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1

Gastroprotective effect of Piper betle Linn. leaves grown in Sri Lanka  

PubMed Central

Background: Piper betle Linn. (Piperaceae) is used as a remedy for gastric ulcers in traditional medicinal systems in Sri Lanka. However, the gastroprotective activity has never been proven scientifically using betel leaves grown in Sri Lanka. Objective: To evaluate the gastroprotective activity of hot aqueous extract (HAE) and cold ethanolic extract (CEE) of P. betle in rats as the experimental model. Materials and Methods: Three doses (200, 300, and 500 mg/kg/bw) of both extracts were evaluated for the gastroprotective activity against ethanol induced gastric ulcers in rats. The parameters evaluated were (a) effects of HAE on mucus content adhering to the wall of the gastric mucosa, (b) acidity (total and free), (c) volume and (d) pH of the gastric juice. Results: Oral administration of HAE and CEE provided marked dose dependent (HAE: r2 = 0.97; CEE: r2 = 0.96) and significant (P ? 0.05) protection against gastric damage caused by absolute ethanol. The gastroprotective effect of CEE was comparable with that of HAE. Further, gastroprotective activity of the highest dose of both extracts were significantly greater (P ? 0.05) than that of misoprostol, the reference drug. The HAE significantly (P ? 0.05) increased the mucus content adhering to the wall of the gastric mucosa and inhibited the volume of gastric acid. However, acidity (total and free) and pH of the gastric juice remained unaltered. Conclusion: It is concluded that both HAE and CEE of P. betle leaves have a strong gastroprotective activity.

Arawwawala, L. D. A. M.; Arambewela, L. S. R.; Ratnasooriya, W. D.

2014-01-01

2

Antioxidant, analgesic and anti-inflammatory activities of the methanolic extract of Piper betle leaves  

PubMed Central

Objective: The present study was designed to evaluate the antioxidant, analgesic, and anti-inflammatory activities of the methanolic extract of Piper betle leaves (MPBL). Materials and Methods: MPBL was evaluated for anti-inflammatory activity using carrageenan-induced hind paw edema model. Analgesic activity of MPBL was evaluated by hot plate, writhing, and formalin tests. Total phenolic and flavonoids content, total antioxidant activity, scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, peroxynitrate (ONOO) as well as inhibition of total ROS generation, and assessment of reducing power were used to evaluate antioxidant potential of MPBL. Results: The extract of MPBL, at the dose of 100 and 200 mg/kg, produced a significant (p<0.05) increase in pain threshold in hot plate method whereas significantly (p<0.05) reduced the writhing caused by acetic acid and the number of licks induced by formalin in a dose-dependent manner. The same ranges of doses of MPBL caused significant (p<0.05) inhibition of carrageenan-induced paw edema after 4 h in a dose-dependent manner. In DPPH, ONOO-, and total ROS scavenging method, MPBL showed good antioxidant potentiality with the IC50 value of 16.33±1.02, 25.16±0.61 , and 41.72±0.48 µg/ml, respectively with a significant (p<0.05) good reducing power. Conclusion: The findings of the study suggested that MPBL has strong analgesic, anti-inflammatory, and antioxidant effects, conforming the traditional use of this plant for inflammatory pain alleviation to its antioxidant potentiality.

Alam, Badrul; Akter, Fahima; Parvin, Nahida; Sharmin Pia, Rashna; Akter, Sharmin; Chowdhury, Jesmin; Sifath-E-Jahan, Kazi; Haque, Ekramul

2013-01-01

3

Investigations on Piper betle grown in Sri Lanka  

PubMed Central

Piper betle is an economically important plant cultivated in Sri Lanka. Although more than 12 cultivars of betel are reported in Sri Lanka, very few scientific investigations have been carried out on them. Studies on the chemical constituents indicated that safrole is the major constituent, followed by chavibitol acetate, in the essential oil of common betel leaves of Sri Lanka. Investigations on the bioactivities of P. betle revealed the presence of antimicrobial, insecticidal, antioxidant, antinociceptive, antidiabetic and gastroprotective activities. In addition, P. betle was found to be safe in terms of hepatotoxicity, renotoxicity, hematotoxicity, gross morphology, weights of organs, stress or aversive behaviors in rats. The above findings indicate the vast potential of P. betle yet to be harnessed for the benefit of mankind and the betel industry of Sri Lanka.

Arambewela, L. S. R.; Arawwawala, L. D. A. M.; Kumaratunga, K. G; Dissanayake, D. S; Ratnasooriya, W. D.; Kumarasingha, S. P.

2011-01-01

4

Piper nigrum, Piper betle and Gnetum gnemon- Natural Food Sources with Anti-Quorum Sensing Properties  

PubMed Central

Various parts of Piper nigrum, Piper betle and Gnetum gnemon are used as food sources by Malaysians. The purpose of this study is to examine the anti-quorum sensing (anti-QS) properties of P. nigrum, P. betle and G. gnemon extracts. The hexane, chloroform and methanol extracts of these plants were assessed in bioassays involving Pseudomonas aeruginosa PA01, Escherichia coli [pSB401], E. coli [pSB1075] and Chromobacterium violaceum CV026. It was found that the extracts of these three plants have anti-QS ability. Interestingly, the hexane, chloroform and methanol extracts from P. betle showed the most potent anti-QS activity as judged by the bioassays. Since there is a variety of plants that serve as food sources in Malaysia that have yet to be tested for anti-QS activity, future work should focus on identification of these plants and isolation of the anti-QS compounds.

Tan, Li Ying; Yin, Wai-Fong; Chan, Kok-Gan

2013-01-01

5

Psidium guajava and Piper betle leaf extracts prolong vase life of cut carnation (Dianthus caryophyllus) flowers.  

PubMed

The effect of leaf extracts of Psidium guajava and Piper betle on prolonging vase life of cut carnation flowers was studied. "Carola" and "Pallas Orange" carnation flowers, at bud stage, were pulsed 24 hours with a floral preservative. Then, flowers were placed in a vase solution containing sprite and a "germicide" (leaf extracts of P. guajava and P. betle, 8-HQC, or a copper coin). Flowers treated with 8-HQC, copper coin, and leaf extracts had longer vase life, larger flower diameter, and higher rate of water uptake compared to control (tap water). The leaf extracts of P. guajava and P. betle showed highest antibacterial and antifungal activities compared to the other treatments. Both showed similar effects on flower quality as the synthetic germicide, 8-HQC. Therefore, these extracts are likely natural germicides to prolong vase life of cut flowers. PMID:22619568

Rahman, M M; Ahmad, S H; Lgu, K S

2012-01-01

6

Psidium guajava and Piper betle Leaf Extracts Prolong Vase Life of Cut Carnation (Dianthus caryophyllus) Flowers  

PubMed Central

The effect of leaf extracts of Psidium guajava and Piper betle on prolonging vase life of cut carnation flowers was studied. “Carola” and “Pallas Orange” carnation flowers, at bud stage, were pulsed 24 hours with a floral preservative. Then, flowers were placed in a vase solution containing sprite and a “germicide” (leaf extracts of P. guajava and P. betle, 8-HQC, or a copper coin). Flowers treated with 8-HQC, copper coin, and leaf extracts had longer vase life, larger flower diameter, and higher rate of water uptake compared to control (tap water). The leaf extracts of P. guajava and P. betle showed highest antibacterial and antifungal activities compared to the other treatments. Both showed similar effects on flower quality as the synthetic germicide, 8-HQC. Therefore, these extracts are likely natural germicides to prolong vase life of cut flowers.

Rahman, M. M.; Ahmad, S. H.; Lgu, K. S.

2012-01-01

7

Piper betle shows antioxidant activities, inhibits MCF-7 cell proliferation and increases activities of catalase and superoxide dismutase  

PubMed Central

Background Breast cancer is the most common form of cancer and the focus on finding chemotherapeutic agents have recently shifted to natural products. Piper betle is a medicinal plant with various biological activities. However, not much data is available on the anti-cancer effects of P. betle on breast cancer. Due to the current interest in the potential effects of antioxidants from natural products in breast cancer treatment, we investigated the antioxidant activities of the leaves of P. betle and its inhibitory effect on the proliferation of the breast cancer cell line, MCF-7. Methods The leaves of P. betle were extracted with solvents of varying polarities (water, methanol, ethyl acetate and hexane) and their phenolic and flavonoid content were determined using colorimetric assays. Phenolic composition was characterized using HPLC. Antioxidant activities were measured using FRAP, DPPH, superoxide anion, nitric oxide and hyroxyl radical scavenging assays. Biological activities of the extracts were analysed using MTT assay and antioxidant enzyme (catalase, superoxide dismutase, glutathione peroxidase) assays in MCF-7 cells. Results Overall, the ethyl acetate extract showed the highest ferric reducing activity and radical scavenging activities against DPPH, superoxide anion and nitric oxide radicals. This extract also contained the highest phenolic content implying the potential contribution of phenolics towards the antioxidant activities. HPLC analyses revealed the presence of catechin, morin and quercetin in the leaves. The ethyl acetate extract also showed the highest inhibitory effect against the proliferation of MCF-7 cells (IC50=65 ?g/ml). Treatment of MCF-7 cells with the plant extract increased activities of catalase and superoxide dismutase. Conclusions Ethyl acetate is the optimal solvent for the extraction of compounds with antioxidant and anti-proliferative activities. The increased activities of catalase and superoxide dismutase in the treated cells could alter the antioxidant defense system, potentially contributing towards the anti-proliferative effect. There is great potential for the ethyl acetate extract of P. betle leaf as a source of natural antioxidants and to be developed as therapeutics in cancer treatment.

2012-01-01

8

In vitro antifungal activity of hydroxychavicol isolated from Piper betle L  

PubMed Central

Background Hydroxychavicol, isolated from the chloroform extraction of the aqueous leaf extract of Piper betle L., (Piperaceae) was investigated for its antifungal activity against 124 strains of selected fungi. The leaves of this plant have been long in use tropical countries for the preparation of traditional herbal remedies. Methods The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of hydroxychavicol were determined by using broth microdilution method following CLSI guidelines. Time kill curve studies, post-antifungal effects and mutation prevention concentrations were determined against Candida species and Aspergillus species "respectively". Hydroxychavicol was also tested for its potential to inhibit and reduce the formation of Candida albicans biofilms. The membrane permeability was measured by the uptake of propidium iodide. Results Hydroxychavicol exhibited inhibitory effect on fungal species of clinical significance, with the MICs ranging from 15.62 to 500 ?g/ml for yeasts, 125 to 500 ?g/ml for Aspergillus species, and 7.81 to 62.5 ?g/ml for dermatophytes where as the MFCs were found to be similar or two fold greater than the MICs. There was concentration-dependent killing of Candida albicans and Candida glabrata up to 8 × MIC. Hydroxychavicol also exhibited an extended post antifungal effect of 6.25 to 8.70 h at 4 × MIC for Candida species and suppressed the emergence of mutants of the fungal species tested at 2 × to 8 × MIC concentration. Furthermore, it also inhibited the growth of biofilm generated by C. albicans and reduced the preformed biofilms. There was increased uptake of propidium iodide by C. albicans cells when exposed to hydroxychavicol thus indicating that the membrane disruption could be the probable mode of action of hydroxychavicol. Conclusions The antifungal activity exhibited by this compound warrants its use as an antifungal agent particularly for treating topical infections, as well as gargle mouthwash against oral Candida infections.

2010-01-01

9

Growth inhibitory response and ultrastructural modification of oral-associated candidal reference strains (ATCC) by Piper betle L. extract.  

PubMed

Candida species have been associated with the emergence of strains resistant to selected antifungal agents. Plant products have been used traditionally as alternative medicine to ease mucosal fungal infections. This study aimed to investigate the effects of Piper betle extract on the growth profile and the ultrastructure of commonly isolated oral candidal cells. The major component of P. betle was identified using liquid chromatography-mass spectrophotometry (LC-MS/MS). Seven ATCC control strains of Candida species were cultured in yeast peptone dextrose broth under four different growth environments: (i) in the absence of P. betle extract; and in the presence of P. betle extract at respective concentrations of (ii) 1 mg?mL(-1); (iii) 3 mg?mL(-1); and (iv) 6 mg?mL(-1). The growth inhibitory responses of the candidal cells were determined based on changes in the specific growth rates (µ). Scanning electron microscopy (SEM) was used to observe any ultrastructural alterations in the candida colonies. LC-MS/MS was performed to validate the presence of bioactive compounds in the extract. Following treatment, it was observed that the µ-values of the treated cells were significantly different than those of the untreated cells (P<0.05), indicating the fungistatic properties of the P. betle extract. The candidal population was also reduced from an average of 13.44×10(6) to 1.78×10(6) viable cell counts (CFU)?mL(-1). SEM examination exhibited physical damage and considerable morphological alterations of the treated cells. The compound profile from LC-MS/MS indicated the presence of hydroxybenzoic acid, chavibetol and hydroxychavicol in P. betle extract. The effects of P. betle on candida cells could potentiate its antifungal activity. PMID:24406634

Nordin, Mohd-Al-Faisal; Wan Harun, Wan Himratul-Aznita; Abdul Razak, Fathilah; Musa, Md Yusoff

2014-03-01

10

Growth inhibitory response and ultrastructural modification of oral-associated candidal reference strains (ATCC) by Piper betle L. extract  

PubMed Central

Candida species have been associated with the emergence of strains resistant to selected antifungal agents. Plant products have been used traditionally as alternative medicine to ease mucosal fungal infections. This study aimed to investigate the effects of Piper betle extract on the growth profile and the ultrastructure of commonly isolated oral candidal cells. The major component of P. betle was identified using liquid chromatography-mass spectrophotometry (LC-MS/MS). Seven ATCC control strains of Candida species were cultured in yeast peptone dextrose broth under four different growth environments: (i) in the absence of P. betle extract; and in the presence of P. betle extract at respective concentrations of (ii) 1 mg?mL?1; (iii) 3 mg?mL?1; and (iv) 6 mg?mL?1. The growth inhibitory responses of the candidal cells were determined based on changes in the specific growth rates (µ). Scanning electron microscopy (SEM) was used to observe any ultrastructural alterations in the candida colonies. LC-MS/MS was performed to validate the presence of bioactive compounds in the extract. Following treatment, it was observed that the µ-values of the treated cells were significantly different than those of the untreated cells (P<0.05), indicating the fungistatic properties of the P. betle extract. The candidal population was also reduced from an average of 13.44×106 to 1.78×106 viable cell counts (CFU)?mL?1. SEM examination exhibited physical damage and considerable morphological alterations of the treated cells. The compound profile from LC-MS/MS indicated the presence of hydroxybenzoic acid, chavibetol and hydroxychavicol in P. betle extract. The effects of P. betle on candida cells could potentiate its antifungal activity.

