meteorology 107 (2001) 167­175 Reduction of transpiration through foliar of chitosan, a natural beta-1-4-linked glucosamine polymer, to reduce plant transpiration. Chitosan-chambers, where transpiration was measured by weighing pots. In an accompanying field study, water use

Flury, Markus

21

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

22

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

23

Carbohydrates in plant immunity and plant protection: roles and potential application as foliar sprays  

PubMed Central

Increasing interest is devoted to carbohydrates for their roles in plant immunity. Some of them are elicitors of plant defenses whereas other ones act as signaling molecules in a manner similar to phytohormones. This review first describes the main classes of carbohydrates associated to plant immunity, their role and mode of action. More precisely, the state of the art about perception of “PAMP, MAMP, and DAMP (Pathogen-, Microbe-, Damage-Associated Molecular Patterns) type” oligosaccharides is presented and examples of induced defense events are provided. A particular attention is paid to the structure/activity relationships of these compounds. The role of sugars as signaling molecules, especially in plant microbe interactions, is also presented. Secondly, the potentialities and limits of foliar sprays of carbohydrates to stimulate plant immunity for crop protection against diseases are discussed, with focus on the roles of the leaf cuticle and phyllosphere microflora. PMID:25408694

Trouvelot, Sophie; Héloir, Marie-Claire; Poinssot, Benoît; Gauthier, Adrien; Paris, Franck; Guillier, Christelle; Combier, Maud; Trdá, Lucie; Daire, Xavier; Adrian, Marielle

2014-01-01

24

Quinclorac Ester Toxicity and Metabolism in Leafy Spurge ( Euphorbia esula) Soil Systems: Effects of Foliar vs Soil Applications  

Microsoft Academic Search

Quinclorac and 13 synthesized esters were monitored for toxicity in foliar- and soil-treated leafy spurge plants. Foliar treatment at 0.5 ?mol\\/plant with quinclorac resulted with 100% mortality, whereas treatment with esters at 2 ?mol\\/plant showed initial toxicity symptoms, but the plants recovered with time (24 weeks). Foliar toxicity symptoms and mortality increased throughout 24 weeks after soil treatment at 0.4

Donald G. Rusness; Janice K. Huwe; Gerald L. Lamoureux

1998-01-01

25

First evidence on phloem transport of nanoscale calcium oxide in groundnut using solution culture technique  

NASA Astrophysics Data System (ADS)

Nanoscale materials, whose size typically falls below 100 nm, exhibit novel chemical, physical and biological properties which are different from their bulk counterparts. In the present investigation, we demonstrated that nanoscale calcium oxide particles (n-CaO) could transport through phloem tissue of groundnut unlike the corresponding bulk materials. n-CaO particles are prepared using sol-gel method. The size of the as prepared n-CaO measured (69.9 nm) using transmission electron microscopic technique (TEM). Results of the hydroponics experiment using solution culture technique revealed that foliar application of n-CaO at different concentrations (10, 50, 100, 500, 1,000 ppm) on groundnut plants confirmed the entry of calcium into leaves and stems through phloem compared to bulk source of calcium sprayed (CaO and CaNO3). After spraying of n-CaO, calcium content in roots, shoots and leaves significantly increased. Based on visual scoring of calcium deficiency correction and calcium content in plant parts, we may establish the fact that nanoscale calcium oxide particles (size 69.9 nm) could move through phloem tissue in groundnut. This is the first report on phloem transport of nanoscale calcium oxide particles in plants and this result points to the use of nanoscale calcium oxide particles as calcium source to the plants through foliar application, agricultural crops in particular, as bulk calcium application through foliar nutrition is restricted due to its non-mobility in phloem.

Deepa, Manchala; Sudhakar, Palagiri; Nagamadhuri, Kandula Venkata; Balakrishna Reddy, Kota; Giridhara Krishna, Thimmavajjula; Prasad, Tollamadugu Naga Venkata Krishna Vara

2014-08-01

26

Calcium  

MedlinePLUS

... it from: Dairy products. Low-fat milk, yogurt, cheese, and cottage cheese are good sources of calcium. Veggies. You'll ... burritos or wraps. Fill them with eggs and cheese for breakfast; turkey, cheese, lettuce, tomato, and light ...

27

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

PubMed Central

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 (GR50) differed statistically for the three genotypes under study (P < 0.001). CLPlus genotypes showed the highest values of GR50, 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, Maria Laura

2012-01-01

28

Comparative degradation of [14C]-2,4-dichlorophenoxyacetic acid in wheat and potato after Foliar application and in wheat, radish, lettuce, and apple after soil application.  

PubMed

The fate of 2,4-dichlorophenoxyacetic acid (2,4-D) applied foliarly as the 2-ethylhexyl ester (EHE) to wheat and potatoes, to the soil as the dimethylamine (DMA) salt under apple tree canopies, and preplant as the free acid for wheat, lettuce, and radish was studied to evaluate metabolic pathways. Crop fractions analyzed for (14)C residues included wheat forage, straw, and grain; potato vine and tubers; and apple fruit. The primary metabolic pathway for foliar application in wheat is ester hydrolysis followed by the formation of base-labile 2,4-D conjugates. A less significant pathway for 2,4-D in wheat was ring hydroxylation to give NIH-shift products 2,5-dichloro-4-hydroxyphenoxyacetic acid (4-OH-2,5-D), 4-OH-2,3-D, and 5-OH-2,4-D both free and as acid-labile conjugates. The primary metabolic pathway in potato was again ester hydrolysis. 2,4-D acid was further transformed to 4-chlorophenoxyacetic acid and 4-OH-2,5-D. For the soil applications, (14)C residues in the crops were low, and characterization of the (14)C residues indicated association with or incorporation into the biochemical matrix of the tissue. The degradative pathways observed in wheat are similar to those characterized in other intact plant studies but differ from those in studies in wheat cell suspension culture in that no amino acid conjugates were observed. PMID:11170570

Hamburg, A; Puvanesarajah, V; Burnett, T J; Barnekow, D E; Premkumar, N D; Smith, G A

2001-01-01

29

Cottonseed, Protein, Oil Yields and Oil Properties as Affected by Nitrogen Fertilization and Foliar Application of Potassium and a Plant Growth Retardant  

Microsoft Academic Search

Field experiments were conducted in two successive seasons, at the Agricultural Research Center, Giza, Egypt. The aim was to investigate the effect of N-fertilization rate (95.2 and 142.8 kg of N\\/ha, applied as ammonium nitrate containing 33.5% N in two equal doses at 6 and 8 weeks after sowing), together with foliar application of potassium (applied as potassium sulfate containing

Zakaria M. Sawan; Saeb A. Hafez; Ahmed E. Basyony; Abou-El-Ela R. Alkassas

2006-01-01

30

Foliar Application Of Boron Influences The Leaf Mineral Status, Vegetative And Reproductive Growth, Yield And Fruit Quality Of ‘Kinnow’ Mandarin (Citrus Reticulata Blanco.)  

Microsoft Academic Search

The effects of foliar application of boron (B) in the form of boric acid on vegetative and reproductive growth, yield and fruit quality of ‘Kinnow’ mandarin (Citrus reticulate Blanco.) were investigated. Kinnow mandarin was sprayed with different concentration of boric acid viz. (0.1%, 0.2%, 0.3% and 0.4%) at fruit set stage. Leaf nitrogen (N), phosphorus (P), potassium (K), B, and

S. Ullah; A. S. Khan; A. U. Malik; I. Afzal; M. Shahid; K. Razzaq

2012-01-01

31

Nontarget effects of foliar fungicide application on the rhizosphere: diversity of nifH gene and nodulation in chickpea field  

PubMed Central

Aims This study explores nontarget effects of fungicide application on field-grown chickpea. Methods and Results Molecular methods were used to test the effects of foliar application of fungicide on the diversity and distribution of nifH genes associated with two chickpea cultivars and their nodulation. Treatments were replicated four times in a split-plot design in the field, in 2008 and 2009. Chemical disease control did not change the richness of the nifH genes associated with chickpea, but selected different dominant nifH gene sequences in 2008, as revealed by correspondence analysis. Disease control strategies had no significant effect on disease severity or nifH gene distribution in 2009. Dry weather conditions rather than disease restricted plant growth that year, suggesting that reduced infection rather than the fungicide is the factor modifying the distribution of nifH gene in chickpea rhizosphere. Reduced nodule size and enhanced N2-fixation in protected plants indicate that disease control affects plant physiology, which may in turn influence rhizosphere bacteria. The genotypes of chickpea also affected the diversity of the nifH gene in the rhizosphere, illustrating the importance of plant selective effects on bacterial communities. Conclusions We conclude that the chemical disease control affects nodulation and the diversity of nifH gene in chickpea rhizosphere, by modifying host plant physiology. A direct effect of fungicide on the bacteria cannot be ruled out, however, as residual amounts of fungicide were found to accumulate in the rhizosphere soil of protected plants. Significance and Impact of the Study Systemic nontarget effect of phytoprotection on nifH gene diversity in chickpea rhizosphere is reported for the first time. This result suggests the possibility of manipulating associative biological nitrogen fixation in the field. PMID:22335393

Yang, C; Hamel, C; Vujanovic, V; Gan, Y

2012-01-01

32

Genome-wide profiling and analysis of Festuca arundinacea miRNAs and transcriptomes in response to foliar glyphosate application.  

PubMed

Glyphosate is a broad spectrum herbicide which has been widely used for non-selective weed control in turfgrass management. Festuca arundinacea cv. Falcon was shown to be one of the tolerant turfgrass species in response to varying levels of glyphosate [5% (1.58 mM), 20% (6.32 mM)] recommended for weed control. However, there is a lack of knowledge on the mRNA expression patterns and miRNA, critical regulators of gene expression, in response to varying levels of glyphosate treatments. Here, we investigate the transcriptome and miRNA-guided post-transcriptional networks using plant miRNA microarray and Affymetrix GeneChip Wheat Genome Array platforms. Transcriptome analysis revealed 93 up-regulated and 78 down-regulated genes, whereas a smaller number showed inverse differential expressions. miRNA chip analysis indicated a number of (34 out of the 853) plant miRNAs were differentially regulated in response to glyphosate treatments. Target transcripts of differentially regulated miRNAs were predicted and nine of them were quantified by quantitative real-time PCR (qRT-PCR). Target transcripts of miRNAs validate the expression level change of miRNAs detected by miRNA microarray analysis. Down-regulation of miRNAs upon 5 and 20% glyphosate applications led to the up-regulation of their target observed by qRT-PCR or vice versa. Quantification of F. arundinacea miRNA, homologous of osa-miR1436, revealed the agreement between the Affymetrix and miRNA microarray analyses. In addition to miRNA microarray experiment, 25 conserved F. arundinacea miRNAs were identified through homology-based approach and their secondary structures were predicted. The results presented serve as analyses of genome-wide expression profiling of miRNAs and target mRNAs in response to foliar glyphosate treatment in grass species. PMID:20213187

Unver, Turgay; Bakar, Mine; Shearman, Robert C; Budak, Hikmet

2010-04-01

33

EFFECTIVENESS OF DIFFERENT FOLIAR IRON APPLICATIONS TO CONTROL IRON CHLOROSIS IN ORANGE TREES GROWN ON A CALCAREOUS SOIL  

Microsoft Academic Search

The effectiveness on controlling Fe chlorosis in orange trees grown on calcareous soils was tested. The treatments were Fe(II) sulfate (500 mg Fe L), sulfuric acid (0.5 mM H2SO4), Fe(III)-chelate (Hampiron 654 GS, 120 mg Fe L) and distilled water as a control. A non-ionic wetting agent was used in all treatments. The use of frequent foliar sprays alleviated Fe

Maribela Pestana; Pedro José Correia; Amarilis de Varennes; Javier Abadía; Eugénio Araújo Faria

2001-01-01

34

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

35

The role of calcium in improving photosynthesis and related physiological and biochemical attributes of spring wheat subjected to simulated acid rain.  

PubMed

The response of photosynthesis parameters, catalase, superoxide dismutase and peroxidase activity, malondialdehyde, proline, chlorophyll, yield and yield components to foliar application of calcium and simulated acid rain in wheat were investigated. Foliar treatment of calcium led to significant increases in the photosynthesis rate, transpiration rate, stomatal conductance, proline, chlorophyll, yield and yield components in plants subjected to acid rain. Antioxidant enzyme activity and lipid peroxidation in the wheat leaves decreased because of calcium foliar application. Calcium hindered degradation of the rubisco subunits under acid rain treatment compared with water-treated plants. Results suggest that acid rain induces the production of free radicals resulting in lipid peroxidation of the cell membrane so that significant increase in antioxidant enzyme activity was observed. In addition, photosynthetic parameters i.e. photosynthesis rate, transpiration rate and stomatal conductance were drastically suppressed by acid rain. The cellular damage caused by free radicals might be reduced or prevented by a protective metabolism including antioxidative enzymes and calcium. We report that foliar application of calcium before acid rain may ameliorate the adverse effects of acid rain in wheat plants. PMID:24431486

Dolatabadian, Aria; Sanavy, Seyed Ali Mohammad Modarres; Gholamhoseini, Majid; Joghan, Aydin Khodaei; Majdi, Mohammad; Kashkooli, Arman Beyraghdar

2013-04-01

36

Quantifying the non-fungicidal effects of foliar applications of fluxapyroxad (Xemium) on stomatal conductance, water use efficiency and yield in winter wheat.  

PubMed

The active ingredient fluxapyroxad belongs to the chemical group of carboxamides and is a new generation succinate dehydrogenase inhibitor (SDHI) in complex II of the mitochondrial respiratory chain. It has strong efficacy against the key foliar diseases of winter wheat in the UK: Septoria leaf blotch, yellow stripe rust and brown rust. Fluxapyroxad is marketed under the brand name of Xemium, was launched in 2012 and is available in the UK as a solo product (Imtrex) for co-application with triazoles, in co-formulation with epoxiconazole (Adexar), or in a three way formulation with epoxiconazole and pyraclostrobin (Ceriax). The objective of the study was to quantify the direct effects of Xemium on stomatal conductance and yield, mediated through stimulation of host physiology. Three field experiments and two controlled environment (CE) experiments were conducted across three cropping seasons (2010-2012) in Herefordshire and Cambridge, in the UK. Xemium was evaluated against boscalid, pyraclostrobin (F500), epoxiconazole and an untreated control. Across site-seasons, disease severity was significantly reduced when Xemium was applied as a foliar spray. Healthy canopy size and duration was increased by Xemium and canopy greening effects were seen shortly after application. Stomatal conductance was found to be consistently lower in Xemium treated plants but reduced stomatal opening was not found to be detrimental to yield in these experiments. Large, beneficial effects of Xemium on water use efficiency were found at the canopy level and this finding was supported by measurements of instantaneous water use efficiency at the leaf level. Effects on season long water use efficiency were largely driven by improvements in yield for a given amount of water uptake. Foliar applications of Xemium reduced the water required to produce 1.0 t grain per hectare by 82,330 L(82 t) when compared with an untreated crop. Yield was significantly higher in Xemium treatments and this was achieved primarily through increases in grains ear. Evidence is presented hereto show that in addition to controlling visible disease symptoms, Xemium is able to exert positive physiological effects on the host. The yield increase from plots treated with Xemium applied at standard commercial timings was shown to exceed that which can be explained solely through good disease control and the associated loss of healthy canopy area. Approximately 1.0 t ha(-1) (12%) yield was produced by Xemium treatments which could not be accounted for through the control of visible disease symptoms. PMID:25151827

Smith, J; Grimmer, M; Waterhouse, S; Paveley, N

2013-01-01

37

Synthesis and application of nanostructured calcium phosphate ceramics for bone regeneration.  

PubMed

In the past two decades, nanotechnology has entered the field of regenerative medicine, resulting in the development of a novel generation of instructive, nanostructured biomaterials that are able to orchestrate cellular behavior by presenting specific morphological and biological cues. Using nanotechnology, materials containing nanosized features (e.g., pores, patterns, textures, grain sizes) can be obtained that exhibit properties that are considerably altered compared with micron-structured materials. Inspired by the hierarchical nanostructure of bone, the application of nanostructured materials for bone regeneration is gaining increasing interest in the field of biomaterials research. Because crystallographic and chemical studies have shown that synthetic hydroxyapatite closely resembles the inorganic phase found in bone and teeth, synthesis and applications of nanostructured calcium phosphate ceramics have been reviewed. Synthesis techniques for the preparation of calcium phosphate nanoparticles include precipitation, sol-gel, and hydrothermal processes, whereas four main biomedical applications of nanostructured calcium phosphate ceramics in bone regeneration have been addressed in more detail, that is, (1) polymer/calcium phosphate nanocomposites, (2) nanostructured monophasic calcium phosphate bone fillers, (3) nanostructured precursor phases for calcium phosphate cements, and (4) nanostructured calcium phosphate coatings. PMID:23015272

Alves Cardoso, D; Jansen, J A; Leeuwenburgh, S C G

2012-11-01

38

Foliar application of Zn at flowering stage improves plant's performance, yield and yield attributes of black gram.  

PubMed

Black gram plants subjected to varying levels of Zn supply (0.01 to 10 microM Zn) showed optimum growth and dry matter yield in plants receiving 1 microM Zn. The dry matter yield of plants decreased in plants receiving 0.01 and 0.1 microM Zn (deficient) and excess levels of Zn (2 and 10 microM Zn). The plants grown with Zn deficient supply showed delayed flowering, premature bud abscission, reduced size of anthers, pollen producing capacity, pollen viability and stigma receptivity resulting in poor pod formation and seed yield. Providing Zn as a foliar spray at pre-flowering stage minimized the severity of Zn deficiency on reproductive structure development and enhanced the seed nutritional status by enhancing seed Zn density, seed carbohydrate (sugar and starch content) and storage proteins (albumins, globulins, glutenins, and prolamines). PMID:23898554

Pandey, Nalini; Gupta, Bhavana; Pathak, Girish Chandra

2013-07-01

39

[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

40

Supplemental Foliar Potassium Applications during Muskmelon Fruit Development Can Improve Fruit Quality, Ascorbic Acid, and Beta-carotene Contents  

Microsoft Academic Search

Muskmelon (Cucumis melo L. (Reticulatus Group)) fruit sugar content is directly related to potassium (K)- mediated phloem transport of sucrose into the fruit. However, during fruit growth and maturation, soil fertilization alone is often inadequate (due to poor root uptake and competitive uptake inhibition from calcium and magnesium) to satisfy the numerous K-dependent processes, such as photosynthesis, phloem transport, and

Gene E. Lester; John L. Jifon; Gordon Rogers

41

Calcium Deficient Hydroxyapatite for Medical Application Prepared by Hydrothermal Method  

NASA Astrophysics Data System (ADS)

Hydrothermal processing plays a key role in the synthesis of biomaterials with excellent biocompatibility in the physiological environment. Especially, calcium phosphates are paid to much attention for the regenerative medicine. Two kinds of porous materials of hydroxyapatite with 70% porosity were prepared. One of them is a newly developed calcium-deficient hydroxyapatite composed of rod-shaped particles of about 20 ?m in length synthesized hydrothermally (HHA) and the other one is the stoichiometric hydroxyapatite (SHA) prepared by the conventional sintering method. These materials were used for animal implantation tests to compare these biological responses. In the rabbit femur, implanted HHA was slowly resorbed and then most of the implanted HHA was resorbed after 72 weeks. The implanted SHA was unresorbed throughout the experimental period. The volume of newly formed bone and the number of osteoclasts in the implanted region were significantly larger in HHA than in SHA after 24 weeks. Results in the present research suggested that the activity of osteoclasts correlated to the bone forming activity of osteoblasts. The method to synthesize biodegradable pure calcium-deficient HA is expected to provide adequate biodegradability and bone replaceability.

Ioku, Koji; Kamitakahara, Masanobu; Ikeda, Tohru

2010-11-01

42

Foliar applied urea improves freezing protection to avocado and peach  

Microsoft Academic Search

The effect of foliar applied urea on freeze hardiness was evaluated under orchard and laboratory conditions. Freezing injury and senescence of avocado (Persea americana Mill.) cv. ‘Hass’ leaves in the orchard was inversely correlated to N content. Three foliar applications of 2% low-biuret urea caused a 26% nitrogen enrichment of leaves. Consequently, leaf freezing hardiness was increased and senescence retarded.

S. Zilkah; Z. Wiesmann; I. Klein; I. David

1996-01-01

43

Effects of atmospheric CO{sub 2} enrichment and foliar methanol application on net photosynthesis of sour orange tree (Citrus Aurantium; Rutaceae) leaves  

SciTech Connect

Foliar spray applications of 40% aqueous methanol were made to sunlit leaves of sour orange trees that had been grown continuously in clear-plastic-wall open-top enclosures maintained out-of-doors at Phoenix, Arizona, for over 5.5 years in ambient air of approximately 400 {mu}mol mol{sup -1} CO{sub 2} and in air enriched with CO{sub 2} to a concentration of approximately 700 {mu}mol mol{sup -1}. No unambiguous effects of the methanol applications were detected in photosynthesis measurements made on foliage in either of the two CO{sub 2} treatments. THe 75% increase in CO{sub 2}, however, raised the upper-limiting leaf temperature for positive net photosynthesis by approximately 7 C, which resulted in a 75% enhancement in net photosynthesis at a leaf temperature of 31 C, a 100% enhancement at a leaf temperature of 35 C, and a 200% enhancement at 42 C. 13 refs., 2 figs., 1 tab.

Idso, S.B.; Garcia, R.L.; Kimball, B.A. [Water Conservation Lab., Phoenix, AR (United States); Idso, K.E.; Hoober, J.K. [Arizona State Univ., Tempe, AR (United States)

1995-01-01

44

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

45

The composite of hydroxyapatite and calcium sulphate: a review of preclinical evaluation and clinical applications.  

PubMed

Recent publications have shown that the combination of ?-calcium sulfate hemihydrate, the densest form of hydrates and hydroxyapatite (HA) particles gives good clinical outcome in various applications. It has large potential as bone substitute since the material transforms to bone throughout the entire volume and not only by creeping substitution, from the surface toward the inside. Release of important proteins for osteogenesis has been observed around implanted material and is speculated to be due to fast dissolution of the calcium sulfate phase in combination with the osteoconductive and bioactive nature of HA. In diabetic foot infection, the osteoconductive HA/calcium sulfate material has been successfully used loaded with antibiotics and since it is injectable, the application is minimally invasive, easy and precise. It is a bone substitute for the future. PMID:24053255

Nilsson, Malin; Zheng, Ming H; Tägil, Magnus

2013-09-01

46

[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

47

Synthesis and characterization of bioresorbable calcium phosphosilicate nanocomposite particles for fluorescence imaging and biomedical applications  

Microsoft Academic Search

Organically doped calcium phosphosilicate nanoparticles (CPSNPs) were developed and characterized, driven by the need for non-toxic vectors for drug delivery and fluorescence biological imaging applications. In particular, advancement in drug delivery for the chemotherapeutic treatment of cancers is required to increase drug efficacy and improve patient quality of life. Additionally, brighter and more photostable fluorophores are needed to meet demands

Thomas T. Morgan

2010-01-01

48

Long-range relativistic interactions in the Cowan-Griffin approximation and their QED retardation: Application to helium, calcium, and cadmium dimers  

E-print Network

: Application to helium, calcium, and cadmium dimers Robert Moszynski* and Grzegorz Lach Department of Chemistry, and applications to the helium, calcium, and cadmium dimers are presented. DOI: 10.1103/PhysRevA.68.052706 PACS

Bussery-Honvault, Béatrice

49

Microwave hydrothermal transformation of amorphous calcium carbonate nanospheres and application in protein adsorption.  

PubMed

Calcium carbonate and calcium phosphate are the main components of biominerals. Among all of the forms of biominerals, amorphous calcium carbonate (ACC) and amorphous calcium phosphate (ACP) are the most important forms because they play a pivotal role in the process of biomineralization and are the precursors to the crystalline polymorphs. In this work, we first synthesized ACC in vitro using adenosine 5'-triphosphate disodium salt (ATP) as the stabilizer and investigated the transformation of the ACC under microwave hydrothermal conditions, and ACC/ACP composite nanospheres and carbonated hydroxyapatite (CHA) nanospheres were successfully prepared. In this novel strategy, ATP has two main functions: it serves as the stabilizer for ACC and the phosphorus source for ACP and CHA. Most importantly, the morphology and the size of the ACC precursor can be well-preserved after microwave heating, so it provides a new method for the preparation of calcium phosphate nanostructured materials using phosphorus-containing biomolecule-stabilized ACC as the precursor. Furthermore, the as-prepared ACC/ACP composite nanospheres have excellent biocompatibility and high protein adsorption capacity, indicating that they are promising for applications in biomedical fields such as drug delivery and protein adsorption. PMID:24568728

Qi, Chao; Zhu, Ying-Jie; Chen, Feng

2014-03-26

50

Controls on foliar nutrient and aluminium concentrations in a tropical tree flora: phylogeny, soil chemistry and interactions among elements.  

PubMed

Foliar elemental concentrations are predictors of life-history variation and contribute to spatial patterns in biogeochemical cycling. We examined the contributions of habitat association, local soil environment, and elemental interactions to variation in foliar elemental concentrations in tropical trees using methods that account for phylogeny. We sampled top-soils and leaves of 58 tropical trees in heath forest (HF) on nutrient-poor sand and mixed dipterocarp forest (MDF) on nutrient-rich clay soils. A phylogenetic generalized least squares method was used to determine how foliar nutrient and aluminium (Al) concentrations varied in response to habitat distribution, soil chemistry and other elemental concentrations. Foliar nitrogen (N) and Al concentrations were greater for specialists of MDF than for specialists of HF, while foliar calcium (Ca) concentrations showed the opposite trend. Foliar magnesium (Mg) concentrations were lower for generalists than for MDF specialists. Foliar element concentrations were correlated with fine-scale variation in soil chemistry in phylogenetically controlled analyses across species, but there was limited within-species plasticity in foliar elemental concentrations. Among Al accumulators, foliar Al concentration was positively associated with foliar Ca and Mg concentrations, and negatively associated with foliar phosphorus (P) concentrations. The Al-accumulation trait and relationships between foliar elemental and Al concentrations may contribute to species habitat partitioning and ecosystem-level differences in biogeochemical cycles. PMID:25138655

Metali, Faizah; Abu Salim, Kamariah; Tennakoon, Kushan; Burslem, David F R P

2015-01-01

51

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. PMID:11891267

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

2002-01-01

52

Application of calcium phosphate as a controlled-release device.  

PubMed

Calcium phosphate (CaP)-based compounds are biocompatible and have been accepted as promising candidates for novel drug-releasing devices. CaP is biodegradable and can be utilized as a durable drug release reservoir. We developed an injectable self-setting apatite cement. When a plasmid DNA complex containing CaP was injected into tumor-bearing mice, it solidified in the body and slowly released the DNA complex, inducing durable gene expression and high therapeutic effect on solid tumors. Encapsulation of a drug by CaP acts as a protective capsule for the unstable contents and improves biocompatibility. CaP nanocapsules encapsulating a plasmid DNA complex or drug-involved micelle were prepared, and they showed high stability against enzyme and protein degradation. CaP also showed high potential as a durable acid pH buffer. Aqueous alginate solution was found to form a soft gel in the body and was investigated as a drug-releasing device. However, degradation of the alginate gel is sometimes too rapid in an acidic environment such as the area around osteoporotic bones. We found that amorphous CaP powder added to the alginate gel could control the dissociation rate, buffering the pH inside the gel. Alginate gel including CaP powder and a drug for osteoporosis allowed sustained release of the drug under acidic conditions, and a good therapeutic effect was achieved in osteoporosis model rats. CaP could thus be a valuable material for drug-delivery systems as a slow-releasing drug reservoir, a protective coating, or a pH buffer. PMID:24189411

Ito, Tomoko; Otsuka, Makoto

2013-01-01

53

Oxidative and Molecular Responses in Capsicum annuum L. after Hydrogen Peroxide, Salicylic Acid and Chitosan Foliar Applications  

PubMed Central

Hydrogen peroxide (H2O2) is an important ROS molecule (Reactive oxygen species) that serves as a signal of oxidative stress and activation of signaling cascades as a result of the early response of the plant to biotic stress. This response can also be generated with the application of elicitors, stable molecules that induce the activation of transduction cascades and hormonal pathways, which trigger induced resistance to environmental stress. In this work, we evaluated the endogenous H2O2 production caused by salicylic acid (SA), chitosan (QN), and H2O2 elicitors in Capsicum annuum L. Hydrogen peroxide production after elicitation, catalase (CAT) and phenylalanine ammonia lyase (PAL) activities, as well as gene expression analysis of cat1, pal, and pathogenesis-related protein 1 (pr1) were determined. Our results displayed that 6.7 and 10 mM SA concentrations, and, 14 and 18 mM H2O2 concentrations, induced an endogenous H2O2 and gene expression. QN treatments induced the same responses in lesser proportion than the other two elicitors. Endogenous H2O2 production monitored during several days, showed results that could be an indicator for determining application opportunity uses in agriculture for maintaining plant alert systems against a stress. PMID:23676352

Mejia-Teniente, Laura; de Dalia Duran-Flores, Flor; Chapa-Oliver, Angela Maria; Torres-Pacheco, Irineo; Cruz-Hernandez, Andres; Gonzalez-Chavira, Mario M.; Ocampo-Velazquez, Rosalia V.; Guevara-Gonzalez, Ramon G.

2013-01-01

54

Mg2+ substituted calcium phosphate nano particles synthesis for non viral gene delivery application.  

PubMed

Gene therapy provides a unique approach to medicine as it can be adapted towards the treatment of both inherited and acquired diseases. Recently, calcium phosphate vectors as a new generation of the non viral gene delivery nano carriers have been studied because of their biocompatibility and DNA condensation and gene transfer ability. Substituting cations, like magnesium, affects physical and chemical properties of calcium phosphate nano particles. In this study, Mg(2+) substituted calcium phosphate nano particles have been prepared using the simple sol gel method. X-ray diffraction analysis, Fourier transform infra red spectroscopy, transmission electron microscopy, specific surface area analysis, zeta potential measurement and ion release evaluation were used for characterization of the samples. It was concluded that presence of Mg ions decrease particle size and crystallinity of the samples and increase positive surface charge as well as beta tricalcium phosphate fraction in chemical composition of calcium phosphate. These properties result in increasing the DNA condensation ability, specific surface area and dissolution rate of the samples which make them suitable particles for gene delivery application. PMID:20464457

Hanifi, A; Fathi, M H; Sadeghi, H Mir Mohammad; Varshosaz, J

2010-08-01

55

Preparation of polyelectrolyte/calcium phosphate hybrids for drug delivery application.  

PubMed

Biocompatible and biodegradable polyelectrolyte complex consisting of carboxylmethyl cellulose (CMC) and chitosan (CHI) were studied as a template for calcium phosphate biomimetic mineralization. CMC/CHI/calcium phosphate hybrids were prepared using different concentrations of simulated body fluid (2, 5 and 10×SBF) for producing hybrids with different organic/inorganic ratio. These hybrids were characterized using X-ray diffraction (XRD), infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The equilibrium swelling extents of the hybrids were found to be dependent on the inorganic % in the hybrids. The release profile of bovine serum albumin as a model drug in simulated intestine solution (pH 7.4) during 24h has established the efficiency of the hybrids as a sustained delivery system. The hybrids developed in this contribution exhibit a great potential in bone tissue engineering and drug delivery applications. PMID:25256512

Salama, Ahmed; El-Sakhawy, Mohamed

2014-11-26

56

Effect of Foliar Nitrogen Application on Nitrogen Metabolism, Water Status, and Plant Growth in Two Maize Cultivars under Short-term Moderate Stress  

Microsoft Academic Search

Two contrasting maize (Zea mays L.) cultivars, i.e. ‘Shaandan 9’ (S9) and ‘Shaandan 911’(S911) were investigated by examining foliar nitrogen (N) modulation of N metabolism, water status and plant growth under short-term moderate water stress (SMWS). On 10th day of SMWS, dry matter (DM), relative water content (RWC) and nitrate reductase activity (NRA) were significantly decreased, whereas concentrations of free

LiXin Zhang; ShengXiu Li; ZongSuo Liang; ShiQing Li

2009-01-01

57

The influence of foliar and soil fertilization of humic acid on yield and quality of pepper  

Microsoft Academic Search

Humic acid (HA) is the result of organic matter decomposition and is beneficial to plant growth and development. The objective of the study was to find the influence of foliar and soil HA application on fruit quality and yield of organically grown pepper. Pepper plants were treated with soil and foliar HA applications at various concentrations (0 ml\\/l, 10 ml\\/l,

Yasar Karakurt; Husnu Unlu; Halime Unlu; Huseyin Padem

2009-01-01

58

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

59

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

60

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. PMID:22263898

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

2012-01-01

61

Application of calcium silicate for medicinal preparation. I. Solid preparation adsorbing an oily medicine to calcium silicate.  