Nordin, Mohd-Al-Faisal; Wan Harun, Wan Himratul-Aznita; Abdul Razak, Fathilah; Musa, Md Yusoff

2014-01-01

11

Antioxidant enzyme activity and malondialdehyde levels can be modulated by Piper betle, tocotrienol rich fraction and Chlorella vulgaris in aging C57BL/6 mice  

PubMed Central

OBJECTIVE: The aim of this study was to determine the erythrocyte antioxidant enzyme activity and the superoxide dismutase, catalase, glutathione peroxidase, and plasma malondialdehyde levels in aging mice and to evaluate how these measures are modulated by potential antioxidants, including the tocotrienol-rich fraction, Piper betle, and Chlorella vulgaris. METHOD: One hundred and twenty male C57BL/6 inbred mice were divided into three age groups: young (6 months old), middle-aged (12 months old), and old (18 months old). Each age group consisted of two control groups (distilled water and olive oil) and three treatment groups: Piper betle (50 mg/kg body weight), tocotrienol-rich fraction (30 mg/kg), and Chlorella vulgaris (50 mg/kg). The duration of treatment for all three age groups was two months. Blood was withdrawn from the orbital sinus to determine the antioxidant enzyme activity and the malondialdehyde level. RESULTS: Piper betle increased the activities of catalase, glutathione peroxidase, and superoxide dismutase in the young, middle, and old age groups, respectively, when compared to control. The tocotrienol-rich fraction decreased the superoxide dismutase activity in the middle and the old age groups but had no effect on catalase or glutathione peroxidase activity for all age groups. Chlorella vulgaris had no effect on superoxide dismutase activity for all age groups but increased glutathione peroxidase and decreased catalase activity in the middle and the young age groups, respectively. Chlorella vulgaris reduced lipid peroxidation (malondialdehyde levels) in all age groups, but no significant changes were observed with the tocotrienol-rich fraction and the Piper betle treatments. CONCLUSION: We found equivocal age-related changes in erythrocyte antioxidant enzyme activity when mice were treated with Piper betle, the tocotrienol-rich fraction, and Chlorella vulgaris. However, Piper betle treatment showed increased antioxidant enzymes activity during aging.

Aliahmat, Nor Syahida; Noor, Mohd Razman Mohd; Yusof, Wan Junizam Wan; Makpol, Suzana; Ngah, Wan Zurinah Wan; Yusof, Yasmin Anum Mohd

2012-01-01

12

Piper betle induces phase I & II genes through Nrf2/ARE signaling pathway in mouse embryonic fibroblasts derived from wild type and Nrf2 knockout cells  

PubMed Central

Background Nuclear factor-erythroid 2 p45 related factor 2 (Nrf2) is a primary transcription factor, protecting cells from oxidative stress by regulating a number of antioxidants and phase II detoxifying enzymes. Dietary components such as sulforaphane in broccoli and quercetin in onions have been shown to be inducers of Nrf2. Piper betle (PB) grows well in tropical climate and the leaves are used in a number of traditional remedies for the treatment of stomach ailments and infections among Asians. The aim of this study was to elucidate the effect of Piper betle (PB) leaves extract in Nrf2 signaling pathway by using 2 types of cells; mouse embryonic fibroblasts (MEFs) derived from wild-type (WT) and Nrf2 knockout (N0) mice. Methods WT and N0 cells were treated with 5 and 10 ?g/ml of PB for 10 and 12-h for the determination of nuclear translocation of Nrf2 protein. Luciferase reporter gene activity was performed to evaluate the antioxidant response element (ARE)-induction by PB. Real-time PCR and Western blot were conducted on both WT and N0 cells after PB treatment for the determination of antioxidant enzymes [superoxide dismutase (SOD1) and heme-oxygenase (HO-1)], phase I oxidoreductase enzymes [NAD(P)H: quinone oxidoreductase (NQO1)] and phase II detoxifying enzyme [glutathione S-transferase (GST)]. Results Nuclear translocation of Nrf2 by PB in WT cells was better after 10 h incubation compared to 12 h. Real time PCR and Western blot analysis showed increased expressions of Nrf2, NQO1 and GSTA1 genes with corresponding increases in glutathione, NQO1 and HO-1 proteins in WT cells. Reporter gene ARE was stimulated by PB as shown by ARE/luciferase assay. Interestingly, PB induced SOD1 gene and protein expressions in N0 cells but not in WT cells. Conclusion The results of this study confirmed that PB activated Nrf2-ARE signaling pathway which subsequently induced some phase I oxidoreductase, phase II detoxifying and antioxidant genes expression via ARE reporter gene involved in the Nrf2 pathway with the exception of SOD1 which may not be dependent on this pathway.

2014-01-01

13

Comparative effect of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction on antioxidant enzymes activity in cellular ageing of human diploid fibroblasts  

PubMed Central

Background Human diploid fibroblasts (HDFs) undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular ageing. Even though beneficial effects of Piper betle, Chlorella vulgaris and tocotrienol-rich fraction (TRF) have been reported, ongoing studies in relation to ageing is of interest to determine possible protective effects that may reverse the effect of ageing. The aim of this study was to evaluate the effect of P. betle, C. vulgaris and TRF in preventing cellular ageing of HDFs by determining the activity of antioxidant enzymes viz.; catalase, superoxide dismutase (SOD) and glutathione peroxidase. Methods Different passages of HDFs were treated with P. betle, C. vulgaris and TRF for 24 h prior to enzymes activity determination. Senescence-associated beta-galactosidase (SA ?-gal) expression was assayed to validate cellular ageing. Results In cellular ageing of HDFs, catalase and glutathione peroxidase activities were reduced, but SOD activity was heightened during pre-senescence. P. betle exhibited the strongest antioxidant activity by reducing SA ?-gal expression, catalase activities in all age groups, and SOD activity. TRF exhibited a strong antioxidant activity by reducing SA ?-gal expression, and SOD activity in senescent HDFs. C. vulgaris extract managed to reduce SOD activity in senescent HDFs. Conclusion P. betle, C. vulgaris, and TRF have the potential as anti-ageing entities which compensated the role of antioxidant enzymes in cellular ageing of HDFs.

2013-01-01

14

Effect of Piper betle and Brucea javanica on the Differential Expression of Hyphal Wall Protein (HWP1) in Non-Candida albicans Candida (NCAC) Species  

PubMed Central

The study aimed to identify the HWP1 gene in non-Candida albicans Candida species and the differential expression of HWP1 following treatment with Piper betle and Brucea javanica aqueous extracts. All candidal suspensions were standardized to 1 × 106?cells/mL. The suspension was incubated overnight at 37?°C (C. parapsilosis, 35°C). Candidal cells were treated with each respective extract at 1, 3, and 6?mg/mL for 24?h. The total RNA was extracted and reverse transcription-polymerase chain reaction was carried out with a specific primer of HWP1. HWP1 mRNAs were only detected in C. albicans, C. parapsilosis, and C. tropicalis. Exposing the cells to the aqueous extracts has affected the expression of HWP1 transcripts. C. albicans, C. parapsilosis, and C. tropicalis have demonstrated different intensity of mRNA. Compared to P. betle, B. javanica demonstrated a higher suppression on the transcript levels of HWP1 in all samples. HWP1 was not detected in C. albicans following the treatment of B. javanica at 1?mg/mL. In contrast, C. parapsilosis and C. tropicalis were shown to have HWP1 regulation. However, the expression levels were reduced upon the addition of higher concentration of B. javanica extract. P. betle and B. javanica have potential to be developed as oral health product.

Jamil, Nur Alyaa; Jamaludin, Nor Hazwani; Nordin, Mohd-Al-Faisal

2013-01-01

15

Prenylhydroxybenzoic acid compounds with pungent activity from Piper arieianum (CDC) leaves.  

PubMed

Prenylhydroxybenzoic acid derivatives and other two analogues previously reported were isolated from Piper arieianum leaves. The structures of the compounds were assigned from detailed spectroscopical analysis (NMR 1D and 2D and HR ESI TOF MS) data and by comparison with data from the literature. These molecules posses pungent activity different to that of capsaicin and their activity is related to their structure and their mechanism of action can involve interactions with TRPV1 channel. PMID:21211807

Correa, Edwin; Sterner, Olov; Echeverri, Fernando

2011-02-01

16

Circadian rhythm of anti-fungal prenylated chromene in leaves of Piper aduncum.  

PubMed

Leaves of Piper aduncum accumulate the anti-fungal chromenes methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate (1) and methyl 2,2-dimethyl-8-(3'-methyl-2'-butenyl)-2H-1-chromene-6-carboxylate (2). The enzymatic formation of 2 from dimethylallyl diphosphate and 1 was investigated using cell-free extracts of the title plant. An HPLC assay for the prenylation reaction was developed and the enzyme activity measured in the protein extracts. The prenyltransferase that catalyses the transfer of the dimethylallyl group to C-2' of 1 was soluble and required dimethylallyl diphosphate as the prenyl donor. In the leaves, the biosynthesis of the prenylated chromene 2 was time-regulated and prenyltransferase activity depended upon circadian variation. Preliminary characterisation and purification experiments on the prenyltransferase from P. aduncum have been performed. PMID:16042156

Morandim, Andreia de A; Bergamo, Débora Cristina B; Kato, Massuo Jorge; Cavalheiro, Alberto José; Bolzani, Vanderlan da S; Furlan, Maysa

2005-01-01

17

Eupomatenoid-5 Isolated from Leaves of Piper regnellii Induces Apoptosis in Leishmania amazonensis  

PubMed Central

Leishmania spp. are protozoa responsible for leishmaniasis, a neglected disease that kills up to 50,000 people every year. Current therapies mainly rely on antimonial drugs that are inadequate because of their poor efficacy and safety and increased drug resistance. An urgent need exists to find new and more affordable drugs. Our previous study demonstrated the antileishmanial activity of eupomatenoid-5, a neolignan obtained from leaves of Piper regnellii var. pallescens. The aim of the present study was to clarify the mode of action of eupomatenoid-5 against L. amazonensis. We used biochemical and morphological techniques and demonstrated that eupomatenoid-5 induced cell death in L. amazonensis promastigotes, sharing some phenotypic features observed in metazoan apoptosis, including increased reactive oxygen species production, hypopolarization of mitochondrial potential, phosphatidylserine exposure, decreased cell volume, and G0/G1 phase cell cycle arrest.

Garcia, Francielle Pelegrin; Ueda-Nakamura, Tania; Silva, Sueli de Oliveira

2013-01-01

18

Antifungal activity of extracts from Piper aduncum leaves prepared by different solvents and extraction techniques against dermatophytes Trichophyton rubrum and Trichophyton interdigitale  

PubMed Central

The effects of different solvents and extraction techniques upon the phytochemical profile and anti-Trichophyton activity of extracts from Piper aduncum leaves were evaluated. Extract done by maceration method with ethanol has higher content of sesquiterpenes and antifungal activity. This extract may be useful as an alternative treatment for dermatophytosis.

Santos, Maximillan Leite; Magalhaes, Chaiana Froes; da Rosa, Marcelo Barcellos; de Assis Santos, Daniel; Brasileiro, Beatriz Goncalves; de Carvalho, Leandro Machado; da Silva, Marcelo Barreto; Zani, Carlos Leomar; de Siqueira, Ezequias Pessoa; Peres, Rodrigo Loreto; Andrade, Anderson Assuncao

2013-01-01

19

Antifungal activity of extracts from Piper aduncum leaves prepared by different solvents and extraction techniques against dermatophytes Trichophyton rubrum and Trichophyton interdigitale.  