PubMed

Calcium silicate (Florite RE, FLR), a fine porous powder, was recently approved as a medicinal additive. In this study we sought to make a solid preparation by absorbing an oily medicine to FLR; tocopheryl nicotinate (TN) was used as the oily medicine. TN adsorbed to FLR powder (TN-PO) was prepared by adsorbing TN ethanol solution to FLR and granulating with hydroxypropylcellulose (HPC) in order to improve the flowability. The results were as follows. FLR showed an excellent liquid holding ability compared with other excipients, and this was attributed to the high capillarity of the pores. In the adsorbing process, FLR particles were granulated with TN overflowing from the pores or adhering to the particle surface. The angle of repose was decreased with increasing TN content, which was attributed to the process of granulation, and the angle of repose of the granules with a binder (TN-GR) was below 40 degrees at any TN content. These results show that FLR is an useful additive for the solid preparation of an oily medicine. PMID:7859331

Yuasa, H; Asahi, D; Takashima, Y; Kanaya, Y; Shinozawa, K

1994-11-01

62

Synthesis and characterization of bioresorbable calcium phosphosilicate nanocomposite particles for fluorescence imaging and biomedical applications  

NASA Astrophysics Data System (ADS)

Organically doped calcium phosphosilicate nanoparticles (CPSNPs) were developed and characterized, driven by the need for non-toxic vectors for drug delivery and fluorescence biological imaging applications. In particular, advancement in drug delivery for the chemotherapeutic treatment of cancers is required to increase drug efficacy and improve patient quality of life. Additionally, brighter and more photostable fluorophores are needed to meet demands for improved sensitivity and experimental diversity, which may lead to improvements in early detection of solid tumors and advancement in understanding of biological processes. A literature survey on the state of the field for nanoparticle based biological fluorescence imaging and drug delivery is presented in Chapter 1. Chapter 2 focuses on the characterization techniques used in this work. The development and optical characterization of 20-40 nm diameter, citrate functionalized Cy3 amidite doped calcium phosphosilicate nanoparticles (Cy3 CPSNPs) for in vitro fluorescence imaging is outlined in Chapters 3 and 4, respectively. In particular, sodium citrate was used to functionalize the surface and provide electrosteric dispersion of these particles. CPSNPs stabilized with sodium citrate routinely exhibited highly negative zeta potentials greater than -25 mV in magnitude. Furthermore, the fluorescence quantum yield of the encapsulated fluorophore was improved by more than 4.5-fold when compared to the unencapsulated dye. The bioimaging and drug delivery capability of CPSNPs was explored. Cy3 CPSNPs dissolved quickly in the acidic environment experienced during endocytosis, releasing the encapsulated fluorophore. This is consistent with solution phase experiments that show the particles are dissolved at pH 5. CPSNPs loaded with fluorescein and a hydrophobic growth inhibitor, ceramide C6, proved the ability to simultaneously image and delivery of the hydrophobic drug to cells in vitro. Chapter 5 examined the colloidal stability of citrate and polyethylene glycol (PEG) functionalized CPSNPs in 70 volume % ethanol/30% water, both experimentally using TEM and theoretically using DLVO and polymeric steric dispersion theories. There are three basic mechanisms for colloidal stability for macroscopic suspensions (i.e., for particulate diameters down to ˜100nm), metastable electrostatic in which some finite degree of agglomeration continuously takes place because a finite energy barrier against agglomeration; and electrosteric and steric mechanisms in which infinitely high potential energy barriers toward agglomeration are present leading to thermodynamically stable suspensions. One of the fundamental issues addressed in this chapter was whether the mechanisms of electrosteric or steric dispersion, based on relatively large adsorbed polyelectrolytes for macroscopic size particulates, scales with particles in the range of ˜40 nm diameter such that a small, charged organic molecule such as citrate provides the thermodynamic colloidal stability of electrosteric mechanisms as suggested by preliminary theoretical calculations. The particle diameter-number distributions for as-prepared and after drying (at 25°C) and redispersion were used as metrics for thermodynamic colloidal stability. How efficiently particles redispersed after drying and reintroduction into the 70:30 ethanol:water solvent was used as the primary metric for whether the metastable electrostatic mechanism or thermodynamically stable electrosteric or steric approaches were responsible for the robust dispersion experimentally observed in the colloids. These experiments found that, even with the thin electrosteric layer provided by the adsorbed citrate, particles were electrosterically dispersed, and were unagglomerated when dried under argon and redispersed. Preliminary work outlining the synthesis and characterization of silver core, calcium phosphosilicate shell nanoparticles for surface plasmon coupled emission and metal enhanced fluorescence applications is discussed in Chapter 6. Thin (2-5 nm) calcium phosphosilicat

Morgan, Thomas T.

63

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

64

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

65

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

PubMed Central

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.

2012-01-01

66

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.

67

Foliar Fertilization of Keith Kelling  

E-print Network

/branch sandy, low OM soils worse · Premium mixes promoted · Mn increased yield on high OM, high pH soils #12.5 69.2 66.9 55.4 78.7 55.0 LSD (10%) NS 1.2 NS NS NS ------------------------- Leaf Tissue B ---------------------- 0 36.8 33.8 -- -- -- 0.5 39.1 36.3 -- -- -- LSD (10%) 2.1 1.0 -- -- -- 1 Applied as a foliar spray

Balser, Teri C.

68

One-step bulk preparation of calcium carbonate nanotubes and its application in anticancer drug delivery.  

PubMed

Bulk fabrication of ordered hollow structural particles (HSPs) with large surface area and high biocompatibility simultaneously is critical for the practical application of HSPs in biosensing and drug delivery. In this article, we describe a smart approach for batch synthesis of calcium carbonate nanotubes (CCNTs) based on supported liquid membrane (SLM) with large surface area, excellent structural stability, prominent biocompatibility, and acid degradability. The products were characterized by transmission electron micrograph, X-ray diffraction, Fourier transform infrared spectra, UV-vis spectroscopy, zeta potential, and particle size distribution. The results showed that the tube-like structure facilitated podophyllotoxin (PPT) diffusion into the cavity of hollow structure, and the drug loading and encapsulation efficiency of CCNTs for PPT are as high as 38.5 and 64.4 wt.%, respectively. In vitro drug release study showed that PPT was released from the CCNTs in a pH-controlled and time-dependent manner. The treatment of HEK 293T and SGC 7901 cells demonstrated that PPT-loaded CCNTs were less toxic to normal cells and more effective in antitumor potency compared with free drugs. In addition, PPT-loaded CCNTs also enhanced the apoptotic process on tumor cells compared with the free drugs. This study not only provides a new kind of biocompatible and pH-sensitive nanomaterial as the feasible drug container and carrier but more importantly establishes a facile approach to synthesize novel hollow structural particles on a large scale based on SLM technology. PMID:22351100

Tang, Jing; Sun, Dong-Mei; Qian, Wen-Yu; Zhu, Rong-Rong; Sun, Xiao-Yu; Wang, Wen-Rui; Li, Kun; Wang, Shi-Long

2012-06-01

69

Calcium supplements  

MedlinePLUS

... The two main forms of calcium pills are: Calcium carbonate: Over-the-counter antacid products, such as Tums and Rolaids contain calcium carbonate. These sources of calcium carbonate do not cost ...

70

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

71

Effect of encapsulated calcium carbide and urea application methods on denitrification and N loss from flooded rice  

Microsoft Academic Search

Poor N fertilizer use efficiency by flooded rice is caused by gaseous losses of N. Improved fertilizer management and use of nitrification inhibitors may reduce N losses. A microplot study using15N-labelled urea was conducted to investigate the effects of fertilizer application method (urea broadcast, incorporated, deep-placed) and nitrification inhibitor [encapsulated calcium carbide (ECC)] treatments on emission of N2+N20 and total

D. G. Keerthisinghe; Lin Xin-Jian; Luo Qi-xiang; A. R. Mosier

1995-01-01

72

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

73

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

74

Foliar and soil fertilization of humic acid affect productivity and quality of tomato  

Microsoft Academic Search

The objective of the study was to determine the effect of foliar and soil fertilization with humic acid (HA) on quality, growth and yield of tomato under greenhouse conditions in 2004 and 2005. Tomato plants were treated with soil and foliar HA applications at different concentrations (0 ml\\/l, 10 ml\\/l and 20 ml\\/l). Three weeks after planting HA was sprayed

Ertan Yildirim

2007-01-01

75

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

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

2014-07-01

76

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

77

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

78

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

79

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

2013-07-01

80

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

81

Porous calcium polyphosphate scaffolds for bone substitute applications — in vitro characterization  

Microsoft Academic Search

Porous structures were formed by gravity sintering calcium polyphosphate (CPP) particles of either 106–150 or 150–250?m size to form samples with 30–45vol% porosity with pore sizes in the range of 100?m (40–140?m). Tensile strength of the samples assessed by diametral compression testing indicated relatively high values for porous ceramics with a maximum strength of 24.1MPa for samples made using the

R. M Pilliar; M. J Filiaggi; J. D Wells; M. D Grynpas; R. A Kandel

2001-01-01

82

A dual?analysis approach in tribochemistry: application to ZDDP\\/calcium borate additive interactions  

Microsoft Academic Search

Tribochemical interactions between zinc dithiophosphate (ZDDP) and micellar calcium borate (CB) under boundary lubrication\\u000a were investigated by coupling, in the same location of the wear track, both analytical TEM analysis of collected wear fragments\\u000a from the tribofilm and XPS surface analysis of the tribofilm directly underneath. This is the so?called dual?analysis approach,\\u000a which improves the interpretation of tribochemical reactions. The

K. Varlot; J. M. Martin; C. Grossiord; R. Vargiolu; B. Vacher; K. Inoue

1999-01-01

83

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

84

[Biocompatibility of alpha-calcium sulfate hemihydrate (CSH)/multi-walled carbon nanotube (MWCNT) composites for bone reconstruction application].  

PubMed

We examined the biocompatibility and the safety of a-calcium sulfate hemihydrate (CSH)/multi-walled carbon nanotube (MWCNT) composites for bone reconstruction application. The biocompatibility of the CSH/MWCNT composites was evaluated by the measures which taking L929 fibroblast cells cultured in the extracted liquid of the composite soaking solution and putting bone marrow stromal cells planted on the composite pellets in vitro, respectively. The cell proliferation was evaluated by MTT test and further observed using an inverted optical microscope and a scanning electric microscope. The toxicity of the composites was evaluated by acute and subacute systemic toxicity test. Long-term muscle and bone implantation in vivo tests were also conducted. L929 fibroblast cells grew well in the extracted liquid, as well as bone marrow stromal cells that could adhere on the surface of sample pellets and proliferated rapidly. MTT test showed that there were no significant differences between the experimental and control groups (P > 0.05). In vivo test manifested that the composites were no toxicity, no irritation to skin and good for bone defect reconstruction. It was proved that a-calcium sulfate hemihydrate (CSH)/multi-walled carbon nanotube (MWCNT) composites exhibited excellent biocompatibility for the potential application in bone tissue engineering. PMID:22712392

Lou, Yi; Pan, Zongyou; Wu, Ruikai; Xue, Enxing; Jiang, Libo; Yang, Guangyong; Zhou, Yang; Liu, Jianli; Huang, Qing; Xu, Huazi

2012-03-01

85

HumanWildlife Interactions 8(1):139149, Spring 2014 Evaluation of foliar sprays to reduce crop  

E-print Network

,000 managing crop damage caused by grazing Canada geese (Branta canadensis). Foliar applications of a chemical, South Dakota, USA Canada geese (Branta canadensis) historically nested throughout the Great Plains

86

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

87

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. PMID:23176249

2012-01-01

88

Foliar washoff of pesticides by rainfall  

SciTech Connect

Several insecticides were subjected to simulated rainfall after application on octadecylsilanized/trimethylsilanized glass or foliar surfaces. Flucythrinate (cyano(3-phenoxy-phenyl)methyl 4-(difluoromethoxy)-..cap alpha..-(1-methylethyl)-benzeneacetate), fenvalerate ((RS)-cyano(3-phenoxyphenyl)methyl (RS)-4-chloro-..cap alpha..-(1-methylethyl)benzene-acetate), and azinphosmethyl (O,O-dimethyl S-((4-oxo-1,2,3-benzotriazin-3(4H)-yl)-methyl) phosphorodithioate) showed 35-61% washoff by 25 mm of simulated rainfall, while methyl parathion (O,O-dimethyl O-4-nitrophenyl phosphorothioate) loss was over 90% of that applied. Washoff was initially rapid, but reached a secondary slower phase. Chlordimeform (N'-(4-chloro-2-methylphenyl)-N,N-dimethylmethanimidamide) and diazinon (O,O-diethyl O-(6-methyl-2-(1-methylethyl)-4-pyrimidinyl) phosphorothioate), in addition to exhibiting rapid volatilization, suffered nearly complete washoff by 25 mm of simulated rainfall. The use of octadecylsilanized/trimethylsilanized glass slides as a model for cotton leaf surfaces yielded results similar to those seen on actual cotton leaves (Gossypium hirsutum L.). 34 references, 4 tables.

Cohen, M.L.; Steinmetz, W.D.

1986-05-01

89

Bioactive calcium sulfate/magnesium phosphate cement for bone substitute applications.  

PubMed

A novel calcium sulfate/magnesium phosphate cement (CSMPC) composite was prepared and studied in the present work. The physical properties including the phases, the microstructures, the setting properties and the compressive strengths of the CSMPCs were studied. The bio-performances of the CSMPCs were comprehensively evaluated using in vitro simulated body fluid (SBF) method and in vitro cell culture. The dependence of the physical and chemical properties of the CSMPC on its composition and microstructure was studied in detail. It is found that the CSMPC composites exhibited mediate setting times (6-12 min) compared to the calcium sulfate (CS) and the magnesium phosphate cement (MPC). They showed an encapsulation structure in which the unconverted hexagonal prism CSH particles were embedded in the xerogel-like MPC matrix. The phase compositions and the mechanical properties of the CSMPCs were closely related to the content of MPC and the hardening process. The CSMPCs exhibited excellent bioactivity and good biocompatibility to support the cells to attach and proliferate on the surface. The CSMPC composite has the potential to serve as bone grafts for the bone regeneration. PMID:24411353

Yang, Guangyong; Liu, Jianli; Li, Fan; Pan, Zongyou; Ni, Xiao; Shen, Yue; Xu, Huazi; Huang, Qing

2014-02-01

90

Photochemical green synthesis of calcium-alginate-stabilized Ag and Au nanoparticles and their catalytic application to 4-nitrophenol reduction.  

PubMed

Silver and gold nanoparticles have been grown on calcium alginate gel beads using a green photochemical approach. The gel served as both a reductant and a stabilizer. The nanoparticles were characterized using UV-visible spectroscopy, X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), energy dispersive X-ray (EDS), and selected area electron diffraction (SAED) analyses. The particles are spherical, crystalline, and the size ranges for both Ag and Au nanoparticles are <10 nm. It is noticed from the sorption experiment that the loading of gold on calcium alginate beads is much more compared to that of Ag. The effectiveness of the as-prepared dried alginate-stabilized Ag and Au nanoparticles as a solid phase heterogeneous catalyst has been evaluated, for the first time, on the well-known 4-nitrophenol (4-NP) reduction to 4-aminophenol (4-AP) in the presence of excess borohydride. The reduction was very efficient and followed zero-order kinetics for both Ag and Au nanocomposites. The effects of borohydride, initial 4-NP concentration, and catalyst dose were evaluated. The catalyst efficiency was examined on the basis of turnover frequency (TOF) and recyclability. The catalytic efficiency of alginate-based Ag catalyst was much more compared to that of the Au catalyst. The as-prepared new solid-phase biopolymer-based catalysts are very efficient, stable, easy to prepare, eco-friendly, and cost-effective, and they have the potential for industrial applications. PMID:19957940

Saha, Sandip; Pal, Anjali; Kundu, Subrata; Basu, Soumen; Pal, Tarasankar

2010-02-16

91

Chinese Privet: Foliar application in water (inconsistent)  

E-print Network

(ASAP after stump is cut) Garlon 4----20% solution Tropical soda apple: Garlon/Remedy----.5% solution for spot treatment 1 quart per acre broadcast Milestone (best material)----5-7 oz acre broadcast (soil residual also) Spot spray----10 ml or 1/3 oz. per gallon Grazon Next or Forefront----0.5% solution for spot

Jawitz, James W.

92

Calcium Carbonate  

MedlinePLUS

... heart. Calcium carbonate also is used as an antacid to relieve heartburn, acid indigestion, and upset stomach. ... use.Do not take calcium carbonate as an antacid for more than 2 weeks unless your doctor ...

93

Ultrastructural Evidence for Protection of the Outer Hair Cells of the Inner Ear during Intense Noise Exposure by Application of the Organic Calcium Channel Blocker Diltiazem  

Microsoft Academic Search

Outer hair cells could be protected during intense noise exposure by the application of the calcium channel blocker diltiazem given before and after noise treatment. After various experimental approaches, the ultrastructural morphology was analysed for the different animal populations in the basal part of the second turn of the cochlea, which was the most destroyed area after an acute noise

Ulf-Rüdiger Heinrich; Jan Maurer; Wolf Mann

1999-01-01

94

Application of real-time confocal microscopy to intracellular calcium ion dynamics in rat arterioles.  

PubMed

The regulation of cytosolic Ca(2+) homeostasis is essential for cells, including vascular smooth muscle cells. Arterial tone, which underlies the maintenance of peripheral resistance in the circulation, is a major contributor to the control of blood pressure. Confocal microscopy was employed to study the alteration in intracellular calcium ion concentration ([Ca(2+)](i)) in arterioles (external diameters <100 microm) with respect to selected modifying reagents. 5-Hydroxytryptamine (1 microM), ATP (10 microM), and endothelin 1-3 (5 nM) elicited an increase in [Ca(2+)](i) in most arteriole smooth muscle cells. The [Ca(2+)](i) increase sometimes propagated in an intercellular manner. When noradrenaline (10 microM) was used as a stimulant, [Ca(2+)](i) increase was observed only in a portion of the smooth muscle cells. It was also noted that the reaction of these cells with respect to ATP is different between testis and brain arterioles; the [Ca(2+)](i) increase in testicular arterioles is dependent on Ca(2+) influx from extracellular space, whereas in cerebral arterioles it plays a role in both the influx of extracellular Ca(2+) and the release of Ca(2+) from intracellular stores (i.e., sarco/endoplasmic reticulum). These results indicate that arterioles in different tissues may differ greatly in their responses. Real-time confocal microscopy was found to be a useful tool for investigating the structural and functional changes in living tissues. PMID:11976902

Saino, Tomoyuki; Matsuura, Makoto; Satoh, Yoh-ichi

2002-04-01

95

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

96

[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

97

75 FR 28608 - Calcium Hydroxide; Receipt of Application for Emergency Exemption, Solicitation of Public Comment  

Federal Register 2010, 2011, 2012, 2013

...nurseries to control Eleutherodactylus frogs. The applicant proposes the use of a new...nurseries to control Eleutherodactylus frogs. Information in accordance with 40 CFR...hydroxide is necessary to control the tropical frogs, Eleutherodactylus coqui and E....

2010-05-21

98

Effect of cluster thinning and prohexadione calcium applications on phenolic composition and sensory properties of red wines.  

PubMed

The overall objective of this study was to investigate the effect of manual cluster thinning (CT) and the application of the growth regulator Prohexadione calcium (ProCa) on the phenolic composition and the sensory profile of Tempranillo and Grenache wines produced from treated vines in La Rioja (Spain). ProCa was applied at preblooming and CT was carried out at veraison in two consecutive years. Different physicochemical parameters and analyses of phenolic compounds were carried out in control, CT and ProCa grapes and wines and wine sensory was performed. Thinning treatments decreased crop yield, besides ProCa application reduced berry size, and berry weight. Color and phenolic composition of Grenache and Tempranillo wines in general were affected by thinning treatments, with an increase in anthocyanin, flavanol and flavonol concentrations. In sensory analysis, wines obtained from thinned vines presented higher values for several aromatic (e.g., white and yellow fruits, fresh flowers) and taste attributes (i.e., astringency, bitternes, persistence). CT and ProCa treatments resulted in an improvement in wine quality. In general, similar results in phenolic composition, sensory properties and quality of wines were obtained by manual and chemical cluster thinning. ProCa as a growth regulator may be an option for a quality vitiviniculture. PMID:23293882

Avizcuri-Inac, José-Miguel; Gonzalo-Diago, Ana; Sanz-Asensio, Jesús; Martínez-Soria, María-Teresa; López-Alonso, Miguel; Dizy-Soto, Marta; Echávarri-Granado, José-Federico; Vaquero-Fernández, Luis; Fernández-Zurbano, Purificación

2013-02-01

99

6 Nondestructive Estimation of Foliar Pigment  

E-print Network

by accurate measurements of the pigments present in plant leaves that play very important role in plant photosynthesis and protection. There are three major classes of pigments found in plants: chlorophylls141 6 Nondestructive Estimation of Foliar Pigment (Chlorophylls, Carotenoids, and Anthocyanins

Gitelson, Anatoly

100

Hyperspectral remote sensing of foliar nitrogen content  

E-print Network

mass-based nitrogen concentration (%N) has been reported in some temperate and boreal forests. This re sensed data, BRF spectra in the interval 710­790 nm provide critical information for correction on surface albedo and may offer a simple approach for monitoring foliar nitrogen using satellite data. We

Myneni, Ranga B.

101

Preparation and Properties of Nano-sized Calcium Fluoride for Dental Applications  

PubMed Central

Objectives The aim of the present study was to prepare nano-sized calcium fluoride (CaF2) that could be used as a labile F reservoir for more effective F regimens and as an agent for use in the reduction of dentin permeability. Methods Nano-sized CaF2 powders were prepared using a spray-drying system with a two-liquid nozzle. The properties of the nano CaF2 were studied and the effectiveness of a fluoride (F) rinse with nano CaF2 as the F source was evaluated. The thermodynamic solubility product of the nano CaF2 solution was determined by equilibrating the nano sample in solutions presaturated with respect to macro CaF2. Reactivity of the nano CaF2 was assessed by its reaction with dicalcium phosphate dehydrate (DCPD). F deposition by 13.2 mmol/L F rinse with the nano CaF2 as the F source was determined using a previously published in vitro model. Results X-ray diffraction (XRD) analysis showed pattern of low crystalline CaF2. BET measurements showed that the nano CaF2 had a surface area of 46.3 m2/g, corresponding to a particle size of 41 nm. Transmission Electron Microscopy (TEM) examinations indicated that the nano CaF2 contained clusters comprising particles of (10 to 15) nm in size. The nano CaF2 displayed much higher solubility and reactivity than its macro counterpart. The CaF2 ion activity product (IAP) of the solution in equilibrium with the nano CaF2 was (1.52 ± 0.05) × 10-10, which was nearly four times greater than the Ksp (3.9 × 10-11) for CaF2. The reaction of DCPD with nano CaF2 resulted in more F-containing apatitic materials compared to the reaction with macro CaF2. The F deposition by the nano CaF2 rinse was (2.2 ± 0.3) ?g/cm2 (n = 5), which was significantly (p < 0.001) greater than that ((0.31 ± 0.06) ?g/cm2) produced by the NaF solution. Significance The nano CaF2 can be used as an effective anticaries agent in increasing the labile F concentration in oral fluid and thus enhance the tooth remineralization. It can also be very useful in the treatment for the reduction of dentin permeability. PMID:17481724

Sun, Limin; Chow, Laurence C.

2008-01-01

102

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

103

Relative bioavailability of calcium from calcium formate, calcium citrate, and calcium carbonate  

E-print Network

of calcium from calcium formate, a new experimental dietary calcium supplement, to that of calcium citrate and calcium carbonate. In a four-way crossover study, either a placebo or 1200 mg of calcium as calcium carbonate, calcium citrate, or calcium formate...

Hanzlik, Robert P.; Fowler, S. C.; Fisher, D. H.

2005-06-01

104

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

105

X-Ray Detector with CMOS Sensor Camera Application of Calcium Denisty Measurement  

Microsoft Academic Search

This paper presented a design of an x-ray-detector using CMOS image sensor. The main components consist of CMOS sensor, taper fiber optic, and image intensifier screen. CMOS sensor offers various advantages including miniature-sized, low power consumption and cost effective. CMOS-based digital camera becomes hence very demanding due to its potential application in multimedia and information technology. To apply the CMOS

Y. Pititheerapab; T. Chanmalueang; T. Rerksngaem; C. Kitipol; C. Pintavirooj

2006-01-01

106

Microstructure, corrosion properties and bio-compatibility of calcium zinc phosphate coating on pure iron for biomedical application.  

PubMed

In order to improve the biocompatibility and the corrosion resistance in the initial stage of implantation, a phosphate (CaZn2(PO4)2·2H2O) coating was obtained on the surface of pure iron by a chemical reaction method. The anti-corrosion property, the blood compatibility and the cell toxicity of the coated pure iron specimens were investigated. The coating was composed of some fine phosphate crystals and the surface of coating was flat and dense enough. The electrochemical data indicated that the corrosion resistance of the coated pure iron was improved with the increase of phosphating time. When the specimen was phosphated for 30min, the corrosion resistance (Rp) increased to 8006 ?. Compared with that of the naked pure iron, the anti-hemolysis property and cell compatibility of the coated specimen was improved significantly, while the anti-coagulant property became slightly worse due to the existence of element calcium. It was thought that phosphating treatment might be an effective method to improve the biocompatibility of pure iron for biomedical application. PMID:24268250

Chen, Haiyan; Zhang, Erlin; Yang, Ke

2014-01-01

107

Characterization and application of calcium-dependent ?-propeller phytase from Bacillus amyloliquefaciens DS11.  

PubMed

The enzyme phytase has broad biotechnological applications, especially in the reduction of phytate, antinutritional factors that chelate essential minerals, in human and animal food. We investigated the enzymatic properties of ?-propeller phytase (BPP) from Bacillus amyloliquefaciens DS11. Thermal refolding analysis demonstrated that BPP can remarkably restore its enzymatic activity in the presence of 5 mM Ca(2+) to 87% of its original activity after heating to 100 °C and subsequent cooling, indicating that the enzyme requires Ca(2+) for appropriate refolding. Furthermore, pH-dependent kinetic studies showed that BPP required excess Ca(2+) for its enzymatic activity as the pH decreased, suggesting that the optimal Ca(2+)-phytate ratio for enzymatic catalysis depends on the pH value of the environment. Finally, we verified the practical application of BPP at two different pH's using soybean meal as a natural source of phytate. As compared to a commercial phytase, BPP efficiently hydrolyzed food phytate over neutral pH ranges. PMID:22775008

Shim, Jae-Hoon; Oh, Byung-Chul

2012-08-01

108

Calcium Film Based Testing of Edge-Seal Materials for Photovoltaic Applications (Presentation)  

SciTech Connect

Because of the sensitivity of some photovoltaic devices to moisture-induced corrosion, they are packaged using impermeable front- and back-sheets with an edge seal to prevent moisture ingress. Evaluation of edge seal materials can be difficult because of the low permeation rates involved and/or non-Fickian behavior. Here, using a Ca film deposited on a glass substrate, we demonstrate the evaluation of edge seal materials in a manner that effectively duplicates their use in a photovoltaic application and compare the results with standard methods for measuring water vapor transport. We demonstrate how moisture permeation data from polymer films can be used to estimate moisture ingress rates and compare the results of these two methods. Encapsulant materials were also evaluated for comparison and to highlight the need for edge seals. Of the materials studied, dessicant-filled polyisobutene materials demonstrate by far the best potential to keep moisture out for a 20 to 30 year lifetime.

Kempe, M.; Dameron, A.; Reese, M.

2011-04-01

109

Ecological Applications, 17(3), 2007, pp. 869881 2007 by the Ecological Society of America  

E-print Network

, Cornus florida (flowering dogwood) has been described as a calcium ``pump'' that draws calcium from greater concentrations of calcium than three other dominant understory species (Tsuga canadensis, Acer increases in the foliar biomass of T. canadensis, a species whose calcium-poor foliage increases soil

Peet, Robert K.

110

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

111

Assessment of gadolinium calcium oxoborate (GdCOB) for laser applications  

NASA Astrophysics Data System (ADS)

Increasing demand for growing high quality laser crystals puts a question about their most important parameters that one should concentrate on to get a desired product which will exhibit best properties in practical use. And by no means, this is a simple question. Apart of the usual lasing properties associated with a special dopant in the host material itself, one needs to consider another two lasing phenomena, namely second (SHG) and higher harmonic generation, and self-frequency doubling (SFD). Not necessarily all of these three can meet altogether in the same host material to yield in its best appearance in every case. We have made a review of basic properties of gadolinium oxoborate GdCa4O(BO3)3 (GdCOB) crystal and came to the conclusion that, currently, as a host material this is probably the best in all of its lasing applications. Although GdCOB has low thermal conductivity, which requires a suitable cooling, on the other hand it has got small thermo-optic coefficients which govern good operation in SHG and SFD experiments. Two inch dia. Nd-doped crystals were grown by the Czochralski technique. Since a large discrepancy in the literature exists on exact values of nonlinear coefficients, one is never sure about this whether theoretically predicted phase-matching angles (PMA) are those that are really optimal. Besides, none has yet measured the values of nonlinear coefficients as a function of doping concentration. Therefore we have not decided to cut numerous differently oriented samples for generation of different wavelengths in SHG and SFD, but rather tried to generate different wavelengths from the same samples. We have also not paid special attention to get highest possible conversion efficiencies. However, we have concentrated our attention on potential use of the core region in laser technique. Unlike in YAG crystals, when the core is by all means a parasitic structure, we discovered that the core region in GdCOB, that majority of investigators are even not aware of its presence in the crystal, can be also useful in laser technique. According to our best knowledge, a SHG of red light in this work is the second reported case in the world-wide literature.

Bajor, A. L.; Kisielewski, J.; K?os, A.; Kopczy?ski, K.; ?ukasiewicz, T.; Mierczyk, J.; M?y?czak, J.

2011-12-01

112

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

113

Calcium orthophosphates  

PubMed Central

The present overview is intended to point the readers’ attention to the important subject of calcium orthophosphates. This type of materials is of special significance for human beings, because they represent the inorganic part of major normal (bones, teeth and antlers) and pathological (i.e., those appearing due to various diseases) calcified tissues of mammals. For example, atherosclerosis results in blood vessel blockage caused by a solid composite of cholesterol with calcium orthophosphates, while dental caries and osteoporosis mean a partial decalcification of teeth and bones, respectively, that results in replacement of a less soluble and harder biological apatite by more soluble and softer calcium hydrogenphosphates. Therefore, the processes of both normal and pathological calcifications are just an in vivo crystallization of calcium orthophosphates. Similarly, dental caries and osteoporosis might be considered an in vivo dissolution of calcium orthophosphates. Thus, calcium orthophosphates hold a great significance for humankind, and in this paper, an overview on the current knowledge on this subject is provided. PMID:23507744

Dorozhkin, Sergey V.

2011-01-01

114

Calcium and olfactory transduction.  

PubMed

1. Inorganic cations, organic calcium antagonists, and calmodulin antagonists were applied to olfactory epithelia of frogs (Rana pipiens) while recording electroolfactogram (EOG) responses. 2. Inorganic cations inhibited EOGs in a rank order, reflecting their calcium channel blocking potency: La3+ greater than Zn2+ greater than Cd2+ greater than Al3+ greater than Ca2+ greater than Sr2+ greater than Co2+ greater than Ba2+ greater than Mg2+. Barium ion significantly enhanced EOGs immediately following application. 3. Diltiazem and verapamil produced dose-dependent EOG inhibition. 4. Calmodulin antagonists inhibited EOGs without correlation to their anti-calmodulin potency. PMID:2904344

Winegar, B D; Rosick, E R; Schafer, R

1988-01-01

115

Foliar phloem infrastructure in support of photosynthesis  

PubMed Central

Acclimatory adjustments of foliar minor loading veins in response to growth at different temperatures and light intensities are evaluated. These adjustments are related to their role in providing infrastructure for the export of photosynthetic products as a prerequisite for full acclimation of photosynthesis to the respective environmental conditions. Among winter-active apoplastic loaders, higher photosynthesis rates were associated with greater numbers of sieve elements per minor vein as well as an increased apparent total membrane area of cells involved in phloem loading (greater numbers of cells and/or greater cell wall invaginations). Among summer-active apoplastic loaders, higher photosynthesis rates were associated with increased vein density and, possibly, a greater number of sieve elements and companion cells per minor vein. Among symplastic loaders, minor loading vein architecture (number per vein and arrangement of cells) was apparently constrained, but higher photosynthesis rates were associated with higher foliar vein densities and larger intermediary cells (presumably providing a greater volume for enzymes involved in active raffinose sugar synthesis). Winter-active apoplastic loaders thus apparently place emphasis on adjustments of cell membrane area (presumably available for transport proteins active in loading of minor veins), while symplastic loaders apparently place emphasis on increasing the volume of cells in which their active loading step takes place. Presumably to accommodate a greater flux of photosynthate through the foliar veins, winter-active apoplastic loaders also have a higher number of sieve elements per minor loading vein, whereas symplastic loaders and summer-active apoplastic loaders have a higher total number of veins per leaf area. These latter adjustments in the vasculature (during leaf development) may also apply to the xylem (via greater numbers of tracheids per vein and/or greater vein density per leaf area) serving to increase water flux to mesophyll tissues in support of high rates of transpiration typically associated with high rates of photosynthesis. PMID:23785375

Adams, William W.; Cohu, Christopher M.; Muller, Onno; Demmig-Adams, Barbara

2013-01-01

116

Development and Application of Image Analysis to Quantify Calcium Lactate Crystals on the Surface of Smoked Cheddar Cheese  

Microsoft Academic Search

Calcium lactate crystals that form white specks or haze on the surface of cheese constitute a significant quality problem for producers of Cheddar cheese. Sub- jective methods to evaluate crystal coverage of cheese surfaces have been reported previously, but objective methods are currently lacking. The objectives of this work were to develop and evaluate an objective method tomeasuretheareaoccupiedbycalciumlactatecrystals on surfaces

P. Rajbhandari; P. S. Kindstedt

2005-01-01

117

[Application of Laser-based geological techniques to bone research: Calcium oxide distribution analyses of animal bones].  

PubMed

The structural similarities between the inorganic component of bone tissue and geological formations make it possible that mathematic models may be used to determine weight percentage composition of different mineral element oxides constituting the inorganic component of bone tissue. The determined weight percentage composition can be verified with the determination of element oxide concentration values by laser induced plasma spectroscopy and inductively coupled plasma optical emission spectrometry. It can be concluded from calculated weight percentage composition of the inorganic component of bone tissue and laboratory analyses that the properties of bone tissue are determined primarily by hydroxylapatite. The inorganic bone structure can be studied well by determining the calcium oxide concentration distribution using the laser induced plasma spectroscopy technique. In the present study, thin polished bone slides prepared from male bovine tibia were examined with laser induced plasma spectroscopy in a regular network and combined sampling system to derive the calculated calcium oxide concentration distribution. The superficial calcium oxide concentration distribution, as supported by "frequency distribution" curves, can be categorized into a number of groups. This, as such, helps in clearly demarcating the cortical and trabecular bone structures. Following analyses of bovine tibial bone, the authors found a positive association between the attenuation value, as determined by quantitative computer tomography and the "?" density, as used in geology. Furthermore, the calculated "?" density and the measured average calcium oxide concentration values showed inverse correlation. Orv. Hetil., 2014, 155(45), 1783-1793. PMID:25362641

Andrássy, László; Maros, Gyula; Kovács, István János; Horváth, Agnes; Gulyás, Katalin; Bertalan, Eva; Besnyi, Anikó; Füri, Judit; Fancsik, Tamás; Szekanecz, Zoltán; Bhattoa, Harjit Pal

2014-11-01

118

Calcium alginate entrapped preparations of Aspergillus oryzae ? galactosidase: Its stability and applications in the hydrolysis of lactose  

Microsoft Academic Search

Insoluble concanavalin A–? galactosidase complex was obtained by using jack bean extract and this complex was crosslinked with glutaraldehyde, in order to maintain the integrity of complex in the presence of its substrate or products. Concanavalin A–? galactosidase complex retained 92% of the initial enzyme activity whereas crosslinked complex showed 88% activity. Entrapment of concanavalin A–? galactosidase complex into calcium

Toshiba Haider; Qayyum Husain

2007-01-01

119

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

120

16 The Response of Foliar Carbohydrates to Elevated [CO2  

E-print Network

16 The Response of Foliar Carbohydrates to Elevated [CO2] Alistair Rogers and Elizabeth A. Ainsworth 16.1 Introduction Accumulation of foliar carbohydrates is one of the most pronounced and uni]). Carbohydrates are both the product of photosynthetic cells and the substrate for sink metabolism. However

Rogers, Alistair

121

Foliar Lead Uptake by Lettuce Exposed to Atmospheric Fallouts  

E-print Network

Foliar Lead Uptake by Lettuce Exposed to Atmospheric Fallouts G A ¨E L L E U Z U , S O P H I E S O gardens near industrial plants. The mechanisms of foliar uptake of lead by lettuce (Lactuca sativa) exposed to the atmospheric fallouts of a lead-recycling plant were studied. After43daysofexposure

Mailhes, Corinne

122

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

123

Phytotoxicity of foliar-applied urea  

PubMed Central

Recent work in our laboratory showed that the adverse effect of urea fertilizer on seed germination and seedling growth in soil is due to ammonia produced through hydrolysis of urea by soil urease (NH2CONH2 + H2O ? 2NH3 + CO2) and can be eliminated by amending the fertilizer with a small amount of a urease inhibitor such as phenylphosphorodiamidate. Because the leaf-tip necrosis often observed after foliar fertilization of plants with urea is usually attributed to ammonia formed through hydrolysis of urea by plant urease, we studied the possibility that this necrosis could be eliminated or reduced by adding phenylphosphorodiamidate to the urea fertilizer. We found that, although addition of this urease inhibitor to foliar-applied urea increased the urea content and decreased the ammonia content and urease activity of soybean [Glycine max. (L.) Merr.] leaves fertilized with urea, it increased the leaf-tip necrosis observed after fertilization. We conclude that this necrosis resulted from accumulation of toxic amounts of urea rather than from formation of toxic amounts of ammonia. This conclusion was supported by our finding that the necrotic areas of soybean leaves treated with urea or with urea and phenylphosphorodiamidate contained much higher concentrations of urea than did the nonnecrotic areas. Images PMID:16594077

Krogmeier, Michael J.; McCarty, Gregory W.; Bremner, John M.

1989-01-01

124

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

125

Rosuvastatin calcium  

Microsoft Academic Search

Rosuvastatin calcium (Crestor; AstraZeneca), the seventh drug in the statin class, was approved by the US FDA in August 2003 for the reduction of cholesterol levels in patients with hypercholesterolaemia. Billed as the most potent statin available, can it overcome initial setbacks and make a significant impact in the multi-billion-dollar market for cholesterol-lowering drugs?

Mark Thornton; Peter Kirkpatrick; Jeremy Quirk

2003-01-01

126

Management of Pratylenchus penetrans on Oriental Lilies with Drip and Foliar-applied Nematicides.  

PubMed

Pratylenchus penetrans is a pest for producers of oriental lilies in northern California. Concern over groundwater contamination from 1,2-dichloropropane following shank injections of 1,3-dichloropropene-l,2-dichloropropane mixture and granular applications of aldicarb prompted testing for alternative methods of controlling P. penetrans. In field trials, nematicides applied by drip irrigation (ethoprop, fenamiphos, oxamyl, sodium tetrathiocarbonate, water extracts of marigold and vetch, and 1,3-D plus emulsifier) were tested with and without foliar applications of oxamyl. Nematode populations were reduced (P = 0.05) relative to controls in soil or roots on one or more sampling dates by all drip-applied nematicides except the plant extracts. On some sampling dates, additional reductions (P = 0.05) occurred as a result of three foliar applications of oxamyl. Foliar-applied oxamyl alone also reduced (P = 0.05) nematodes in soil or roots. Lily bulb weight was not affected (P = 0.05) by chemical treatments. PMID:19279836

Westerdahl, B B; Giraud, D; Radewald, J D; Anderson, C A; Darso, J

1993-12-01

127

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

128

Remote sensing of foliar biochemistry with a terrestrial laser scanner  

NASA Astrophysics Data System (ADS)

Foliar biochemistry provides important information about the physiological status of plants. Several different tools and techniques have been developed to infer plant biochemistry (such as state and change of foliar nitrogen (N) and chlorophyll) using remote sensing. However, few techniques allow accurate mapping of foliar biochemistry in 3-dimensions at a sub-cm level. Scanning laser technology is available that measures the x,y,z location of each reflected laser pulse in addition to the intensity of the reflected laser light within a mm-scale ground instantaneous field of view at a very high sampling rate (up to 50,000 points sec-1 in this study). We examined the ability to quantify foliar N of spring wheat (Triticum aestivum L.) and chlorophyll content of two broadleaf tree species saplings (Quercus macrocarpa and Acer saccharum) using a green (532 nm) terrestrial laser scanner. The return intensity of the reflected green laser light was significantly correlated with foliar N concentration of wheat (r2 = 0.68) and the foliar chlorophyll content (r2 = 0.77) of the broadleaf saplings. The results indicate that laser scanners are useful to obtain spatially explicit estimates of foliar biochemistry.

Eitel, J.; Vierling, L. A.; Long, D. S.

2011-12-01

129

Foliar nutrient status of Pinus ponderosa exposed to ozone and acid rain  

SciTech Connect

A direct effect of foliar exposure to acid rain may be increased leaching of nutrient elements. Ozone exposure, through degradation of the cuticle and cellular membranes, may also result in increased nutrient leaching. To test these hypotheses, the foliar concentrations of 13 nutrient elements were monitored for mature branches of three clones of Pinus ponderosa exposed to ozone and/or acid rain. The three clones represented three distinct levels of phenotypic vigor. Branches were exposed to charcoal filtered, ambient, or 2 x ambient concentrations of ozone and received no acid rain (NAP), pH 5.1 rain (5.1), or pH 3.0 (3.0) rain. Following 10 months of continuous ozone exposure and 3 months of weekly rain applications, the concentrations of P and Mg differed significantly among rain treatments with a ranking of: 5.1 < NAP < 3.0. The S concentration increased with rain application regardless of pH. For the clones of moderate and low vigor, the concentration of N decreased with increasing rain acidity. There was no evidence of significant ozone or ozone x acid rain response. Among the three families, high phenotypic vigor was associated with significantly greater concentrations of N, P, K, Mg, B and An. These results indicate generally negligible leaching as a result of exposure to acid rain and/or ozone for one growing season. Increases in foliar concentrations of S, Mg and P are possibly the result of evaporative surface deposition from the rain solution.

Anderson, P.D.; Houpis, J.L.J. (Lawrence Livermore National Lab., CA (United States))

1991-05-01

130

Foliar washoff potential and simulated surface runoff losses of trifloxysulfuron in cotton.  

PubMed

The surface runoff potential of trifloxysulfuron {N-[(4,6-dimethoxy-2-pyrimidinyl)carbamoyl]-3-(2,2,2-trifluoroethoy)-pyridin-2-sulfonamide sodium salt} in cotton (Gossypium hirsutum L.) production systems has not been evaluated. The objectives of this study were to (i) determine sorption/desorption coefficients for trifloxysulfuron; (ii) quantify foliar washoff of trifloxysulfuron when applied to cotton at the five-leaf stage; and (iii) determine the surface runoff potential of trifloxysulfuron when applied to cotton at the five-leaf stage and to bare soil. Freundlich sorption and desorption coefficients were 1.15 and 1.22, respectively. Sorption data indicated that trifloxysulfuron was moderately sorbed to soil and that it will be transported primarily in the dissolved phase of surface runoff. Foliar washoff studies revealed that approximately 91% of trifloxysulfuron applied to cotton at the five-leaf stage was available for washoff 72 h after application. Simulated rainfall (7.5 cm h-1) applied 1 day after herbicide application (7.9 g ha-1) resulted in average concentrations of trifloxysulfuron in surface runoff water of 0.8 microg L-1 for bare plots and 1.3 microg L-1 for cotton plots. Cumulative trifloxysulfuron losses in surface runoff from bare plots and cotton plots were 0.13 and 0.21 g ha-1, respectively. These values correspond to fractional losses of 1.7% for bare plots and 2.7% for cotton plots. Greater runoff losses of trifloxysulfuron from cotton plots were attributed to foliar washoff. Trifloxysulfuron runoff losses may be curtailed if the herbicide is applied early postemergence when canopy coverage is minimal, thereby reducing the potential for foliar washoff. PMID:16848537

Matocha, Mark A; Krutz, L Jason; Reddy, Krishna N; Senseman, Scott A; Locke, Martin A; Steinriede, Robert W; Palmer, Eric W

2006-07-26

131

Calcium addition at the Hubbard Brook Experimental Forest increases the capacity for stress tolerance and carbon capture in red spruce ( Picea rubens ) trees during the cold season  

Microsoft Academic Search

Red spruce (Picea rubens Sarg.) trees are uniquely vulnerable to foliar freezing injury during the cold season (fall and winter), but are also capable\\u000a of photosynthetic activity if temperatures moderate. To evaluate the influence of calcium (Ca) addition on the physiology\\u000a of red spruce during the cold season, we measured concentrations of foliar polyamines and free amino acids (putative stress-protection

Paul G. Schaberg; Rakesh Minocha; Stephanie Long; Joshua M. Halman; Gary J. Hawley; Christopher Eagar

132

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

133

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

134

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

135

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

136

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

137

Regional Assessment of N Saturation using Foliar and Root  

Microsoft Academic Search

N saturation induced by atmospheric N deposition can have serious consequences for forest health in many regions. In order to evaluate whether foliar $$\\\\delta^{15}\\\\hbox{N}$$ may be a robust, regional-scale measure of the onset of N saturation in forest ecosystems, we assembled a large dataset on atmospheric N deposition, foliar and root $$\\\\delta^{15}\\\\hbox{N}$$ and N concentration, soil C:N, mineralization and nitrification.

L. H. Pardo; P. H. Templer; C. L. Goodale; S. Duke; P. M. Groffman; M. B. Adams; P. Boeckx; J. Boggs; J. Campbell; B. Colman; J. Compton; B. Emmett; P. Gundersen; J. Kjønaas; G. Lovett; M. Mack; A. Magill; M. Mbila; M. J. Mitchell; G. McGee; S. McNulty; K. Nadelhoffer; S. Ollinger; D. Ross; H. Rueth; L. Rustad; P. Schaberg; S. Schiff; P. Schleppi; J. Spoelstra; W. Wessel

2006-01-01

138

Effects of crown position and initial spacing on foliar nutrient composition of seven bottomland hardwoods. Forest Service research note  

SciTech Connect

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. falcata var. pagodifolia Ell.), and swamp chestnut oak (Q. michauxii Nutt.), were sampled after the seventh growing season to determine foliar nutrient concentrations. Foliage samples were collected from the upper, middle, and lower crown positions and from the entire crown. Determinations were made for levels of nitrogen, phosphorus, potassium, calcium, and magnesium. Spacing had no effect on nutrient concentrations. Nutrient levels differed by crown position for some nutrients in most species. Most of the differences were in the nitrogen, calcium, and magnesium levels.

Kennedy, H.E.

1993-01-01

139

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

140

Foliar or root exposures to smelter particles: consequences for lead compartmentalization and speciation in plant leaves.  

PubMed

In urban areas with high fallout of airborne particles, metal uptake by plants mainly occurs by foliar pathways and can strongly impact crop quality. However, there is a lack of knowledge on metal localization and speciation in plants after pollution exposure, especially in the case of foliar uptake. In this study, two contrasting crops, lettuce (Lactuca sativa L.) and rye-grass (Lolium perenne L.), were exposed to Pb-rich particles emitted by a Pb-recycling factory via either atmospheric or soil application. Pb accumulation in plant leaves was observed for both ways of exposure. The mechanisms involved in Pb uptake were investigated using a combination of microscopic and spectroscopic techniques (electron microscopy, laser ablation, Raman microspectroscopy, and X-ray absorption spectroscopy). The results show that Pb localization and speciation are strongly influenced by the type of exposure (root or shoot pathway) and the plant species. Foliar exposure is the main pathway of uptake, involving the highest concentrations in plant tissues. Under atmospheric fallouts, Pb-rich particles were strongly adsorbed on the leaf surface of both plant species. In lettuce, stomata contained Pb-rich particles in their apertures, with some deformations of guard cells. In addition to PbO and PbSO4, chemical forms that were also observed in pristine particles, new species were identified: organic compounds (minimum 20%) and hexagonal platy crystals of PbCO3. In rye-grass, the changes in Pb speciation were even more egregious: Pb-cell wall and Pb-organic acid complexes were the major species observed. For root exposure, identified here as a minor pathway of Pb transfer compared to foliar uptake, another secondary species, pyromorphite, was identified in rye-grass leaves. Finally, combining bulk and spatially resolved spectroscopic techniques permitted both the overall speciation and the minor but possibly highly reactive lead species to be determined in order to better assess the health risks involved. PMID:24508855

Schreck, Eva; Dappe, Vincent; Sarret, Géraldine; Sobanska, Sophie; Nowak, Dorota; Nowak, Jakub; Stefaniak, El?bieta Anna; Magnin, Valérie; Ranieri, Vincent; Dumat, Camille

2014-04-01

141

Calcium source (image)  

MedlinePLUS

... kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the heart and circulatory system, as well as the secretion of essential hormones. There are many ways to supplement calcium, including a growing number of fortified foods.

142

Reparative hard tissue formation following calcium hydroxide application after partial pulpotomy in cariously exposed pulps of permanent teeth.  

PubMed

In a prospective study, partial pulpotomy was performed on six permanent molars with deep carious lesions and pulpal involvement. The bleeding pulp was irrigated with normal tap water until bleeding had stopped and the exposed pulp was covered with calcium hydroxide followed by zinc oxide eugenol, and finally covered with a semipermanent restoration. All teeth showed hard tissue barrier formation, both clinically and radiographically, within three months and were free from subjective and objective symptoms through the observation period (average observation period was 26 months). The patients also experienced the therapy positively. These findings and those of others have helped gain more recognition for partial pulpotomy as a strong possible alternative therapy when pulps are exposed by deep carious lesions and a bleeding pulp is exposed during the excavation process. The rationale for this therapy is to remove the infected and/or inflamed pulpal areas beneath the carious lesion and disintegrated tissue. A rapid and simplified procedure would allow the general practitioner to perform this procedure when necessary at dental clinics, without specialist facilities under conditions that avoid unnecessary contamination of the pulp. PMID:10321166

Nosrat, I V; Nosrat, C A

1998-05-01

143

Core-Shell Hollow Microspheres of Magnetic Iron Oxide@Amorphous Calcium Phosphate: Synthesis Using Adenosine 5'-Triphosphate and Application in pH-Responsive Drug Delivery.  

PubMed

Drug nanocarriers with magnetic targeting and pH-responsive drug-release behavior are promising for applications in controlled drug delivery. Magnetic iron oxides show excellent magnetism, but their application in drug delivery is limited by low drug-loading capacity and poor control over drug release. Herein, core-shell hollow microspheres of magnetic iron oxide@amorphous calcium phosphate (MIO@ACP) were prepared and investigated as magnetic, pH-responsive drug nanocarriers. Hollow microspheres of magnetic iron oxide (HMIOs) were prepared by etching solid MIO microspheres in hydrochloric acid/ethanol solution. After loading a drug into the HMIOs, the drug-loaded HMIOs were coated with a protective layer of ACP by using adenosine 5'-triphosphate (ATP) disodium salt (Na2 ATP) as stabilizer, and drug-loaded core-shell hollow microspheres of MIO@ACP (HMIOs/drug/ACP) were obtained. The as-prepared HMIOs/drug/ACP drug-delivery system exhibits superparamagnetism and pH-responsive drug-release behavior. In a medium with pH?7.4, drug release was slow, but it was significantly accelerated at pH?4.5 due to dissolution of the ACP shell. Docetaxel-loaded core-shell hollow microspheres of MIO@ACP exhibited high anticancer activity. PMID:25100227

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

2014-10-01

144

Enhanced selenium content in buckwheat ( Fagopyrum esculentum Moench) and pumpkin ( Cucurbita pepo L.) seeds by foliar fertilisation  

Microsoft Academic Search

The fruit and thin-husked seeds of the pumpkin ( Cucurbita pepo L.) and buckwheat grain ( Fagopyrum esculentum Moench), both grown in Slovenia, were analysed for selenium (Se) content following foliar application of Se(VI) solution during the period of blooming. Samples were digested by a H 2SO 4-HNO 3-H 2O 2-V 2O 5 mixture and Se determined, based on hydride

Vekoslava Stibilj; Ivan Kreft; Polona Smrkolj; Jože Osvald

2004-01-01

145

Role of polyhydroxybutyrate in mitochondrial calcium uptake  

PubMed Central

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

2013-01-01

146

Biological control of foliar pathogens by means of Trichoderma harzianum and potential modes of action  

Microsoft Academic Search

Biocontrol of foliar diseases is an alternative means of management of foliar pathogens. One of the most studied commercial biocontrol agents is isolate T39 of Trichoderma harzianum which can be regarded as a model to demonstrate biocontrol under commercial conditions and the mechanisms involved. This biocontrol agent (BCA) controls the foliar pathogens, Botrytis cinerea, Pseuperonospora cubensis, Sclerotinia sclerotiorum and Sphaerotheca

Y. Elad

2000-01-01

147

CONTROLS OVER FOLIAR N:P RATIOS IN TROPICAL RAIN FORESTS  

Microsoft Academic Search

Correlations between foliar nutrient concentrations and soil nutrient availability have been found in multiple ecosystems. These relationships have led to the use of foliar nutrients as an index of nutrient status and to the prediction of broadscale patterns in ecosystem processes. More recently, a growing interest in ecological stoichiometry has fueled multiple analyses of foliar nitrogen : phosphorus (N:P) ratios

Alan R. Townsend; Cory C. Cleveland; Gregory P. Asner; Mercedes M. C. Bustamante

2007-01-01

148

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

149

Studies on sintering additives for hydroxyapatite, and controlled porosity structures of calcium aluminates and polypropylene-tricalcium phosphate for bone graft applications  

NASA Astrophysics Data System (ADS)

Tissue engineering has made a significant contribution in developing new biomaterials that can restore the structural features and physiological functions of natural tissues. Various materials, such as metals, ceramics, polymers and composites have been developed for their use in hard tissue engineering applications. Part A of this thesis describes my research on HAp ceramics. HAp, a bioactive ceramic, is known for its osteoconductivity, but shows poor mechanical performance. This program aimed at improving mechanical performance of synthetic HAp by introducing small quantities of various sintering additives. A range of oxide-based sintering additives were selected and prepared. Dense compacts were prepared using a uniaxial press with an average green density of 1.6 g/cc. Results showed that some of these sintering additives improved densification, hardness and compression strength of synthetic HAp compared to the pure composition. A maximum bulk density of 3.06 g/cc was achieved for 2.5 wt% addition of MgO. A Microhardness of 4.9 GPa (505 HV) was measured for 2.5 wt% addition of BaO, and the highest compression strength (220MPa) was reported for 2.5 wt% addition of CaO. Cytotoxicity and cell proliferation studies with a modified human osteoblast (HOB) cell-line (OPC1) proved most of these materials non-toxic and biocompatible. Microscopic observation revealed that bone cells were attached and grew well on most of these ceramic matrices. Part B describes my work on development of controlled porosity polypropylene-tricalcium phosphate composite scaffolds via the fused deposition modeling (FDM) process. Hg-porosimetry was performed to determine pore size and their distribution. Uniaxial compression testing performed on samples with 36 vol% porosity and pore size of 160 mum showed the best compressive strength of 12.7 MPa. Part C includes my research on development of "3-D honeycomb" porous calcium aluminate structures via the indirect FDM process. Samples of 29% and 44% VFP (designed) with average pore size of 300 mum showed compressive strength between 2 and 24 MPa. Cell proliferation studies conducted with OPC1 cells on polymer-ceramic composite scaffolds and porous calcium aluminate structures showed good cell attachment and a steady cell growth behavior during the first three weeks of in vitro analyses.

Kalita, Samar Jyoti

150

Correcting Iron Deficiencies in Soybean with Foliar Iron Fertilizer  

E-print Network

Correcting Iron Deficiencies in Soybean with Foliar Iron Fertilizer Kevin Bronson, Calvin TrostleH soils in our region is conducive to "lime-induced chlorosis" or iron (Fe) deficiency in soybean. High p indicators of iron deficiency for chlorotic and green soybean, Ropesville, Texas, 2001 Soil type Soil Ca (ppm

Mukhtar, Saqib

151

Response of soybeans to foliar sprays of fungicides  

E-print Network

) Pseudomonas glycinea 0.2 Soybean cyst nematode Heterodera glycines 2.0 Other nematodes Root-knot, Stubby rootResponse of soybeans to foliar sprays of fungicides in 2005 Publication 450-561 2006 was supported by the Virginia Agricultural Experiment Station, the Virginia Soybean Board, and the Virginia

Liskiewicz, Maciej

152

Original article Foliar senescence in maize plants grown  

E-print Network

Original article Foliar senescence in maize plants grown under different water regimes Arturo) Abstract - The leaf ontogeny of potted maize plants subjected to severe water stress was carried out and water-stressed plants received 100 and 50 % of the water evapotranspired, respectively. After 30 days

Paris-Sud XI, Université de

153

Effect of Zinc Application on Growth and Some Biochemical Characteristics of Costmary (Chrysanthemum balsamita L.)  

Microsoft Academic Search

A pot experiment was conducted to investigate the effects of different zinc (Zn) application methods (soil and foliar application) and concentrations (1 and 2 mg kg in soil application and 1 and 3 g L in foliar application) on the growth, some biochemical characteristics, and nutrient concentrations of costmary (Chrysanthemum balsamita L.). Growth parameters were increased by zinc application regardless

Zaynab Derakhshani; Abbas Hassani; Mir Hassan Rasouli Sadaghiani; Mohammad Bagher Hassanpouraghdam; Bahman Hosseini Khalifani; Mahdie Dalkani

2011-01-01

154

Calcium carbonate overdose  

MedlinePLUS

... is an ingredient that is commonly found in antacids (for heartburn) and some dietary supplements. Calcium carbonate ... Products containing calcium carbonate, including Certain antacids ... mineral supplements Note: This list may not be all-inclusive.

155

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

156

Calcium and Mitosis  

NASA Technical Reports Server (NTRS)

Although the mechanism of calcium regulation is not understood, there is evidence that calcium plays a role in mitosis. Experiments conducted show that: (1) the spindle apparatus contains a highly developed membrane system that has many characteristics of sarcoplasmic reticulum of muscle; (2) this membrane system contains calcium; and (3) there are ionic fluxes occurring during mitosis which can be seen by a variety of fluorescence probes. Whether the process of mitosis can be modulated by experimentally modulating calcium is discussed.

Hepler, P.

1983-01-01

157

Intracellular compartmentalization of Indo1 and Mag-indo-1: consequences on intracellular calcium and magnesium sensing and imaging for biomedical applications  

Microsoft Academic Search

Indo-1 and Mag-indo-1 are well known fluorescent probes which consist in two different cages of complexation covalently bound to the same fluorophor. The ionic rap of Indo-1 fit perfectly the size of the calcium ion and its sensitivity is well adapted to the basal concentration of calcium ion in the cytoplasm. Although Mag-indo-1 was designed to complex magnesium, it has

Pierre M. Viallet; Tuan Vo-Dinh; T. Bunde; Judith Pescot; Jean Vigo; Jean-Marie Salmon

1997-01-01

158

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

159

Stochastic models of intracellular calcium signals  

NASA Astrophysics Data System (ADS)

Cellular signaling operates in a noisy environment shaped by low molecular concentrations and cellular heterogeneity. For calcium release through intracellular channels-one of the most important cellular signaling mechanisms-feedback by liberated calcium endows fluctuations with critical functions in signal generation and formation. In this review it is first described, under which general conditions the environment makes stochasticity relevant, and which conditions allow approximating or deterministic equations. This analysis provides a framework, in which one can deduce an efficient hybrid description combining stochastic and deterministic evolution laws. Within the hybrid approach, Markov chains model gating of channels, while the concentrations of calcium and calcium binding molecules (buffers) are described by reaction-diffusion equations. The article further focuses on the spatial representation of subcellular calcium domains related to intracellular calcium channels. It presents analysis for single channels and clusters of channels and reviews the effects of buffers on the calcium release. For clustered channels, we discuss the application and validity of coarse-graining as well as approaches based on continuous gating variables (Fokker-Planck and chemical Langevin equations). Comparison with recent experiments substantiates the stochastic and spatial approach, identifies minimal requirements for a realistic modeling, and facilitates an understanding of collective channel behavior. At the end of the review, implications of stochastic and local modeling for the generation and properties of cell-wide release and the integration of calcium dynamics into cellular signaling models are discussed.

Rüdiger, Sten

2014-01-01

160

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

161

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

162

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. PMID:21366919

2011-01-01

163

Effects of induced water stress on leaf trichome density and foliar nutrients of three elm (Ulmus) species: implications for resistance to the elm leaf beetle.  

PubMed

Seedlings of three elm species with variable susceptibility to the elm leaf beetle (Pyrrhalta luteola Müller) (Coleoptera: Chrysomelidae) were subjected to three water stress treatments (no stress, low stress, and high stress) in a greenhouse experiment. The species tested were Ulmus pumila L. (Siberian elm = highly susceptible), U. parvifolia Jacq. (Chinese elm = resistant), and U. americana L. (American elm = intermediate). The seedlings were analyzed for changes in the levels of selected host traits (trichome density, foliar concentration of nitrogen [N], phosphorus [P], potassium [K], calcium [Ca], magnesium [Mg], iron [Fe], and manganese [Mn]), some of which had previously been implicated in resistance to the elm leaf beetle. Density of leaf abaxial surface trichomes (simple, bulbous, and total trichomes) and foliar Fe and Mg concentrations increased significantly in the highly susceptible Siberian elms under water stress. In contrast, stress reduced trichome density in the moderately susceptible American elms, but it had no effect on levels of foliar mineral nutrients. The stress treatments had no influence on host traits in the resistant Chinese elms. The results suggest that environmental stress can alter plant traits that are likely involved in determining resistance of elms to the elm leaf beetle. PMID:17540070

Bosu, Paul P; Wagner, Michael R

2007-06-01

164

Improved biocompatibility of poly(lactic-co-glycolic acid) orv and poly-L-lactic acid blended with nanoparticulate amorphous calcium phosphate in vascular stent applications.  

PubMed

Biodegradable polymers used as vascular stent coatings and stent platforms encounter a major challenge: biocompatibility in vivo, which plays an important role in in-stent restenosis (ISR). Co-formulating amorphous calcium phosphate (ACP) into poly(lactic-co-glycolic acid) (PLGA) or poly-L-lactic acid (PLLA) was investigated to address the issue. For stent coating applications, metal stents were coated with polyethylene-co-vinyl acetate/poly-n-butyl methacrylate (PEVA/PBMA), PLGA or PLGA/ACP composites, and implanted into rat aortas for one and three months. Comparing with both PEVA/PBMA and PLGA groups after one month, the results showed that stents coated with PLGA/ACP had significantly reduced restenosis (PLGA/ACP vs. PEVA/PBMA vs. PLGA: 21.24 +/- 2.59% vs. 27.54 +/- 1.19% vs. 32.12 +/- 3.93%, P < 0.05), reduced inflammation (1.25 +/- 0.35 vs. 1.77 +/- 0.38 vs. 2.30 +/- 0.21, P < 0.05) and increased speed of re-endothelialization (1.78 +/- 0.46 vs. 1.17 +/- 0.18 vs. 1.20 +/- 0.18, P < 0.05). After three months, the PLGA/ACP group still displayed lower inflammation score (1.33 +/- 0.33 vs. 2.27 +/- 0.55, P < 0.05) and higher endothelial scores (2.33 +/- 0.33 vs. 1.20 +/- 0.18, P < 0.05) as compared with the PEVA/PBMA group. Moreover, for stent platform applications, PLLA/ACP stent tube significantly reduced the inflammatory cells infiltration in the vessel walls of rabbit iliac arteries relative to their PLLA cohort (NF-kappaB-positive cells: 23.31 +/- 2.33/mm2 vs. 9.34 +/- 1.35/mm2, P < 0.05). No systemic biochemical or pathological evidence of toxicity was found in either PLGA/ACP or PLLA/ACP. The co-formulation of ACP into PLGA and PLLA resulted in improved biocompatibility without systemic toxicity. PMID:24749387

Zheng, Xiaoxin; Wang, Yujue; Lan, Zhiyuan; Lyu, Yongnan; Feng, Gaoke; Zhang, Yipei; Tagusari, Shizu; Kislauskis, Edward; Robich, Michael P; McCarthy, Stephen; Sellke, Frank W; Laham, Roger; Jiang, Xuejun; Gu, Wei Wang; Wu, Tim

2014-06-01

165

Quantitative determination of the composition of multi-shell calcium phosphate-oligonucleotide nanoparticles and their application for the activation of dendritic cells.  

PubMed

Biodegradable calcium phosphate nanoparticles as carriers for the immunoactive toll-like receptor ligands CpG and polyinosinic-polycytidylic acid for the activation of dendritic cells (DC) combined with the viral antigen hemagglutinin (HA) were prepared. A purification method based on ultracentrifugation and ultrasonication was developed to separate the nanoparticles from dissolved biomolecules. The number of biomolecules, i.e., oligonucleotides and peptide, incorporated into the nanoparticles was quantitatively determined by UV-spectroscopy, using fluorescent derivatives of the biomolecules. The immunostimulatory effects of purified calcium phosphate nanoparticles on DC were studied, i.e., cytokine production and activation of the cells in terms of the upregulation of surface molecules. Purified calcium phosphate nanoparticles, i.e., without dissolved biomolecules, are capable of inducing adaptive immunity by activation of DC. Immunostimulatory effects of purified calcium phosphate nanoparticles on DC were demonstrated by increased expression of co-stimulatory molecules and MHC II and by cytokine secretion. In addition, DC treated with purified functionalized calcium phosphate nanoparticles induced an antigen-specific T-cell response in vitro. PMID:21784177

Sokolova, V; Knuschke, T; Buer, J; Westendorf, A M; Epple, M

2011-11-01

166

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

167

Foliar responses of Peristrophe bicalyculata to coal smoke pollution  

Microsoft Academic Search

Study of the foliar responses ofPeristrophe bicalyculata (Reth) Nees to the pollution caused by thermal power plant emissions revealed that the stomatal size, pore length, density,\\u000a and index, as well as the photosynthetic rate and total chlorophyll content were reduced inP. bicalyculata plants at the polluted site in pre-flowering, flowering as well as post-flowering stage of plant growth. Contrary to

Mahmooduzzafar Farah Nighat; Muhammad Iqbal

1999-01-01

168

The growth and chemical composition of soybeans as influenced by varying sulphur applications, varying soluble salts and varying calcium: sodium ratios  

E-print Network

on the Concentration and Total Uptiice of Calcium bv PLants Table 7 ~ Ths Effect of tbe Combinations of Sulphur' Soluble ~ts~ and Calci~Sium Ratio on the Concentration and Total Uptake of Calcium bv Plants MoKe/gmi Total M, E, Sulphur None None None 750 750... with ccrossing soluble salts, Again the greater pox tion of this decrease oan be accounted fox bf decreasing yield (Tables 9 and 11)& A highly' significant decrease in ma~sium co~ation occurred with dscxeaxd. ng ca3. cium sodium ratio (' fable 9 and Pig. 5...

Peters, Doyle Burne

2012-06-07

169

A nonadherent cell-based HTS assay for N-type calcium channel using calcium 3 dye.  

PubMed

The N-type calcium channel is a member of the voltage-sensitive calcium channel family and plays a major role in the regulation of neurotransmitter release in the central and peripheral nervous systems. Inhibition of the N-type calcium channel by intrathecal administration of the channel-specific blocker omega-conotoxin MVIIA (ziconotide) is efficacious in the treatment of severe chronic pain. While no orally active small molecules that block the N-type calcium channel are currently available, the discovery of such potentially valuable therapeutics would benefit from a reliable, high throughput assay. However, the assay of N-type calcium channel activity by measuring calcium influx using nonadherent cells in a high throughput fashion has not been achieved before, likely owing to a number of technical hurdles. For example, the measurement of calcium levels in nonadherent cells using conventional calcium indicators, such as Fluo-3 or Fluo-4, requires dyeloading the cells in suspension and subsequent removal of extracellular dye. This limits plate throughput and requires constant handling of the cells. To assay the N-type calcium channel activity using a nonadherent cell line in a high throughput manner, we investigated the application of no-wash calcium assay kits from Molecular Devices Corp. (Sunnyvale, CA): FLIPR Calcium, FLIPR Calcium Plus, and FLIPR Calcium 3. We show here that the FLIPR Calcium 3 assay kit can be used with nonadherent IMR-32 cells to measure potassium-evoked, omega-conotoxin MVIIA-reversible calcium flux with high throughput (15,000 data points/day), high quality (Z approximately 0.6), and minimal handling of the cells. Thus, this assay can be used to reliably and efficiently screen large compound libraries in the search for small molecule N-type calcium channel blockers. PMID:17199507

Lubin, Mary Lou; Reitz, Tasha L; Todd, Matthew J; Flores, Christopher M; Qin, Ning; Xin, Hong

2006-12-01

170

Original article Availability of calcium from skim milk, calcium sulfate  

E-print Network

Original article Availability of calcium from skim milk, calcium sulfate and calcium carbonate that the calcium in milk was more efficiently used than that from any other source. Carbonate, gluconate, citrate; accepted 19 November 1999) Abstract --Dairy products provide abundant, accessible calcium for humans, while

Paris-Sud XI, Université de

171

Calcium is incorporated into the calcium carbonate matrix of otoliths  

E-print Network

118 Calcium is incorporated into the calcium carbonate matrix of otoliths and into the calcium). In addition to calcium, trace elements, such as strontium, are also incorporated into the calcified components valence) allow strontium ions to act as replace- ments for calcium during the pro- cess of calcification

172

Synthesis and characterization of pure and zinc doped calcium pyrophosphate dihydrate nanoparticles  

Microsoft Academic Search

Calcium phosphate based biomaterials are widely used in dentistry and as a bone substitutes in orthopedic applications. Calcium pyrophosphate (CPP) - a type of calcium phosphate and a shortest linear polyphosphate can also be used as a bone graft. Successive applications of theses materials depend on the degree of bio-resorption, mechanical strength and bio-compatibility. Zinc improves the bone activity of

S. R. Vasant; M. J. Joshi

2011-01-01

173

Fabrication of a calcium phosphate scaffold with a three dimensional channel network and its application to perfusion culture of stem cells  

Microsoft Academic Search

Purpose – The purpose of this paper is to adopt rapid prototyping (RP) technology to fabricate self-hardening calcium phosphate composite (CPC) scaffolds with a controlled internal channel network to facilitate nutrient supplying and cell growth using RP technique and investigate their in vitro performance. Design\\/methodology\\/approach – Porous scaffolds should possess branched channels to ensure uniform cell feeding and even flow

Shanglong Xu; Dichen Li; Bingheng Lu; Yiping Tang; Chaofeng Wang; Zhen Wang

2007-01-01

174

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. PMID:24956191

Dorozhkin, Sergey V.