PubMed

The effects of different solvents and extraction techniques upon the phytochemical profile and anti-Trichophyton activity of extracts from Piper aduncum leaves were evaluated. Extract done by maceration method with ethanol has higher content of sesquiterpenes and antifungal activity. This extract may be useful as an alternative treatment for dermatophytosis. PMID:24688522

Santos, Maximillan Leite; Magalhães, Chaiana Froés; da Rosa, Marcelo Barcellos; de Assis Santos, Daniel; Brasileiro, Beatriz Gonçalves; de Carvalho, Leandro Machado; da Silva, Marcelo Barreto; Zani, Carlos Leomar; de Siqueira, Ezequias Pessoa; Peres, Rodrigo Loreto; Andrade, Anderson Assunção

2013-12-01

20

In vitro schistosomicidal effects of aqueous and dichloromethane fractions from leaves and stems of Piper species and the isolation of an active amide from P. amalago L. (Piperaceae).  

PubMed

Dichloromethane and aqueous fractions from leaves and stems of Piper arboreum Aubl., P. aduncum L., P. amalago L., P. crassinervium H.B. & K., P. diospyrifolium Kunth, P. hispidum Sw. and P. xylosteoides (Kunth) Steud. were tested against adult worms of Schistosoma mansoni. The in vitro activity was evaluated in terms of mortality, number of separated worms and number of worms with reduced motor activity. Most dichloromethane fractions from all Piper species showed moderate schistosomicidal activity, but aqueous fractions were not active. The dichloromethane fraction of P. amalago leaves (at 100 ?g/ml) showed the highest activity, resulting in worm mortality, the separation of worm pairs and reduced motor activity. Chromatographic fractionation of the dichloromethane fraction of P. amalago leaves led to the isolation of its major compound, which was also tested against adults of S. mansoni. The isolated piperamide N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl] pyrrolidine, at 100 ? m, resulted in the mortality of all adult worms after 24 h of incubation. The findings suggest that species of Piper are potential sources of schistosomicidal compounds. PMID:23561585

Carrara, V S; Vieira, S C H; de Paula, R G; Rodrigues, V; Magalhães, L G; Cortez, D A G; Da Silva Filho, A A

2013-04-01

21

Five new prenylated p-hydroxybenzoic acid derivatives with antimicrobial and molluscicidal activity from Piper aduncum leaves.  

PubMed

Five new prenylated benzoic acid derivatives, methyl 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxybenzoate (1), 1-(1-methylethyl)-4-methyl-3-cyclohexenyl 3,5-bis(3-methyl-2-butenyl)-4-hydroxybenzoate (2), 1-(1-methylethyl)-4-methyl-3-cyclohexenyl 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoate (3), methyl 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoate (4), and 4-hydroxy-3-(3-methyl-2-butenyl)-5-(3-methyl-2-butenyl)-benzoic acid (5) were isolated from the dried leaves of Piper aduncum L. (Piperaceae). Together with the new metabolites, four known prenylated benzoic acid derivatives, 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoic acid (6), 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoic acid (nervogenic acid, 7), methyl 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoate (8), and methyl 4-hydroxy-3-(3-methyl-2-butenyl)-benzoate (9) as well as, dillapiol (10), myristicin, and the three sesquiterpenes humulene, caryophyllene epoxide, and humulene epoxide were isolated. Compounds 7, 8, and 9 are reported as natural products for the first time. The structures of the isolates were elucidated by spectroscopic methods, mainly 1D-and 2D-NMR spectroscopy. Isolates 4-7, 9, and 10 were molluscicidal while 2, 5-7, and 9 displayed significant antibacterial activities. PMID:8302955

Orjala, J; Erdelmeier, C A; Wright, A D; Rali, T; Sticher, O

1993-12-01

22

Two maize END-1 orthologs, BETL9 and BETL9like, are transcribed in a non-overlapping spatial pattern on the outer surface of the developing endosperm.  

PubMed

In the course of a project aimed to isolate transfer cells-specific genes in maize endosperm we have identified the BETL9 gene. BETL9 encodes for a small protein very similar in sequence to the product of the barley transfer cell-specific gene END-1. Both BETL9 and END-1 proteins are lipid transfer proteins, but their function is currently unknown. In situ hybridization analysis confirms that the BETL9 gene is exclusively transcribed in the basal endosperm transfer cell layer during seed development since 10 days after pollination. However, immunolocalization data indicates that the BETL9 protein accumulates in the maternal placento-chalaza cells located just beside the transfer cell layer. This suggests that the BETL9 protein should be transported to the maternal side to exert its, still unknown, function. In addition, we have identified a second maize gene very similar in sequence to BETL9 and we have named it BETL9like. In situ hybridization shows that BETL9like is also specifically transcribed in the developing maize endosperm within the same time frame that BETL9, but in this case it is exclusively expressed in the aleurone cell layer. Consequently, the BETL9 and BETL9like genes are transcribed in a non-overlapping pattern on the outer surface of the maize endosperm. The BETL9 and BETL9like promoter sequences, fused to the GUS reporter gene, accurately reflected the expression pattern observed for the genes in maize. Finally, we have identified in the Arabidopsis genome a set of four genes orthologous to BETL9 and BETL9like and analyzed the activity of their promoters in Arabidopsis transgenic plants carrying fusions of their promoter sequences to the GUS reporter. As in the case of the maize genes, the Arabidopsis orthologs showed highly complementary expression patterns. PMID:24834070

Royo, Joaquín; Gómez, Elisa; Sellam, Olivier; Gerentes, Denise; Paul, Wyatt; Hueros, Gregorio

2014-01-01

23

Two maize END-1 orthologs, BETL9 and BETL9like, are transcribed in a non-overlapping spatial pattern on the outer surface of the developing endosperm  

PubMed Central

In the course of a project aimed to isolate transfer cells-specific genes in maize endosperm we have identified the BETL9 gene. BETL9 encodes for a small protein very similar in sequence to the product of the barley transfer cell-specific gene END-1. Both BETL9 and END-1 proteins are lipid transfer proteins, but their function is currently unknown. In situ hybridization analysis confirms that the BETL9 gene is exclusively transcribed in the basal endosperm transfer cell layer during seed development since 10 days after pollination. However, immunolocalization data indicates that the BETL9 protein accumulates in the maternal placento-chalaza cells located just beside the transfer cell layer. This suggests that the BETL9 protein should be transported to the maternal side to exert its, still unknown, function. In addition, we have identified a second maize gene very similar in sequence to BETL9 and we have named it BETL9like. In situ hybridization shows that BETL9like is also specifically transcribed in the developing maize endosperm within the same time frame that BETL9, but in this case it is exclusively expressed in the aleurone cell layer. Consequently, the BETL9 and BETL9like genes are transcribed in a non-overlapping pattern on the outer surface of the maize endosperm. The BETL9 and BETL9like promoter sequences, fused to the GUS reporter gene, accurately reflected the expression pattern observed for the genes in maize. Finally, we have identified in the Arabidopsis genome a set of four genes orthologous to BETL9 and BETL9like and analyzed the activity of their promoters in Arabidopsis transgenic plants carrying fusions of their promoter sequences to the GUS reporter. As in the case of the maize genes, the Arabidopsis orthologs showed highly complementary expression patterns.

Royo, Joaquin; Gomez, Elisa; Sellam, Olivier; Gerentes, Denise; Paul, Wyatt; Hueros, Gregorio

2014-01-01

24

Volatile chemical constituents of Piper aduncum L and Piper gibbilimbum C. DC (Piperaceae) from Papua New Guinea.  

PubMed

Exhaustive hydro-distillation of the leaves of Piper aduncum and fruits of Piper gibbilimbum (Piperaceae) afforded colorless and pale orange colored oils in 0.35 and 0.30 % yields, respectively. Detailed chemical analysis by GC/MS indicated the volatile constituents of Piper aduncum to be composed of dill apiole (43.3%), beta-caryophyllene (8.2%), piperitione (6.7%) and alpha-humulene (5.1%), whilst the oil of P. gibbilimbum is dominated by the gibbilimbols A-D (74.2%), with the remaining major constituents being the terpenes camphene (13.6%) and alpha-pinene (6.5%). PMID:17851397

Rali, Topul; Wossa, Stewart W; Leach, David N; Waterman, Peter G

2007-01-01

25

MUTAGENICITY OF NITRITE-TREATED AQUEOUS EXTRACT OF 'PIPER BETLE'; L  

EPA Science Inventory

Betel quid is chewed as a masticatory material by people in certain areas of Asia. The quid chewing has been related to oral cancer by epidemiological study. The mutagenic components in the aqueous extracts of betel quid ingredients were studied. Only nitrite-treated aqueous extr...

26

Piper Oil Field  

Microsoft Academic Search

The Piper Field is located in UK block 15\\/17 near the eastern part of the Moray Firth Basin, 125 miles northeast of Aberdeen, Scotland. The field was discovered in Dec. 1972. Five appraisal wells and one exploratory well were drilled in 1973. A steel platform with 36 well slots and space for 2 drilling rigs was centrally located over the

1979-01-01

27

Antifungal activity of Piper diospyrifolium Kunth (Piperaceae) essential oil  

PubMed Central

In vitro activity of the essential oil from Piper diospyrifolium leaves was tested using disk diffusion techniques. The antifungal assay showed significant potencial antifungal activity: the oil was effective against several clinical fungal strains. The majority compounds in the essential oil were identified as sesquiterpenoids by GC-MS and GC-FID techniques.

Vieira, Silvia Cristina Heredia; de Paulo, Luis Fernando; Svidzinski, Terezinha Inez Estivaleti; Dias Filho, Benedito Prado; Nakamura, Celso Vataru; de Souza, Amanda; Young, Maria Claudia Marx; Cortez, Diogenes Aparicio Garcia

2011-01-01

28

Cytotoxic and antibacterial dihydrochalcones from Piper aduncum.  

PubMed

Bioactivity-guided fractionation of a CH2Cl2 extract from the leaves of Piper aduncum afforded three new dihydrochalcones, piperaduncins A [3], B [4], and C [5], as well as two known dihydrochalcones, 2',6'-dihydroxy-4'-methoxydihydrochalcone [1] and 2',6',4-trihydroxy-4'-methoxydihydrochalcone [2] (asebogenin), together with sakuranetin, anodendroic acid methyl ester, and the carotenoid lutein. The structures of the isolates were elucidated by spectroscopic methods, mainly 1D- and 2D nmr spectroscopy. The proposed stereochemistry for compound 4 was deduced by NOESY spectroscopy and the corresponding energy minimum was established by molecular modelling calculations and translated into a 3D structure. PMID:8158163

Orjala, J; Wright, A D; Behrends, H; Folkers, G; Sticher, O; Rüegger, H; Rali, T

1994-01-01

29

77 FR 56993 - Airworthiness Directives; Piper Aircraft, Inc. Airplanes  

Federal Register 2010, 2011, 2012, 2013

...2120-AA64 Airworthiness Directives; Piper Aircraft, Inc. Airplanes AGENCY: Federal Aviation...airworthiness directive (AD) for certain Piper Aircraft, Inc. Models PA-24, PA-24-250...identified in this AD, contact Piper Aircraft, Inc., 2926 Piper Drive, Vero...

2012-09-17

30

Antimycobacterial compounds from Piper sanctum.  

PubMed

Bioassay-guided chromatographic separation of the antimycobacterial extract of the leaves of Piper sanctum afforded 14 new compounds, identified as 2-oxo-12-(3',4'-methylenedioxyphenyl)dodecane (1), 2-oxo-14-(3',4'-methylenedioxyphenyl)tetradecane (2), 2-oxo-16-(3',4'-methylenedioxyphenyl)hexadecane (3), 2-oxo-18-(3',4'-methylenedioxyphenyl)octadecane (4), 2-oxo-14-(3',4'-methylenedioxyphenyl)-trans-13-tetradecene (5), 2-oxo-16-(3',4'-methylenedioxyphenyl)-trans-15-hexadecene (6), 2-oxo-18-(3',4'-methylenedioxyphenyl)-trans-17-octadecene (7), 2-oxo-16-phenyl-trans-3-hexadecene (8), methyl [6-(10-phenyldecanyl)tetrahydropyran-2-yl]acetate (9), methyl 2-(6-tridecyltetrahydro-2H-pyran-2-yl)acetate (10), methyl 2-(5-tetradecyltetrahydro-2-furanyl)acetate (11), 2-oxo-14-(3',4'-methylenedioxyphenyl)-trans-3-tetradecene (12), 2-oxo-16-(3',4'-methylenedioxyphenyl)-trans-3-hexadecene (13), and 2-oxo-16-phenyl-3-hexadecane (14). In addition, p-eugenol (15), methyleugenol (16), Z-piperolide (17), demethoxyyangonin (18), 5,6-dehydro-7,8-dihydromethysticin (19), cepharanone B (20), piperolactam A (21), cepharadione B (22), N-trans-feruloyltyramine (23), and N-trans-(p-coumaroyl)tyramine (24) were obtained from the anti-TBC stem extract of the plant. GC-MS and HPLC analyses of the essential oils of the leaves and stem revealed that safrol (25) was the major component of the oils. Compounds 2, 3, 6, 18-21, and 24 inhibited the growth of Mycobacterium tuberculosis when tested by the MABA assay, with MIC values ranging from 4 to 64 microg/mL. PMID:15620234

Mata, Rachel; Morales, Iliana; Pérez, Olga; Rivero-Cruz, Isabel; Acevedo, Laura; Enriquez-Mendoza, Isolda; Bye, Robert; Franzblau, Scott; Timmermann, Barbara

2004-12-01

31

Efficacy of an herbal formulation LI10903F containing Dolichos biflorus and Piper betle extracts on weight management  

PubMed Central

Background A novel herbal formulation LI10903F, alternatively known as LOWAT was developed based on its ability to inhibit adipogenesis and lipogenesis in 3T3-L1 adipocytes model. The clinical efficacy and tolerability of LI10903F were evaluated in an eight-week, randomized, double-blind, placebo-controlled, clinical trial in 50 human subjects with body mass index (BMI) between 30 and 40 kg/m2 (clinical trial registration number: ISRCTN37381706). Participants were randomly assigned to either a placebo or LI10903F group. Subjects in the LI10903F group received 300 mg of herbal formulation thrice daily, while subjects in the placebo group received 300 mg of placebo capsules thrice daily. All subjects were provided a standard diet (2,000 kcal daily) and participated in a moderate exercise of 30 min walk for five days a week. Additionally, the safety of this herbal formulation was evaluated by a series of acute, sub-acute toxicity and genotoxicity studies in animals and cellular models. Results After eight weeks of supplementation, statistically significant net reductions in body weight (2.49 kg; p=0.00005) and BMI (0.96 kg/m2; p=0.00004) were observed in the LI10903F group versus placebo group. Additionally, significant increase in serum adiponectin concentration (p=0.0076) and significant decrease in serum ghrelin concentration (p=0.0066) were found in LI10903F group compared to placebo group. Adverse events were mild and were equally distributed between the two groups. Interestingly, LI10903F showed broad spectrum safety in a series of acute, sub-acute toxicity and genotoxicity studies. Conclusions Results from the current research suggest that LI10903F or LOWAT is well-tolerated, safe and effective for weight management.