2013-01-01

175

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

176

Reporting neural activity with genetically encoded calcium indicators  

Microsoft Academic Search

Genetically encoded calcium indicators (GECIs), based on recombinant fluorescent proteins, have been engineered to observe\\u000a calcium transients in living cells and organisms. Through observation of calcium, these indicators also report neural activity.\\u000a 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

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

2008-01-01

177

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

178

Micro Determination of Calcium  

Microsoft Academic Search

Hildebrand and Reilly1 have recently described a complexometric titration method for the determination of calcium: the indicator used, `Calcon', is superior to `Solochrome' black in that calcium can be determined independently of magnesium, and, unlike the murexide method, a sharp end-point is obtained. All three methods employ ethylenediamine tetraacetic acid. The purpose of the present communication is to direct attention

A. B. Gilbert

1959-01-01

179

Effect of a plant growth regulator prohexadione-calcium on insect pests of apple and pear.  

PubMed

The effect of prohexadione-calcium, a plant growth regulator that inhibits gibberellin metabolism, on Cacopsylla pyricoloa (Foerster) in pear trees, and Choristoneura rosaceana (Harris) and Aphis spireacola Patch, in apple trees was studied. C. pyricoloa and A. spireacola populations were significantly reduced in prohexadione-calcium-treated pear and apple, respectively. Insecticide control of both pests with imidacloprid was synergized in treatments with prohexadione-calcium. In apples treated with prohexadione-calcium, there was a significant reduction in the number of C. rosaceana shelters per tree and amount of fruit injury at harvest attributable to the C. rosaceana. There was an additive effect when tebufenozide was used to control C. rosaceana in trees treated with prohexadione-calcium. Prohexadione-calcium significantly reduced vegetative growth in both pears and apples. Synergistic and additive treatment effects of prohexadione-calcium and pesticides used in this study may be due to better penetration and coverage of pesticides due to reduced foliar growth or to changes in the nutritional quality of the host plants. PMID:15889734

Paulson, G S; Hull, L A; Biddinger, D J

2005-04-01

180

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

181

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

...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...

2014-04-01

182

Anatomía foliar y caulinar de Stemodia hassleriana (Scrophulariaceae), una especie endémica del Paraguay  

Microsoft Academic Search

Summary: Foliar and caulinar anatomy of Stemodia hassleriana (Scrophulariaceae), a species endemic to Paraguay. Foliar and caulinar anatomy of Stemodia hassleriana Chodat, a species endemic to Paraguay is studied. This species is distinguished from the remaining species of Stemodia from Paraguay since it presents the stems with collenchyma and six notorious ribs. Stem and leaves anatomical structures are described and

MARÍA DE LAS MERCEDES SOSA

183

Regional assessment of N saturation using foliar and root d15 L. H. PARDO1,  

E-print Network

consequences for forest health in many regions. In order to evaluate whether foliar d15 N may be a robust the following species: American beech>yellow birch>sugar maple. Other factors that affected foliar d15 N forests respond to the cascading effects of N deposition. I

Templer, Pamela

184

Ozone air pollution and foliar injury development on native plants of Switzerland  

Microsoft Academic Search

The objectives of this study were to examine the foliar sensitivity to ozone exposure of 12 tree, shrub, and herbaceous species native to southern Switzerland and determine the seasonal cumulative ozone exposures required to induce visible foliar injury. The study was conducted from the beginning of May through the end of August during 2000 and 2001 using an open-top chamber

Kristopher Novak; John M. Skelly; Marcus Schaub; Norbert Kräuchi; Christian Hug; Werner Landolt; Peter Bleuler

2003-01-01

185

Ozone air pollution and foliar injury development on native plants of Switzerland  

Microsoft Academic Search

The objectives of this study were to examine the foliar sensitivity to ozone exposure of 12 tree, shrub, and herbaceous species native to southern Switzerland and determine the seasonal cumulative ozone exposures required to induce visible foliar injury. The study was conducted from the beginning of May through the end of August during 2000 and 2001 using an open-top chamber

Kristopher Novak; John M. Skelly; Marcus Schaub; Norbert Krauchi; Christian Hug; Werner Landolt; Peter Bleuler

186

Foliar Uptake of Fog in the Coast Redwood Ecosystem: a Novel Drought-Alleviation  

E-print Network

273 Foliar Uptake of Fog in the Coast Redwood Ecosystem: a Novel Drought-Alleviation Strategy Shared by Most Redwood Forest Plants Emily Limm1 , Kevin Simonin2 , and Todd Dawson3 Key words: fog, understory, Polystichum munitum, leaf wetness, foliar uptake, drought, climate Introduction Fog inundates

Standiford, Richard B.

187

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...

188

Fast Spatiotemporal Smoothing of Calcium Measurements in Dendritic Trees  

E-print Network

1 Fast Spatiotemporal Smoothing of Calcium Measurements in Dendritic Trees Eftychios A smoothing of calcium signals in dendritic trees, given spatially localized imaging data obtained via multi that the cost of the algorithm is also linear in the size of the dendritic tree, making the approach applicable

Columbia University

189

PHOTOSENSITIVE CENTERS AND CHARGE TRANSFER PROCESSES IN BARIUM CALCIUM TITANATE  

E-print Network

PHOTOSENSITIVE CENTERS AND CHARGE TRANSFER PROCESSES IN BARIUM CALCIUM TITANATE G.MALOVICHKO, V calcium titanate crystals, Ba0.77Ca0.23TiO3, in the temperature range between 4.2 K and 300 K are reported of crystals from barium titanate (BT) family make them promising candidates for various applications

Malovichko, Galina

190

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

191

Delayed degradation in soil of foliar herbicides glyphosate and sulcotrione previously absorbed by plants: Consequences on herbicide fate and risk assessment  

Microsoft Academic Search

Following application, pesticides can be intercepted and absorbed by weeds and\\/or crops. Plants containing pesticides residues may then reach the soil during the crop cycle or after harvest. However, the fate in soil of pesticides residues in plants is unknown. Two commonly used foliar herbicides, glyphosate and sulcotrione, 14C-labeled, were applied on leaves of oilseed rape and\\/or maize, translocation was

Jérémy Doublet; Laure Mamy; Enrique Barriuso

2009-01-01

192

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

193

Hormonal Control of Calcium Homeostasis  

Microsoft Academic Search

Calcium homeostasis in the extracellular fluid is tightly controlled and defended physiologically. Hypercalce- mia always represents considerable underlying pathol- ogy and occurs when the hormonal control of calcium homeostasis is overwhelmed. The major hormones that are responsible for normal calcium homeostasis are parathyroid hormone and 1,25-dihydroxyvitamin D; these hormones control extracellular fluid calcium on a chronic basis. Over- or underproduction

Gregory R. Mundy; Theresa A. Guise

1999-01-01

194

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

195

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

196

Calcium addition at the Hubbard Brook Experimental Forest increases sugar storage, antioxidant activity and cold tolerance in native red spruce (Picea rubens).  

PubMed

In fall (November 2005) and winter (February 2006), we collected current-year foliage of native red spruce (Picea rubens Sarg.) growing in a reference watershed and in a watershed treated in 1999 with wollastonite (CaSiO(3), a slow-release calcium source) to simulate preindustrial soil calcium concentrations (Ca-addition watershed) at the Hubbard Brook Experimental Forest (Thornton, NH). We analyzed nutrition, soluble sugar concentrations, ascorbate peroxidase (APX) activity and cold tolerance, to evaluate the basis of recent (2003) differences between watersheds in red spruce foliar winter injury. Foliar Ca and total sugar concentrations were significantly higher in trees in the Ca-addition watershed than in trees in the reference watershed during both fall (P=0.037 and 0.035, respectively) and winter (P=0.055 and 0.036, respectively). The Ca-addition treatment significantly increased foliar fructose and glucose concentrations in November (P=0.013 and 0.007, respectively) and foliar sucrose concentrations in winter (P=0.040). Foliar APX activity was similar in trees in both watersheds during fall (P=0.28), but higher in trees in the Ca-addition watershed during winter (P=0.063). Cold tolerance of foliage was significantly greater in trees in the Ca-addition watershed than in trees in the reference watershed (P<0.001). Our results suggest that low foliar sugar concentrations and APX activity, and reduced cold tolerance in trees in the reference watershed contributed to their high vulnerability to winter injury in 2003. Because the reference watershed reflects forest conditions in the region, the consequences of impaired physiological function caused by soil Ca depletion may have widespread implications for forest health. PMID:18381266

Halman, Joshua M; Schaberg, Paul G; Hawley, Gary J; Eagar, Christopher

2008-06-01

197

Foliar flavonoids of Annonaceae from Brazil: taxonomic significance.  

PubMed

Foliar flavonoids of 31 species of the Annonaceae native to Brazil, amounting to 76 compounds, were isolated and identified. All phenols found were glycosides of either flavones (apigenin, scutellarein, hispidulin and luteolin) or flavonols (kaempferol, rhamnocitrin, 6-hydroxyrhamnocitrin, quercetin, isorhamnetin and rhamnetin), with the latter predominating. Some members of the tribe Bocageeae are distinctive for accumulating 6-oxygenated flavones and flavonols, in addition to 7-O-methylated flavonols, a feature possibly linked to the assumed advanced condition of the tribe within the family. Members of Duguetia stand out for the apparent absence of quercetin glycosides. Anaxagorea dolichocharpa seemingly lacks flavones and flavonols entirely. A UPGMA analysis based on the distribution of flavonoids does not group the analyzed species according to the available tribal division of the Annonaceae. However, several taxonomically meaningful groupings emerged through the multivariate analysis. PMID:11130666

Santos, D Y; Salatino, M L

2000-11-01

198

[Microbial geochemical calcium cycle].  

PubMed

The participation of microorganisms in the geochemical calcium cycle is the most important factor maintaining neutral conditions on the Earth. This cycle has profound influence on the fate of inorganic carbon, and, thereby, on the removal of CO2 from the atmosphere. The major part of calcium deposits was formed in the Precambrian, when prokaryotic biosphere predominated. After that, calcium recycling based on biogenic deposition by skeletal organisms became the main process. Among prokaryotes, only a few representatives, e.g., cyanobacteria, exhibit a special calcium function. The geochemical calcium cycle is made possible by the universal features of bacteria involved in biologically mediated reactions and is determined by the activities of microbial communities. In the prokaryotic system, the calcium cycle begins with the leaching of igneous rock predominantly through the action of the community of organotrophic organisms. The release of carbon dioxide to the soil air by organotrophic aerobes leads to leaching with carbonic acid and soda salinization. Under anoxic conditions, of major importance is the organic acid production by primary anaerobes (fermentative microorganisms). Calcium carbonate is precipitated by secondary anaerobes (sulfate reducers) and to a smaller degree by methanogens. The role of the cyanobacterial community in carbonate deposition is exposed by stromatolites, which are the most common organo-sedimentary Precambrian structures. Deposition of carbonates in cyanobacterial mats as a consequence of photoassimilation of CO2 does not appear to be a significant process. It is argued that carbonates were deposited at the boundary between the "soda continent", which emerged as a result of subaerial leaching with carbonic acid, and the ocean containing Ca2+. Such ecotones provided favorable conditions for the development of the benthic cyanobacterial community, which was a precursor of stromatolites. PMID:11910807

Zavarzin, G A

2002-01-01

199

Relationship between photosynthetic phosphorus-use efficiency and foliar phosphorus fractions in tropical tree species  

PubMed Central

How plants develop adaptive strategies to efficiently use nutrients on infertile soils is an important topic in plant ecology. It has been suggested that, with decreasing phosphorus (P) availability, plants increase photosynthetic P-use efficiency (PPUE) (i.e., the ratio of instantaneous photosynthetic carbon assimilation rate per unit foliar P). However, the mechanism to increase PPUE remains unclear. In this study, we tested whether high PPUE is explained by an optimized allocation of P in cells among P-containing biochemical compounds (i.e., foliar P fractions). We investigated the relationships among mass-based photosynthetic carbon assimilation rate (Amass), PPUE, total foliar P concentration, and foliar P fractions in 10 tree species in two tropical montane rain forests with differing soil P availability (five species on sedimentary soils and five species on P-poorer ultrabasic serpentine soils) on Mount Kinabalu, Borneo. We chemically fractionated foliar P into the following four fractions: metabolic P, lipid P, nucleic acid P, and residual P. Amass was positively correlated with the concentrations of total foliar P and of metabolic P across 10 tree species. Mean Amass and mean concentrations of total foliar P and of each foliar P fraction were lower on the P-poorer ultrabasic serpentine soils than on the sedimentary soils. There was a negative relationship between the proportion of metabolic P per total P and the proportion of lipid P per total P. PPUE was positively correlated with the ratio of metabolic P to lipid P. High PPUE is explained by the net effect of a relatively greater investment of P into P-containing metabolites and a relatively lesser investment into phospholipids in addition to generally reduced concentrations of all P fractions. We conclude that plants optimize the allocation of P among foliar P fractions for maintaining their productivity and growth and for reducing demand for P as their adaptation to P-poor soils. PMID:24455122

Hidaka, Amane; Kitayama, Kanehiro

2013-01-01

200

Relationship between photosynthetic phosphorus-use efficiency and foliar phosphorus fractions in tropical tree species.  

PubMed

How plants develop adaptive strategies to efficiently use nutrients on infertile soils is an important topic in plant ecology. It has been suggested that, with decreasing phosphorus (P) availability, plants increase photosynthetic P-use efficiency (PPUE) (i.e., the ratio of instantaneous photosynthetic carbon assimilation rate per unit foliar P). However, the mechanism to increase PPUE remains unclear. In this study, we tested whether high PPUE is explained by an optimized allocation of P in cells among P-containing biochemical compounds (i.e., foliar P fractions). We investigated the relationships among mass-based photosynthetic carbon assimilation rate (A mass), PPUE, total foliar P concentration, and foliar P fractions in 10 tree species in two tropical montane rain forests with differing soil P availability (five species on sedimentary soils and five species on P-poorer ultrabasic serpentine soils) on Mount Kinabalu, Borneo. We chemically fractionated foliar P into the following four fractions: metabolic P, lipid P, nucleic acid P, and residual P. A mass was positively correlated with the concentrations of total foliar P and of metabolic P across 10 tree species. Mean A mass and mean concentrations of total foliar P and of each foliar P fraction were lower on the P-poorer ultrabasic serpentine soils than on the sedimentary soils. There was a negative relationship between the proportion of metabolic P per total P and the proportion of lipid P per total P. PPUE was positively correlated with the ratio of metabolic P to lipid P. High PPUE is explained by the net effect of a relatively greater investment of P into P-containing metabolites and a relatively lesser investment into phospholipids in addition to generally reduced concentrations of all P fractions. We conclude that plants optimize the allocation of P among foliar P fractions for maintaining their productivity and growth and for reducing demand for P as their adaptation to P-poor soils. PMID:24455122

Hidaka, Amane; Kitayama, Kanehiro

2013-12-01

201

[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

202

Ultrathin calcium silicate hydrate nanosheets with large specific surface areas: synthesis, crystallization, layered self-assembly and applications as excellent adsorbents for drug, protein, and metal ions.  

PubMed

A simple and low-cost solution synthesis is reported for low-crystalline 1.4 nm tobermorite-like calcium silicate hydrate (CSH) ultrathin nanosheets with a thickness of ~2.8 nm and with a large specific surface area (SSA), via a reaction-rate-controlled precipitation process. The BET SSA of the CSH ultrathin nanosheets can reach as high as 505 m(2) g(-1) . The CSH ultrathin nanosheets have little cytotoxicity and can be converted to anhydrous calcium silicate (ACS) ultrathin nanosheets with a well preserved morphology via a heat treatment process. The crystallinity of CSH ultrathin nanosheets can be improved by solvothermal treatment in water/ethanol binary solvents or a single solvent of water, producing well-crystalline 1.1 nm tobermorite-like CSH nanobelts or nanosheets. CSH ultrathin nanosheets acting as building blocks can self-assemble into layered nanostructures via three different routes. The CSH ultrathin nanosheets are investigated as promising adsorbents for protein (hemoglobin, Hb), drug (ibuprofen, IBU), and metal ions (Cr(3+) , Ni(2+) , Cu(2+) , Zn(2+) , Cd(2+) , Pb(2+) ). The highest adsorbed percentages of Hb and IBU are found to be 83% and 94%, respectively. The highest adsorption capacities of Hb and IBU are found to be as high as 878 milligram Hb per gram CSH and 2.2 gram IBU per gram CSH, respectively. The ppm level metal ions can be totally adsorbed from aqueous solution in just a few minutes. Thus, the CSH ultrathin nanosheets are a promising candidate as excellent adsorbents in the biomedical field and for waste water treatment. Several empirical laws are summarized based on the adsorption profiles of Hb and IBU using CSH ultrathin nanosheets as the adsorbent. Furthermore, the ACS ultrathin nanosheets as adsorbents for Hb protein and IBU drug are investigated. PMID:23585365

Wu, Jin; Zhu, Ying-Jie; Chen, Feng

2013-09-01

203

Gravimetric Determination of Calcium as Calcium Carbonate Hydrate.  

ERIC Educational Resources Information Center

The gravimetric determination of calcium as calcium carbonate is described. This experiment is suitable for undergraduate quantitative analysis laboratories. It is less expensive than determination of chloride as silver chloride. (BB)

Henrickson, Charles H.; Robinson, Paul R.

1979-01-01

204

Calcium revisited: part I  

PubMed Central

In February 2013, the US Preventive Services Task Force (see www.uspreventiveservicestaskforce.org) recommended ‘against daily supplementation with 400?IU or less of vitamin D3 and 1000, mg or less of calcium for the primary prevention of fractures in non institutionalized postmenopausal women', which illustrates the divergence of opinions. This review wants to shed an objective light on the importance of calcium for bone health. It cannot compete with an exhaustive analysis of the literature by an institute. It does not mention all significant references. But it highlights some pivotal studies from the past and it refers to recent studies that opened new views or added essential data to known facts. It also reflects the personal perception of the author. The first part deals mainly with intake, absorption, needs and recommendations; the second part will discuss the effects of calcium and its supplements on bone. PMID:24422133

Burckhardt, Peter

2013-01-01

205

The processing, properties, and applications of calcium aluminate–phenol resin composite 1 1 This paper was originally submitted to Advanced Cement Based Materials on 15 October 1997 and accepted on 22 March 1998. The paper was received at the Editorial Office of Cement and Concrete Research on 20 August 1998 and accepted in final form on 14 September 1998  

Microsoft Academic Search

The processing, properties, and a few applications of calcium aluminate–phenol resin composite with very high flexural strength are discussed. This composite contains a very large amount of cement (70 vol%) but shows unusual engineering properties, which have not yet been achieved by traditional cement-based materials. The flexural strength of the composite is found to be 120 to 220 MPa; in

G. K. Dinilprem Pushpalal; Tadashi Kobayashi; Toshio Kawano; Naomi Maeda

1999-01-01

206

Foliar exposure of the crop Lactuca sativa to silver nanoparticles: evidence for internalization and changes in Ag speciation.  

PubMed

The impact of engineered nanomaterials on plants, which act as a major point of entry of contaminants into trophic chains, is little documented. The foliar pathway is even less known than the soil-root pathway. However, significant inputs of nanoparticles (NPs) on plant foliage may be expected due to deposition of atmospheric particles or application of NP-containing pesticides. The uptake of Ag-NPs in the crop species Lactuca sativa after foliar exposure and their possible biotransformation and phytotoxic effects were studied. In addition to chemical analyses and ecotoxicological tests, micro X-ray fluorescence, micro X-ray absorption spectroscopy, time of flight secondary ion mass spectrometry and electron microscopy were used to localize and determine the speciation of Ag at sub-micrometer resolution. Although no sign of phytotoxicity was observed, Ag was effectively trapped on lettuce leaves and a thorough washing did not decrease Ag content significantly. We provide first evidence for the entrapment of Ag-NPs by the cuticle and penetration in the leaf tissue through stomata, for the diffusion of Ag in leaf tissues, and oxidation of Ag-NPs and complexation of Ag(+) by thiol-containing molecules. Such type of information is crucial for better assessing the risk associated to Ag-NP containing products. PMID:24275476

Larue, Camille; Castillo-Michel, Hiram; Sobanska, Sophie; Cécillon, Lauric; Bureau, Sarah; Barthès, Véronique; Ouerdane, Laurent; Carrière, Marie; Sarret, Géraldine

2014-01-15

207

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

208

Nuclear calcium signaling.  

PubMed

Calcium is the major intracellular messenger linking synaptic activity in neurons to gene expression to control diverse functions including adaptive responses to synaptic activity as well as survival and death (Bading et al. 1993; Hardingham et al. 1997; Chawla and Bading 2001; West et al. 2001; Zhang et al. 2007; Flavell and Greenberg 2008; Mellstrom et al. 2008; Redmond 2008; Wayman et al. 2008; Bootman et al. 2009; Zhang et al. 2009; Hardingham and Bading 2010). Calcium entry at the synapse acts locally to activate signaling cascades which regulate posttranslational modifications essential for synaptic plasticity, such as the insertion of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) into the postsynaptic membrane (Soderling 2000; Malinow and Malenka 2002; Ehrlich and Malinow 2004). Synaptic activity can also evoke calcium signals in the nucleus which regulate gene pools largely through the phosphorylation of cAMP response element-binding protein (CREB) and its coactivator, CREB-binding protein (CBP) (Bading et al. 1993; Hardingham et al. 1997; Hardingham et al. 1999; Hu et al. 1999; Hardingham et al. 2001b; Impey et al. 2002; Zhang et al. 2009). Distinct mechanisms have been proposed to mediate synaptically generated calcium signals in subcompartments of pyramidal neurons; N-methyl-D -aspartate receptors (NMDARs) and ryanodine receptors have been implicated in the spine, inositol 3,4,5 triphosphate (IP3) receptors in the dendrites, and L-type voltage-gated calcium channels (VGCCs) at the soma and nucleus, although both NMDARs and IP3 receptors can also contribute to somatic and nuclear calcium signals under certain stimulation conditions (Nakamura et al. 1999; Bardo et al. 2006; Raymond and Redman 2006; Watanabe et al. 2006; Hong and Ross 2007; Hagenston et al. 2008; Bengtson et al. 2010). We review here the calcium signaling pathways underlying synaptically activated gene transcription leading to long-lasting changes in synaptic efficacy and memory as well as the physiological mechanisms by which synaptic activity evokes nuclear calcium signals. PMID:22351065

Bengtson, C Peter; Bading, Hilmar

2012-01-01

209

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

210

Shrimp pond effluent dominates foliar nitrogen in disturbed mangroves as mapped using hyperspectral imagery.  

PubMed

Conversion of mangroves to shrimp ponds creates fragmentation and eutrophication. Detection of the spatial variation of foliar nitrogen is essential for understanding the effect of eutrophication on mangroves. We aim (i) to estimate nitrogen variability across mangrove landscapes of the Mahakam delta using airborne hyperspectral remote sensing (HyMap) and (ii) to investigate links between the variation of foliar nitrogen mapped and local environmental variables. In this study, multivariate prediction models achieved a higher level of accuracy than narrow-band vegetation indices, making multivariate modeling the best choice for mapping. The variation of foliar nitrogen concentration in mangroves was significantly influenced by the local environment: (1) position of mangroves (seaward/landward), (2) distance to the shrimp ponds, and (3) predominant mangrove species. The findings suggest that anthropogenic disturbances, in this case shrimp ponds, influence nitrogen variation in mangroves. Mangroves closer to the shrimp ponds had higher foliar nitrogen concentrations. PMID:24103095

Fauzi, Anas; Skidmore, Andrew K; van Gils, Hein; Schlerf, Martin; Heitkönig, Ignas M A

2013-11-15

211

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 ...

212

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2011 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2011-04-01

213

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2010 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2010-04-01

214

21 CFR 184.1199 - Calcium gluconate.  

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2014-04-01

215

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2013 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2013-04-01

216

21 CFR 184.1199 - Calcium gluconate.  

Code of Federal Regulations, 2012 CFR

...1199 Calcium gluconate. (a) Calcium gluconate ([CH2 OH(CHOH...Reg. No. 299-28-5) is the calcium salt of gluconic acid which may...neutralization of gluconic acid with lime or calcium carbonate. (b) The...

2012-04-01

217

21 CFR 184.1191 - Calcium carbonate.  

...1) As a byproduct in the “Lime soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the “Carbonation process”; or (3) By precipitation of calcium carbonate from calcium...

2014-04-01

218

Modulation of L-type calcium channels by sodium ions.  

PubMed Central

It is universally believed that the removal of external sodium ions is without effect on calcium current. We now report that in enzymatically isolated guinea pig ventricular cells, the replacement of external sodium ions with certain other cations causes a 3- to 6-fold increase in peak L-type calcium current. The increase in current is reversibly blocked by L-type calcium-channel antagonists, not mediated by changes in internal calcium, and is inhibited by intracellular 5'-adenylyl imidodiphosphate, a nonhydrolyzable ATP analogue. The effects of sodium removal (and isoproterenol) were almost completely blocked by intracellular application of a specific (peptide) inhibitor of cAMP-dependent protein kinase. These experiments demonstrate a previously unknown effect of sodium ions to modulate calcium-channel phosphorylation via cAMP-dependent protein kinase. PMID:1374902

Balke, C W; Wier, W G

1992-01-01

219

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

220

Foliar ? 13 C values of nine dominant species in the Loess Plateau of China  

Microsoft Academic Search

The foliar stable carbon isotope compositions (?13C) of nine dominant species in seven sites, Yangling, Yongshou, Tongchuan, Fuxian, Ansai, Mizhi, and Shenmu, standing from\\u000a the south to the north in the Loess Plateau of China were studied. The results showed that foliar ?13C values ranged from ?22.61 to ?30.73 ‰ with an average of ?27.23 ‰ in 141 C3 plant

S.-X. Zheng; Z.-P. Shangguan

2007-01-01

221

Regional Assessment of N saturation using foliar and root ?15N  

Microsoft Academic Search

N saturation induced by atmospheric N deposition can have serious consequences for forest health in many regions. In order to evaluate whether foliar d15N may be a robust, regional-scale measure of the onset of N saturation in forest ecosystems, we assembled a large dataset on atmospheric N deposition, foliar and root d15N and N concentration, soil C:N, mineralization and nitrification.

L. H. Pardo; P. Templer; C. L. Goodale; S. Duke; P. Groffman; M. B. Adams; P. Boeckx; J. Boggs; J. Campbell; J. Compton; B. Emmett; P. Gundersen; G. Lovett; M. Mack; A. Magill; M. J. Mitchell; M. Mbila; G. McGee; S. McNulty; K. Nadelhoffer; B. Colman; S. Ollinger; D. Ross; H. Rueth; L. Rustad; P. Schaberg; S. Schiff; P. Schleppi; J. Spoelstra; W. Wessel

222

The influence of adjuvants on the foliar absorption of nitrogen and phosphorus  

E-print Network

'uvants Many times the concentration of the test compound, whether it is an insecticide, herbicide, or foliar fertilizer, is greatly exceeded by the concentration of the adjuvant (63). At this point, the adjuvants themselves may exert various effects...'uvants Many times the concentration of the test compound, whether it is an insecticide, herbicide, or foliar fertilizer, is greatly exceeded by the concentration of the adjuvant (63). At this point, the adjuvants themselves may exert various effects...

Stein, Larry Alfred

2012-06-07

223

Foliar carbon isotope discrimination in Larix species and sympatric evergreen conifers: a global comparison  

Microsoft Academic Search

Larches (Larix spp.), deciduous conifers, occur in the northern hemisphere in cold-temperate and boreal climates – an environment normally\\u000a thought to favor evergreen tree species. We compare foliar carbon isotope discrimination (?), instantaneous water use efficiency,\\u000a total foliar nitrogen concentration, and specific leaf area (for a subset of sites) between Larix spp. and co-occurring evergreen conifers at 20 sites throughout

Brian D. Kloeppel; Stith T. Gower; Isabel W. Treichel; Slava Kharuk

1998-01-01

224

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

225

Calcium silicate insulation structure  

DOEpatents

An insulative structure including a powder-filled evacuated casing utilizes a quantity of finely divided synthetic calcium silicate having a relatively high surface area. The resultant structure-provides superior thermal insulating characteristics over a broad temperature range and is particularly well-suited as a panel for a refrigerator or freezer or the insulative barrier for a cooler or a insulated bottle.

Kollie, Thomas G. (Oak Ridge, TN); Lauf, Robert J. (Oak Ridge, TN)

1995-01-01

226

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. PMID:24982964

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

2014-01-01

227

Foliar water uptake of Tamarix ramosissima from an atmosphere of high humidity.  

PubMed

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. PMID:24982964

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

2014-01-01

228

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

229

Defoaming effect of calcium soap  

Microsoft Academic Search

The effect of calcium oleate on foam stability was studied for aqueous solutions of two commonly used surfactants (anionic and nonionic) under alkaline conditions in the absence of oil. For the anionic surfactant, defoaming by calcium oleate appears to involve two mechanisms. One is that oleate and calcium ions are presumably incorporated into the surfactant monolayers with a resulting decrease

Hui Zhang; Clarence A. Miller; Peter R. Garrett; Kirk H. Raney

2004-01-01

230

Osteoinduction by calcium phosphate biomaterials  

Microsoft Academic Search

Different materials were implanted in muscles of dogs to study the osteoinduction of calcium phosphate biomaterials. Bone formation was only seen in calcium phosphate biomaterials with micropores, and could be found in hydroxyapatite (HA) ceramic, tricalcium phosphate\\/hydroxyapatite ceramic (BCP), ß-TCP ceramic and calcium phosphate cement. The osteoinductive potential was different in different materials. The results indicate that osteoinduction can be

Huipin Yuan; Zongjian Yang; Yubao Li; Xingdong Zhang; J. D. De Bruijn; K. De Groot

1998-01-01

231

The effect of signal noise on the remote sensing of Foliar biochemical concentration  

NASA Technical Reports Server (NTRS)

Spectral measurements made using an imaging spectrometer contain systematic and random noise, while the former can be corrected the latter remains a source of error in the remotely sensed signal. A number of investigators have tried to determine the signal-to-noise-ratio (SNR) of the instrument, or the resultant imagery. However, the level of noise at which spectra are too noisy to be useful is not usually determined. The first attempt was by Goetz and Calvin, who suggested that the depth of the absorption feature should be at least an order of magnitude greater than the noise and more recently Dekker suggested a SNR of around 600:1 was required in visible/near infrared wavelengths to measure a 1/gl change in chlorophyll a concentration water. The wide range of applications of imaging spectroscopy make it difficult to set SNR specifications as they are dependent on a number of factors, one of the most important being reflectance of a particular target. For example, the SNR of imagery for vegetated targets is relatively low simply because vegetation has a relatively low level of reflectance. The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) is being used to estimate the concentration of biochemicals within vegetation canopies. This paper reports a study undertaken to identify first, wavebands that were highly correlated with foliar biochemical concentration and second, to determine how sensitive these correlations were to sensor noise.

Smith, Geoffrey M.; Curran, Paul J.

1993-01-01

232

Characterization of polyketide metabolites from foliar endophytes of Picea glauca.  

PubMed

A collection of 250 foliar endophytes of Picea glauca (white spruce) yielded several isolates that produced metabolites toxic to Choristoneura fumiferana (spruce budworm). Three of these strains were selected for further study based on their ability to be cultured and produce secondary metabolites under laboratory conditions. The culture filtrate of each was extracted and analyzed by LC-MS and LC-NMR, and the major metabolites were isolated and characterized. Structures were elucidated by spectroscopic analyses including 2D NMR and HRMS and by comparison to literature data. In some cases the extract was methylated in order to facilitate separation, but the original natural structure was determined by comparing the NMR data of the isolated methylated product with that of the stop-flow NMR of the underivatized extract (i.e., 2a, 2b, and 4). Two of these metabolites, 1 and 2a, are new structures, 3 and 4 are reported here for the first time as fungal metabolites, and 5- 10 as known fungal metabolites from other species. Tyrosol (10) was the only common metabolite found in all three extracts but did not account for the observed toxicity to C. fumiferana. PMID:18636777

Sumarah, Mark W; Puniani, Eva; Blackwell, Barbara A; Miller, J David

2008-08-01

233

A model of propagating calcium-induced calcium release mediated by calcium diffusion  

Microsoft Academic Search

The effect of sudden local fluctuations of the free sarcoplasmic (Ca++)i in cardiac cells on calcium release and calcium uptake by the sarcoplasmic reticulum (SR) was calculated with the aid of a simplified model of SR calcium handling. The model was used to evaluate whether propagation of calcium tran- sients and the range of propagation velocities observed experimentally (0.05-15 mm

PETER H. BACKX; PIETER P. DE TOMBE; JURJEN H. K. VAN DEEN

1989-01-01

234

Response of sugar maple to calcium addition to northern hardwood forest.  

PubMed

Watershed budget studies at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA, have demonstrated high calcium depletion of soil during the 20th century due, in part, to acid deposition. Over the past 25 years, tree growth (especially for sugar maple) has declined on the experimental watersheds at the HBEF. In October 1999, 0.85 Mg Ca/ha was added to Watershed 1 (W1) at the HBEF in the form of wollastonite (CaSiO3), a treatment that, by summer 2002, had raised the pH in the Oie horizon from 3.8 to 5.0 and, in the Oa horizon, from 3.9 to 4.2. We measured the response of sugar maple to the calcium fertilization treatment on W1. Foliar calcium concentration of canopy sugar maples in W1 increased markedly beginning the second year after treatment, and foliar manganese declined in years four and five. By 2005, the crown condition of sugar maple was much healthier in the treated watershed as compared with the untreated reference watershed (W6). Following high seed production in 2000 and 2002, the density of sugar maple seedlings increased significantly on W1 in comparison with W6 in 2001 and 2003. Survivorship of the 2003 cohort through July 2005 was much higher on W1 (36.6%) than W6 (10.2%). In 2003, sugar maple germinants on W1 were approximately 50% larger than those in reference plots, and foliar chlorophyll concentrations were significantly greater (0.27 g/m2 vs. 0.23 g/m2 leaf area). Foliage and fine-root calcium concentrations were roughly twice as high, and manganese concentrations twice as low in the treated than the reference seedlings in 2003 and 2004. Mycorrhizal colonization of seedlings was also much greater in the treated (22.4% of root length) than the reference sites (4.4%). A similar, though less dramatic, difference was observed for mycorrhizal colonization of mature sugar maples (56% vs. 35%). These results reinforce and extend other regional observations that sugar maple decline in the northeastern United States and southern Canada is caused in part by anthropogenic effects on soil calcium status, but the causal interactions among inorganic nutrition, physiological stress, mycorrhizal colonization, and seedling growth and health remain to be established. PMID:16761605

Juice, Stephanie M; Fahey, Timothy J; Siccama, Thomas G; Driscoll, Charles T; Denny, Ellen G; Eagar, Christopher; Cleavitt, Natalie L; Minocha, Rakesh; Richardson, Andrew D

2006-05-01

235

Voltage-Gated Calcium Channels  

NASA Astrophysics Data System (ADS)

Voltage Gated Calcium Channels is the first comprehensive book in the calcium channel field, encompassing over thirty years of progress towards our understanding of calcium channel structure, function, regulation, physiology, pharmacology, and genetics. This book balances contributions from many of the leading authorities in the calcium channel field with fresh perspectives from risings stars in the area, taking into account the most recent literature and concepts. This is the only all-encompassing calcium channel book currently available, and is an essential resource for academic researchers at all levels in the areas neuroscience, biophysics, and cardiovascular sciences, as well as to researchers in the drug discovery area.