2012-01-01

32

Antioxidant and cytoprotective activities of Piper betle, Areca catechu, Uncaria gambir and betel quid with and without calcium hydroxide  

PubMed Central

Background Betel quid chewing is a popular habit in Southeast Asia. It is believed that chewing betel quid could reduce stress, strengthen teeth and maintain oral hygiene. The aim of this study was to investigate the antioxidant and cytoprotective activities of each of the ingredients of betel quid and compared with betel quid itself (with and without calcium hydroxide). The correlation of their cytoprotective and antioxidant activities with phenolic content was also determined. Methods Five samples (betel leaf, areca nut, gambir, betel quid and betel quid containing calcium hydroxide) were extracted in deionized distilled water for 12 hours at 37°C. Antioxidant activities were evaluated for radical scavenging activity using DPPH assay, ferric reducing activity using FRAP assay and lipid peroxidation inhibition activity using FTC assay. Total phenolic content (TPC) was determined using Folin-Ciocalteu procedure. Phenolic composition was analyzed using LC-MS/MS. Cytoprotective activity towards human gingival fibroblast cells was examined using MTT assay. Results Among the ingredients of betel quid, gambir demonstrated the highest antioxidant (DPPH - IC50?=?6.4?±?0.8 ?g/mL, FRAP - 5717.8?±?537.6 ?mol Fe(II)/mg), total phenolic content (TPC - 1142.5?±?106.8 ?g TAE/mg) and cytoprotective (100.1?±?4.6%) activities. Betel quid when compared with betel quid containing calcium hydroxide has higher antioxidant (DPPH - IC50 =59.4?±?4.4 ?g/mL, FRAP - 1022.2?±?235.7 ?mol Fe(II)/mg), total phenolic content (TPC - 140.0?±?22.3 ?g TAE/mg), and cytoprotective (113.5?±?15.9%) activities. However, all of the five samples showed good lipid peroxidation inhibition compared to vitamin E. LC-MS/MS analysis revealed the presence of quinic acid as the major compound of gambir and betel quid. A positive correlation was observed between TPC and radical scavenging (r?=?0.972), reducing power (r?=?0.981) and cytoprotective activity (r?=?0.682). Conclusions The betel quid has higher TPC, and antioxidant and cytoprotective activities than betel quid with calcium hydroxide. The quinic acid in betel quid may play an important role in the oral health protection.

2013-01-01

33

Heterologous Expression of BetL, a Betaine Uptake System, Enhances the Stress Tolerance of Lactobacillus salivarius UCC118  

Microsoft Academic Search

Given the increasing commercial and clinical relevance of probiotic cultures, improving the technological robustness of what are often process-sensitive cultures is an important biological goal. The nisin-controlled expression system was used to direct the heterologous expression of the listerial betaine uptake system BetL in the probiotic strain Lactobacillus salivarius UCC118. Following nisin induction, strains expressing betL exhibited a significant increase

Vivien M. Sheehan; Roy D. Sleator; Gerald F. Fitzgerald; Colin Hill

2006-01-01

34

Analysis of the role of betL in contributing to the growth and survival of Listeria monocytogenes LO28.  

PubMed

Survival of the food-borne pathogen Listeria monocytogenes in environments of elevated osmolarity and reduced temperature is attributed, at least in part, to the accumulation of the trimethylammonium compound glycine betaine. Previously we identified betL, a gene encoding the secondary glycine betaine transporter BetL, which we linked to the salt tolerance of Listeria. In this report, we demonstrate that betL, preceded by a consensus sigmaB-dependent promoter, is regulated by osmotic up-shock, at least in part at the level of transcription. Using allelic exchange mutagenesis we constructed an in-frame deletion in betL, and used this mutant to determine the role of BetL in contributing to the growth and survival of L. monocytogenes, both in a high risk food (Camembert cheese) and animal model. Our results indicate that while BetL plays an important role in glycine betaine mediated osmoprotection, mutating the gene does not significantly effect either the cryotolerance or virulence of the organism. PMID:11016615

Sleator, R D; Gahan CGM; O'Driscoll, B; Hill, C

2000-09-25

35

Sequestration of prenylated benzoic acid and chromenes by Naupactus bipes (Coleoptera: Curculionidae) feeding on Piper gaudichaudianum (Piperaceae)  

Microsoft Academic Search

The curculionid beetle Naupactus\\u000a bipes (Germar, 1824) (Coleoptera: Curculionidae: Brachycerinae) has shown feeding preference for leaves of Piper gaudichaudianum, demonstrating an unexpected specificity for an insect considered to be a generalist. The leaves of P. gaudichaudianum contain the prenylated chromenes gaudichaudianic acid (4, major compound) and its methyl ester (5) in addition to a chromene (3) lacking one prenyl residue.

Clécio S. Ramos; Sergio A. Vanin; Massuo J. Kato

2009-01-01

36

76 FR 18033 - Airworthiness Directives; Piper Aircraft, Inc. (Type Certificate Previously Held by The New Piper...  

Federal Register 2010, 2011, 2012, 2013

...2120-AA64 Airworthiness Directives; Piper Aircraft, Inc. (Type Certificate Previously Held by The New Piper Aircraft, Inc.) Models PA-46-310P, PA...AD) that applies to certain Piper Aircraft, Inc. Models PA-46-310P and...

2011-04-01

37

Caffeic acid esters and lignans from Piper sanguineispicum.  

PubMed

Three new caffeic acid esters (1-3), four new lignans (4-7), and the known compounds (7'S)-parabenzlactone (8), dihydrocubebin (9), and justiflorinol (10) have been isolated from leaves of Piper sanguineispicum. Their structures were determined by spectroscopic methods, including 1D and 2D NMR, HRCIMS, CD experiments, and chemical methods. Compounds 1-10 were assessed for their antileishmanial potential against axenic amastigote forms of Leishmania amazonensis. Caffeic acid esters 1 and 3 exhibited the best antileishmanial activity (IC(50) 2.0 and 1.8 ?M, respectively) with moderate cytotoxicity on murine macrophages. PMID:20954722

Cabanillas, Billy Joel; Le Lamer, Anne-Cécile; Castillo, Denis; Arevalo, Jorge; Rojas, Rosario; Odonne, Guillaume; Bourdy, Geneviève; Moukarzel, Béatrice; Sauvain, Michel; Fabre, Nicolas

2010-11-29

38

Bioactive aristolactams from Piper umbellatum  

Microsoft Academic Search

Four alkaloids named piperumbellactams A–D (1–4) were isolated from branches of Piper umbellatum together with known N-hydroxyaristolam II (5), N-p-coumaroyl tyramine (6), 4-nerolidylcatechol (7), N-trans-feruloyltyramine, E-3-(3,4-dihydroxyphenyl)-N-2-[4-hydroxyphenylethyl]-2-propenamide, ?-amyrin, friedelin, apigenin 8-C-neohesperidoside, acacetin 6-C-?-d-glucopyranoside, ?-sitosterol, its 3-O-?-d-glucopyranoside and its 3-O-?-d-[6?-dodecanoyl]-glucopyranoside. Glycosidase inhibition, antioxidant and antifungal activities of these compounds were evaluated. Compounds 1–3 showed moderate ?-glucosidase enzyme inhibition with IC50 values 98.07±0.44,

Turibio Kuiate Tabopda; Joseph Ngoupayo; Jiawei Liu; Anne-Claire Mitaine-Offer; Sheraz A. Khan Tanoli; Shamsun Nahar Khan; Muhammad Shaiq Ali; Bonaventure Tchaleu Ngadjui; Etienne Tsamo; Marie-Aleth Lacaille-Dubois; Bang Luu

2008-01-01

39

75 FR 43809 - Airworthiness Directives; Piper Aircraft, Inc. PA-28, PA-32, PA-34, and PA-44 Series Airplanes  

Federal Register 2010, 2011, 2012, 2013

...2120-AA64 Airworthiness Directives; Piper Aircraft, Inc. PA-28, PA-32, PA- 34...airworthiness directive (AD) for certain Piper Aircraft, Inc. (Piper) PA-28, PA-32...identified in this AD, contact Piper Aircraft, Inc., 2926 Piper Drive, Vero...

2010-07-27

40

The Primordial Inflation Polarization Explorer (PIPER)  

NASA Technical Reports Server (NTRS)

The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne polarimeter that will measure the polarization of the cosmic microwave background to search for evidence for inflation. PIPER will observe more than half of the sky in four frequency bands from 200 to 600 GHz with a beam size of 21 arcminutes at the lowest frequency. PIPER simultaneously measures all four Stokes parameters using four co-aligned 32 by 40 element planar bolometer arrays. We give an instrument overview and report on the current status of the instrument.

Chuss, David

2010-01-01

41

Bioactive aristolactams from Piper umbellatum.  

PubMed

Four alkaloids named piperumbellactams A-D (1-4) were isolated from branches of Piper umbellatum together with known N-hydroxyaristolam II (5), N-p-coumaroyl tyramine (6), 4-nerolidylcatechol (7), N-trans-feruloyltyramine, E-3-(3,4-dihydroxyphenyl)-N-2-[4-hydroxyphenylethyl]-2-propenamide, beta-amyrin, friedelin, apigenin 8-C-neohesperidoside, acacetin 6-C-beta-d-glucopyranoside, beta-sitosterol, its 3-O-beta-d-glucopyranoside and its 3-O-beta-d-[6'-dodecanoyl]-glucopyranoside. Glycosidase inhibition, antioxidant and antifungal activities of these compounds were evaluated. Compounds 1-3 showed moderate alpha-glucosidase enzyme inhibition with IC50 values 98.07+/-0.44, 43.80+/-0.56 and 29.64+/-0.46, respectively. In DPPH radical scavenging assay, compounds 2, 3 and 6 showed potent inhibitory activity while compounds 4, 5 and 7 showed potent antifungal activity. PMID:18400239

Tabopda, Turibio Kuiate; Ngoupayo, Joseph; Liu, Jiawei; Mitaine-Offer, Anne-Claire; Tanoli, Sheraz A Khan; Khan, Shamsun Nahar; Ali, Muhammad Shaiq; Ngadjui, Bonaventure Tchaleu; Tsamo, Etienne; Lacaille-Dubois, Marie-Aleth; Luu, Bang

2008-05-01

42

Acción biocida de plantas de Piper tuberculatum Jacq. sobre Diatraea saccharalis (Lepidóptera, Pyralidae)  

Microsoft Academic Search

The biocid action of DCM:MeOH (2:1), EtOH and aqueous extracts of leaves, stems and mature spikes (with fruits and seeds) of field plants and DCM:MeOH (2:1) extract of in vitro plants of Piper tuberculatum on III larval stage of Diatraea saccharalis was evaluated. The method was by inoculating the previously eluted extract with distillate water as topic applications on the

Gladys V. Soberón; Consuelo Rojas; Jorge Saavedra; Massuo J. Kato; Guillermo E. Delgado

43

A chromene and prenylated benzoic acid from Piper aduncum.  

PubMed

In addition to nerolidol, 2',6'-dihydroxy-4'-methoxydihydrochalcone, methyl 2,2-dimethyl-8-(3'-methyl-2'-butenyl)-2H-1-chromene-6-carboxylate, methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate and methyl 8-hydroxy-2,2-dimethyl-2H-1-chromene-6-carboxylate, two new natural products were isolated from the leaves of Piper aduncum, 2,2-dimethyl-2H-1-chromene-6-carboxylic acid and 3-(3',7'-dimethyl-2',6'-octadienyl)-4-methoxybenzoic acid. The structures of the isolates were established based on analysis of spectroscopic data, including ES-MS. The DNA-damaging activity of the isolated compounds was also investigated against mutant strains of Saccharomyces cerevisiae. PMID:10423861

Baldoqui, D C; Kato, M J; Cavalheiro, A J; Bolzani, V da S; Young, M C; Furlan, M

1999-08-01

44

Efficacy of Piper (Piperaceae) extracts for control of common home and garden insect pests.  

PubMed

Extracts from three species of the plant family Piperaceae, Piper nigrum [L.], Piper guineense [Schum & Thonn, and Piper tuberculatum [Jacq.], were tested for efficacy against insects from five orders. All three species contain isobutyl amides, plant secondary compounds that act as neurotoxins in insects. These materials are considered safe to mammals because Piper spp. were used for centuries for spice and medicinal purposes. When 24-h P. nigrum LC50 values were compared between common insect pests from eastern Canada and the northeastern United States, the most sensitive species in order of increasing lethal concentration were eastern tent caterpillar, Malacosoma americanum (F.) < European pine sawfly larvae, Neodiprion sertifer (Geoffroy) < spindle ermine moth larvae, Yponomeuta cagnagella [Hübner] < viburnum leaf beetle larvae, Pyrrhalta viburni [Paykull] < stripped cucumber beetle adults, Acalymma vittatum (F.) < Colorado potato beetle adults, Leptinotarsa decemlineata (Say) < Japanese beetle adults, Popillia japonica [Newman] < hairy chinch bug, Blissus leucopterus hirtis [Montandon]. The life stage tested was the point at which each species causes the greatest amount of damage to the host plant and the point at which most gardeners would likely choose to treat with a conventional synthetic insecticide. Greenhouse trials revealed that the pepper formulations also had a repellent activity, thus protecting plant leaves from 1) herbivory (lily leaf beetle, Lilioceris lilii [Scopoli], adults and larvae and stripped cucumber beetle adults) and 2) oviposition [European corn borer, Ostrinia nubilalis (Hübner)]. Combinations with other botanical extracts were additive at best in toxicity and repellent trials. Nontarget toxicity to beneficial invertebrates is a possibility because the P. nigrum LC50 for beneficial ladybird beetles was 0.2%. P. nigrum extracts can provide a reasonable level of control against lepidopteran and European pine sawfly larvae and also will work as a short-term repellent and feeding deterrent. It is recommended that the use of Piper extracts be restricted to small-scale spot treatments in residential areas where insect pest outbreaks have occurred. PMID:15384353

Scott, I M; Jensen, H; Nicol, R; Lesage, L; Bradbury, R; Sánchez-Vindas, P; Poveda, L; Arnason, J T; Philogène, B J R

2004-08-01

45

The Primordial Inflation Polarization Explorer (PIPER)  

NASA Technical Reports Server (NTRS)

The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne instrument to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the polarization of the cosmic microwave background. PIPER combines cold (1.5 K) optics, 5120 bolometric detectors, and rapid polarization modulation using VPM grids to achieve both high sensitivity and excellent control of systematic errors. A series of flights alternating between northern and southern hemisphere launch sites will produce maps in Stokes I, Q, U, and V parameters at frequencies 200, 270, 350, and 600 GHz (wavelengths 1500, 1100, 850, and 500 microns) covering 85% of the sky. We describe the PIPER instrument and discuss the current status and expected science returns from the mission.

Kogut, Alan J.

2012-01-01

46

The Primordial Inflation Polarization Explorer (PIPER)  

NASA Technical Reports Server (NTRS)

The Primordial Inflation Polarization Explorer (PIPER) is a ba1loon-borne instrument designed to search for the faint signature of inflation in the polarized component of the cosmic microwave background (CMB). PIPER will measure the CMB polarization at 4 frequencies (l per flight) using a pair of cryogenic telescopes, one for measuring each of Stokes Q and U in the instrument frame. Each telescope receives both linear orthogonal polarizations in two 32 by 40 element planar arrays that utilize Transition-Edge Sensors (TES). The first element in each telescope is a variable-delay polarization modulator (VPM) that fully modulates the Stokes parameter to which the telescope is sensitive.

Chuss, David T.

2010-01-01

47

Molecular and Physiological Analysis of the Role of Osmolyte Transporters BetL, Gbu, and OpuC in Growth of Listeria monocytogenes at Low Temperatures  

PubMed Central

Listeria monocytogenes is a ubiquitous food-borne pathogen found widely distributed in nature as well as an undesirable contaminant in a variety of fresh and processed foods. This ubiquity can be at least partly explained by the ability of the organism to grow at high osmolarity and reduced temperatures, a consequence of its ability to accumulate osmo- and cryoprotective compounds termed osmolytes. Single and multiple deletions of the known osmolyte transporters BetL, Gbu, and OpuC significantly reduce growth at low temperatures. During growth in brain heart infusion broth at 7°C, Gbu and OpuC had a more pronounced role in cryoprotection than did BetL. However, upon the addition of betaine to defined medium, the hierarchy of transporter importance shifted to Gbu > BetL > OpuC. Upon the addition of carnitine, only OpuC appeared to play a role in cryoprotection. Measurements of the accumulated osmolytes showed that betaine is preferred over carnitine, while in the absence of a functional Gbu, carnitine was accumulated to higher levels than betaine was at 7°C. Transcriptional analysis of the genes encoding BetL, Gbu, and OpuC revealed that each transporter is induced to different degrees upon cold shock of L. monocytogenes LO28. Additionally, despite being transcriptionally up-regulated upon cold shock, a putative fourth osmolyte transporter, OpuB (identified by bioinformatic analysis and encoded by lmo1421 and lmo1422), showed no significant contribution to listerial chill tolerance. Growth of the quadruple mutant LO28?BCGB (?betL ?opuC ?gbu ?opuB) was comparable to the that of the triple mutant LO28?BCGsoe (?betL ?opuC ?gbu) at low temperatures. Here, we conclude that betaine and carnitine transport upon low-temperature exposure is mediated via three osmolyte transporters, BetL, Gbu, and OpuC.

Wemekamp-Kamphuis, Henrike H.; Sleator, Roy D.; Wouters, Jeroen A.; Hill, Colin; Abee, Tjakko

2004-01-01

48

Differential induction of chitinase in Piper colubrinum in response to inoculation with Phytophthora capsici, the cause of foot rot in black pepper  

PubMed Central

Plant chitinases have been of particular interest since they are known to be induced upon pathogen invasion. Inoculation of Piper colubrinum leaves with the foot rot fungus, Phytophthora capsici leads to increase in chitinase activity. A marked increase in chitinase activity in the inoculated leaves was observed, with the maximum activity after 60 h of inoculation and gradually decreased thereafter. Older leaves showed more chitinase activity than young leaves. The level of chitinase in black pepper (Piper nigrum L.) upon inoculation was found to be substantially high when compared to P. colubrinum. RT–PCR using chitinase specific primers revealed differential accumulation of mRNA in P. colubrinum leaves inoculated with P. capsici. However, hyphal extension assays revealed no obvious differences in the ability of the protein extracts to inhibit growth of P. capsici in vitro.

Sandeep Varma, R.; Johnson George, K.; Balaji, S.; Parthasarathy, V.A.

2009-01-01

49

Cumulative Trauma Disorders in Betel Pepper Leaf-Cullers Visiting a Rehabilitation Clinic: Experience in Taitung  

Microsoft Academic Search

Background: Betel pepper (Piper betle L.) cultivation is an important agricultural industry in Taitung, Taiwan, and culling leaves is very labor-intensive. This case study compares the proportion of cumulative trauma disorders (CTDs) between cullers and those with other occupations. Methods: Patients with musculoskeletal disorders in the rehabilitation clinic of a local hospital in Taitung were enrolled. This all female cohort

Lin-Yi Wang; Ya-Ping Pong; Sheng-Hsiang Su; Chang-hsueh Tsai; Chau-Peng Leong

50

Anticancer Principles from Medicinal Piper (?? H? Ji?o) Plants  

PubMed Central

The ethnomedical uses of Piper (?? Hú Ji?o) plants as anticancer agents, in vitro cytotoxic activity of both extracts and compounds from Piper plants, and in vivo antitumor activity and mechanism of action of selected compounds are reviewed in the present paper. The genus Piper (Piperaceae) contains approximately 2000 species, of which 10 species have been used in traditional medicines to treat cancer or cancer-like symptoms. Studies have shown that 35 extracts from 24 Piper species and 32 compounds from Piper plants possess cytotoxic activity. Amide alkaloids account for 53% of the major active principles. Among them, piplartine (piperlongumine) shows the most promise, being toxic to dozens of cancer cell lines and having excellent in vivo activity. It is worthwhile to conduct further anticancer studies both in vitro and in vivo on Piper plants and their active principles.

Wang, Yue-Hu; Morris-Natschke, Susan L.; Yang, Jun; Niu, Hong-Mei; Long, Chun-Lin; Lee, Kuo-Hsiung

2014-01-01

51

The Primordial Inflation Polarization Explorer (PIPER)  

NASA Technical Reports Server (NTRS)

The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne experiment designed to search for the polarized imprint of gravitational waves from cosmic inflation. The discovery of such a signal would provide direct evidence for inflation, and its characterization would provide a means to explore energy scales orders of magnitude larger than any conceivable particle accelerator. PIPER will consist of two cryogenic telescopes-one for each of the Q and U Stokes parameters. Each will use a variable-delay polarization modulator (VPM) as its first element. This architecture is designed to minimize both T->B and E->B systematics. The detectors will be four 32x40 arrays of BUG detectors, utilizing transition-edge sensors and time-domain multiplexing. Each flight will observe approximately 25% of the sky at a single frequency. Additional flights will increase the frequency coverage.

Chuss, David T.

2008-01-01

52

GC–MS Analysis of the Essential Oils of Piper nigrum L. and Piper longum L  

Microsoft Academic Search

A simple, rapid and solvent-free method based on gas chromatography–mass spectrometry (GC–MS) following microwave distillation\\u000a and headspace solid-phase microextraction (MD–HS-SPME) was developed for the analysis of the essential oils in two traditional\\u000a Chinese medicines, Piper nigrum L. and Piper longum L. Thirty compounds were separated and identified from P. nigrum L. The main components were ?-caryophyllene (23.49%), 3-carene (22.20%), d-limonene

Ling Liu; Guoxin Song; Yaoming Hu

2007-01-01

53

Dihydrochalcones and benzoic acid derivatives from Piper dennisii.  

PubMed

Two new dihydrochalcones (1, 2), as well as eight known compounds, piperaduncin C (3), 2',6'-dihydroxy-4'-methoxydihydrochalcone (4), 4,2',6'-trihydroxy-4'-methoxydihydrochalcone (5), 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoic acid (6), 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoic acid (7), 4-hydroxy-3-(3-methyl-2-butenoyl)-5-(3-methyl-2-butenyl)-benzoic acid (8), 2,2-dimethyl-8-(3-methyl-2-butenyl)-2H-1-chromene-6-carboxylic acid (9), and 3-(3',7'-dimethyl-2',6'-octadienyl)-4-methoxybenzoic acid (10) were isolated from the leaves of Piper dennisii Trelease (Piperaceae), using a bioassay-guided fractionation to determine their antileishmanial potential. Among them, compound 10 exhibited the best antileishmanial activity (IC50 = 20.8 µM) against axenic amastigote forms of Leishmania amazonensis, with low cytotoxicity on murine macrophages. In the intracellular macrophage-infected model, compound 10 proved to be more active (IC50 = 4.2 µM). The chemical structures of compounds 1-10 were established based on the analysis of the spectroscopic data. PMID:22516933

Cabanillas, Billy Joel; Le Lamer, Anne-Cécile; Castillo, Denis; Arevalo, Jorge; Estevez, Yannick; Rojas, Rosario; Valadeau, Céline; Bourdy, Geneviève; Sauvain, Michel; Fabre, Nicolas

2012-06-01

54

The Primordial Inflation Polarization Explorer (PIPER)  

NASA Technical Reports Server (NTRS)

The Primordial Inflation Polarization Explorer (PIPER) is it balloon-borne instrument designed to search for the faint signature of inflation in the polarized component of the cosmic microwave background (C-N-113). Each flight will be configured for a single frequency, but in order to aid in the removal of the polarized foreground signal due to Galactic dust, the filters will be changed between flights. In this way, the CMB polarization at a total of four different frequencies (200, 270, 350, and 600 GHz) will be, measured on large angular scales. PIPER consists of a pair of cryogenic telescopes, one for measuring each of Stokes Q and U in the instrument frame. Each telescope receives both linear orthogonal polarizations in two 32 x 40 element planar arrays that utilize Transition-Edge Sensors (TES). The first element in each telescope is a variable-delay polarization modulator (VPM) that fully modulates the linear Stokes parameter to which the telescope is sensitive. There are several advantages to this architecture. First, by modulating at the front of the optics, instrumental polarization is unmodulated and is therefore cleanly separated from source polarization. Second, by implementing this system with the appropriate symmetry, systematic effects can be further mitigated. In the PIPER design, many of the. systematics are manifest in the unmeasured linear Stokes parameter for each telescope and this can be separated from the desired signal. Finally, the modulation cycle never mixes the Q and U linear Stokes parameters, and thus residuals in the modulation do not twist the observed polarization vector. This is advantageous because measuring the angle of linear polarization is critical for separating the inflationary signal from other polarized components.