Zamponi, Gerald Werner

236

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

237

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

238

Calcium in Plants  

PubMed Central

Calcium is an essential plant nutrient. It is required for various structural roles in the cell wall and membranes, it is a counter?cation for inorganic and organic anions in the vacuole, and the cytosolic Ca2+ concentration ([Ca2+]cyt) is an obligate intracellular messenger coordinating responses to numerous developmental cues and environmental challenges. This article provides an overview of the nutritional requirements of different plants for Ca, and how this impacts on natural flora and the Ca content of crops. It also reviews recent work on (a) the mechanisms of Ca2+ transport across cellular membranes, (b) understanding the origins and specificity of [Ca2+]cyt signals and (c) characterizing the cellular [Ca2+]cyt?sensors (such as calmodulin, calcineurin B?like proteins and calcium?dependent protein kinases) that allow plant cells to respond appropriately to [Ca2+]cyt signals. PMID:12933363

WHITE, PHILIP J.; BROADLEY, MARTIN R.

2003-01-01

239

Foliar uptake of cesium from the water column by aquatic macrophytes.  

PubMed

The probable occurrence and rate of foliar absorption of stable cesium (133Cs) from the water column by aquatic macrophyte species was analyzed following the addition of 133Cs into a small reservoir near Aiken, South Carolina, USA. An uptake parameter u (10(3)Lkg(-1)d(-1)) and a loss rate parameter k (d(-1)) were estimated for each species using time series of 133Cs concentrations in the water and plant tissues. Foliar uptake, as indicated by rapid increases in plant concentrations following the 133Cs addition, occurred in two floating-leaf species, Brasenia schreberi and Nymphaea odorata, and two submerged species, Myriophyllum spicatum and Utricularia inflata. These species had values of u> or =0.75 x 10(3)Lkg(-1)d(-1). Less evidence for foliar uptake was observed in three emergent species, including Typha latifolia. Ratios of u to k for B. schreberi, M. spicatum, N. odorata and U. inflata can be used to estimate concentration ratios (CR) at equilibrium, and these estimates were generally within a factor of 2 of the CR for 137Cs for these species in the same reservoir. This correspondence suggests that foliar uptake of Cs was the principal absorption mechanism for these species. Assessments of: (1) the prevalence of foliar uptake of potassium, rubidium and Cs isotopes by aquatic macrophytes and (2) the possible importance of foliar uptake of Cs in other lentic systems are made from a review of foliar uptake studies and estimation of comparable u and k values from lake studies involving Cs releases. PMID:15990203

Pinder, J E; Hinton, T G; Whicker, F W

2006-01-01

240

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

241

Root zone calcium modulates the response of potato plants to heat stress.  

PubMed

Potato plant growth and development are known to be severely impacted by heat stress. Here plants grown in a chemically inert medium of 1 : 1 quartzite : perlite (v : v) were subjected to either 35/25 degrees C (stress) or 20/15 degrees C (control) day/night air temperatures and four concentrations of root zone calcium (5, 25, 125 and 600 &mgr;M Ca) for 3 weeks. We report for the first time that potato plant growth under heat stress can persist at specific levels of Ca2+ in the root zone and that the Ca2+ level required for growth under heat stress exceeds that required for growth under normal temperatures. We also provide strong, initial evidence that the ability of high Ca2+ levels to mitigate heat stress effects results from shifts in meristematic activity. Total foliar mass and leaf area were essentially unaffected by Ca2+ level under control temperatures. Under heat stress, leaf area was reduced to about 5% of the control at 5 and 25 &mgr;M Ca but to only 70% of the control at 125 and 600 &mgr;M Ca. Likewise, total foliar mass was reduced under heat stress to about 30% of the control at 5 and 25 &mgr;M Ca but total foliar mass was greater under heat stress than control conditions at 125 and 600 &mgr;M Ca. This increase at higher Ca2+ concentrations was due primarily to axillary shoot growth. Anatomical studies of leaves grown under heat stress show that cell expansion was impaired by heat stress and this impairment was overcome by increasing root zone calcium levels. These results provide insight into the mechanism by which root zone Ca2+ may modulate plant response to heat stress. PMID:12010474

Kleinhenz, Matthew D; Palta, Jiwan P

2002-05-01

242

Complexometric Determination of Calcium  

Microsoft Academic Search

\\u000a Ethylenediaminetetraacetate (EDTA) complexes with numerous mineral ions, including calcium and magnesium. This reaction can\\u000a be used to determine the amount of these minerals in a sample by a complexometric titration. Endpoints in the titration are\\u000a detected using indicators that change color when they complex with mineral ions. Calmagite and eriochrome black T (EBT) are\\u000a such indicators that change from blue

S. Suzanne Nielsen

2010-01-01

243

Calcium signaling in plants  

Microsoft Academic Search

.   Changes in the cytosolic concentration of calcium ions ([Ca2+]i) play a key second messenger role in signal transduction. These changes are visualized by making use of either Ca2+-sensitive fluorescent dyes or the Ca2+-sensitive photoprotein, aequorin. Here we describe the advances made over the last 10 years or so, which have conclusively\\u000a demonstrated a second messenger role for [Ca2+]i in

J. J. Rudd; V. E. Franklin-Tong

1999-01-01

244

Estimating Calcium Requirements  

Microsoft Academic Search

\\u000a Nutrient requirements are used by many groups to determine food choices and meal plans for feeding people across the lifespan.\\u000a They are used to evaluate sources of nutrients and for food labels to educate the consumer. Requirements also provide a guideline\\u000a to determine whether supplements are needed. If calcium requirements are underestimated, inadequate intakes are more likely,\\u000a which may compromise

Connie M. Weaver; Kathleen M. Hill

245

Sequential application of epsilon-polylysine, lauric arginate and acidic calcium sulfate for inactivation of pathogens on raw chicken and beef  

E-print Network

Salmonella and Escherichia coli O157:H7 (EC) contamination continues to be one of the major concerns for the microbiological safety of raw poultry and beef products. Application of more than one decontamination agent as a multi-hurdle intervention...

Benli, Hakan

2009-05-15

246

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. PMID:23326555

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

2013-01-01

247

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. PMID:23388118

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

2013-01-01

248

Ozone air pollution and foliar injury development on native plants of Switzerland.  

PubMed

The objectives of this study were to examine the foliar sensitivity to ozone exposure of 12 tree, shrub, and herbaceous species native to southern Switzerland and determine the seasonal cumulative ozone exposures required to induce visible foliar injury. The study was conducted from the beginning of May through the end of August during 2000 and 2001 using an open-top chamber research facility located within the Lattecaldo Cantonal Forest Nursery in Canton Ticino, southern Switzerland (600 m asl). Plants were examined daily and dates of initial foliar injury were recorded in order to determine the cumulative AOT40 ppb h ozone exposure required to cause visible foliar injury. Plant responses to ozone varied significantly among species; 11 species exhibited visible symptoms typical of exposures to ambient ozone. The symptomatic species (from most to least sensitive) were Populus nigra, Viburnum lantana, Salix alba, Crataegus monogyna, Viburnum opulus, Tilia platyphyllos, Cornus alba, Prunus avium, Fraxinus excelsior, Ribes alpinum, and Tilia cordata; Clematis spp. did not show foliar symptoms. Of the 11 symptomatic species, five showed initial injury below the critical level AOT40 10 ppmh O3 in the 2001 season. PMID:12804826

Novak, Kristopher; Skelly, John M; Schaub, Marcus; Kräuchi, Norbert; Hug, Christian; Landolt, Werner; Bleuler, Peter

2003-01-01

249

Application of intact cell-based NFAT-?-lactamase reporter assay for Pasteurella multocida toxin-mediated activation of calcium signaling pathway  

PubMed Central

Pasteurella multocida toxin (PMT) stimulates and subsequently uncouples phospholipase C ?1 (PLC?1) signal transduction through its selective action on the alpha subunit of the Gq protein. Here, we describe the application of an NFAT-?-lactamase reporter assay as a functional readout for PMT-induced activation of the Gq-protein-coupled PLC?1-IP3-Ca2+ signaling pathway. Use of the NFAT-?-lactamase reporter assay with a cell-permeable fluorogenic substrate provides high sensitivity due to the absence of endogenous ?-lactamase activity in mammalian cells. This assay system was optimized for cell density, dose and time exposure of PMT stimulation. It is suited for quantitative characterization of PMT activity in mammalian cells and for use as a high-throughput screening method for PMT deletion and point mutants suitable for vaccine development. This method has application for diagnostic screening of clinical isolates of toxinogenic P. multocida. PMID:18190943

Luo, Shuhong; Ho, Mengfei; Wilson, Brenda A.

2009-01-01

250

Foliar uptake of cesium, iodine and strontium and their transfer to the edible parts of beans, potatoes and radishes  

NASA Astrophysics Data System (ADS)

Considerable fractions of radionuclide solutions deposited on the surface of the leaves may be transferred to the edible parts of plants. In radishes we observed a transfer of more than 40% of the applied cesium radioisotope within a few days. A rather similar uptake was found for beans and potatoes when harvested a month after application of radioactivity. As much as 60% of the applied cesium-isotope remained in (or on) the potato leaves even 8 days after application. The major part could however be washed off the leaves a few hours after application. When radishes were showered with water within 7 h after the application of activity the uptake was greatly reduced. No competitive effect of potassium chloride for the foliar uptake of cesium was found. A 10 -2 M colloidal suspension of Prussian Blue, a chelating agent for monovalent alkali metals such as potassium, cesium, or other monovalent cations, applied as droplets to the leaves one day prior to application of active cesium was found to strongly inhibit the transfer of cesium to the radish. The transfer of iodine and strontium to the edible parts was found to be negligible (or slower) as compared to cesium. In most cases no detectable amounts of these two nuclides were transfered to the edible parts of the radish after 2-5 weeks.

Oestling, O.; Kopp, P.; Burkart, W.

251

[Calcium--essential for everybody].  

PubMed

Calcium regulates majority of metabolic processes within human organism and its optimal intake decreases risk of metabolic illnesses conditioned by diet. Deficiency of calcium results in higher body max index, increase risk of insulin resistance, diabetes type 2 and osteoporosis. Diet delivering full calcium load diminished impendency of hypertension; calcium regulates tension of smooth muscles of blood vessels, limits neurotransmitters activity and also diminish hazardous activity of sodium chloride. Anticancerogenic activity of calcium results from formation insoluble bile acids and fat acids salts, and most of all, from inhibition of intestine mucosa cells hyper proliferation. Due to presence of vitamin D3, CLA, proteins and bioactive peptides emerging from them, milk is more efficient in prophylaxis of diet conditioned illnesses than calcium supplements. Efficiency of milk and dairy products in treatment of obesity, sclerosis and hypertension has been proved by DASH diet. PMID:25095643

Cichosz, Grazyna; Czeczot, Hanna

2014-06-01

252

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

253

Chemistry misconceptions associated with understanding calcium and phosphate homeostasis  

NSDL National Science Digital Library

Successful learning of many aspects in physiology depends on a meaningful understanding of fundamental chemistry concepts. Two conceptual diagnostic questions measured student understanding of the chemical equilibrium underlying calcium and phosphate homeostasis. One question assessed the ability to predict the change in phosphate concentration when calcium ions were added to a saturated calcium phosphate solution. Fifty-two percent of the students correctly predicted that the phosphate concentration would decrease in accord with the common ion effect. Forty-two percent of the students predicted that the phosphate concentration would not change. Written explanations showed that most students failed to evoke the idea of competing chemical equilibria. A second question assessed the predicted change in calcium concentration after solid calcium phosphate was added to a saturated solution. Only 11% of the students correctly predicted no change in calcium concentration; 86% of the students predicted an increase, and many based their prediction on a mistaken application of Le Chatelier's principle to heterogeneous equilibria. These results indicate that many students possess misconceptions about chemical equilibrium that may hamper understanding of the processes of calcium and phosphate homeostasis. Instructors can help students gain greater understanding of these physiochemical phenomena by adopting strategies that enable students achieve more accurate conceptions of chemical equilibria.

William H. Cliff (Niagara University Biology)

2009-12-01

254

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

255

Calcium Phosphate Biomaterials: An Overview  

Microsoft Academic Search

Calcium phosphates are used by our body to build bones and are being applied to produce biomaterials for bone repair. It is\\u000a well-known that calcium phosphate biomaterials guide new bone formation, form a tight bond with the newly formed bone, and\\u000a are therefore, by definition, osteoconductive. Besides their osteoconductive property, it was found that calcium phosphate\\u000a biomaterials, only with specific

Huipin Yuan; KLAAS DE GROOT

256

Calcium channel antagonism by pizotifen  

Microsoft Academic Search

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

S J Peroutka; S B Banghart; G S Allen

1985-01-01

257

Original article Intestinal absorption of calcium  

E-print Network

Original article Intestinal absorption of calcium from yogurt in lactase-deficient subjects-tolerated and efficient source of calcium in subjects with lactase deficiency. calcium absorption / lactase-deficiency absorption of calcium (FACa) was measured using radioactive cal- cium and 200 mg of calcium carrier provided

Paris-Sud XI, Université de

258

High Blood Pressure and Calcium Antagonism  

Microsoft Academic Search

Calcium ions are intimately involved in many aspects of cardiovascular function. Modification of calcium homeostasis therefore represents a key target for pharmacological intervention to achieve therapeutic control of hypertension. The calcium channel blockers (CCBs) act by blocking calcium influx through voltage-dependent L (long-acting) channels without affecting calcium release from the sarcoplasmic reticulum. The effect of blocking these channels is a

José L. Palma-Gámiz

1997-01-01

259

Mechanical signalling, calcium and plant form  

Microsoft Academic Search

Calcium is a dynamic signalling molecule which acts to transduce numerous signals in plant tissues. The basis of calcium signalling is outlined and the necessity for measuring and imaging of calcium indicated. Using plants genetically transformed with a cDNA for the calcium-sensitive luminescent protein, aequorin, we have shown touch and wind signals to immediately increase cytosol calcium. Touch and wind

Anthony Trewavas; Marc Knight

1994-01-01

260

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. PMID:23638877

Nimmrich, V; Eckert, A

2013-01-01

261

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. PMID:23825677

Wu, Jing; Wang, Yiming; Lin, Xiangui

2013-01-01

262

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

263

Secondary calcium solid electrolyte high temperature battery  

NASA Astrophysics Data System (ADS)

The application of polycrystalline Ca(2+) conducting beta-double prime alumina solid electrolytes to a new type of high temperature battery is investigated, experimentally. The negative electrode in the battery consisted of a calcium-silicon alloy whose redox electrochemistry was mediated by the solid electrolyte via molten salt eutectic CaCl2 (51.4 m/o), and CaI2 (mp 550 C). The molten salt and the calcium alloy material were separated from the positive active material via the Ca2 Ca(2+) conducting polycrystalline electrolyte. The positive electrode consisted of a solid-state matrix having related crystallographic structure. The electrochemical reversibility of the cells was measured at 580 C. The charge-discharge characteristics of the cells are plotted vs. time in a graph.

Sammells, A. F.; Schumacher, B.

1986-01-01

264

75 FR 39025 - Determination That ACTONEL (Risendronate Sodium) Tablets, 75 Milligrams, and ACTONEL WITH CALCIUM...  

Federal Register 2010, 2011, 2012, 2013

...CALCIUM (Risendronate Sodium and Calcium Carbonate (Copackaged)) Tablets, 35...CALCIUM (risendronate sodium and calcium carbonate (copackaged)) Tablets, 35...CALCIUM (risendronate sodium and calcium carbonate (copackaged)) Tablets,...

2010-07-07

265

The oxidation of calcium sulphite by calcium nitrate  

Microsoft Academic Search

Crushed powder mixtures of calcium sulphite and calcium nitrate exhibit an exothermic reaction between 650 and 700K. This rate process has been investigated by dynamic and isothermal DSC experiments, complemented with isothermal rate studies based on gas evolution in a vacuum apparatus, together with some product analyses. It is concluded that the overall reaction is complicated, including several concurrent contributing

Andrew K Galwey; Clodagh Ettarh

1998-01-01

266

Thermally Triggered Calcium Phosphate Formation from Calcium-Loaded Liposomes  

E-print Network

Thermally Triggered Calcium Phosphate Formation from Calcium-Loaded Liposomes Phillip B 15, 1997X A thermally triggered liposome-based mineralization system is described that is metastable liposome suspension whose bulk ionic concentration was highly supersaturated with respect to hydroxyapatite

267

Fabrication and Evaluation of Ceramic Implant Materials for Replacement of Teeth and Bone - Mechanical Strength Testing of Highly Porous Calcium Aluminate Ceramics.  

National Technical Information Service (NTIS)

Porous calcium aluminate ceramics have been considered for applications as structural materials in orthopedic and dental prostheses. Calcium aluminate specimens varying in chemical composition from 23 to 34 weight percent CaO and varying in amount of poro...

S. F. Hulbert, J. J. Klawitter, C. N. Wilson

1971-01-01

268

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. PMID:24955932

Dorozhkin, Sergey V.

2010-01-01

269

Preparation of Calcium-Loaded Liposomes and Their Use in Calcium Phosphate Formation  

E-print Network

Preparation of Calcium-Loaded Liposomes and Their Use in Calcium Phosphate Formation Phillip B Received October 15, 1997X Liposome encapsulation technology has been used to entrap aqueous calcium salts of unencapsulated calcium by ion exchange resulted in calcium-loaded liposome suspensions with calcium concentration

270

An Evaluation of the Allelopathic Potential of Selected Perennial Groundcovers: Foliar Volatiles of Catmint ( Nepeta × faassenii ) Inhibit Seedling Growth  

Microsoft Academic Search

Six perennial groundcovers including Alchemilla mollis, Nepeta faassenii, Phlox subulata, Sedum acre, Solidago cutleri, and Thymus praecox were investigated for the allelopathic potential of their respective foliar tissues via evaluation of volatile constituents produced by foliage. These groundcovers were selected for further laboratory evaluation because of superior performance as weed-suppressive groundcovers in previous field experiments. Foliar volatile components of N.

Seok Hyun Eom; Hyun Seuk Yang; Leslie A. Weston

2006-01-01

271

Effect of strontium ions substitution on gene delivery related properties of calcium phosphate nanoparticles  

Microsoft Academic Search

Gene therapy has been considered a strategy for delivery of therapeutic nucleic acids to a specific site. Calcium phosphates\\u000a are one gene delivery vector group of interest. However, low transfection efficiency has limited the use of calcium phosphate\\u000a in gene delivery applications. Present work aims at studying the fabrication of strontium substituted calcium phosphate nanoparticles\\u000a with improved gene delivery related

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

2010-01-01

272

21 CFR 184.1201 - Calcium glycerophosphate.  

Code of Federal Regulations, 2012 CFR

...hygroscopic powder. It is prepared by neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a mixture of calcium ?-, and D-, and L -?-glycerophosphate. (b) The...

2012-04-01

273

CALCIUM CARBONATE DEPOSITION IN GEOTHERMAL WELLBORES  

E-print Network

CALCIUM CARBONATE DEPOSITION IN GEOTHERMAL WELLBORES MIRAVALLES GEOTHERMAL FIELD COSTA RICA CALCIUM CARBONATE DEPOSITION IN GEOTHERMAL WELLBORES MIRAVALLES GEOTHERMAL FIELD COSTA RICA BY Eduardo University. #12;ABSTRACT Calcium carbonate deposition takes place in the wells of the Miravalles geothermal

Stanford University

274

21 CFR 184.1210 - Calcium oxide.  

Code of Federal Regulations, 2013 CFR

...Substances Affirmed as GRAS § 184.1210 Calcium oxide. (a) Calcium oxide (CaO, CAS Reg. No. 1305-78-8...lime, burnt lime, or calx. It is produced from calcium carbonate, limestone, or oyster shells by...

2013-04-01

275

21 CFR 184.1201 - Calcium glycerophosphate.  

...hygroscopic powder. It is prepared by neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a mixture of calcium ?-, and D-, and L -?-glycerophosphate. (b) The...

2014-04-01

276

21 CFR 184.1210 - Calcium oxide.  

...Specific Substances Affirmed as GRAS § 184.1210 Calcium oxide. (a) Calcium oxide (CaO, CAS Reg. No. 1305-78-8...lime, burnt lime, or calx. It is produced from calcium carbonate, limestone, or oyster shells by...

2014-04-01

277

21 CFR 184.1210 - Calcium oxide.  

Code of Federal Regulations, 2010 CFR

...Substances Affirmed as GRAS § 184.1210 Calcium oxide. (a) Calcium oxide (CaO, CAS Reg. No. 1305-78-8...lime, burnt lime, or calx. It is produced from calcium carbonate, limestone, or oyster shells by...

2010-04-01

278

21 CFR 184.1201 - Calcium glycerophosphate.  

Code of Federal Regulations, 2011 CFR

...hygroscopic powder. It is prepared by neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a mixture of calcium ?-, and D-, and L -?-glycerophosphate. (b) The...

2011-04-01

279

21 CFR 184.1210 - Calcium oxide.  

Code of Federal Regulations, 2011 CFR

...Substances Affirmed as GRAS § 184.1210 Calcium oxide. (a) Calcium oxide (CaO, CAS Reg. No. 1305-78-8...lime, burnt lime, or calx. It is produced from calcium carbonate, limestone, or oyster shells by...

2011-04-01

280

21 CFR 184.1201 - Calcium glycerophosphate.  

Code of Federal Regulations, 2013 CFR

...hygroscopic powder. It is prepared by neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a mixture of calcium ?-, and D-, and L -?-glycerophosphate. (b) The...

2013-04-01

281

21 CFR 184.1201 - Calcium glycerophosphate.  

Code of Federal Regulations, 2010 CFR

...hygroscopic powder. It is prepared by neutralizing glycerophosphoric acid with calcium hydroxide or calcium carbonate. The commercial product is a mixture of calcium ?-, and D-, and L -?-glycerophosphate. (b) The...

2010-04-01

282

21 CFR 184.1210 - Calcium oxide.  

Code of Federal Regulations, 2012 CFR

...Substances Affirmed as GRAS § 184.1210 Calcium oxide. (a) Calcium oxide (CaO, CAS Reg. No. 1305-78-8...lime, burnt lime, or calx. It is produced from calcium carbonate, limestone, or oyster shells by...

2012-04-01

283

21 CFR 172.720 - Calcium lactobionate.  

Code of Federal Regulations, 2011 CFR

...Calcium lactobionate. The food additive calcium lactobionate may be safely used in food in accordance with the following...conditions: (a) The food additive is the calcium...D-gluconic acid) produced by the oxidation of lactose. (b)...

2011-04-01

284

Vitamin D, Calcium, and Bone Health  

MedlinePLUS

... SITE › Vitamin D, Calcium, and Bone Health Share: Vitamin D, Calcium, and Bone Health March 2012 Download ... also helps keep your bones strong. Why are vitamin D and calcium important to bone health? Vitamin ...

285

[Effects of plant foliar litter diversity on the growth of Chinese fir seedling and the absorption of (15NH4)2SO4].  

PubMed

Effects of plant foliar litter species composition on the growth of the potted Chinese fir seedling and the absorption of (15NH4)2SO4 was studied. The result showed that there were significant growth responses to foliar litter treatments. A very noticeable trend was that as the tree species of foliar litter placed on pots increases, the growth of Chinese fir seedlings increases steadily. Seedling growth in four-species mixed foliar litter were the largest and that in Cunninghamia lanceolata + Michelia macclurei + Kalooanax septemlobus foliar litter mixture were the second. The others were in order of seedlings in C. lanceolata + M. macclurei + Castanopsis carlesii foliar litter mixture > C. lanceolata + K. septemlobus foliar litter mixture > C. lanceolata + C. carlesii > control (no foliar litter) > C. lanceolata + M. macclurei foliar litter mixture > Chinese fir foliar litter treatment. The recovery of (15NH4)2SO4 by Chinese fir seedlings in no foliar litter treatment was maximum, and seedlings grown in four foliar litter mixture was the second, then it was in order of C. lanceolata + C. carlesii + K. septemlobus = C. lanceolata + C. carlesii + M. macclurei > C. lanceolata + K. septemlobus > C. lanceolata + C. carlesii > C. lanceolata + M. macclurei > C. lanceolata foliar litter treatment. In addition, the residue of (15NH4)2SO4 was greater in soil with foliar litter treatment than in no foliar litter soil. Both of the residual amount of (15NH4)2SO4 in soil and the total recovery of (15NH4)2SO4 increased with the increasing tree species of applied foliar litter. PMID:12557677

Huang, Zhiqun; Wang, Silong; Liao, Liping; Gao, Hong; Chen, Longchi

2002-10-01

286

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

287

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

288

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

289

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

290

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

291

Calcium intake and serum calcium status in Mongolian children.  

PubMed

Dietary calcium intake in relation to calcium status in Mongolian children was investigated. This survey was a cross-sectional survey. A total of 835 children were randomly selected from 4 economic regions and Ulaanbaatar city. Information on dietary intake was collected from 835 children in the 1-3, 4-7, and 8-14 year old groups by a 24-h recall method. The average daily intake of calcium from diet was calculated for individuals. Blood samples were collected from 104 children. The mean of daily calcium intakes as 273±30.0mg in 1-3-year old children, 309.0±30.0mg in 4-7 year old children, and 317.0±31.0mg in 8-14 year old children, respectively. There were statistically significant differences in calcium intakes between the age groups 1-3 years, 4-7 years, and 1-3 years, 8-14 years of children (p<0.001). Calcium intakes in all studied children of all age groups were lower (39%, 30.9%, and 24.4%) than the recommended level of calcium intakes. In 22.1% of studied children, the serum total calcium concentration levels were below the normal range. Based on the total serum calcium, the prevalence of hypocalcemia was higher among children in the age group 8-14 years (27.6%) than the prevalence among children in the age group <1 year (p<0.05). Based on the corrected serum calcium values, the prevalence of hypocalcemia was higher (52.4%, 63.6%, and 51.1%) among children in the age groups 1-3, 4-7, and 8-14 years. The mean level of corrected serum calcium were low (2.02±0.04, 2.05±0.73, and 1.99±0.64mg) in children in the age groups 1-3, 4-7, and 8-14 years. These findings suggest that low dietary calcium intakes may be reflected by hypocalcemia in Mongolian children. In conclusion, there is a need to improve a consumption of milk, dairy products in Mongolian children. In addition, there is need to use a vitamin D supplementation with a calcium supplementation in children with severe vitamin D deficiency rickets. This article is part of a Special issue entitled "16th Vitamin D Workshop". PMID:24681400

Uush, Tserendolgor

2014-10-01

292

Impact of zinc application methods on green gram (Vigna radiata L.) productivity and grain zinc fortification.  

PubMed

Application of Zn @ 0, 5.5 kg, 22 kg Zn ha(-1), 0.1% Zn foliar application, 5.5 kg Zn + 0.1% Znspray, increased the yield, concentration and its uptake in seed and straw in all the green gram genotypes. However, combined application of 5.5 kg Zn ha(-1) + 0.1% Zn as foliar increased the straw yield by 56.4% and seed yield by 57%, which was the highest. Maximum Zn concentration in straw and seed (5.48 and 3.5 folds over control) was achieved when combined application of soil + foliar was made. Soil + foliar application of Zn increased the seed crude protein by 26.9% over control. Seed and straw Zn content showed a significant and positive correlation with all yield attributes except branches per plant. PMID:25204058

Roy, P Deb; Narwal, R P; Malik, R S; Saha, B N; Kumar, S

2014-09-01

293

Calcium-sensing receptor and calcium kidney stones  

PubMed Central

Calcium nephrolithiasis may be considered as a complex disease having multiple pathogenetic mechanisms and characterized by various clinical manifestations. Both genetic and environmental factors may increase susceptibility to calcium stones; therefore, it is crucial to characterize the patient phenotype to distinguish homogeneous groups of stone formers. Family and twin studies have shown that the stone transmission pattern is not mendelian, but complex and polygenic. In these studies, heritability of calcium stones was calculated around 50% Calcium-sensing receptor (CaSR) is mostly expressed in the parathyroid glands and in renal tubules. It regulates the PTH secretion according to the serum calcium concentration. In the kidney, it modulates electrolyte and water excretion regulating the function of different tubular segments. In particular, CaSR reduces passive and active calcium reabsorption in distal tubules, increases phosphate reabsorption in proximal tubules and stimulates proton and water excretion in collecting ducts. Therefore, it is a candidate gene for calcium nephrolithiasis. In a case-control study we found an association between the normocitraturic stone formers and two SNPs of CaSR, located near the promoters region (rs7652589 and rs1501899). This result was replicated in patients with primary hyperparathyroidism, comparing patients with or without kidney stones. Bioinformatic analysis suggested that the minor alleles at these polymorphisms were able to modify the binding sites of specific transcription factors and, consequently, CaSR expression. Our studies suggest that CaSR is one of the candidate genes explaining individual predisposition to calcium nephrolithiasis. Stone formation may be favored by an altered CaSR expression in kidney medulla involving the normal balance among calcium, phosphate, protons and water excretion. PMID:22107799

2011-01-01

294

Assessment of crop foliar nitrogen using a novel dual-wavelength laser system and implications for conducting laser-based plant physiology  

NASA Astrophysics Data System (ADS)

Advanced technologies for improved nitrogen (N) fertilizer management are paramount for sustainably meeting future food demands. Green laser systems that measure pulse return intensity can provide more reliable information about foliar N than can traditional passive remote sensing devices during the critical early crop growth stages (e.g., before canopy closure when vegetation and soil signals are spectrally mixed) when further decisions regarding N management can be made. However, current green laser systems are not designed for agricultural applications and only employ a single green laser wavelength, which may limit applications because many factors that require normalization techniques can affect pulse return intensity. Here, we describe the design of a tractor-mountable, green (532 nm)- and red (658 nm) dual wavelength laser system and evaluate the potential of an additional red reference wavelength to improve laser based estimates of foliar N by calculating laser spectral indices based on ratio combinations of green laser return intensity (GLRI) and red laser return intensity (RLRI). We hypothesized that such laser spectral indices aid in accounting for factors that confound laser based foliar N estimates including variations in leaf angle, measurement distance, soil returns, and mixed edge returns. Leaf level measurements in winter wheat (Triticum aestivum) revealed that the two laser spectral indices improved the relationship with foliar N (r2 > 0.71, RMSE < 0.28%) compared to the sole use of GLRI (r2 = 0.47, RMSE = 0.38%). Laboratory measurements also showed that laser spectral indices reduced the effect of measurement distance on laser readings and allowed leaf returns to be better separated from edge returns and soil returns. However, laboratory measurements showed that laser spectral indices did not account for variations in leaf angle, possibly explaining the weak relationships (r2 < 0.36, RMSE = 0.49%) between foliar N and laser spectral indices observed when employing the laser system under field conditions. In fact, the strongest relationship at the field canopy level was shown for GLRI (r2 = 0.65, RMSE = 0.37%) alone. Laboratory measurements suggest that the better performance of GLRI compared to ratio-based laser spectral indices may result from pronounced differences in the leaf-level bidirectional reflectance distribution factor (BRDFleaf) between the green and red laser wavelengths, thus confounding leaf angle effects so that they are not cancelled when calculating laser spectral indices. This finding suggests that the small spot size of the laser pulses (?5 mm diameter) interacts with BRDFleaf at very fine scales, therefore causing differential, wavelength-specific scattering effects. Additional study of BRDFleaf at the mm scale is therefore warranted, and should be carefully considered in future development and use of multi-wavelength laser systems for remotely sensing foliar biochemistry.

Eitel, Jan U. H.; Magney, Troy S.; Vierling, Lee A.; Dittmar, Günter

2014-11-01

295

Variation in foliar nitrogen and albedo in response to nitrogen fertilization and elevated CO2.  

PubMed

Foliar nitrogen has been shown to be positively correlated with midsummer canopy albedo and canopy near infrared (NIR) reflectance over a broad range of plant functional types (e.g., forests, grasslands, and agricultural lands). To date, the mechanism(s) driving the nitrogen–albedo relationship have not been established, and it is unknown whether factors affecting nitrogen availability will also influence albedo. To address these questions, we examined variation in foliar nitrogen in relation to leaf spectral properties, leaf mass per unit area, and leaf water content for three deciduous species subjected to either nitrogen (Harvard Forest, MA, and Oak Ridge, TN) or CO(2) fertilization (Oak Ridge, TN). At Oak Ridge, we also obtained canopy reflectance data from the airborne visible/infrared imaging spectrometer (AVIRIS) to examine whether canopy-level spectral responses were consistent with leaf-level results. At the leaf level, results showed no differences in reflectance or transmittance between CO(2) or nitrogen treatments, despite significant changes in foliar nitrogen. Contrary to our expectations, there was a significant, but negative, relationship between foliar nitrogen and leaf albedo, a relationship that held for both full spectrum leaf albedo as well as leaf albedo in the NIR region alone. In contrast, remote sensing data indicated an increase in canopy NIR reflectance with nitrogen fertilization. Collectively, these results suggest that altered nitrogen availability can affect canopy albedo, albeit by mechanisms that involve canopy-level processes rather than changes in leaf-level reflectance. PMID:22294028

Wicklein, Haley F; Ollinger, Scott V; Martin, Mary E; Hollinger, David Y; Lepine, Lucie C; Day, Michelle C; Bartlett, Megan K; Richardson, Andrew D; Norby, Richard J

2012-08-01

296

Ozone exposure thresholds and foliar injury on forest plants in Switzerland  

Microsoft Academic Search

Canton Ticino in southern Switzerland is exposed to some of the highest concentrations of tropospheric ozone in Europe. During recent field surveys in Canton Ticino, foliar symptoms identical to those caused by ozone have been documented on native tree and shrub species. In Europe, the critical ozone level for forest trees has been defined at an AOT40 of 10 ppm.h

D. VanderHeyden; J. Skelly; J. Innes; C. Hug; J. Zhang; W. Landolt; P. Bleuler

2000-01-01

297

Ozone exposure thresholds and foliar injury on forest plants in Switzerland  

Microsoft Academic Search

Canton Ticino in southern Switzerland is exposed to some of the highest concentrations of tropospheric ozone in Europe. During recent field surveys in Canton Ticino, foliar symptoms identical to those caused by ozone have been documented on native tree and shrub species. In Europe, the critical ozone level for forest trees has been defined at an AOT40 of 10 ppm.h

D. VanderHeyden; J. Skelly; J. Innes; C. Hug; J. Zhang; W. Landolt; P. Bleuler

2001-01-01

298

Infestation pattern of foliar nematode, Aphelenchoides ritzemabosi (Nematoda: Aphelenchoididae), on boysenberry  

Microsoft Academic Search

Infestation behaviour of the foliar nematode, Aphelenchoides ritzemabosi on boysenberry (Rugus strigosus) plants was studied in 2 commercial gardens at Motueka, South Island, New Zealand. Nematodes overwintered in the pruned stubs of old fruited canes, then invaded primocanes (new growth produced before winter) in early spring when plants broke dormancy, causing a brown streaking and epidermal peeling on stems. The

Marion A. Foot; P. Smale; E. J. Holmes-Libbis

1981-01-01

299

New Phytol. (1985) 99, 407^16 DIRECT FOLIAR EFFECTS OF SIMULATED  

E-print Network

New Phytol. (1985) 99, 407^16 DIRECT FOLIAR EFFECTS OF SIMULATED ACID RAIN IL LEAF SURFACE to damage from simulated acid rain. The species examined differed in the type and extent of epicuticular wax different among species, and is highly correlated with previous reports of damage from simulated acid rain

Neufeld, Howard S.

300

Retrieval of foliar information about plant pigment systems from high resolution spectroscopy  

E-print Network

Retrieval of foliar information about plant pigment systems from high resolution spectroscopy Susan November 2007 Received in revised form 6 October 2008 Accepted 8 October 2008 Keywords: Plant pigments for the significance of pigments in plant functions. Photosynthetic pigments fill multiple roles from increasing

Gitelson, Anatoly

301

FOLIAR RESORPTION OF NUTRIENTS IN SELECTED SYMPATRIC TREE SPECIES IN GALLERY FOREST ?BLACK SEA REGION  

Microsoft Academic Search

Gallery forests in Central Black Sea Region are dominated by Platanus orientalis L. The studies were performed in four sites (Mert River, Adalar, Kurupelit and Taflan Regions) located in V-shaped river valleys and differing with soil conditions. Nutrient concen- trations were measured in green and senescent leaves in selected sympatric tree species. Foliar nutrient resorption efficiency (RE; as the ratio

Hamdi Güray KUTBAY; Duygu KILIC; Hasan KORKMAZ; Erkan YALÇIN; Zeki APAYDIN

302

Development of an Index of Balsam Fir Vigor by Foliar Spectral Reflectance  

Microsoft Academic Search

The potential to measure indices of forest vigor from foliar spectral reflectance was assessed in a range of balsam fir conditions achieved through stand manipulations. In order of increasing vigor, treatments consisted of root pruning, control, thinning, and thinning in combination with fertilization. Concentrations of chlorophyll and nitrogen increased significantly from the low to high vigor plots, and shoot lengths

Joan E. Luther; Allan L. Carroll

1999-01-01

303

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/...

304

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 ...

305

Root and foliar nutrient concentrations in loblolly pine: Effects of season, site, and fertilization  

Microsoft Academic Search

Nitrogen (N) and phosphorus (P) concentrations in the roots and foliage of plantation-grown loblolly pine were examined over a period of 18 months. Samples were collected from 4 sites on the lower coastal plain of North Carolina, each representing a distinct combination of soil moisture and soil fertility. The patterns in foliar and root nutrient concentrations followed similar trends over

M. B. Adams; R. G. Campbell; H. L. Allen; C. B. Davey

1987-01-01

306

Diversity of Foliar Trichomes and Their Systematic Relevance in the Genus Hibiscus (Malvaceae)  

Microsoft Academic Search

Qualitative and quantitative micromorphological characters, distribution and systematic relevance of both glandular and eglandular foliar trichomes in species of genus Hibiscus (Malvaceae) including H. caesius, H. mutabilis, H. rosa-sinensis, H. sabdariffa, H. schizopetalus, H. syriacus and H. trionum were characterized. Diversity of these epidermal appendages were separated into eight main types. Glandular capitate trichomes were the most abundant on both

NIGHAT SHAHEEN; MIR AJAB; GHAZALAH YASMIN; MUHAMMAD QASIM HAYAT

307

Absorption of foliar-applied arsenic by the arsenic hyperaccumulating fern (Pteris vittata L.)  

E-print Network

predominantly from anthropogenic activities. Because arsenic is a potent toxin and highly carcinogenic domains of the plant system through foliar pathways spurred us to explore if the fronds of the Chinese, 200, and 400 ppm) were applied to young and fertile fronds. A positive linear relationship existed

Ma, Lena

308

New Phytol. (1985) 99, 389^H)5 389 DIRECT FOLIAR EFFECTS OF SIMULATED  

E-print Network

the most. For Liriodendron and Platanus, older leaves showed more damage than younger ones, whereas of extremely low pH causes foliar damage and growth reductions. Lowered rates of photosynthesis in Piatarms may, photosynthesis, growth, leaf conductance. INTRODUCTION Acid rain occurs over much of the eastern United States

Neufeld, Howard S.

309

Herbivory, foliar survival and shoot growth in fragmented populations of Aristotelia chilensis  

NASA Astrophysics Data System (ADS)

Habitat fragmentation may modify ecological interactions such as herbivory, and these changes can impinge upon plant fitness. Through a natural experiment, we evaluated if herbivory, foliar survival and shoot growth of the evergreen tree Aristotelia chilensis differ between a continuous forest (600 ha) and small fragments (˜3 ha) of the Maulino forest. From September 2002, we monthly recorded leaf emergence, area lost to herbivores and survival in four cohorts of leaves. Although herbivory of A. chilensis was low overall (foliar area loss <12%), herbivory was higher in the continuous forest than in small fragments. Nevertheless, differences in herbivory hold only for the first cohort of leaves, which were the largest ones. At the end of the growing season, herbivory rates in the continuous forest and fragments converge for all cohorts. Except for the first cohort of leaves, whose survival was higher in the fragments than in the continuous forest, foliar survival and shoot growth was similar in the continuous forest and fragments, and there was no correlation between herbivory and foliar survival or shoot growth. Although Maulino forest fragmentation negatively affects the intensity of herbivory, this effect is only transient, affecting only leaves that emerge early in the season, and might not affect the vegetative fitness of A. chilensis adults. The consequences of changes in ecological interactions triggered by forest fragmentation ought to be assessed rather than inferred from variations in patterns of resource use.

Vásquez, P. A.; Grez, A. A.; Bustamante, R. O.; Simonetti, J. A.

2007-01-01

310

Foliar salt accumulation and injury in crops sprinkled with saline water  

Microsoft Academic Search

Many crops accumulate salts through the leaves when they are wetted by sprinkler irrigation. This accumulation may cause foliar injury and decrease crop yield. This study was conducted to test the salt sensitivity of sprinkled alfalfa, barley, cauliflower, cotton, potato, safflower, sesame, sorghum, sugarbeet, sunflower and tomato. Plants were grown in a greenhouse in covered sand cultures that were trickle-irrigated

E. V. Maas; S. R. Grattan; G. Ogata

1982-01-01

311

Regular paper Visible foliar injury caused by ozone alters the relationship between SPAD  

E-print Network

, foliar stipple, ozone, Rudbeckia laciniata, SPAD meter Abstract The ability of the SPAD-502 chlorophyll meter to quantify chlorophyll amounts in ozone-affected leaves of cutleaf coneflower (Rudbeckia laciniata var. digitata) was assessed in this study. When relatively uninjured leaves were measured (percent

Neufeld, Howard S.

312

Controls over foliar N:P ratios in tropical rain forests.  

PubMed

Correlations between foliar nutrient concentrations and soil nutrient availability have been found in multiple ecosystems. These relationships have led to the use of foliar nutrients as an index of nutrient status and to the prediction of broadscale patterns in ecosystem processes. More recently, a growing interest in ecological stoichiometry has fueled multiple analyses of foliar nitrogen:phosphorus (N:P) ratios within and across ecosystems. These studies have observed that N:P values are generally elevated in tropical forests when compared to higher latitude ecosystems, adding weight to a common belief that tropical forests are generally N rich and P poor. However, while these broad generalizations may have merit, their simplicity masks the enormous environmental heterogeneity that exists within the tropics; such variation includes large ranges in soil fertility and climate, as well as the highest plant species diversity of any biome. Here we present original data on foliar N and P concentrations from 150 mature canopy tree species in Costa Rica and Brazil, and combine those data with a comprehensive new literature synthesis to explore the major sources of variation in foliar N:P values within the tropics. We found no relationship between N:P ratios and either latitude or mean annual precipitation within the tropics alone. There is, however, evidence of seasonal controls; in our Costa Rica sites, foliar N:P values differed by 25% between wet and dry seasons. The N:P ratios do vary with soil P availability and/or soil order, but there is substantial overlap across coarse divisions in soil type, and perhaps the most striking feature of the data set is variation at the species level. Taken as a whole, our results imply that the dominant influence on foliar N:P ratios in the tropics is species variability and that, unlike marine systems and perhaps many other terrestrial biomes, the N:P stoichiometry of tropical forests is not well constrained. Thus any use of N:P ratios in the tropics to infer larger-scale ecosystem processes must comprehensively account for the diversity of any given site and recognize the broad range in nutrient requirements, even at the local scale. PMID:17489459

Townsend, Alan R; Cleveland, Cory C; Asner, Gregory P; Bustamante, Mercedes M C

2007-01-01

313

Calcium binding protein-mediated regulation of voltage-gated calcium channels linked to human diseases  

Microsoft Academic Search

Calcium ion entry through voltage-gated calcium channels is essential for cellular signalling in a wide variety of cells and multiple physiological processes. Perturbations of voltage-gated calcium channel function can lead to pathophysiological consequences. Calcium binding proteins serve as calcium sensors and regulate the calcium channel properties via feedback mechanisms. This review highlights the current evidences of calcium binding protein-mediated channel

Nasrin Nejatbakhsh; Zhong-ping Feng

2011-01-01

314

Effects of Calcium Magnesium Acetate Deicer on Small Ponds in Interior Alaska  

Microsoft Academic Search

Whole-lake experiments were conducted on three ponds in interior Alaska to test the effects of calcium magnesium acetate (CMA), an experimental road deicer, on aquatic organisms. The CMA added to the test ponds equalled approximately one chemical application applied to 0.4 km of a typical section of road (one lane) draining entirely to a small pond. Calcium elevation did not

Jacqueline D. LaPerriere; Caryn L. Rea

1989-01-01

315

Atmospheric change alters foliar quality of host trees and performance of two outbreak insect species.  

PubMed

This study examined the independent and interactive effects of elevated carbon dioxide (CO(2)) and ozone (O(3)) on the foliar quality of two deciduous trees species and the performance of two outbreak herbivore species. Trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera) were grown at the Aspen FACE research site in northern Wisconsin, USA, under four combinations of ambient and elevated CO(2) and O(3). We measured the effects of elevated CO(2) and O(3) on aspen and birch phytochemistry and on gypsy moth (Lymantria dispar) and forest tent caterpillar (Malacosoma disstria) performance. Elevated CO(2) nominally affected foliar quality for both tree species. Elevated O(3) negatively affected aspen foliar quality, but only marginally influenced birch foliar quality. Elevated CO(2) slightly improved herbivore performance, while elevated O(3) decreased herbivore performance, and both responses were stronger on aspen than birch. Interestingly, elevated CO(2) largely offset decreased herbivore performance under elevated O(3). Nitrogen, lignin, and C:N were identified as having strong influences on herbivore performance when larvae were fed aspen, but no significant relationships were observed for insects fed birch. Our results support the notion that herbivore performance can be affected by atmospheric change through altered foliar quality, but how herbivores will respond will depend on interactions among CO(2), O(3), and tree species. An emergent finding from this study is that tree age and longevity of exposure to pollutants may influence the effects of elevated CO(2) and O(3) on plant-herbivore interactions, highlighting the need to continue long-term atmospheric change research. PMID:21971584

Couture, John J; Meehan, Timothy D; Lindroth, Richard L

2012-03-01

316

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

317

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. PMID:25035804

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

2014-01-01

318

Climatic limits on foliar growth during major droughts in the Southwestern U.S.A.  

USGS Publications Warehouse

Pronounced droughts during the 1950s and 2000s in the Southwestern U.S.A. (SW) provide an opportunity to compare mesoscale ecosystem responses to anomalously dry conditions before and during the regional warming that started in the late 1970s. This year-round warming has produced fewer cool season freezes, losses in regional snowpack, an 8-10 day advance in spring onset, and hotter summers, all of which should affect vegetation differently across seasons and elevations. Here, we examine indices that represent climatic limits on foliar growth for both drought periods, and evaluate these indices for areas that experienced tree mortality during the 2000s drought. Relative to the 1950s drought, warmer conditions during the 2000s drought decreased the occurrence of temperatures too low for foliar growth at lower elevations in winter and higher elevations in summer. Higher vapor pressure deficits (VPDs) largely driven by warmer temperatures in the more recent drought were more limiting to foliar growth from spring through summer at lower and middle elevations. At many locations where tree mortality occurred during the 2000s drought, low-temperature constraints on foliar growth were extremely unlimiting, whereas VPD constraints were extremely limiting from early spring through late autumn. Our analysis shows that in physiographically complex regions like the SW, seasonality and elevational gradients are important for understanding vegetative responses to warming. It also suggests that continued warming will increase the degree to which VPD limits foliar growth during future droughts, and expand its reach to higher elevations and other seasons.

Weiss, Jeremy L.; Betancourt, Julio L.; Overpeck, Jonathan T.

2012-01-01

319

Articles Lead in Calcium Supplements  

E-print Network

Intercalibrated measurements of lead in calcium supplements indicate the importance of rigorous analytical techniques to accurately quantify contaminant exposures in complex matrices. Without such techniques, measurements of lead concentrations in calcium supplements may be either erroneously low, by as much as 50%, or below the detection limit needed for new public health criteria. In this study, we determined the lead content of 136 brands of supplements that were purchased in 1996. The calcium in the products was derived from natural sources (bonemeal, dolomite, or oyster shell) or was synthesized and/or refined (chelated and nonchelated calcium). The dried products were acid digested and analyzed for lead by high resolution-inductively coupled plasma-mass spectrometry. The method’s limit of quantitation averaged 0.06 µg/g, with a coefficient of variation of 1.7 % and a 90–100 % lead recovery of a bonemeal standard reference material. Two-thirds of those calcium supplements failed to meet the 1999 California criteria for acceptable lead levels (1.5 µg/daily dose of calcium) in consumer products. The nonchelated synthesized and/or refined calcium products, specifically antacids and infant formulas, had the lowest lead concentrations, ranging from nondetectable to 2.9 µg Pb/g calcium, and had the largest proportion of brands meeting the new criteria (85 % of the antacids and 100 % of the infant formulas). Key words: antacids, bonemeal, calcium supplements, dolomite, inductively coupled plasma-mass spectrometry (ICP-MS), infant formulas, lead, nutritional supplements, oyster shell, vitamins. Environ Health Perspect 108:309–313 (2000). [Online 21 February 2000

Genine M. Scelfo; A. Russell Flegal

320

Calcium/Calmodulin-Mediated Gravitropic Response in Plants  

NASA Technical Reports Server (NTRS)

The goal of this project was to gain a fundamental understanding of how calcium/calmodulin-mediated signaling is involved in gravity signal transduction in plants. During the period of support, significant progress was made in elucidating the role of calmodulin and its target proteins in gravitropism. This laboratory has made breakthroughs by cloning and characterizing genes that are involved in calcium/calmodulin-mediated signaling. Some of these genes show altered expression under hypergravity and simulated microgravity conditions. A major advance was made in our attempts to understand gravity signal transduction by cloning and characterizing a catalase which requires calcium/calmodulin for its activation. Our results suggest that calcium/calmodulin have dual roles in regulating the level of hydrogen peroxide (H202), a signal molecule that plays a major role in gravitropism. It is well established that auxin plays a major role in gravitropism. Our results indicate that there is a 'cross-talk' between calcium/calmodulin-mediated signaling and auxin-mediated signal transduction. Auxin-regulated SAUR proteins that are involved in gravitropism bind to calmodulin in a calcium-dependent manner. A novel chimeric calcium/calmodulin-dependent protein kinase was cloned and characterized and its role in gravity signal transduction was investigated. These studies have provided some answers to the fundamental questions about how signal molecules such as calcium, H202, and hormones such as auxin bring about the ultimate gravitropic response and the integral role of calmodulin in gravity signal transduction. This NASA-funded study has led to some spinoffs that have applications in solving agricultural problems. The Washington State University Research Foundation has obtained several patents related to this work.

Poovaiah, B. W.

2002-01-01

321

Fast Spatiotemporal Smoothing of Calcium Measurements in Dendritic Trees  

PubMed Central

We discuss methods for fast spatiotemporal smoothing of calcium signals in dendritic trees, given single-trial, spatially localized imaging data obtained via multi-photon microscopy. By analyzing the dynamics of calcium binding to probe molecules and the effects of the imaging procedure, we show that calcium concentration can be estimated up to an affine transformation, i.e., an additive and multiplicative constant. To obtain a full spatiotemporal estimate, we model calcium dynamics within the cell using a functional approach. The evolution of calcium concentration is represented through a smaller set of hidden variables that incorporate fast transients due to backpropagating action potentials (bAPs), or other forms of stimulation. Because of the resulting state space structure, inference can be done in linear time using forward-backward maximum-a-posteriori methods. Non-negativity constraints on the calcium concentration can also be incorporated using a log-barrier method that does not affect the computational scaling. Moreover, by exploiting the neuronal tree structure we show that the cost of the algorithm is also linear in the size of the dendritic tree, making the approach applicable to arbitrarily large trees. We apply this algorithm to data obtained from hippocampal CA1 pyramidal cells with experimentally evoked bAPs, some of which were paired with excitatory postsynaptic potentials (EPSPs). The algorithm recovers the timing of the bAPs and provides an estimate of the induced calcium transient throughout the tree. The proposed methods could be used to further understand the interplay between bAPs and EPSPs in synaptic strength modification. More generally, this approach allows us to infer the concentration on intracellular calcium across the dendritic tree from noisy observations at a discrete set of points in space. PMID:22787437

Pnevmatikakis, Eftychios A.; Kelleher, Keith; Chen, Rebecca; Saggau, Petter; Josic, Kresimir; Paninski, Liam

2012-01-01

322

Formate oxidation-driven calcium carbonate precipitation by Methylocystis parvus OBBP.  

PubMed

Microbially induced carbonate precipitation (MICP) applied in the construction industry poses several disadvantages such asammonia release to the air and nitric acid production. An alternative MICP from calcium formate by Methylocystis parvus OBBP is presented here to overcome these disadvantages. To induce calcium carbonate precipitation, M. parvus was incubated at different calcium formate concentrations and starting culture densities. Up to 91.4% ± 1.6% of the initial calcium was precipitated in the methane-amended cultures compared to 35.1% ± 11.9% when methane was not added. Because the bacteria could only utilize methane for growth, higher culture densities and subsequently calcium removals were exhibited in the cultures when methane was added. A higher calcium carbonate precipitate yield was obtained when higher culture densities were used but not necessarily when more calcium formate was added. This was mainly due to salt inhibition of the bacterial activity at a high calcium formate concentration. A maximum 0.67 ± 0.03 g of CaCO3 g of Ca(CHOOH)2(-1) calcium carbonate precipitate yield was obtained when a culture of 10(9) cells ml(-1) and 5 g of calcium formate liter(-)1 were used. Compared to the current strategy employing biogenic urea degradation as the basis for MICP, our approach presents significant improvements in the environmental sustainability of the application in the construction industry. PMID:24837386

Ganendra, Giovanni; De Muynck, Willem; Ho, Adrian; Arvaniti, Eleni Charalampous; Hosseinkhani, Baharak; Ramos, Jose Angel; Rahier, Hubert; Boon, Nico

2014-08-01

323

Calcium carbonate and calcium sulfate in Martian meteorite EETA79001  

NASA Technical Reports Server (NTRS)

Chips of glassy Lithology C of EETA79001 were studied by scanning electron microscopy and energy dispersive X-ray spectroscopy to determine the mineralogy and petrogenesis of the glass that was shown by others to contain trapped Mars-like gases. Calcium carbonite was identified as massive to acicular crystals for which Ca, C, and O were the major elements. Calcium sulfate was identified as prismatic-acicular crystals with Ca and S as the major elements.

Gooding, J. L.; Wentworth, S. J.

1987-01-01

324

Influence of dietary calcium on bone calcium utilization  

SciTech Connect

In Experiment 1, 10 microCi /sup 45/Ca/day were administered to 125 hens for 10 days. Hens were then allocated to five treatments with calcium levels ranging from .08 to 3.75% of the diet. In Experiment 2, hens with morning oviposition times were randomly allocated to 11 treatments that were periods of time postoviposition ranging from 6 hr to 24 hr, in 2-hr increments (Experiment 2). At the end of each 2-hr period, eggs from 25 hens were removed from the uterus. The 18-, 20-, and 22-hr treatments were replicated three times. In Experiment 3, hens were fed either ad libitum or feed was withheld the last 5 or 6 hr before oviposition. In Experiment 4, hens were fed 10 microCi of /sup 45/Ca for 15 days to label skeletal calcium. Hens were divided into two groups and fed a .08 or 3.75% calcium diet for 2 days. On the second day, 25 hens fed the 3.75% calcium diet were intubated with 7 g of the same diet containing .5 g calcium at 1700, 2100, 0100, 0500, and 0700 hr. The measurements used were egg weight, shell weight, and /sup 45/Ca content of the egg shell. Results indicated a significant linear or quadratic regression of dietary calcium levels on /sup 45/Ca accumulation in eggshells and eggshell weight (Experiment 1). As the calcium level of the diet increased, eggshell weight increased and /sup 45/Ca recovery decreased. Utilization of skeletal calcium for shell formation ranged from 28 to 96%. In Experiment 2, the rate of shell calcification was not constant throughout the calcification process but varied significantly.

Farmer, M.; Roland, D.A. Sr.; Clark, A.J.

1986-02-01

325

Total body calcium analysis. [neutron irradiation  

NASA Technical Reports Server (NTRS)

A technique to quantitate total body calcium in humans is developed. Total body neutron irradiation is utilized to produce argon 37. The radio argon, which diffuses into the blood stream and is excreted through the lungs, is recovered from the exhaled breath and counted inside a proportional detector. Emphasis is placed on: (1) measurement of the rate of excretion of radio argon following total body neutron irradiation; (2) the development of the radio argon collection, purification, and counting systems; and (3) development of a patient irradiation facility using a 14 MeV neutron generator. Results and applications are discussed in detail.

Lewellen, T. K.; Nelp, W. B.

1974-01-01

326

21 CFR 184.1207 - Calcium lactate.  

Code of Federal Regulations, 2010 CFR

...as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6 H10 CaO6 .xH2 O, where...commercially by the neutralization of lactic acid with calcium carbonate or calcium hydroxide. (b) The ingredient...

2010-04-01

327

21 CFR 184.1207 - Calcium lactate.  

...as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6 H10 CaO6. xH2 O, where...commercially by the neutralization of lactic acid with calcium carbonate or calcium hydroxide. (b) The ingredient...

2014-04-01

328

21 CFR 184.1207 - Calcium lactate.  

Code of Federal Regulations, 2012 CFR

...as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6 H10 CaO6 .xH2 O, where...commercially by the neutralization of lactic acid with calcium carbonate or calcium hydroxide. (b) The ingredient...

2012-04-01

329

INTRODUCTION Pedogenic (secondary) calcium carbonate is,  

E-print Network

INTRODUCTION Pedogenic (secondary) calcium carbonate is, by definition, a product of soil processes of calcium for pe- dogenic calcium carbonate (Gile et al., 1979). In regard to the source of the carbonate; Cerling et al., 1989; Quade et al., 1989). Because pedogenic calcium carbonate is read- ily soluble, its

Ahmad, Sajjad

330

21 CFR 184.1207 - Calcium lactate.  

Code of Federal Regulations, 2013 CFR

...as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6 H10 CaO6 .xH2 O, where...commercially by the neutralization of lactic acid with calcium carbonate or calcium hydroxide. (b) The ingredient...

2013-04-01

331

21 CFR 184.1207 - Calcium lactate.  

Code of Federal Regulations, 2011 CFR

...as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6 H10 CaO6 .xH2 O, where...commercially by the neutralization of lactic acid with calcium carbonate or calcium hydroxide. (b) The ingredient...

2011-04-01

332

Discovery of the Calcium Isotopes  

E-print Network

Twenty four calcium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

J. L. Gross; M. Thoennessen

2010-04-28

333

Children's Bone Health and Calcium  

MedlinePLUS

... Research Information Clinical Trials Resources and Publications Children's Bone Health and Calcium: Condition Information Skip sharing on ... media links Share this: Page Content What is bone health and how do you build strong bones? ...

334

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

335

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

336

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. PMID:23384444

Amberg, Gregory C.; Navedo, Manuel F.

2013-01-01

337

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

338

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

339

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

340

CASE REPORT Calcium Oxalate Precipitates  

E-print Network

We report a case of calcium oxalate deposition in a renomedullary interstitial cell tumor (RICT) in a patient dying of full-blown AIDS. The precipitates showed birefringence using a partially polaris ed light and were stained black in Yasue’s silver nit rate-rubeanic acid method. The combination of calcium oxalosis and RICT has not been reported before and might possibly be due to systemic biochemical alterations of the glycosaminoglycans as a result of profound metabolic disturbances in AIDS

Irene Pecorella; Sebastian B Lucas; Antonio Ciardi; Lorenzo Memeo; Robert F Miller

341

Calcium Intake and Body Weight  

Microsoft Academic Search

ABSTRACT Five clinical studies of calcium intake, designed with a primary skeletal end point, were reevaluated to explore associations be- tween calcium intake and body weight. All subjects were women, clustered in three main age groups: 3rd, 5th, and 8th decades. Total sample,size was,780. Four of the studies,were,observational;,two were cross-sectional, in which body mass index was regressed against entry level

K. Michael Davies; Robert P. Heaney; Robert R. Recker; Joan M. Lappe; M. Janet Barger-lux; Karen Rafferty; Sharilyn Hinders

2000-01-01

342

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

343

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

344

Biomimetic calcium phosphate coatings on recombinant spider silk fibres  

Microsoft Academic Search

Calcium phosphate ceramic coatings, applied on surfaces of metallic and polymeric biomaterials, can improve their performance in bone repair and regeneration. Spider silk is biocompatible, strong and elastic, and hence an attractive biomaterial for applications in connective tissue repair. Recently, artificial spider silk, with mechanical and structural characteristics similar to those of native spider silk, has been produced from recombinant

Liang Yang; My Hedhammar; Tobias Blom; Klaus Leifer; Jan Johansson; Pamela Habibovic; Clemens A. van Blitterswijk

2010-01-01

345

Modification of calcium carbonate surface properties: macroscopic and microscopic investigations  

Microsoft Academic Search

Understanding the wettability of mineral powders and its modification by the addition of various surface active agents is crucial for many industrial applications. In many cases, wettability is investigated by macroscopic characterization techniques. In this framework, we decided to study non-porous calcium carbonate powders coated by known amounts of water-repellent molecules. A detailed characterization of the interface, focusing on the

M. Chamerois; M. François; F. Villiéras; J. Yvon

1999-01-01

346

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. PMID:23507726

Dorozhkin, Sergey V.

2011-01-01

347

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

348

Calcium isotope analysis by mass spectrometry.  

PubMed

The variations in the isotopic composition of calcium caused by fractionation in heterogeneous systems and by nuclear reactions can provide insight into numerous biological, geological, and cosmic processes, and therefore isotopic analysis finds a wide spectrum of applications in cosmo- and geochemistry, paleoclimatic, nutritional, and biomedical studies. The measurement of calcium isotopic abundances in natural samples has challenged the analysts for more than three decades. Practically all Ca isotopes suffer from significant isobaric interferences, whereas low-abundant isotopes can be particularly affected by neighboring major isotopes. The extent of natural variations of stable isotopes appears to be relatively limited, and highly precise techniques are required to resolve isotopic effects. Isotope fractionation during sample preparation and measurements and instrumental mass bias can significantly exceed small isotope abundance variations in samples, which have to be investigated. Not surprisingly, a TIMS procedure developed by Russell et al. (Russell et al., 1978. Geochim Cosmochim Acta 42: 1075-1090) for Ca isotope measurements was considered as revolutionary for isotopic measurements in general, and that approach is used nowadays (with small modifications) for practically all isotopic systems and with different mass spectrometric techniques. Nevertheless, despite several decades of calcium research and corresponding development of mass spectrometers, the available precision and accuracy is still not always sufficient to achieve the challenging goals. The present article discusses figures of merits of presently used analytical methods and instrumentation, and attempts to critically assess their limitations. In Sections 2 and 3, mass spectrometric methods applied to precise stable isotope analysis and to the determination of (41)Ca are described. Section 4 contains a short summary of selected applications, and includes tracer experiments and the potential use of biological isotope fractionation in medical studies, paleoclimatic and paleoceanographic, and other terrestrial as well as extraterrestrial investigations. PMID:19551693

Boulyga, Sergei F

2010-01-01

349

Calcium homeostasis in barley aleurone  

SciTech Connect

Under the auspices of the Department of Energy we investigated calcium homeostasis in aleurone cells of barley. This investigation was initiated to explore the role played by extracellular Ca{sup 2+} in gibberellic acid (GA)-induced synthesis and secretion of hydrolases in the aleurone layer. We have focused our attention on four topics that relate to the role of Ca{sup 2+} in regulating the synthesis of {alpha}-amylase. First, we determined the stoichiometry of Ca{sup 2+} binding to the two principal classes of barley {alpha}-amylase and examined some of the biochemical and physical properties of the native and Ca{sup 2+}-depleted forms of the enzyme. Second, since {alpha}-amylase is a Ca{sup 2+} containing metalloenzyme that binds one atom of Ca{sup 2+} per molecule, we developed methods to determine the concentration of Ca{sup 2+} in the cytosol of the aleurone cell. We developed a technique for introducing Ca{sup 2+}-sensitive dyes into aleurone protoplasts that allows the measurement of Ca{sup 2+} in both cytosol and endoplasmic reticulum (ER). Third, because the results of our Ca{sup 2+} measurements showed higher levels of Ca{sup 2+} in the ER than in the cytosol, we examined Ca{sup 2+} transport into the ER of control and GA-treated aleurone tissue. And fourth, we applied the technique of patch-clamping to the barley aleurone protoplast to examine ion transport at the plasma membrane. Our results with the patch-clamp technique established the presence of K{sup +} channels in the plasma membrane of the aleurone protoplast, and they showed that this cell is ideally suited for the application of this methodology for studying ion transport. 34 refs.

Jones, R.L.

1990-02-21

350

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

351

Agronomy & Soil S Cotton Yield Response to Soil and Foliar-Applied Potassium as Influenced by Irrigation  

Microsoft Academic Search

The impact of moisture deficit stress on the yield response of cotton (Gossypium hirsutum L.) to foliar-applied K is not well understood. Studies were conducted in Arkansas from1999 through 2002 at three field locations to evaluate the effect of irrigation and soil-applied K on the yield response of cotton to foliar-applied K. Eight treatments consisting of soil-applied K and no

D. L. Coker; D. M. Oosterhuis; R. S. Brown

2009-01-01

352

Interspecific divergence in foliar nutrient dynamics and stem growth in a temperate forest in response to chronic nitrogen inputs  

Microsoft Academic Search

We studied the effects of excessive nitrogen (N) fertilization on foliar nutrient dynamics and stem growth in three important tree species in a mixed-deciduous forest. Stem diameter growth, foliar N concentrations, nitrogen- phosphorus (N\\/P) ratios, and nutrient resorption were determined for Acer rubrum L. (ACRU), Liriodendron tulipi- fera L. (LITU), and Prunus serotina Ehrh. (PRSE) on two 30-year-old watersheds at

Jeffrey D. May; Sarah Beth Burdette; Frank S. Gilliam; Mary Beth Adams

2005-01-01

353

The influence of a surfactant upon the foliar penetration of DEF (S, S, S-tributylphosphorotrithioate) in cotton  

E-print Network

THE INFLUENCE OF A SURFACTANT UPON THE FOLIAR PENETRATION OF DEF (S, S, S-TRIBUTYLPHOS- PHOROTRITHIOATE) IN COTTON A Thesis by Richard D. Baker Submitted to the Graduate College of the Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE January 1967 Major Subject: Plant Physiology THE INFLUENCE OF A SURFACTANT UPON THE FOLIAR PENETRATION OF DEF (S& S, S-TRIBUTYLPHOS- PHOROTRITHIOATE) IN COTTON A Thesis by Richard D. Baker Approved...

Baker, Richard Darrell

2012-06-07

354

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. PMID:18422426

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

2008-01-01

355

Phytotoxic activity of foliar volatiles and essential oils of Calamintha nepeta (L.) Savi.  

PubMed

Foliar volatiles and essential oils of Calamintha nepeta (L.) Savi, a Mediterranean plant species belonging to the Labiatae family, were investigated for their phytotoxic activities on seed germination and root growth of crops (Lactuca sativa L. and Raphanus sativus L.) and weed species (Lolium perenne L. and Amaranthus retroflexus L.). Foliar volatiles of C. nepeta (L.) Savi strongly inhibited both germination and root growth of lettuce, and its essential oils, especially at 125, 250 and 500 ?L/L, inhibited both processes in lettuce, radish and A. retroflexus L. species, while displaying a little effect on L. perenne L. By GC-MS, 28 chemicals were identified: 17 monoterpenes, 8 sesquiterpenes, 1 diterpene and 2 miscellaneous. Pulegone was the main constituent of the C. nepeta (L.) Savi essential oils. The terpenic components of essentials oils were probably responsible for the phytotoxic activities. PMID:23216166

Araniti, Fabrizio; Lupini, Antonio; Sorgonà, Agostino; Statti, Giancarlo Antonio; Abenavoli, Maria Rosa

2013-01-01

356

In Vivo Calcium Dynamics During Neural Crest Cell Migration and Patterning Using GCaMP3  

PubMed Central

Examining calcium dynamics within the neural crest (NC) has the potential to shed light on mechanisms that regulate complex cell migration and patterning events during embryogenesis. Unfortunately, typical calcium indicators are added to culture media or have low signal to noise after microinjection into tissue that severely limits analyses to cultured cells or superficial events. Here, we studied in vivo calcium dynamics during NC cell migration and patterning, using a genetically encoded calcium sensor, GCaMP3. We discovered that trunk NC cells displayed significantly more spontaneous calcium transients than cranial NC cells, and during cell aggregation versus cell migration events. Spontaneous calcium transients were more prevalent during NC cell aggregation into discrete sympathetic ganglia (SG). Blocking of N-cadherin activity in trunk NC cells near the presumptive SG led to a dramatic decrease in the frequency of spontaneous calcium transients. Detailed analysis and mathematical modeling of cell behaviors during SG formation showed NC cells aggregated into clusters after displaying a spontaneous calcium transient. This approach highlights the novel application of a genetically encoded calcium indicator to study subsets of cells during ventral events in embryogenesis. PMID:21864525

McKinney, Mary Cathleen; Kulesa, Paul M.