Chuss, David T.; Ade, Peter A. R.; Benford, Dominic J.; Bennett, Charles L.; Dotson, Jessie L.; Eimer, Joseph R.; Fixsen, Dale J.; Halpern, Mark; Hilton, Gene; Hinderks, James; Hinshaw, Gary; Irwin, Kent; Jackson, Michael L.; Jah, Muzariatu A.; Jethava, Nikhil; Jhabvala, Christine; Kogut, Alan J.; Lowe, Luke; McCullagh, Nuala; Miller, Timothy; Mirel, Paul; Moseley, S. Harvey; Rodriguez, Samelys; Rostem, Karwan; Sharp, Elmer

2010-01-01

55

Analysis of amide compounds in different parts of Piper ovatum Vahl by high-performance liquid chromatographic  

PubMed Central

Background: Piper ovatum (Piperaceae) has been used in traditional medicine for the treatment of inflammations and as an analgesic. Previous studies have showed important biological activities of the extracts and amides from P. ovatum leaves. Objective: In this study, a high-performance liquid chromatographic (HPLC) method was developed and validated for quantitative determination of the amides in different parts of Piper ovatum. Materials and Methods: The analysis was carried out on a Metasil ODS column (150 × 4.6 mm, 5?m) at room temperature. HPLC conditions were as follows: acetonitrile (A), and water (B), 1.0% acetic acid. The gradient elution used was 0–30 min, 0-60% A; 30–40 min, 60% A. Flow rate used was 1.0mL/min, and detection at 280nm. Results: The validation using piperlonguminine, as the standard, demonstrated that the method shows linearity (linear correlation coefficient = 0.998), precision (relative standard deviation <5%) and accuracy (mean recovery = 103.78%) in the concentration range 31.25 – 500?g/mL. The limit of detection and quantification were 1.21 and 4.03?g/mL, respectively. This method allowed the identification and quantification of piperlonguminine and piperovatine in the hydroethanolic extracts of P. ovatum obtained from the leaves, stems and roots. All the extracts showed the same chromatographic profile. The leaves and roots contained the highest concentrations of piperlonguminine and the stems and leaves showed the most concentrations of piperovatine. Conclusion: This HPLC method is suitable for routine quantitative analysis of amides in extracts of Piper ovatum and phytopharmaceuticals containing this herb.

Silva, Daniel R.; Brenzan, Mislaine A.; Kambara, Lauro M.; Cortez, Lucia E. R.; Cortez, Diogenes A. G.

2013-01-01

56

Piper nigrum and piperine: an update.  

PubMed

Black pepper (Piper nigrum L.) is a very widely used spice, known for its pungent constituent piperine. However, in addition to its culinary uses, pepper has important medicinal and preservative properties, and, more recently, piperine has been shown to have fundamental effects on p-glycoprotein and many enzyme systems, leading to biotransformative effects including chemoprevention, detoxification, and enhancement of the absorption and bioavailability of herbal and conventional drugs. Based on modern cell, animal, and human studies, piperine has been found to have immunomodulatory, anti-oxidant, anti-asthmatic, anti-carcinogenic, anti-inflammatory, anti-ulcer, and anti-amoebic properties. In this review, the chemical constituents, biological activities, effects of processing, and future potential of black pepper and piperine have been discussed thoroughly. PMID:23625885

Meghwal, Murlidhar; Goswami, T K

2013-08-01

57

Acaricidal activity and repellency of essential oil from Piper aduncum and its components against Tetranychus urticae.  

PubMed

The chemical composition of essential oil of leaves of Piper aduncum L., growing wild in a fragment of the Atlantic Rainforest biome in northeastern Brazil, was determined through gas chromatography-mass spectrometry. The acaricidal activity and repellency of the essential oil and its components [dillapiole (0.28 g/ml), ?-humulene (0.016 g/ml), (E)-nerolidol (0.0007 g/ml) and ?-caryophyllene (0.0021 g/ml)] were evaluated in the laboratory against adults of Tetranychus urticae Koch. The mites were more susceptible to the oil in fumigation tests (LC(50) = 0.01 ?l/l of air) than in contact test with closed Petri dish (LC(50) = 7.17 ?l/ml); mortality was reduced by approximately 50 % in the latter test. The repellent action of the oil and toxicity by fumigation and contact did not differ significantly from the positive control (eugenol). The repellent activity was attributed to the components (E)-nerolidol, ?-humulene and ?-caryophyllene, whereas toxicity by fumigation and contact was attributed to ?-caryophyllene. The effect of Piper oil and the role of its components regarding host plant preference with a two-choice leaf disk test are also discussed. PMID:22415244

Araújo, Mário J C; Câmara, Cláudio A G; Born, Flávia S; Moraes, Marcílio M; Badji, César A

2012-06-01

58

Derivatives of pheophorbide-a and pheophorbide-b from photocytotoxic Piper penangense extract.  

PubMed

In our screening program for new photosensitizers from Malaysian biodiversity for photodynamic therapy (PDT) of cancer, MeOH extracts of ten terrestrial plants from Cameron Highlands in Pahang, Peninsular Malaysia, were tested. In a short-term 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, 20 ?g/ml each of these extracts were incubated in a pro-myelocytic leukemia cell-line, HL60, with or without irradiation with 9.6 J/cm(2) of a broad spectrum light. Three samples, Labisia longistyla, Dichroa febrifuga, and Piper penangense, were photocytotoxic by having at least twofold lower cell viability when irradiated compared to the unirradiated assay. The extract of the leaves of Piper penangense, a shrub belonging to the family Piperaceae and widely distributed in the tropical and subtropical regions in the world, was subsequently subjected to bioassay-guided fractionation using standard chromatography methods. Eight derivatives of pheophorbide-a and -b were identified from the fractions that exhibited strong photocytotoxicity. By spectroscopic analysis, these compounds were identified as pheophorbide-a methyl ester (1), (R,S)-13(2) -hydroxypheophorbide-a methyl ester (2 and 3), pheophorbide-b methyl ester (4), 13(2) -hydroxypheophorbide-b methyl ester (5), 15(2) -hydroxylactone pheophorbide-a methyl ester (6), 15(2) -methoxylactone pheophorbide-a methyl ester (7), 15(2) -methoxylactone pheophorbide-b methyl ester (8). PMID:21404433

Kamarulzaman, Fadzly Adzhar; Shaari, Khozirah; Ho, Anthony Siong Hock; Lajis, Nordin Haji; Teo, Soo Hwang; Lee, Hong Boon

2011-03-01

59

Bioactivities of Piper aduncum L. and Piper obliquum Ruiz & Pavon (Piperaceae) essential oils from Eastern Ecuador.  

PubMed

Essential oils from aerial parts of Piper aduncum (Matico) and Piper obliquum (Anis del Oriente) of ecuadorian origin were analyzed by GC-FID, GC-MS, (13)C NMR and their biological and pharmacological activities were assessed. Chemical composition proved to be unusually different from previous reports for safrole-rich P. obliquum (45.8%), while P. aduncum main constituent was dillapiol (45.9%). No genotoxic activity was found in the Ames/Salmonella typhimurium (TA98 and TA100) assay, either with or without S9 activation. Mutagen-protective properties, evaluated using sodium azide, 2-nitrofluorene and 2-aminoanthracene as mutagens/promutagens, was observed against promutagen 2-aminoanthracene, likely in consequence of microsomial deactivation. Antimicrobial assays have been performed on Gram+/Gram- bacteria, dermatophyte and phytopathogenic fungi and best results were provided by P. aduncum against fungal strains with complete inhibition at 500?g/ml. Preliminary analgesic and antithrombotic activities evidenced the absence of the former in hot plate and edema assays and a limited antiplatelet action against three different agonists (ADP, AA and U46619). Both oils have a very limited antioxidant capacity. PMID:21783920

Guerrini, Alessandra; Sacchetti, Gianni; Rossi, Damiano; Paganetto, Guglielmo; Muzzoli, Mariavittoria; Andreotti, Elisa; Tognolini, Massimiliano; Maldonado, Maria E; Bruni, Renato

2009-01-01

60

Antiparasitic activity of prenylated benzoic acid derivatives from Piper species.  

PubMed

Fractionation of dichloromethane extracts from the leaves of Piper heterophyllum and P. aduncum afforded three prenylated hydroxybenzoic acids, 3-[(2E,6E,10E)-11-carboxy-3,7,15-trimethyl-2,6,10,14-hexadecatetraenyl)-4,5-dihydroxybenzoic acid, 3-[(2E,6E,10E)-11-carboxy-13-hydroxy-3,7,15-trimethyl-2,6,10,14-hexadecatetraenyl]-4,5-dihydroxybenzoic acid and 3-[(2E,6E,10E)-11-carboxy-14-hydroxy-3,7,15-trimethyl-2,6,10,15-hexadecatetraenyl]-4,5-dihydroxybenzoic acid, along with the known compounds, 4,5-dihydroxy-3-(E,E,E-11-formyl-3,7,15-trimethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid (arieianal), 3,4-dihydroxy-5-(E,E,E-3,7,11,15-tetramethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid, 4-hydroxy-3-(E,E,E-3,7,11,15-tetramethyl-hexadeca-2,6,10,14-tetraenyl)benzoic acid, 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxy-benzoic acid, 4-hydroxy-3-(3,7-dimethyl-2,6-octadienyl)benzoic acid and 4-hydroxy-3-(3-methyl-1-oxo-2-butenyl)-5-(3-methyl-2-butenyl)benzoic acid. Their structures were elucidated on the basis of spectroscopic data, including homo- and heteronuclear correlation NMR experiments (COSY, HSQC and HMBC) and comparison with data reported in the literature. Riguera ester reactions and optical rotation measurements established the compounds as racemates. The antiparasitic activity of the compounds were tested against three strains of Leishmania spp., Trypanosoma cruzi and Plasmodium falciparum. The results showed that 3-(3,7-dimethyl-2,6-octadienyl)-4-methoxy-benzoic acid exhibited potent and selective activity against L. braziliensis (IC(50) 6.5 microg/ml), higher that pentamidine used as control. Moreover, 3-[(2E,6E,10E)-11-carboxy-3,7,15-trimethyl- 2,6,10,14-hexadecatetraenyl)-4,5-dihydroxybenzoic acid and 4-hydroxy-3-(3-methyl-1-oxo-2-butenyl)-5-(3-methyl-2-butenyl)benzoic acid showed moderate antiplasmodial (IC(50) 3.2 microg/ml) and trypanocidal (16.5 microg/ml) activities, respectively. PMID:19361822

Flores, Ninoska; Jiménez, Ignacio A; Giménez, Alberto; Ruiz, Grace; Gutiérrez, David; Bourdy, Genevieve; Bazzocchi, Isabel L

2009-03-01

61

77 FR 45979 - Airworthiness Directives; Piper Aircraft, Inc. Airplanes  

Federal Register 2010, 2011, 2012, 2013

...failure of the horizontal stabilator control system and could result in loss of pitch...inspections of the stabilator control system and replacement of parts as necessary...failure of the horizontal stabilator control system on Piper PA-28, PA-32,...

2012-08-02

62

Child Sacrifice: Black America's Price of Paying the Media Piper.  

ERIC Educational Resources Information Center

Explores the sacrifice of African American children to the broadcast media and video games in terms of the players ("media pipers"), the messages ("piping"), and the consequences to children. Proposes some solutions for the problems associated with excessive television viewing and undesirable programming. (SLD)

Orange, Carolyn M.; George, Amiso M.

2000-01-01

63

Multiple Deletions of the Osmolyte Transporters BetL, Gbu, and OpuC of Listeria monocytogenes Affect Virulence and Growth at High Osmolarity  

PubMed Central

The success of Listeria monocytogenes as a food-borne pathogen owes much to its ability to survive a variety of stresses, both in the food environment and, after ingestion, within the animal host. Growth at high salt concentrations is attributed mainly to the accumulation of organic solutes such as glycine betaine and carnitine. We characterized L. monocytogenes LO28 strains with single, double, and triple deletions in the osmolyte transport systems BetL, Gbu, and OpuC. When single deletion mutants were tested, Gbu was found to have the most drastic effect on the rate of growth in brain heart infusion (BHI) broth with 6% added NaCl. The highest reduction in growth rate was found for the triple mutant LO28BCG (?betL ?opuC ?gbu), although the mutant was still capable of growth under these adverse conditions. In addition, we analyzed the growth and survival of this triple mutant in an animal (murine) model. LO28BCG showed a significant reduction in its ability to cause systemic infection following peroral coinoculation with the wild-type parent. Altering OpuC alone resulted in similar effects (R. D. Sleator, J. Wouters, C. G. M. Gahan, T. Abee, and C. Hill, Appl. Environ. Microbiol. 67:2692-2698, 2001), leading to the assumption that OpuC may play an important role in listerial pathogenesis. Analysis of the accumulation of osmolytes revealed that betaine is accumulated up to 300 ?mol/g (dry weight) when grown in BHI broth plus 6% NaCl whereas no carnitine accumulation could be detected. Radiolabeled-betaine uptake studies revealed an inability of BGSOE (?betL ?gbu) and LO28BCG to transport betaine. Indeed, for LO28BCG, no accumulated betaine was found, but carnitine was accumulated in this strain up to 600 ?mol/g (dry weight) of cells, indicating the presence of a possible fourth osmolyte transporter.