2012-01-01

357

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

358

Do Geomagnetic Variations Affect the Foliar Spiral Direction of Coconut Palms?  

Microsoft Academic Search

In coconut palms, leaves are attached to the stem in either an ascending clockwise (left-handed or L) or counter-clockwise (right-handed or R) spiral (1). Foliar spiral direction (FSD) is a classic case of morphological antisymmetry, in which dextral and sinistral forms are not inherited and are equally common within a species (2). FSD would seem a simple stochastic process unworthy

P. V. Minorsky; N. B. Bronstein

2005-01-01

359

Foliar and shoot allometry of pollarded black locust, Robinia pseudoacacia L  

Microsoft Academic Search

Browse of multipurpose tree species such as black locust could be used to broaden grazing options, but the temporal distribution\\u000a of foliage has not been adequately studied. Our objective was to determine effects of harvest date, P fertilization (0 and\\u000a 600 kg ha?1 yr?1), and pollard height (shoots clipped at 5-, 50-, and 100-cm above ground) on foliar and shoot allometry of black

D. M. Burner; D. H. Pote; A. Ares

2006-01-01

360

Regional patterns in foliar 15N across a gradient of nitrogen deposition in the northeastern US  

Microsoft Academic Search

Recent studies have demonstrated that natural abundance 15N can be a useful tool for assessing nitrogen saturation, because as nitrification and nitrate loss increase, ?15N of foliage and soil also increases. We measured foliar ?15N at 11 high-elevation spruce-fir stands along an N deposition gradient in 1987–1988 and at seven paired northern hardwood and spruce-fir stands in 1999. In 1999,

Linda H. Pardo; Steven G. McNulty; Johnny L. Boggs; Sara Duke

2007-01-01

361

Consequences of Enriched Atmospheric CO 2 and Defoliation for Foliar Chemistry and Gypsy Moth Performance  

Microsoft Academic Search

Elevated concentrations of atmospheric CO2 are likely to interact with other factors affecting plant physiology to alter plant chemical profiles and plant–herbivore interactions. We evaluated the independent and interactive effects of enriched CO2 and artificial defoliation on foliar chemistry of quaking aspen (Populus tremuloides) and sugar maple (Acer saccharum), and the consequences of such changes for short-term performance of the

Richard L. Lindroth; Karl K. Kinney

1998-01-01

362

Foliar uptake of cesium from the water column by aquatic macrophytes  

Microsoft Academic Search

The probable occurrence and rate of foliar absorption of stable cesium (133Cs) from the water column by aquatic macrophyte species was analyzed following the addition of 133Cs into a small reservoir near Aiken, South Carolina, USA. An uptake parameter u (103Lkg?1d?1) and a loss rate parameter k (d?1) were estimated for each species using time series of 133Cs concentrations in

J PINDERIII; T. G. Hinton; F. W. Whicker

2006-01-01

363

Foliar uptake of 137Cs from the water column by aquatic macrophytes  

Microsoft Academic Search

A transplant experiment was performed to determine the relative importances of root uptake from the sediments and foliar uptake from the water column in determining the accumulation of 137Cs by aquatic macrophytes. Uncontaminated individuals of three species, Brasenia schreberi, Nymphaea odorata and Nymphoides cordata, were transplanted into pots containing either contaminated sediments (i.e. 1.2 Bq 137Cs g?1 dry mass) or

M. S. Kelly; J. E. Pinder

1996-01-01

364

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

365

Increasing the absorption of foliar applied nutrients with the use of adjuvants  

E-print Network

absorption of herbicides (12), may be useful in increasing the absorption of foliarly applied nutrients. Adjuvants have been shown to improve, reduce, or have no effect on penetration (5, 11, 12, 30). Environment, plant species, plant characteristics... of adjuvant, d) characteristics of the plant species used, e) environmental conditions, and f) method of assessing uptake. It is highly probable that each nutrient or herbicide requires a specific adjuvant (47, 61). Perhaps even the same nutrient requires...

Putman, Joan Ellen

2012-06-07

366

Foliar and wood chemistry of sugar maple along a gradient of soil acidity and stand health  

Microsoft Academic Search

The decline of sugar maple (Acer saccharum Marsh.) in forest of north-eastern North America is an important environmental issue. In this study, relationships between,\\u000a soil, wood and foliar chemistry were assessed for 17 stands distributed within a large area of the Quebec sugar maple forest\\u000a and that were growing on soils with a strong gradient of acidity and base saturation.

Daniel Houle; Sylvie Tremblay; Rock Ouimet

2007-01-01

367

Nondestructive and rapid estimation of hardwood foliar nitrogen status using the SPAD502 chlorophyll meter  

Microsoft Academic Search

The utility of a portable chlorophyll meter (SPAD-502, Minolta Camera Co. Ltd., Japan) for rapidly and nondestructively assessing foliar N status of hardwood species was evaluated in two experiments. In experiment one (established near Raleigh, North Carolina), 0, 56, 168, or 336kgN\\/ha (ammonium nitrate) was applied in June 1998 to sycamore (Platanus occidentalis L.), sweetgum (Liquidambar styraciflua L.), green ash

Scott X. Chang; Daniel J. Robison

2003-01-01

368

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

369

The Use of Cloned Sequences for the Identification of Coconut Foliar Decay Disease-associated DNA  

Microsoft Academic Search

SUMMARY Single-stranded circular DNA associated with foliar decay disease of coconut palm in Vanuatu (FDD-DNA) has been purified and three fragments have been cloned in plasmid pUC19. Clones labelled with 32p by nick translation were used as specific probes for FDD-DNA in dot blot and Southern transfer hybridization assays. These assays were more sensitive than the polyacrylamide gel electrophoresis assay

D. Hanold; P. Langridge; J. W. Randles

1988-01-01

370

Small Circular Single-stranded DNA Associated with Foliar Decay Disease of Coconut Palm in Vanuatu  

Microsoft Academic Search

SUMMARY The single-stranded DNA previously reported to be associated with foliar decay disease of coconut palm appears to be predominantly circular, on the basis of its behaviour in two-dimensional polyacrylamide gel electrophoresis, electron micro- scopy, and its resistance to end-labelling following treatment with alkaline phosphatase and polynucleotide kinase. The DNA sedimented at between 12S and 15S and had a contour

J. W. Randles; D. Hanold; J. F. Julia

1987-01-01

371

Air pollutants effect on monoterpenes composition and foliar chemical parameters in Schinus areira L  

Microsoft Academic Search

Monoterpenes, pigments, lipid peroxidation products, sulfur and water content expressed as dry weight\\/fresh weight ratio were measured in leaves of Schinus areira L. collected in Mendoza, Argentina. The sampling sites showed different SO2, NO2 and PM10 levels, which allowed setting out zones by mapping. Foliar chemical parameters in S. areira were analysed in relation to these zones. High hydroperoxy conjugated

E. D. Wannaz; J. A. Zygadlo; M. L. Pignata

2003-01-01

372

Methylene blue adsorption on graphene oxide/calcium alginate composites.  

PubMed

Graphene oxide has been used as an adsorbent in wastewater treatment. However, the dispersibility in aqueous solution and the biotoxicity to human cells of graphene oxide limits its practical application in environmental protection. In this research, a novel environmental friendly adsorbent, calcium alginate immobilized graphene oxide composites was prepared. The effects of pH, contact time, temperature and dosage on the adsorption properties of methylene blue onto calcium alginate immobilized graphene oxide composites were investigated. The equilibrium adsorption data were described by the Langmuir and Freundlich isotherms. The maximum adsorption capacity obtained from Langmuir isotherm equation was 181.81 mg/g. The pseudo-first order, pseudo-second order, and intraparticle diffusion equation were used to evaluate the kinetic data. Thermodynamic analysis of equilibriums indicated that the adsorption reaction of methylene blue onto calcium alginate immobilized graphene oxide composites was exothermic and spontaneous in nature. PMID:23618299

Li, Yanhui; Du, Qiuju; Liu, Tonghao; Sun, Jiankun; Wang, Yonghao; Wu, Shaoling; Wang, Zonghua; Xia, Yanzhi; Xia, Linhua

2013-06-01

373

Functional and biological diversity of foliar spectra in tree canopies throughout the Andes to Amazon region.  

PubMed

Spectral properties of foliage express fundamental chemical interactions of canopies with solar radiation. However, the degree to which leaf spectra track chemical traits across environmental gradients in tropical forests is unknown. We analyzed leaf reflectance and transmittance spectra in 2567 tropical canopy trees comprising 1449 species in 17 forests along a 3400-m elevation and soil fertility gradient from the Amazonian lowlands to the Andean treeline. We developed quantitative links between 21 leaf traits and 400-2500-nm spectra, and developed classifications of tree taxa based on spectral traits. Our results reveal enormous inter-specific variation in spectral and chemical traits among canopy trees of the western Amazon. Chemical traits mediating primary production were tightly linked to elevational changes in foliar spectral signatures. By contrast, defense compounds and rock-derived nutrients tracked foliar spectral variation with changing soil fertility in the lowlands. Despite the effects of abiotic filtering on mean foliar spectral properties of tree communities, the spectra were dominated by phylogeny within any given community, and spectroscopy accurately classified 85-93% of Amazonian tree species. Our findings quantify how tropical tree canopies interact with sunlight, and indicate how to measure the functional and biological diversity of forests with spectroscopy. PMID:24942328

Asner, Gregory P; Martin, Roberta E; Carranza-Jiménez, Loreli; Sinca, Felipe; Tupayachi, Raul; Anderson, Christopher B; Martinez, Paola

2014-10-01

374

Differential effects of foliar endophytic fungi on insect herbivores attacking a herbaceous plant.  

PubMed

Foliar endophytic fungi appear to be ubiquitous in nature, occurring in a very wide range of herbaceous plants. However, their ecological role within forbs is very poorly known and interactions with foliar-feeding insects virtually unexplored. In this study, leaves of Cirsium arvense were infected with different combinations of endophyte fungi that had been previously isolated from this plant species. Two months later, leaf material was fed to larvae of a generalist insect, Mamestra brassicae, and adults of a specialist feeder, Cassida rubiginosa. Endophytes had different effects on the two insects; one species, Chaetomium cochliodes, reduced growth of M. brassicae but increased feeding by C. rubiginosa. Another species, Cladosporium cladosporioides, increased beetle feeding also, but had no effect on M. brassicae. Interactions were also seen between fungal species and dual infection with C. cladosporioides and Trichoderma viride greatly reduced beetle feeding. It is concluded that endophytes have significant effects on foliar feeding insects that differ with degree of specialism of the herbivore. We suggest that these effects are due to chemical changes in the host, brought about by fungal infection. These fungi have received remarkably little attention in the study of insect-plant interactions and yet could be important determinants of insect growth and even population dynamics. PMID:21989607

Gange, Alan C; Eschen, René; Wearn, James A; Thawer, Alim; Sutton, Brian C

2012-04-01

375

Hydration of calcium oxide surface predicted by reactive force field molecular dynamics.  

PubMed

In this work, we present the parametrization of Ca-O/H interactions within the reactive force field ReaxFF, and its application to study the hydration of calcium oxide surface. The force field has been fitted using density functional theory calculations on gas phase calcium-water clusters, calcium oxide bulk and surface properties, calcium hydroxide, bcc and fcc Ca, and proton transfer reactions in the presence of calcium. Then, the reactive force field has been used to study the hydration of the calcium oxide {001} surface with different water contents. Calcium oxide is used as a catalyzer in many applications such as CO(2) sequestration and biodiesel production, and the degree of surface hydroxylation is a key factor in its catalytic performance. The results show that the water dissociates very fast on CaO {001} bare surfaces without any defect or vacancy. The surface structure is maintained up to a certain amount of water, after which the surface undergoes a structural rearrangement, becoming a disordered calcium hydroxyl layer. This transformation is the most probable reason for the CaO catalytic activity decrease. PMID:22316164

Manzano, Hegoi; Pellenq, Roland J M; Ulm, Franz-Josef; Buehler, Markus J; van Duin, Adri C T

2012-03-01

376

The stability mechanisms of an injectable calcium phosphate ceramic suspension  

PubMed Central

Calcium phosphate ceramics are widely used as bone substitutes in dentistry and orthopedic applications. For minimally invasive surgery an injectable calcium phosphate ceramic suspension (ICPCS) was developed. It consists in a biopolymer (hydroxypropylmethylcellulose: HPMC) as matrix and bioactive calcium phosphate ceramics (biphasic calcium phosphate: BCP) as fillers. The stability of the suspension is essential to this generation of “ready to use” injectable biomaterial. But, during storage, the particles settle down. The engineering sciences have long been interested in models describing the settling (or sedimentation) of particles in viscous fluids. Our work is dedicated to the comprehension of the effect of the formulation on the stability of calcium phosphate suspension before and after steam sterilization. The rheological characterization revealed the macromolecular behavior of the suspending medium. The investigations of settling kinetics showed the influence of the BCP particle size and the HPMC concentration on the settling velocity and sediment compactness before and after sterilization. To decrease the sedimentation process, the granule size has to be smaller and the polymer concentration has to increase. A much lower sedimentation velocity, as compared to Stokes law, is observed and interpreted in terms of interactions between the polymer network in solution and the particles. This experimentation highlights the granules spacer property of hydrophilic macromolecules that is a key issue for interconnection control, one of the better ways to improve osteoconduction and bioactivity. PMID:20229185

Fatimi, Ahmed; Tassin, Jean-Francois; Axelos, Monique A. V.; Weiss, Pierre

2010-01-01

377

Intracellular Calcium Receptors: Calmodulin and Related Proteins  

NASA Technical Reports Server (NTRS)

Studies on intracellular calcium receptors, calmodulin and related proteins were carried out. Calcium binding proteins, like calmodulin fall into a class of proteins that are predominantly intracellular and reversibly bind calcium with dissociation constants in the micromolar to nanomolar range. Calcium regulation of these proteins appears to be due to localized increases in calcium concentrations in the cytoplasm. The main thrust of the research is concerned with purifying and characterizing the calcium receptors and trying to elucidate mechanistically how they are involved in cellular responses.

Watterson, D. M.

1983-01-01

378

Multiple Calcium Stores: Separate but Interacting  

NSDL National Science Digital Library

Multiple mechanisms exist for increasing the concentration of intracellular calcium. This Perspective by Lee is one in a series on intracellular calcium release mechanisms and focuses on the calcium store operated by nicotinic acid adenine dinucleotide phosphate (NAADP). The characterization of the NAADP-operated calcium store as separate from the inositol trisphosphate (IP3)-operated and cyclic ADP-ribose (cADPR)-operated calcium stores is discussed. Lee also addresses the role of NAADP in regulating intracellular calcium fluctuations during fertilization and hormonal activation of pancreatic acinar cells.

Hon Cheung Lee (University of Minnesota;Department of Pharmacology REV)

2000-07-11

379

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

380

Multi-Functions of Carbonated Calcium Deficient Hydroxyapatite (CDHA)  

NASA Astrophysics Data System (ADS)

Natural bone is a complex composite mainly constituted of inorganic minerals and organic collagen molecules. Calcium phosphate (CaP) based materials have been proposed as the predominant bone substitute for bone tissue engineering applications due to their chemical similarity to bone mineral. Amorphous carbonated calcium deficient hydroxyapatite (CDHA) is an important compound among CaP materials because of the amorphous crystallite structure. The presence of extra ions in its lattice structure not only influences cell attachment and proliferation of osteoblasts, but also helps in bone metabolism. Biomimetic coating approach is the most widely used approach to produce CDHA coatings to implant. It is a process using simulated body fluid (SBF) to deposit bone-like CDHA coating to various material surfaces. The CDHA formation mechanism, SBF compositions and reacting conditions of biomimetic coating have already been sufficiently studied and compared in the past 20 years. It is an attempt in this thesis to explore new applications of SBF in biomedical research, focusing on different biomaterial applications: 1) based on the low temperature reaction condition of SBF, bisphosphonate incorporated CDHA coatings were deposited onto Ti6Al4V surface for the treatment of osteoporosis; 2) amorphous calcium phosphate nanospheres with extra elements in the lattice structure were prepared by a novel microwave assisted approach, providing a new potential of CaP materials production; 3) CDHA particles formed in SBF can be used as great fillers with biopolymers for preparing biocomposites for biomedical applications; 4) based on the high activity of CDHA amorphous structure and the stabilization ability of ethanol, yttrium and europium doped calcium phosphates were prepared using CDHA as a sacrificing template. In the end, future work based on these observations in the thesis is addressed, including areas of drug delivery, biocomposite fabrication and preparation of functionalized calcium phosphate materials.

Zhou, Huan

381

Visualizing Calcium Signaling in Astrocytes  

NSDL National Science Digital Library

Astrocytes are nonneuronal cells in the brain (glia) that do not generate electrical impulses but communicate by chemical signaling. This communication can be observed under a microscope with fluorescent calcium indicators that glow more brightly when the concentration of calcium increases inside the cell. Astrocytes release adenosine 5′-triphosphate and other cell signaling molecules that excite membrane receptors on other astrocytes to cause an increase in intracellular calcium in the recipient cell. Many of the substances released by astrocytes also excite neurons, and astrocytes have on their own cell membrane many of the same neurotransmitter receptors used by neurons to communicate across synapses. This allows astrocytes to respond to neural impulse activity, communicate among other astrocytes, and influence neuronal communication by taking up or releasing neurotransmitters from synapses.

R. Douglas Fields (National Institutes of Health;National Institute of Child Health and Human Development REV)

2010-11-09

382

Osteoporosis, calcium and physical activity.  

PubMed Central

Sales of calcium supplements have increased dramatically since 1983, as middle-aged women seek to prevent or treat bone loss due to osteoporosis. However, epidemiologic studies have failed to support the hypothesis that larger amounts of calcium are associated with increased bone density or a decreased incidence of fractures. The authors examine the evidence from controlled trials on the effects of calcium supplementation and physical activity on bone loss and find that weight-bearing activity, if undertaken early in life and on a regular basis, can increase the peak bone mass of early adulthood, delay the onset of bone loss and reduce the rate of loss. All of these factors will delay the onset of fractures. Carefully planned and supervised physical activity programs can also provide a safe, effective therapy for people who have osteoporosis. PMID:3545420

Martin, A D; Houston, C S

1987-01-01

383

The effect of variable calcium and very low calcium diets on human calcium metabolism. Ph.D. Thesis. Final Report  

NASA Technical Reports Server (NTRS)

The effects of a very low calcium diet, with variable high and low protein intake, on the dynamics of calcium metabolism and the mechanism of calciuretics, are examined. The experiment, using male subjects, was designed to study the role of intestinal calcium absorption on urinary calcium excretion, and the rate of production of endogeneously secreted calcium in the gastrointestinal tract. The study showed an average of 70% fractional absorption rate during very low calcium intake, and that a decrease in renal tubular reabsorption of calcium is responsible for calciuretic effects of high protein intake. The study also indicates that there is a tendency to develop osteoporosis after long periods of low calcium intake, especially with a concurrent high protein intake.

Chu, J.

1971-01-01

384

Calcium and aluminium-based fillers as flame-retardant additives in silicone matrices. I. Blend preparation and thermal properties  

Microsoft Academic Search

This series investigates silicone composites with enhanced thermal behaviour for cable applications. Calcium and aluminium-based fillers introduced into silicone formulations were classified according to three categories: non-hydrated fillers such as CaCO3 (precipitated calcium carbonate and natural calcite) and wollastonite, water-releasing fillers such as calcium hydroxide, ATH, boehmite, and hydroxyl-functionalized fillers including alumina and mica. The fillers were first characterized in

Siska Hamdani; Claire Longuet; José-Marie Lopez-Cuesta; François Ganachaud

2010-01-01

385

Interactions of organic calcium channel antagonists with calcium channels in single frog atrial cells  

PubMed Central

Inhibition of whole-cell calcium currents in enzymatically dispersed frog atrial myocytes by D-600, diltiazem, and nifedipine was studied using a single-micropipette voltage-clamp technique. The objective of these experiments was to test the applicability of a modulated-receptor hypothesis similar to that proposed for local anesthetic interactions with sodium channels to account for the tonic and frequency-dependent interactions of these organic compounds with myocardial calcium channels. Data consistent with such a hypothesis include: (a) prominent use-dependent block of iCa by D-600 and diltiazem, which are predominantly charged at physiological pH; (b) iCa block by an externally applied, permanently charged dihydropyridine derivative is greatly attenuated; (c) all three antagonists produce large negative shifts in the voltage dependence of iCa availability; (d) block of iCa by these compounds is state-dependent; (e) reactivation of iCa in the presence of all three antagonists is biexponential, which suggests that drug-free channels recover with a normal time course and drug-bound channels recover more slowly; and (f) the kinetics of the drug-induced slow iCa recovery process may be determined largely by factors such as size and molecular weight, in addition to lipid solubility of the compounds. Experiments in which the pH was modified, however, reveal some important differences for the interaction of organic calcium antagonists with myocardial calcium channels. Acidification, in addition to changing the proportion of charged and neutral antagonist in solution, was found to selectively antagonize tonic inhibition of iCa by diltiazem and nifedipine, without changing the kinetics of the drug-induced slow iCa reactivation process. It is concluded that two distinct receptor sites may be involved in block of iCa by some of these compounds: a proton-accessible site and a proton-inaccessible site. PMID:2582076

1985-01-01

386

Effect of vitamin D or calcium deficiency on duodenal, jejunal and ileal calcium-binding protein and on plasma calcium  

E-print Network

Effect of vitamin D or calcium deficiency on duodenal, jejunal and ileal calcium-binding protein Josas. Summary. In vitamin D-deficient pigs the amount of intestinal calcium-binding protein (CaBP. In chicks and rats, 25-hydroxycholecalciferol (25-OHD,) is the major circulating metabolite of vitamin D3

Paris-Sud XI, Université de

387

21 CFR 184.1212 - Calcium pantothenate.  

...B complex. Only the D- isomer of pantothenic acid has vitamin activity, although both the D- isomer and the DL- racemic mixture of calcium pantothenate are used in food. Commercial calcium pantothenate is prepared synthetically from...

2014-04-01

388

DISSOLUTION AND CRYSTALLIZATION OF CALCIUM SULFITE PLATELETS  

EPA Science Inventory

The paper discusses the dissolution and crystallization of calcium sulfite platelets. The rates of calcium sulfite dissolution and crystallization are important in slurry scrubbing processes for flue gas desulfurization. The rates affect the scrubber solution composition, SO2 abs...

389

Magnesium/Calcium Competition at Excitable Membranes.  

ERIC Educational Resources Information Center

Considers some consequences of altering intracellular calcium supply by magnesium concentration changes. Focuses on using this procedure as an exercise with allied health students as they witness therapeutic uses of magnesium and other calcium entry inhibitors. (DDR)

Belzer, Bill; Fry, Panni

1998-01-01

390

21 CFR 172.715 - Calcium lignosulfonate.  

Code of Federal Regulations, 2010 CFR

...safely used in or on food, subject to the provisions of this section. (a) Calcium lignosulfonate consists of sulfonated lignin, primarily as calcium and sodium salts. (b) It is used in an amount not to exceed that reasonably required to...

2010-04-01

391

21 CFR 182.2227 - Calcium silicate.  

Code of Federal Regulations, 2010 CFR

...Calcium silicate. (a) Product. Calcium silicate. (b) Tolerance. 2 percent and 5 percent. (c) Limitations, restrictions...as safe when used at levels not exceeding 2 percent in table salt and 5 percent in baking powder in accordance with good...

2010-04-01

392

21 CFR 582.2227 - Calcium silicate.  

Code of Federal Regulations, 2010 CFR

...Calcium silicate. (a) Product. Calcium silicate. (b) Tolerance. 2 percent and 5 percent. (c) Limitations, restrictions...as safe when used at levels not exceeding 2 percent in table salt and 5 percent in baking powder in accordance with good...

2010-04-01

393

Towards the development of calcium ion batteries  

E-print Network

A novel system for the study of calcium-ion electroactive materials has been developed, characterized, and utilized to screen a number of candidate calcium intercalation compounds. The system is comprised of a dried, ...

Rogosic, John

2014-01-01

394

Research on the water use efficiency and foliar nutrient status of Populus euphratica and Tamarix ramosissima in the extreme arid region of China  

Microsoft Academic Search

Seasonal variations in foliar stable carbon composition (?13C) and nitrogen (N), phosphorus (P) and potassium (K) concentrations of Populus euphratica Olivier and Tamarix ramosissima Ledeb, as well as correlations between foliar ?13C values and N, P and K concentrations were studied in the Ejina oasis in the lower reaches of the Heihe River, northwestern\\u000a China. Foliar ?13C values, and P

Sheng Kui Cao; Qi Feng; Yong Hong Su; Zong Qiang Chang; Hai Yang Xi

2011-01-01

395

Structural Characteristics of Synthetic Amorphous Calcium Carbonate  

SciTech Connect

Amorphous calcium carbonate (ACC) is an important phase involved in calcification by a wide variety of invertebrate organisms and is of technological interest in the development of functional materials. Despite widespread scientific interest in this phase a full characterization of structure is lacking. This is mainly due to its metastability and difficulties in evaluating structure using conventional structure determination methods. Here we present new findings from the application of two techniques, pair distribution function analysis and nuclear magnetic resonance spectroscopy, which provide new insight to structural aspects of synthetic ACC. Several important results have emerged from this study of ACC formed in vitro using two common preparation methods: (1) ACC exhibits no structural coherence over distances > 15 {angstrom} and is truly amorphous; (2) most of the hydrogen in ACC is present as structural H{sub 2}O, about half of which undergoes restricted motion on the millisecond time scale near room temperature; (3) the short- and intermediate-range structure of ACC shows no distinct match to any known structure in the calcium carbonate system; and (4) most of the carbonate in ACC is monodentate making it distinctly different from monohydrocalcite. Although the structure of synthetic ACC is still not fully understood, the results presented provide an important baseline for future experiments evaluating biogenic ACC and samples containing certain additives that may play a role in stabilization of ACC, crystallization kinetics, and final polymorph selection.

Michel, F. Marc; MacDonald, Jason; Feng, Jian; Phillips, Brian L.; Ehm, Lars; Tarabrella, Cathy; Parise, John B.; Reeder, Richard J. (SBU)

2008-08-06

396

Patterning alginate hydrogels using light-directed release of caged calcium in a microfluidic device  

PubMed Central

This paper describes a simple reversible hydrogel patterning method for 3D cell culture. Alginate gel is formed in select regions of a microfluidic device through light-triggered release of caged calcium. In the pre-gelled alginate solution, calcium is chelated by DM-nitrophen (DM-n) to prevent cross-linking of alginate. After sufficient UV exposure the caged calcium is released from DM-n causing alginate to cross-link. The effect of using different concentrations of calcium and chelating agents as well as the duration of UV exposure is described. Since the cross-linking is based on calcium concentration, the cross-linked alginate can easily be dissolved by EDTA. We also demonstrate application of this capability to patterned microscale 3D co-culture using endothelial cells and osteoblastic cells in a microchannel. PMID:19830565

Chueh, Bor-han; Zheng, Ying; Torisawa, Yu-suke; Hsiao, Amy Y.; Ge, Chunxi; Hsiong, Susan; Huebsch, Nathaniel; Franceschi, Renny; Mooney, David J.

2010-01-01

397

Fiber-enriched double-setting calcium phosphate bone cement.  

PubMed

Calcium phosphate bone cements are useful in orthopedics and traumatology, their main advantages being their biocompatibility and bioactivity, which render bone tissue osteoconductive, providing in situ hardening and easy handling. However, their low mechanical strength, which, in the best of cases, is equal to the trabecular bone, and their very low toughness are disadvantages. Calcium phosphate cement compositions with mechanical properties more closely resembling those of human bone would broaden the range of applications, which is currently limited to sites subjected to low loads. This study investigated the influence of added polypropylene, nylon, and carbon fibers on the mechanical properties of double setting alpha-tricalcium phosphate-based cement, using calcium phosphate cement added to an in situ polymerizable acrylamide-based system recently developed by the authors. Although the addition of fibers was found to reduce the compression strength of the double-setting calcium phosphate cement because of increased porosity, it strongly increased the cement's toughness (J(IC)) and tensile strength. The composites developed in this work, therefore, have a potential application in shapes subjected to flexure. PMID:12734819

dos Santos, Luís Alberto; Carrodéguas, Raúl Garcia; Boschi, Anselmo Ortega; Fonseca de Arruda, Antônio Celso

2003-05-01

398

Foliar sprays of citric acid and salicylic acid alter the pattern of root acquisition of some minerals in sweet basil (Ocimum basilicum L.)  

PubMed Central

The effect of foliar application of two levels of citric acid (CA; 0 and 7 mM) and two levels of salicylic acid (SA; 0 and 1 mM) combined with two levels of nutrient solution strength (full strength and half strength) on mineral acquisition by sweet basil were investigated. The experiment was conducted in a randomized block design arrangement with three replications. SA alone reduced the plant height and thickened the stem. Plants supplied with a full strength solution had a ticker stem, produced more biomass, and showed higher values of Fv/Fm. Some changes in the uptake pattern of some nutrients, especially boron and sulfur, were noticed. Higher boron concentrations in leaves were in plants sprayed with a combination of 7 mM CA and 1 mM of SA. Applying combination of CA and SA was more effective than using them individually that suggests an effective synergism between them. PMID:25400645

Ghazijahani, Noushin; Hadavi, Ebrahim; Jeong, Byoung R.

2014-01-01

399

Bone repletion in calcium deficient rats fed a high calcium diet  

Microsoft Academic Search

The changes in the tibial diaphysis as a result of feeding a high calcium diet to rats previously fed a calcium free diet were determined. The calcium free diet resulted in an increase in the medullary area, and the subsequent feeding of a high calcium diet caused a reduction in medullary area. However, the amount of endosteal bone lost during

M. Stauffer; D. Baylink; J. Wergedal; C. Rich

1972-01-01

400

Br J Nutr . Author manuscript Calcium carbonate suppresses haem toxicity markers without calcium  

E-print Network

Br J Nutr . Author manuscript Page /1 9 Calcium carbonate suppresses haem toxicity markers without-term studies in rats identified calcium carbonate as the most effective calcium salt to bind haem in vitro demonstrated that a diet containing 100 mol/g calcium carbonate did not promote aberrant crypt foci

Paris-Sud XI, Université de

401

Dietary Calcium Intake and The Prevalence of Calcium Supplement Use Among Well-Educated Women  

Microsoft Academic Search

LEARNING OUTCOME: To propagate among women the consumption of adequate dietary calcium to prevent osteoporosis.More women are seeking advice about calcium supplementation as awareness of osteoporosis increases. The purposes of this study were to determine the calcium content of women's diets to see if the recommended dietary allowance (RDA) was being met and to find out the prevalence of calcium

K. G. Galvacs

1997-01-01

402

Production of precipitated calcium carbonate from calcium silicates and carbon dioxide  

Microsoft Academic Search

The possibilities for reducing carbon dioxide emissions from the pulp and paper industry by calcium carbonation are presented. The current precipitated calcium carbonate (PCC) production uses mined, crushed calcium carbonate as raw materials. If calcium silicates were used instead, carbon dioxide emissions from the calcination of carbonates would be eliminated. In Finland, there could, thus, be a potential for eliminating

Sebastian Teir; Sanni Eloneva; Ron Zevenhoven

2005-01-01

403

Effects of supplemental dietary calcium on the intestinal association of calcium, phosphate, and bile acids.  

PubMed

It has been suggested that supplemental dietary calcium decreases hyperproliferation of colonic epithelial cells because calcium precipitates and thus inactivates luminal bile acids. Therefore, 12 healthy men were studied before and after dietary calcium supplementation (35.5 mmol/day) to quantify intestinal associations of calcium, phosphate, and bile acids. The supplemental dietary calcium was almost completely (95%) recovered, mainly in feces. Calcium increased the fecal excretion of both phosphate (31%) and bile acids (53%) and decreased the ratio of dihydroxy to trihydroxy bile acids in duodenal bile almost twofold. In vitro studies showed that precipitation of glycodeoxycholic acid was caused by the formation of insoluble calcium phosphate. Water-soluble and calcium-associated amounts of phosphate and bile acids in feces were measured by resolubilization studies, using the calcium chelator ethylenediaminetetraacetate. In both the control and calcium periods, significant amounts of phosphate (80% and 90%) and bile acids (33% and 50%) were calcium-associated. Moreover, the calcium-induced increments in fecal phosphate and bile acids were completely calcium-associated. Calcium decreased the amount of water-soluble phosphate but not of bile acids. These results indicate that supplemental calcium stimulates formation of insoluble calcium phosphate in the intestinal lumen and thus increases binding of luminal bile acids. PMID:2121581

Van der Meer, R; Welberg, J W; Kuipers, F; Kleibeuker, J H; Mulder, N H; Termont, D S; Vonk, R J; De Vries, H T; De Vries, E G

1990-12-01

404

Ethanol modulates BKCa channels by acting as an adjuvant of calcium.  

PubMed

Ethanol modulation of calcium- and voltage-gated potassium (slo1) channels alters neuronal excitability, cerebrovascular tone, brain function, and behavior, yet the mechanism of this modulation remains unknown. Using patch-clamp electrophysiology on recombinant BK(Ca) channels cloned from mouse brain and expressed in Xenopus laevis oocytes, we demonstrate that ethanol, even at concentrations maximally effective to modulate BK(Ca) channel function (100 mM), fails to gate the channel in absence of activating calcium. Moreover, ethanol does not modify intrinsic, voltage- or physiological magnesium-driven gating. The alcohol works as an adjuvant of calcium by selectively facilitating calcium-driven gating. This facilitation, however, renders differential ethanol effects on channel activity: potentiation at low (<10 microM) and inhibition at high (>10 microM) calcium, this dual pattern remaining largely unmodified by coexpression of brain slo1 channels with the neuronally abundant BK(Ca) channel beta(4) subunit. Calcium recognition by either of the slo1 high-affinity sensors (calcium bowl and RCK1 Asp362/Asp367) is required for ethanol to amplify channel activation by calcium. The Asp362/Asp367 site, however, is necessary and sufficient to sustain ethanol inhibition. This inhibition also results from ethanol facilitation of calcium action; in this case, ethanol favors channel dwelling in a calcium-driven, low-activity mode. The agonist-adjuvant mechanism that we advance from the calcium-ethanol interaction on slo1 might be applicable to data of ethanol action on a wide variety of ligand-gated channels. PMID:18552122

Liu, Jianxi; Vaithianathan, Thirumalini; Manivannan, Kandiah; Parrill, Abby; Dopico, Alejandro M

2008-09-01

405

Tumoral calcium pyrophosphate deposition disease  

Microsoft Academic Search

A report of two patients in which a soft tissue mass, initially regarded as a malignant tumor, was shown to be the result of calcium pyrophosphate deposition disease. The first case, a woman aged 71 years, presented with a mass involving the right fifth finger. In the second case, also a women aged 71 years, the lesion involved the tissues

Hubert A. Sissons; German C. Steiner; Fiona Bonar; Michael May; Zehava S. Rosenberg; Hershel Samuels

1989-01-01

406

Recycling of calcium sulphate dihydrate.  

PubMed

This research was carried out to prepare dental stone from the previously fabricated stone casts. The study included reheating of the used casts at different conditions in an autoclave. Results indicated that calcium sulphate hemihydrate can be reproduced using the previously fabricated stone casts. PMID:9497665

Ibrahim, R M; Seniour, S H; Sheehab, G I

1995-07-01

407

21 CFR 184.1195 - Calcium citrate.  

Code of Federal Regulations, 2010 CFR

...Ca3 (C6 H5 O7 )2 ·4H2 O, CAS Reg. No. 813-0994-095) is the calcium salt of citric acid. It is prepared by neutralizing citric acid with calcium hydroxide or calcium carbonate. It occurs as a fine white, odorless powder...

2010-04-01

408

Calcium and colon cancer: A review  

Microsoft Academic Search

The role of dietary calcium as a protective factor in the etiology of colon cancer is reviewed by examining data from ecological and analytical epidemiological studies. Biological evidence that explains the mechanisms whereby calcium intake could alter risk of developing colon cancer is also presented. The data reviewed here in general support the hypothesis that dietary calcium is linked to

Ann W. Sorenson; Martha L. Slattery; Marilyn H. Ford

1988-01-01

409

Impaired calcium homeostasis in aged hippocampal neurons  

Microsoft Academic Search

Development of neurodegenerative diseases such as Alzheimer's and Parkinson's disease is strongly age-associated. The impairment of calcium homeostasis is considered to be a key pathological event leading to neuronal dysfunction and cell death. However, the exact impact of aging on calcium homeostasis in neurons remains largely unknown. In the present work we have investigated intracellular calcium levels in cultured primary

Parvana Hajieva; Christoph Kuhlmann; Heiko J. Luhmann; Christian Behl

2009-01-01

410

Cardiac resynchronization sensitizes the sarcomere to calcium by reactivating GSK-3?  

PubMed Central

Cardiac resynchronization therapy (CRT), the application of biventricular stimulation to correct discoordinate contraction, is the only heart failure treatment that enhances acute and chronic systolic function, increases cardiac work, and reduces mortality. Resting myocyte function also increases after CRT despite only modest improvement in calcium transients, suggesting that CRT may enhance myofilament calcium responsiveness. To test this hypothesis, we examined adult dogs subjected to tachypacing-induced heart failure for 6 weeks, concurrent with ventricular dyssynchrony (HFdys) or CRT. Myofilament force-calcium relationships were measured in skinned trabeculae and/or myocytes. Compared with control, maximal calcium-activated force and calcium sensitivity declined globally in HFdys; however, CRT restored both. Phosphatase PP1 induced calcium desensitization in control and CRT-treated cells, while HFdys cells were unaffected, implying that CRT enhances myofilament phosphorylation. Proteomics revealed phosphorylation sites on Z-disk and M-band proteins, which were predicted to be targets of glycogen synthase kinase-3? (GSK-3?). We found that GSK-3? was deactivated in HFdys and reactivated by CRT. Mass spectrometry of myofilament proteins from HFdys animals incubated with GSK-3? confirmed GSK-3?–dependent phosphorylation at many of the same sites observed with CRT. GSK-3? restored calcium sensitivity in HFdys, but did not affect control or CRT cells. These data indicate that CRT improves calcium responsiveness of myofilaments following HFdys through GSK-3? reactivation, identifying a therapeutic approach to enhancing contractile function. PMID:24292707

Kirk, Jonathan A.; Holewinski, Ronald J.; Kooij, Viola; Agnetti, Giulio; Tunin, Richard S.; Witayavanitkul, Namthip; de Tombe, Pieter P.; Gao, Wei Dong; Van Eyk, Jennifer; Kass, David A.

2013-01-01

411

Effect of foliar applications of phosphite on post-harvest potato tubers  

Microsoft Academic Search

The utilization of phosphites (Phi) could be considered as another strategy to be included in integrated disease management\\u000a programmes to reduce the intensive use of fungicides and production costs. The aim of the present work was to analyze whether\\u000a the beneficial effects of phosphite treatment previously observed in potato plants grown under greenhouse conditions, were\\u000a reflected after harvest of field

María C. Lobato; Milagros F. Machinandiarena; Cecilia Tambascio; Guillermo A. A. Dosio; Daniel O. Caldiz; Gustavo R. Daleo; Adriana B. Andreu; Florencia P. Olivieri

2011-01-01

412

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

413

Effect of elevated atmospheric carbon dioxide on the use of foliar application of Bacillus thuringiensis  

Microsoft Academic Search

Toxins from Bacillus thuringiensis have been used as pest management tools for more than 50 years. The effect of these toxins depends on the quantity of Bacillus thuringiensis (Bt) toxins ingested by susceptible insects. Food ingestion is affected by CO 2 concentration; plants grown in elevated CO2 often have increased carbon\\/nitrogen ratios (C\\/N), resulting in greater leaf area consumption. Therefore,

C. E. COVIELLA; J. T. TRUMBLE

2000-01-01

414

Effect of elevated atmospheric carbon dioxide on the use of foliar application of Bacillus thuringiensis  

Microsoft Academic Search

Toxins from Bacillus thuringiensis have beenused as pest management tools for more than 50 years. The effect of these toxins depends on the quantityof Bacillus thuringiensis (Bt) toxins ingestedby susceptible insects. Food ingestion is affected byCO2 concentration; plants grown in elevatedCO2 often have increased carbon\\/nitrogen ratios(C\\/N), resulting in greater leaf area consumption. Therefore, we hypothesized that elevated CO2would improve the

C. E. Coviella; J. T. Trumble

2000-01-01

415

Mammary-Specific Ablation of the Calcium-Sensing Receptor During Lactation Alters Maternal Calcium Metabolism, Milk Calcium Transport, and Neonatal Calcium Accrual  

PubMed Central

To meet the demands for milk calcium, the lactating mother adjusts systemic calcium and bone metabolism by increasing dietary calcium intake, increasing bone resorption, and reducing renal calcium excretion. As part of this adaptation, the lactating mammary gland secretes PTHrP into the maternal circulation to increase bone turnover and mobilize skeletal calcium stores. Previous data have suggested that, during lactation, the breast relies on the calcium-sensing receptor (CaSR) to coordinate PTHrP secretion and milk calcium transport with calcium availability. To test this idea genetically, we bred BLG-Cre mice with CaSR-floxed mice to ablate the CaSR specifically from mammary epithelial cells only at the onset of lactation (CaSR-cKO mice). Loss of the CaSR in the lactating mammary gland did not disrupt alveolar differentiation or milk production. However, it did increase the secretion of PTHrP into milk and decreased the transport of calcium from the circulation into milk. CaSR-cKO mice did not show accelerated bone resorption, but they did have a decrease in bone formation. Loss of the mammary gland CaSR resulted in hypercalcemia, decreased PTH secretion, and increased renal calcium excretion in lactating mothers. Finally, loss of the mammary gland CaSR resulted in decreased calcium accrual by suckling neonates, likely due to the combination of increased milk PTHrP and decreased milk calcium. These results demonstrate that the mammary gland CaSR coordinates maternal bone and calcium metabolism, calcium transport into milk, and neonatal calcium accrual during lactation. PMID:23782944

Mamillapalli, Ramanaiah; VanHouten, Joshua; Dann, Pamela; Bikle, Daniel; Chang, Wenhan; Brown, Edward

2013-01-01

416

Foliar concentrations of volunteer willows growing on polluted sediment-derived sites versus sites with baseline contamination levels.  

PubMed

Many alluvial soils along navigable waterways are affected by disposal of dredged sediments or overbank sedimentation and contain metal concentrations that are elevated compared to baseline levels. Uptake patterns for metals and other elements by several volunteer Salix species growing on these sites were determined during a growing season in field plots and compared with the same species growing on soils with baseline contamination levels. For Cd and Zn, foliar concentrations were clearly higher on dredged sediment landfills. Uptake patterns differed significantly between species. A high uptake of Mn and low uptake of Cu, K and S in S. cinerea was attributed to wetland soil chemistry. Site effects on metal uptake were evaluated in more detail for Salix cinerea and S. alba growing on different sediment-derived sites under field conditions. Foliar Cd concentrations were higher in S. cinerea than in S. alba. This appeared to be a genetic feature not influenced by soil chemical properties, as it was observed both on clean sites and polluted sediment-derived sites. For S. cinerea, soil chemistry was reflected in foliar concentrations, while foliar Cd concentrations and bioavailability were found to be independent of the thickness of the polluted horizon. Dredged sediment landfills and freshwater tidal marshes with comparable Cd soil pollution had significantly different foliar Cd concentrations. PMID:15054540

Vandecasteele, Bart; Quataert, Paul; De Vos, Bruno; Tack, Filip M G; Muys, Bart

2004-04-01

417

Decreased Content of Integral Membrane Calcium-Binding Protein (IMCAL) in Tissues of the Spontaneously Hypertensive Rat  

Microsoft Academic Search

Prior studies report that plasma membranes of the spontaneously hypertensive rat (Okamoto-Aoki strain) bind less calcium than do the corresponding preparations from Wistar Kyoto controls. The possibility that the differences result from a decrease in the content of integral membrane calcium-binding protein (IMCAL) was explored by the application of immunoassays with polyclonal antisera and a mouse monoclonal antibody. IMCAL binds

Szloma Kowarski; Lisa A. Cowen; David Schachter

1986-01-01

418

Imaging single-channel calcium microdomains  

PubMed Central

The Ca2+ microdomains generated around the mouth of open ion channels represent the basic building blocks from which cytosolic Ca2+ signals are constructed. Recent improvements in optical imaging techniques now allow these microdomains to be visualized as single channel calcium fluorescence transients (SCCaFTs), providing information about channel properties that was previously accessible only by electrophysiological patch-clamp recordings. We review recent advances in single channel Ca2+ imaging methodologies, with emphasis on total internal reflection fluorescence microscopy (TIRFM) as the technique of choice for recording SCCaFTs from voltage- and ligand-gated plasmalemmal ion channels. This technique of ‘optical patch-clamp recording’ is massively parallel, permitting simultaneous imaging of hundreds of channels; provides millisecond resolution of gating kinetics together with sub-micron spatial resolution of channel locations; and is applicable to diverse families of membrane channels that display partial permeability to Ca2+ ions. PMID:17067668

Demuro, Angelo; Parker, Ian

2006-01-01

419

Calcium Oxide Matrices and Carbon Dioxide Sensors  

PubMed Central

Homogeneous matrices of calcium oxide (CaO) were prepared by mixing this material with polyethylene glycol (PEG) acting as malleable inert support in order to obtain processable composites. Preliminary tests were carried out to assess the best concentration of CaO in the composite, individuated in the CaO/PEG weight ratio of 1/4. Experimental data highlighted that the composite was able to selectively detect carbon dioxide (CO2) via a nanogravimetric method by performing the experiments inside an atmosphere-controlled chamber filled with CO2. Furthermore, the composite material showed a linear absorption of CO2 as a function of the gas concentration inside the atmosphere-controlled chamber, thus paving the way for the possible use of these matrices for applications in the field of sensor devices for long-term evaluation of accumulated environmental CO2. PMID:22778620

Terencio, Tercio Bezerra Correia; Bavastrello, Valter; Nicolini, Claudio

2012-01-01

420

Regulation of Calcium signaling through spatial Organization  

NASA Astrophysics Data System (ADS)

Calcium waves and signals in oocytes are produced and sustained by the release of Ca^2+ from the Endoplasmic Reticulum (ER) through clustered release channels. Changes in the spatial organization of calcium signaling effectors regulate the spatiotemporal features of the calcium signal as is e.g. observed during oocyte maturation. We report here how specific changes in the clustering of the calcium release channels in conjunction with physiologic alterations of other signaling effectors can affect a) the sensitivity of the signaling machinery to external factors, b) the time course of global intracellular signals and c), the speed and propagation range of intracellular calcium waves.

Ullah, Aman; Ullah, Ghanim; Machaca, Khalid; Jung, Peter

2010-03-01

421

Enabling Continental-Scale Analysis of Vegetation Foliar Traits through Consistent Sampling and Analysis Protocols  

NASA Astrophysics Data System (ADS)

The National Ecological Observatory Network (NEON) is a continental-scale ecological observation platform designed to collect and disseminate data that contributes to understanding and forecasting the impacts of climate change, land use change, and invasive species on ecology. NEON will collect in-situ and airborne data over 60 sites across the US, including Alaska, Hawaii, and Puerto Rico. The NEON vegetation sampling protocol currently directs the collection of foliar samples from dominant species at each site; field spectra are collected from the samples that are further analyzed for bulk and isotopic carbon and nitrogen content. Through employment of consistent sampling and analysis strategies, NEON will provide a unique, rich, and varied data collection to support studies of foliar traits within species at specific sites and across/between regions. When combined with the NEON airborne hyperspectral and LiDAR imagery, these data will be key to support validation efforts of existing algorithms for deriving canopy scale nitrogen, carbon and other foliar traits, as well as supporting development of data products that are informed by - and include - the ground data specifically, thereby potentially reducing uncertainties in the observational data products. Presented here are prototype datasets collected at NEON Domain 1 (Harvard Forest, summer 2012) and Domain 17 (San Joaquin Experiment Range, summer 2013). Lessons-learned from the field campaigns are discussed, along with preliminary results from the Harvard Forest campaign, which combine the field and the laboratory data in support of current algorithm validation efforts. Extension of these protocols to future NEON Domain characterization activities is also presented.

Petroy, S. B.; Leisso, N.; Hinckley, E. S.; Meier, C. L.; Barnett, D.

2013-12-01

422

Plant Foliar Response to Soil Nutrient Availability Across Contrasting Geologic Settings  

NASA Astrophysics Data System (ADS)

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 nutrient availability across sites of different underlying geologies. Specifically, we focus on the plant nutrient-use strategies of rock derived nutrients (P and K) and how they relate to soil nutrient status. In order to assess the responses of plant species to nutrient availability, we monitored above ground net primary productivity (current annual increment + litterfall), plant chemistry, and soil nutrients for a period of 24 months. This research was completed in the San Juan Mountain region of southern Colorado, where there is a high local diversity of bedrock geochemistry. Within this region, two small sub-alpine basins were chosen; a sedimentary basin composed of Mesozoic cyclic limestone, sandstone & shale and a volcanic basin composed of Tertiary rhyolite. Across these basins, geology played a significant role in explaining the variability of rock derived nutrient availability. Initial results suggest that differences in bedrock geochemistry have little influence on the aboveground net primary production (ANPP) of plants or on the chemistry of foliar materials. This inflexibility of foliar chemistry to variations in nutrient availability suggests that genetic and physiologic controls play a strong role in determining the chemical content of plant materials. An alternative hypothesis is that deposition of eolian mineral dust into subalpine systems could play a role in offsetting the reliance of vegetation on deeper bedrock derived nutrient sources. An investigation is currently underway to assess the contribution of eolian dust derived nutrients to plant nutrition using Sr as a geochemical tracer.

Castle, S. C.; Neff, J. C.

2007-12-01

423

Native Environment Modulates Leaf Size and Response to Simulated Foliar Shade across Wild Tomato Species  

PubMed Central

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

Filiault, Daniele L.; Kumar, Ravi; Jimenez-Gomez, Jose M.; Schrager, Amanda V.; Park, Daniel S.; Peng, Jie; Sinha, Neelima R.; Maloof, Julin N.

2012-01-01

424

Calcium signals and calcium channels in osteoblastic cells  

NASA Technical Reports Server (NTRS)

Calcium (Ca2+) channels are present in non-excitable as well as in excitable cells. In bone cells of the osteoblast lineage, Ca2+ channels play fundamental roles in cellular responses to external stimuli including both mechanical forces and hormonal signals. They are also proposed to modulate paracrine signaling between bone-forming osteoblasts and bone-resorbing osteoclasts at local sites of bone remodeling. Calcium signals are characterized by transient increases in intracellular Ca2+ levels that are associated with activation of intracellular signaling pathways that control cell behavior and phenotype, including patterns of gene expression. Development of Ca2+ signals is a tightly regulated cellular process that involves the concerted actions of plasma membrane and intracellular Ca2+ channels, along with Ca2+ pumps and exchangers. This review summarizes the current state of knowledge concerning the structure, function, and role of Ca2+ channels and Ca2+ signals in bone cells, focusing on the osteoblast.

Duncan, R. L.; Akanbi, K. A.; Farach-Carson, M. C.

1998-01-01

425

Seasonal trends in reduced leaf gas exchange and ozone-induced foliar injury in three ozone sensitive woody plant species.  

PubMed

Seasonal trends in leaf gas exchange and ozone-induced visible foliar injury were investigated for three ozone sensitive woody plant species. Seedlings of Populus nigra L., Viburnum lantana L., and Fraxinus excelsior L. were grown in charcoal-filtered chambers, non-filtered chambers and open plots. Injury assessments and leaf gas exchange measurements were conducted from June to October during 2002. All species developed typical ozone-induced foliar injury. For plants exposed to non-filtered air as compared to the charcoal-filtered air, mean net photosynthesis was reduced by 25%, 21%, and 18% and mean stomatal conductance was reduced by 25%, 16%, and 8% for P. nigra, V. lantana, and F. excelsior, respectively. The timing and severity of the reductions in leaf gas exchange were species specific and corresponded to the onset of visible foliar injury. PMID:15809106

Novak, K; Schaub, M; Fuhrer, J; Skelly, J M; Hug, C; Landolt, W; Bleuler, P; Kräuchi, N

2005-07-01

426

Calcium signalling in granule neurones studied in cerebellar slices  

Microsoft Academic Search

The cytoplasmic free calcium concentration ([Ca2+i) was studied in Fura-2\\/AM loaded granule neurones in acutely prepared cerebellar slices isolated from neonatal (6 days old) and adult (30 days old) mice. Bath application of elevated (10–50 mM) KCl-containing extracellular solutions evoked [Ca2+]i rise which was dependent on extracellular Ca2+. The K+-induced [Ca2+]i elevation was inhibited to different extends by verapamil, nickel

Sergej Kirischuk; Nana Voitenko; Platon Kostyuk; Alexej Verkhratsky

1996-01-01

427

Fourier transform raman spectroscopy of synthetic and biological calcium phosphates  

Microsoft Academic Search

Fourier-transform (FT) Raman spectroscopy was used to characterize the organic and mineral components of biological and synthetic calcium phosphate minerals. Raman spectroscopy provides information on biological minerals that is complimentary to more widely used infrared methodologies as some infrared-inactive vibrational modes are Raman-active. The application of FT-Raman technology has, for the first time, enabled the problems of high sample fluorescence

G. R. Sauer; W. B. Zunic; J. R. Durig; R. E. Wuthier

1994-01-01

428

Stem Cell-Calcium Phosphate Constructs for Bone Engineering  

Microsoft Academic Search

While human bone-marrow-derived mesenchymal stem cells (hBMSCs) have been investigated, human umbilical cord mesenchymal stem cells (hUCMSCs) are a relatively new cell source. Little has been reported on hUCMSC encapsulation in scaffolds for bone tissue engineering. The objective of this study was to encapsulate hBMSCs and hUCMSCs in calcium phosphate cement (CPC) scaffolds for dental, craniofacial, and orthopedic applications. Stem-cell-encapsulating

H. H. K. Xu; L. Zhao; M. D. Weir

2010-01-01

429

A calcium oxygen secondary battery  

NASA Astrophysics Data System (ADS)

This paper describes a high-temperature electrochemically-reversible calcium-oxygen cell in which the negative electroactive material consists of a calcium-silicon alloy contained within an expanded stainless steel electrode assembly immersed into a binary molten salt CaO-CaCl2 (mp 593 C). The empirical electrochemistry occurring upon electrochemical cycling is: 2CaSi + 1/2 O2(air) going to CaO + CaSi2, with oxygen being reversibly mediated to the binary molten salt via the oxygen vacancy conducting solid electrolyte; charge-discharge curves at 850 C clearly demonstrated voltage plateaus associated with the reversible formation of CaSi and CaSi2. If unit activity Ca were used as the negative electroactive material, the cell thermodynamic open-circuit voltage at 850 C is expected to be about 2.28 V. The theoretical energy density for this system calculates to 985 W h/lb.

Pujare, Nirupama U.; Semkow, Krystyna W.; Sammells, Anthony F.

1988-01-01

430

Photophysiology of turion germination in Spirodela polyrhiza (L.) Schleiden VIII. Calcium dependence and ?-amylase activity  

Microsoft Academic Search

Red-light-induced germination (via phytochrome) of turions of Spirodela polyrhiza (L.) Schleiden, strain SJ, showed an absolute requirement for exogenously applied calcium (Appenroth et al. 1990b, Biochem. Physiol. Pflanzen 186, 209–219). With calcium step-up experiments (from 0.9 µM to 1 mM Ca2+) the influence of Ca2+ on the escape from far-red-light reversibility was investigated. Delaying the time of Ca2+ application after

K. J. Appenroth; J. Komusiewicz; W. Hertel; H. Augsten

1991-01-01

431

Polypropylene\\/calcium carbonate nanocomposites  

Microsoft Academic Search

Polypropylene (PP) and calcium carbonate nanocomposites were prepared by melt mixing in a Haake mixer. The average primary particle size of the CaCO3 nanoparticles was measured to be about 44nm. The dispersion of the CaCO3 nanoparticles in PP was good for filler content below 9.2vol%. Differential scanning calorimetry (DSC) results indicated that the CaCO3 nanoparticles are a very effective nucleating

Chi-Ming Chan; Jingshen Wu; Jian-Xiong Li; Ying-Kit Cheung

2002-01-01

432

Calcium oxalate crystals in plants  

Microsoft Academic Search

Calcium (Ca) oxalate crystals occur in many plant species and in most organs and tissues. They generally form within cells\\u000a although extracellular crystals have been reported. The crystal cells or idioblasts display ultrastructural modifications\\u000a which are related to crystal precipitation. Crystal formation is usually associated with membranes, chambers, or inclusions\\u000a found within the cell vacuole(s). Tubules, modified plastids and enlarged

Vincent R. Franceschi; Harry T. Horner

1980-01-01

433

Integrated Calcium Signaling in Plants  

Microsoft Academic Search

\\u000a Calcium ion (Ca2+) is the most important universal signal carrier used by living organisms, including plants, to convey information to many\\u000a different cellular processes. The cytosolic free Ca2+ concentration ([Ca2+]cyt) has been found to increase in response to many physiological stimuli, including stress. The Ca2+ spikes normally result from two opposing reactions, Ca2+ influx through channels or Ca2+ efflux through

Narendra Tuteja

434

Rhizobium Needs Magnesium, not Calcium  

Microsoft Academic Search

IN tropical countries there occur abundant examples of legumes that are normally nodulated despite the fact that they grow on acid soils, low in calcium. Observations of some particularly striking examples of this behaviour in the poor `Wallum' soils of south-east Queensland led to a re-examination of the symbiotic system in the legumes1. It was postulated that the tropical legume

D. Norris

1958-01-01

435

Asante Calcium Green and Asante Calcium Red—Novel Calcium Indicators for Two-Photon Fluorescence Lifetime Imaging  

PubMed Central

For a comprehensive understanding of cellular processes and potential dysfunctions therein, an analysis of the ubiquitous intracellular second messenger calcium is of particular interest. This study examined the suitability of the novel Ca2+-sensitive fluorescent dyes Asante Calcium Red (ACR) and Asante Calcium Green (ACG) for two-photon (2P)-excited time-resolved fluorescence measurements. Both dyes displayed sufficient 2P fluorescence excitation in a range of 720–900 nm. In vitro, ACR and ACG exhibited a biexponential fluorescence decay behavior and the two decay time components in the ns-range could be attributed to the Ca2+-free and Ca2+-bound dye species. The amplitude-weighted average fluorescence decay time changed in a Ca2+-dependent way, unraveling in vitro dissociation constants KD of 114 nM and 15 nM for ACR and ACG, respectively. In the presence of bovine serum albumin, the absorption and steady-state fluorescence behavior of ACR was altered and its biexponential fluorescence decay showed about 5-times longer decay time components indicating dye-protein interactions. Since no ester derivative of ACG was commercially available, only ACR was evaluated for 2P-excited fluorescence lifetime imaging microscopy (2P-FLIM) in living cells of American cockroach salivary glands. In living cells, ACR also exhibited a biexponential fluorescence decay with clearly resolvable short (0.56 ns) and long (2.44 ns) decay time components attributable to the Ca2+-free and Ca2+-bound ACR species. From the amplitude-weighted average fluorescence decay times, an in situ KD of 180 nM was determined. Thus, quantitative [Ca2+]i recordings were realized, unraveling a reversible dopamine-induced [Ca2+]i elevation from 21 nM to 590 nM in salivary duct cells. It was concluded that ACR is a promising new Ca2+ indicator dye for 2P-FLIM recordings applicable in diverse biological systems. PMID:25140519

Jahn, Karolina; Hille, Carsten

2014-01-01

436

Thermotolerance and antioxidant systems in Agrostis stolonifera: involvement of salicylic acid, abscisic acid, calcium, hydrogen peroxide, and ethylene.  

PubMed

This study investigated whether pre-treating plants with specific putative signaling components and heat acclimation would induce tolerance of a cool-season grass, creeping bentgrass (Agrostis stolonifera var. palustris), to subsequent heat stress and whether thermotolerance induction of those pretreatments was associated with the regulation of antioxidant regenerating enzymes. The treatments included foliar application of salicylic acid (SA), abscisic acid (ABA), calcium chloride (CaCl2), hydrogen peroxide (H2O2), 1-aminocyclopropane-1-carboxylic acid (ACC, a precursor of ethylene prior to the exposure of plants to heat stress (35 degrees C) in a growth chamber. Physiological measurements including turf quality, leaf photosynthetic rate, and levels of oxidative damage demonstrated that all treatments increased heat tolerance. The better heat tolerance for pre-treated plants as compared to controls was related to the protection of oxidative damage under heat stress. APX activity increased over the first 2 days and 5 days of heating for ACC and CaCl2 respectively, but for only 12 h for H2O2. SA and ABA pre-treatments had no effects on APX activity earlier, but maintained APX activity at a significantly higher level than in controls after 24 h of heating. SA and ABA pre-treatments had no effects on POX activity. ACC treatment significantly increased POX activity. Pre-treatment with CaCl2, H2O2, and HA reduced POX activity, particularly during the later phase of heating. Plants treated with SA, CaCl2, H2O2 and HA had lower CAT activity than their control plants prior to heating and within 48 h of heat stress. ABA and ACC pre-treatments maintained higher CAT activity than the controls after 48 h of heating. ACC, CaCl2, or HA pre-treatments increased SOD activity only before 5 days of heat stress. SA and ABA pre-treatments had less effect on APX activity earlier under heat stress. These results suggest that specific groups of potential signaling molecules may induce tolerance of creeping bentgrass to heat stress by reducing oxidative damage. PMID:15128028

Larkindale, Jane; Huang, Bingru

2004-04-01

437

EFFECT OF FOLIAR PREPARATIONS AND VARIETY ON SUGAR BEET YIELD AND QUALITY VPLYV LISTOVÝCH PREPARÁTOV A ODRODY NA ÚRODU A KVALITU CUKROVEJ REPY  

Microsoft Academic Search

Field experiments were conducted at the medium heavy luvisol under the unirrigated conditions at the locality with continental climate in the years 2002 and 2003. Foliar preparationsAvit 35´ andHumix univerzál pluswere sprayed at the sugar beet leaves during the vegetation. These liquid foliar preparations contain growth stimulators (humates, ethanolamine, ureasalicylate) enriched by macroelements and microelements. Two sugar beet varieties (STRUBE-

JANA FECKOVÁ

438

Mon. Not. R. Astron. Soc. 000, 122 (2011) Printed 29 July 2011 (MN LATEX style file v2.2) A grid of NLTE corrections for magnesium and calcium in  

E-print Network

of NLTE corrections for magnesium and calcium in late-type giant and supergiant stars: application to Gaia ?. Received ?; in original form ? ABSTRACT We investigate NLTE effects for magnesium and calcium the Galaxy. Calcium (Ca) and magnesium (Mg) are key elements for the understanding of these events since

Paris-Sud XI, Université de

439

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

440

Endohyphal bacterium enhances production of indole-3-acetic acid by a foliar fungal endophyte.  

PubMed

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. PMID:24086270

Hoffman, Michele T; Gunatilaka, Malkanthi K; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A Elizabeth

2013-01-01

441

Eutrophication of mangroves linked to depletion of foliar and soil base cations.  

PubMed

There is growing concern that increasing eutrophication causes degradation of coastal ecosystems. Studies in terrestrial ecosystems have shown that increasing the concentration of nitrogen in soils contributes to the acidification process, which leads to leaching of base cations. To test the effects of eutrophication on the availability of base cations in mangroves, we compared paired leaf and soil nutrient levels sampled in Nypa fruticans and Rhizophora spp. on a severely disturbed, i.e. nutrient loaded, site (Mahakam delta) with samples from an undisturbed, near-pristine site (Berau delta) in East Kalimantan, Indonesia. The findings indicate that under pristine conditions, the availability of base cations in mangrove soils is determined largely by salinity. Anthropogenic disturbances on the Mahakam site have resulted in eutrophication, which is related to lower levels of foliar and soil base cations. Path analysis suggests that increasing soil nitrogen reduces soil pH, which in turn reduces the levels of foliar and soil base cations in mangroves. PMID:25208516

Fauzi, Anas; Skidmore, Andrew K; Heitkönig, Ignas M A; van Gils, Hein; Schlerf, Martin

2014-12-01

442

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. PMID:24086270

Hoffman, Michele T.; Gunatilaka, Malkanthi K.; Wijeratne, Kithsiri; Gunatilaka, Leslie; Arnold, A. Elizabeth

2013-01-01

443

Effect of foliar disease on the epiphytic yeast communities of creeping bentgrass and tall fescue.  

PubMed

The effect of mechanical wounding or foliar diseases caused by Sclerotinia homoeocarpa or Rhizoctonia solani on the epiphytic yeast communities on creeping bentgrass and tall fescue were determined by leaf washing and dilution plating. Total yeast communities on healthy bentgrass and tall fescue leaves ranged from 7.9 x 103 to 1.4 x 105 CFU.cm-2 and from 2.4 x 103 to 1.6 x 104 CFU.cm-2, respectively. Mechanically wounded leaves (1 of 2 trials) and leaves with disease lesions (11 of 12 trials) supported significantly larger communities of phylloplane yeasts. Total yeast communities on S. homoeocarpa infected or R. solani infected bentgrass leaves were 3.6-10.2 times and 6.2-6.4 times larger, respectively, than the communities on healthy leaves. In general, healthy and diseased bentgrass leaves supported larger yeast communities than healthy or diseased tall fescue leaves. We categorized the majority of yeasts as white-pigmented species, including Cryptococcus laurentii, Cryptococcus flavus, Pseudozyma antarctica, Pseudozyma aphidis, and Pseudozyma parantarctica. The percentage of pink yeasts in the total yeast community ranged from 2.6% to 9.9% on healthy leaves and increased to 32.0%-44.7% on S. homoeocarpa infected leaves. Pink-pigmented yeasts included Rhodotorula glutinis, Rhodotorula mucilaginosa, Sakaguchia dacryoidea, and Sporidiobolus pararoseus. Foliar disease significantly affected community size and composition of epiphytic yeasts on bentgrass and tall fescue. PMID:15644900

Allen, Tom W; Quayyum, Habib A; Burpee, Leon L; Buck, James W

2004-10-01

444

Tissue magnesium and calcium concentration in relation to magnesium and calcium intake in rats  

E-print Network

the $166 million mark in 1986 (16). The Coca-Cola Company has even gotten into the picture by test marketing a calcium-fortified diet soda (17). The use of calcium carbonate antacids (e. g. , TumsR) has also been suggested as a means to increase calcium... the $166 million mark in 1986 (16). The Coca-Cola Company has even gotten into the picture by test marketing a calcium-fortified diet soda (17). The use of calcium carbonate antacids (e. g. , TumsR) has also been suggested as a means to increase calcium...

Pinkham, Carrie Stanton

2012-06-07

445

Assessment of calcium intake by adolescents  

PubMed Central

OBJECTIVE: To evaluate the daily calcium intake of adolescents in schools from Chapecó, Santa Catarina, Southern Brazil, to check if calcium intake is in accordance with the Dietary Reference Intakes (DRI), and to investigate variables associated with daily calcium intake. METHODS: Cross-sectional study approved by the Institutional Review Board and developed in 2010. Students of the 8th grade completed questionnaires with personal data and questions about the calcium-rich foods intake frequency. In order to compare students with adequate (1300mg) or inadequate intake of calcium/day (<1300mg), parametric and nonparametric tests were used. RESULTS: A total of 214 students with a mean age of 14.3±1.0 years were enrolled. The median daily calcium intake was 540mg (interquartile range - IQ: 312-829mg) and only 25 students (11.7%) had calcium intake within the recommendations of the DRI for age. Soft drink consumption ?3 times/week was associated with a lower intake of calcium. CONCLUSIONS: Few students ingested adequate levels of calcium for the age group. It is necessary to develop a program to encourage a greater intake of calcium-rich foods in adolescence. PMID:25119753

de Oliveira, Cristiane Franco; da Silveira, Carla Rosane; Beghetto, Mariur; de Mello, Paula Daniel; de Mello, Elza Daniel

2014-01-01

446

Rapid screening assay for calcium bioavailability studies  

SciTech Connect

Calcium bioavailability has been studied by numerous techniques. The authors report here the use of the gamma emitting isotope of calcium (/sup 47/Ca) in a whole body retention assay system. In this system, calcium sources are administered by oral gavage and subsequent counts are determined and corrected for isotopic decay. Unlike iron and zinc retention curves, which exhibit a 2-3 day equilibration period, calcium reaches equilibration after 24 hours. Autoradiographic analysis of the femurs indicate that the newly absorbed calcium is rapidly distributed to the skeletal system. Moreover, the isotope is distributed along the entire bone. Comparisons of calcium bioavailability were made using intrinsic/extrinsic labeled milk from two species i.e. rat and goat as well as CaCO/sub 3/. In addition, extrinsic labeled cow milk was examined. In the rat, the extrinsic labeled