Wemekamp-Kamphuis, Henrike H.; Wouters, Jeroen A.; Sleator, Roy D.; Gahan, Cormac G. M.; Hill, Colin; Abee, Tjakko

2002-01-01

64

Piper betel leaf: a reservoir of potential xenohormetic nutraceuticals with cancer-fighting properties.  

PubMed

Plants contain a much greater diversity of bioactive compounds than any man-made chemical library. Heart-shaped Piper betel leaves are magnificent reservoirs of phenolic compounds with antiproliferative, antimutagenic, antibacterial, and antioxidant properties. Widely consumed in South Asian countries, the glossy leaf contains a multitude of biophenolics such as hydroxychavicol, eugenol, chavibetol, and piperols. Convincing data underscore the remarkable chemotherapeutic and chemopreventive potential of betel leaves against a variety of cancer types. The leaf constituents modulate an extensive array of signaling molecules such as transcription factors as well as reactive oxygen species (ROS) to control multiple nodes of various cellular proliferation and death pathways. Herein, we provide an overall perspective on the cancer-fighting benefits of the phenolic phytochemicals in betel leaves and a comprehensive overview of the mechanisms responsive to dose-driven ROS-mediated signaling cascades conscripted by bioactive phenolics to confer chemotherapeutic and chemopreventive advantages. Intriguingly, these ROS-triggered responses are contextual and may either elicit a protective xenohormetic antioxidant response to premalignant cells to constitute a chemopreventive effect or generate a curative chemotherapeutic response by pro-oxidatively augmenting the constitutively elevated ROS levels in cancer cells to tip the balance in favor of selective apoptosis induction in cancer cells while sparing normal ones. In conclusion, this review provides an update on how distinct ROS levels exist in normal versus cancer cells and how these levels can be strategically modulated and exploited for therapeutic gains. We emphasize the yet untapped potential of the evergreen vine, betel leaf, for chemopreventive and chemotherapeutic management of cancer. PMID:24449055

Gundala, Sushma R; Aneja, Ritu

2014-05-01

65

76 FR 29176 - Airworthiness Directives; Piper Aircraft, Inc. PA-23, PA-31, and PA-42 Airplanes  

Federal Register 2010, 2011, 2012, 2013

...2120-AA64 Airworthiness Directives; Piper Aircraft, Inc. PA-23, PA-31, and PA-42...directive (AD) that applies to Piper Aircraft, Inc. PA-23, PA-31, and PA-42...affect the handling and performance of the aircraft. It could also allow baggage to be...

2011-05-20

66

Chemical study and larvicidal activity against Aedes aegypti of essential oil of Piper aduncum L. (Piperaceae).  

PubMed

Piper aduncum L. is used in folk medicine to treat respiratory and inflammatory diseases. The aim of this study was to analyze the essential oil from leaves of P. aduncum collected in the Brazilian Cerrado, North of Minas Gerais, as well as to evaluate the larvicidal activity of this oil and of its major constituent. The essential oil was analyzed by gas chromatography coupled to flame ionization detector and gas chromatography coupled to mass spectrometry that allowed characterizing 23 compounds (monoterpenes: 90.4%; sesquiterpenes: 7.0%). The major component was 1,8-cineole (53.9%). This oil showed to be very different from those obtained from the same species. Larvae of A. aegypti were exposed to different concentrations of the essential oil and 1,8-cineole. The mortality rate of 100% was obtained after 24 h of treatment with the oil at concentrations of 500 and 1,000 ppm. After 48 h of treatment, the mortality rate was 80% and 50% for concentrations of 250 and 100 ppm, respectively. The LC?? obtained after 24h was estimated in 289.9 ppm and after 48 h was 134.1 ppm. The major compound 1,8-cineole showed no larvicidal activity. PMID:24270836

Oliveira, Gisele L; Cardoso, Sheila K; Lara, Célio R; Vieira, Thallyta M; Guimarães, Elsie F; Figueiredo, Lourdes S; Martins, Ernane R; Moreira, Davyson L; Kaplan, Maria Auxiliadora C

2013-01-01

67

The public inquiry into the Piper Alpha disaster  

SciTech Connect

This paper reviews the causes and results of the Piper Alpha platform disaster and makes recommendations to prevent the reoccurrence of such an event. The author headed the public inquiry into this disaster. As a result he recommends that the safety regulations with regard to offshore operations be completely rewritten to allow for more site-specific and flexible application of safety system designs. Although the paper makes some other specific recommendations on safety systems, the secondary thrust of the paper is on developing more workable evacuation, escape, and rescue plans.

Cullen, L.W.D.

1993-07-01

68

Simulation Model for the Piper PA-30 Light Maneuverable Aircraft in the Final Approach.  

National Technical Information Service (NTIS)

The report describes the Piper PA-30 'Twin Comanche' aircraft and a representative autopilot during the final approach configuration for simulation purposes. The aircraft is modeled by linearized six-degree-of-freedom perturbation equations referenced to ...

J. S. Koziol

1971-01-01

69

Intrinsic anticarcinogenic effects of Piper sarmentosum ethanolic extract on a human hepatoma cell line  

Microsoft Academic Search

BACKGROUND: Piper sarmentosum, locally known as kaduk is belonging to the family of Piperaceae. It is our interest to evaluate their effect on human hepatoma cell line (HepG2) for the potential of anticarcinogenic activity. RESULTS: The anticarcinogenic activity of an ethanolic extract from Piper sarmentosum in HepG2 and non-malignant Chang's liver cell lines has been previously determined using (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide)

Shahrul Hisham Zainal Ariffin; Wan Haifa Haryani Wan Omar; Zaidah Zainal Ariffin; Muhd Fauzi Safian; Sahidan Senafi; Rohaya Megat Abdul Wahab

2009-01-01

70

Aroma compound analysis of Piper nigrum and Piper guineense essential oils from Cameroon using solid-phase microextraction–gas chromatography, solid-phase microextraction–gas chromatography–mass spectrometry and olfactometry  

Microsoft Academic Search

The investigation of aroma compounds of the essential oils of dried fruits of black pepper (Piper nigrum) and black and white “Ashanti pepper” (Piper guineense) from Cameroon by means of solid-phase microextraction (SPME) was carried out for the first time to identify the odorous target components responsible for the characteristic odor of these valuable spices and food flavoring products. By

Leopold Jirovetz; Gerhard Buchbauer; Martin Benoit Ngassoum; Margit Geissler

2002-01-01

71

Piper sarmentosum enhances fracture healing in ovariectomized osteoporotic rats: a radiological study  

PubMed Central

INTRODUCTION: Osteoporotic fractures are common during osteoporotic states. Piper sarmentosum extract is known to possess antioxidant and anti-inflammatory properties. OBJECTIVES: To observe the radiological changes in fracture calluses following administration of a Piper sarmentosum extract during an estrogen-deficient state. METHODS: A total of 24 female Sprague-Dawley rats (200-250 g) were randomly divided into 4 groups: (i) the sham-operated group; (ii) the ovariectomized-control group; (iii) the ovariectomized + estrogen-replacement therapy (ovariectomized-control + estrogen replacement therapy) group, which was supplemented with estrogen (100 µg/kg/day); and (iv) the ovariectomized + Piper sarmentosum (ovariectomized + Piper sarmentosum) group, which was supplemented with a water-based Piper sarmentosum extract (125 mg/kg). Six weeks after an ovariectomy, the right femora were fractured at the mid-diaphysis, and a K-wire was inserted. Each group of rats received their respective treatment for 6 weeks. Following sacrifice, the right femora were subjected to radiological assessment. RESULTS: The mean axial callus volume was significantly higher in the ovariectomized-control group (68.2±11.74 mm3) than in the sham-operated, estrogen-replacement-therapy and Piper sarmentosum groups (20.4±4.05, 22.4±4.14 and 17.5±3.68 mm3, respectively). The median callus scores for the sham-operated, estrogen-replacement-therapy and Piper sarmentosum groups had median (range, minimum - maximum value) as 1.0 (0 - 2), 1.0 (1 - 2) and 1.0 (1 - 2), respectively, which were significantly lower than the ovariectomized-control group score of 2.0 (2 - 3). The median fracture scores for the sham-operated, estrogen-replacement-therapy and Piper sarmentosum groups were 3.0 (3 - 4), 3.0 (2 - 3) and 3.0 (2 - 3), respectively, which were significantly higher than the ovariectomized-control group score of 2.0 (1 - 2) (p<0.05). CONCLUSION: The Piper sarmentosum extract improved fracture healing, as assessed by the reduced callus volumes and reduced callus scores. This extract is beneficial for fractures in osteoporotic states.

Estai, Mohamed Abdalla; Suhaimi, Farihah Haji; Das, Srijit; Fadzilah, Fazalina Mohd; Majedah Idrus Alhabshi, Sharifah; Shuid, Ahmad Nazrun; Soelaiman, Ima-Nirwana

2011-01-01

72

Potential control of Aedes aegypti (Diptera: Culicidae) with Piper aduncum L. (Piperaceae) extracts demonstrated by chromosomal biomarkers and toxic effects on interphase nuclei.  

PubMed

Dillapiol, a phenylpropanoid isolate from essential oils of leaves of Piper aduncum (Piperaceae), has insecticidal, fungicidal and antimicrobial activities. The insecticidal activity of dillapiol was tested in vivo on the larvae and pupae of Aedes aegypti, the mosquito vector of dengue. Specifically, the effect of dillapiol on the formation of micronuclei and chromosome aberrations was analyzed. Dillapiol treatments comprised two concentrations of 200 and 400 micro dissolved in well water, and a pure well water control used to rear four generations of mosquitoes. Micronuclei occurred in mitotic diploid and tetraploid chromosomes of larvae; nuclear abnormalities also occurred in interphase, metaphase, telophase, and single nucleus cells of pupae. Mortality, oviposition, chromosome breakage, and anaphase bridges were significantly greater in the extract treatments than in controls. The genotoxic effects of dillapiol described here suggest that this natural product may be a useful alternative for the control of A. aegypti. PMID:18767246

Rafael, M S; Hereira-Rojas, W J; Roper, J J; Nunomura, S M; Tadei, W P

2008-01-01

73

Histamine release inhibitory activity of Piper nigrum leaf.  

PubMed

Oral administration of a methanolic extract of Piper nigrum leaf (PN-ext, 50, 200 and 500 mg/kg) showed a potent dose-dependent inhibition of dinitrofluorobenzene (DNFB)-induced cutaneous reaction at 1 h [immediate phase response (IPR)] after and 24 h [late phase response (LPR)] after DNFB challenge in mice which were passively sensitized with anti-dinitrophenyl (DNP) IgE antibody. Ear swelling inhibitory effect of PN-ext (50, 200 and 500 mg/kg, per os (p.o.)) on very late phase response (vLPR) in the model mice was significant but weaker than that on IPR. Oral administration of PN-ext (50, 200 and 500 mg/kg for 7 d) inhibited picryl chloride (PC)-induced ear swelling in PC sensitized mice. PN-ext exhibited in vitro inhibitory effect on compound 48/80-induced histamine release from rat peritoneal mast cells. Two lignans of PN-ext, (-)-cubebin (1) and (-)-3,4-dimethoxy-3,4-desmethylenedioxycubebin (2), were identified as major active principles having histamine release inhibitory activity. PMID:18827366

Hirata, Noriko; Naruto, Shunsuke; Inaba, Kazunori; Itoh, Kimihisa; Tokunaga, Masashi; Iinuma, Munekazu; Matsuda, Hideaki

2008-10-01

74

Don't fear the social relations model: reply to Piper, Ogrodniczuk, Lamarche, and Joyce.  

PubMed

By studying actual therapy groups and using a sophisticated design to determine that clients who are held in higher esteem by their fellow group members show greater improvement over the course of therapy, Piper, Ogrodniczuk, Lamarche, and Joyce (this issue) have made a significant contribution to the group psychotherapy literature. Unfortunately, Piper et al. focused much of their discussion on the difficulties they faced using the social relations model (SRM) and the statistical program SOREMO. Although the SRM is not simple and it takes practice to run SOREMO, the analytic alternative proposed by Piper et al. has a number of serious limitations that prevents it from being a viable alternative. There is much to be gained from learning the SRM; for those group therapists and researchers who do not want to learn the SRM, they can always consult or collaborate with SRM researchers. PMID:16643127

Marcus, David K

2006-04-01

75

The developmental basis of an evolutionary diversification of female gametophyte structure in Piper and Piperaceae  

PubMed Central

Background and Aims Fritillaria-type female gametophyte development is a complex, yet homoplasious developmental pattern that is interesting from both evolutionary and developmental perspectives. Piper (Piperaceae) was chosen for this study of Fritillaria-type female gametophyte development because Piperales represent a ‘hotspot’ of female gametophyte developmental evolution and have been the subject of several recent molecular phylogenetic analyses. This wealth of phylogenetic and descriptive data make Piper an excellent candidate for inferring the evolutionary developmental basis for the origin of Fritillaria-type female gametophytes. Methods Developing ovules of Piper peltatum were taken from greenhouse collections, embedded in glycol methacrylate, and serially sectioned. Light microscopy and laser scanning confocal microscopy were combined to produce three-dimensional computer reconstructions of developing female gametophytes. The ploidies of the developing embryos and endosperms were calculated using microspectrofluorometry. Key Results The data describe female gametophyte development in Piper with highly detailed three-dimensional models, and document two previously unknown arrangements of megaspore nuclei during early development. Also collected were microspectrofluorometric data that indicate that Fritillaria-type female gametophyte development in Piper results in pentaploid endosperm. Conclusions The three-dimensional models resolve previous ambiguities in developmental interpretations of Fritillaria-type female gametophytes in Piper. The newly discovered arrangements of megaspore nuclei that are described allow for the construction of explicit hypotheses of female gametophyte developmental evolution within Piperaceae, and more broadly throughout Piperales. These detailed hypotheses indicate that the common ancestor of Piperaceae minus Verhuellia had a Drusa-type female gametophyte, and that evolutionary transitions to derived tetrasporic female gametophyte ontogenies in Piperaceae, including Fritillaria-type female gametophyte development, are the consequence of key nuclear migration and patterning events at the end of megasporogenesis.

Madrid, Eric N.; Friedman, William E.

2009-01-01

76

Activity of neolignans isolated from Piper regnellii (MIQ.) C. DC. var. pallescens (C. DC.) YUNCK against Trypanosoma cruzi.  

PubMed

The in vitro antiproliferative effects of 4 neolignans purified from the ethyl-acetate extract from leaves of Piper regnellii (MIQ.) C. DC. var. pallescens (C. DC.) YUNCK against Trypanosoma cruzi were investigated. These isolated compounds were identified through spectral analyses of UV, EI-MS, 1H-, 13C-NMR, H-H COSY, gNOE, HETCOR, and HMBC. The compounds eupomatenoid-5, eupomatenoid-6, and conocarpan showed considerable activity against epimastigote forms of T. cruzi, with 50% inhibition concentrations (IC50) of 7.0, 7.5, and 8.0 microg/ml respectively. After methylation, these compounds showed a lessened inhibitory activity to the growth of the protozoan, suggesting that loss of the hydroxyl group from their molecules reduces the activity. The compound eupomatenoid-3 showed lower activity than the hexane fraction. Eupomatenoid-5 was significantly more active than benznidazole, the antiparasitic drug of choice for treatment of Chagas' disease. The crude extract, hexane fraction, and eupomatenoid-5 caused no lysis in sheep blood at concentrations which inhibit the growth of epimastigote forms. The compound eupomatenoid-5 showed low cytotoxic effects against Vero cells. These results provide new perspectives on the development of novel drugs obtained from natural products with trypanocidal activity. However, the extracts and active compound isolated from P. regnellii var. pallescens should be further studied in animal models for in vivo efficacy. PMID:17015964

Luize, Patrícia Shima; Ueda-Nakamura, Tânia; Dias Filho, Benedito Prado; Cortez, Diógenes Aparício Garcia; Nakamura, Celso Vataru

2006-10-01

77

A benzoic acid derivative and flavokawains from Piper species as schistosomiasis vector controls.  

PubMed

The search of alternative compounds to control tropical diseases such as schistosomiasis has pointed to secondary metabolites derived from natural sources. Piper species are candidates in strategies to control the transmission of schistosomiasis due to their production of molluscicidal compounds. A new benzoic acid derivative and three flavokawains from Piper diospyrifolium, P. cumanense and P. gaudichaudianum displayed significant activities against Biomphalaria glabrata snails. Additionally, "in silico" studies were performed using docking assays and Molecular Interaction Fields to evaluate the physical-chemical differences among the compounds in order to characterize the observed activities of the test compounds against Biomphalaria glabrata snails. PMID:24762961

Rapado, Ludmila N; Freitas, Giovana C; Polpo, Adriano; Rojas-Cardozo, Maritza; Rincón, Javier V; Scotti, Marcus T; Kato, Massuo J; Nakano, Eliana; Yamaguchi, Lydia F

2014-01-01

78

A six-year simulated-history match of the piper field  

SciTech Connect

This paper describes the techniques applied and the results achieved in matching the six years of production and pressure history of the Piper field. Although Piper is an excellent oilfield it is nevertheless a difficult one to model using numerical simulation techniques. There are complex fluid-flow patterns across non-sealing faults between the offset sand sequences, together with a variable degree of vertical communication across the main reservoir unit. With six years of field data to match, the task was a large one and the question is raised - that, even though a satisfactory historymatch was achieved, to what extent can it be regarded as unique.

King, P.A.; Abdullah, A.; Brindle, D.; Dake, L.P.; Robinson, T.; Waldron, D.

1983-09-01

79

[Oil of Piper longum unsaponifiable matter prevents cholesterol gallstone formation].  

PubMed

To observe the effect of various doses of oil of Piper longum unsaponifiable matter (OPUM) to cholesterol gallstones in experimental mice. C57BL/6 mice (n = 60) were randomly divided into 6 groups: control group, model group, OPUM (15, 30 and 60 mg x kg(-1)) group and ursodeoxycholic acid (UDCA, 60 mg x kg(-1)) group, administered for 10 weeks. The level of serum lipid and liver function enzymes were tested. The gallbladder was removed and bile was obtained by centrifugation. Next, the levels of the bile total cholesterol (TC), phospholipid (PL) and bile acid (TBA) were measured. The indicators of lipid peroxidation were determined and cholesterol saturation index (CSI) was calculated. The liver histological changes were observed by HE staining. The results showed that serum TC, TG (triglycerides) and AST (aspartate transaminase) contents, gallbladder cholesterol crystallization and CSI increased significantly (P < 0.05). In addition, the activity of SOD decreased significantly and MDA content increased significantly in liver (P < 0.05). HE staining results showed that the hepatic cord disorder and intracellular lipid droplets increased significantly. All results indicate that lithogenic diet lead to the formation of cholesterol gallstones. In OPUM (30 and 60 mg x kg(-1)) group, serum TC, TG and AST content, gallbladder cholesterol crystallization and CSI decreased significantly, the activity of SOD increased significantly and MDA content decreased significantly. HE staining results showed that OPUM can improve the morphology of liver cell, reduce the degree of hepatic cord disorders and restore the cell morphology close to normal. The cause of OPUM prevents cholesterol gallstone formation maybe due to protect the integrity of the liver cells, lower CSI, and reduce cholesterol crystal formation and hence prevent cholesterol gallstone formation. PMID:24133988

Xu, Shuang; Hu, Jin-Feng; Chu, Shi-Feng; Han, Ning; Li, Jing-Wei; Li, Yue-Ting; Chen, Nai-Hong

2013-07-01

80

New amide alkaloid from the aerial part of Piper capense L.f. (Piperaceae).  

PubMed

Together with apigenine dimethylether and piperchabamide A, a new amide alkaloid, Kaousine and the Z form of antiepilepsirine were isolated from the aerial part of Piper capense L.f (Piperaceae). Their structures were elucidated by spectrometric methods and their in vitro antiparasitic activities were evaluated on Plasmodium falciparum. PMID:20227469

Kaou, Ali Mohamed; Mahiou-Leddet, Valérie; Canlet, Cécile; Debrauwer, Laurent; Hutter, Sébastien; Azas, Nadine; Ollivier, Evelyne

2010-09-01

81

Bioactive Markers Based Pharmacokinetic Evaluation of Extracts of a Traditional Medicinal Plant, Piper sarmentosum  

Microsoft Academic Search

In vitro assays are economical and easy to perform but to establish relevance of their results to real clinical outcome in animals or human, pharmacokinetics is prerequisite. Despite various in vitro pharmacological activities of extracts of Piper sarmentosum, there is no report of pharmacokinetics. Therefore, present study aimed to evaluate ethanol extract of fruit of the plant in dose of

Khalid Hussain; Zhari Ismail; Amirin Sadikun; Pazillah Ibrahim

82

5,120 Superconducting Bolometers for the PIPER Balloon-Borne CMB Polarization Experiment  

NASA Technical Reports Server (NTRS)

We are constructing the Primordial Inflation Polarization Explorer (PIPER) to measure the polarization o[ the cosmic microwave background (CMB) and search for the imprint of gravity waves produced during an inflationary epoch in the early universe. The signal is faint and lies behind confusing foregrounds, both astrophysical and cosmological, and so many detectors are required to complete the measurement in a limited time. We will use four of our matured 1,280 pixel, high-filling-factor backshort-under-grid bolometer arrays for efficient operation at the PIPER CMB wavelengths. All four arrays observe at a common wavelength set by passband filters in the optical path. PIPER will fly four times to observe at wavelengths of 1500, 1100, 850, and 500 microns in order to separate CMB from foreground emission. The arrays employ leg-isolated superconducting transition edge sensor bolometers operated at 128mK; tuned resonant backshorts for efficient optical coupling; and a second-generation superconducting quantum interference device (SQUID) multiplexer readout. We describe the design, development, and performance of PIPER bo|ometer array technology to achieve background-limited sensitivity for a cryogenic balloon-borne telescope.

Benford, Dominic J.; Chuss, David T.; Hilton, Gene C.; Irwin, Kent D.; Jethava, Nikhil S.; Jhabvala, Christine A.; Kogut, Alan J.; Miller, Timothy M.; Mirel, Paul; Moseley, S. Harvey; Rostem, Karwan; Sharp, Elmer H.; Staguhn, Johannes G.; Stiehl, gregory M.; Voellmer, George M.; Wollack, Edward J.

2010-01-01

83

5,120 Superconducting Bolometers for the PIPER Balloon-Borne CMB Polarization Experiment  

NASA Technical Reports Server (NTRS)

We are constructing the Primordial Inflation Polarization Explorer (PIPER) to measure the polarization of the cosmic microwave background (CMB) and search for the imprint of gravity waves produced during an inflationary epoch in the early universe. The signal is faint and lies behind confusing foregrounds, both astrophysical and cosmological, and so many detectors are required to complete the measurement in a limited time. We will use four of our matured 1,280 pixel, high-filling-factor backshort-under-grid bolometer arrays for efficient operation at the PIPER CMB wavelengths. All four arrays observe at a common wavelength set by passband filters in the optical path. PIPER will fly four times to observe at wavelengths of 1500, 1100, 850, and 500 microns in order to separate CMB from foreground emission. The arrays employ leg-isolated superconducting transition edge sensor bolometers operated at 145 mK; tuned resonant backshorts for efficient optical coupling; and a second-generation superconducting quantum interference device multiplexer readout. We describe the design, development, and performance of PIPER bolometer array technology to achieve background-limited sensitivity for a cryogenic balloon-borne telescope.

Benford, Dominic J.; Chuss, David T.; Hilton, Gene C.; Irwin, Kent D.; Jethava, Nikhil; Jhabvala, Christine A.; Kogut, Alan J.; Miller, Timothy M.; Moseley, S. Harvey; Rostem, Karwan; Sharp, Elmer H.; Staguhn, Johannes G.; Voellmer, George M.; Wollack, Edward J.

2010-01-01

84

Pressurized fluid extraction of carotenoids from Haematococcus pluvialis and Dunaliella salina and kavalactones from Piper methysticum  

Microsoft Academic Search

Pressurized fluid extraction (PFE) was examined as an alternative technology for the extraction of carotenoids in the green algae Haematococcus pluvialis and Dunaliella salina and kavalactones in Piper methysticum. The extraction process was optimized by varying the key extraction factors of solvent, sample-solvent ratio, temperature, and time. The selectivity and efficiency of extraction parameters were determined with high performance liquid

Judith R Denery; Klaus Dragull; C. S Tang; Qing X Li

2004-01-01

85

Views of Astronaut (Col.) Joe Engle and son Jon with L-5 Piper Cub  

NASA Technical Reports Server (NTRS)

Views of Astronaut (Col.) Joe Engle and son Jon with L-5 Piper Cub at Clover Airport. Photos include Engle turning propeller while his son sits in the cockpit (34323); both Engle and son examine propeller (34324); Engle works on engine while his son sits in cockpit (34325).

1981-01-01

86

Pharmacokinetic and pharmacodynamic drug interactions with Kava ( Piper methysticum Forst. f.)  

Microsoft Academic Search

Kava kava, a beverage or extract prepared from the rhizome of the kava plant (Piper methysticum Forst. f.), was used for many centuries as a traditional beverage in the Pacific Islands. During the past few decades, kava has also gained popularity in Western countries as well, due to its anxiolytic and sedative properties. However, in recent years, kava has been

Jennifer Anke; Iqbal Ramzan

2004-01-01

87

Look at Those Leaves!  

NSDL National Science Digital Library

This Science NetLinks lesson begins with students observing leaves in a hands-on activity. As they observe attributes, they will group the leaves and consider any patterns they see emerge. In the second part of this lesson, students will become more familiar with the seasonal changing of leaves.

Science Netlinks;

2002-02-14

88

Improved exposure characterization with robotic (PIPER) sampling and association with children's respiratory symptoms, asthma and eczema.  

PubMed

Particulate matter (PM) and its constituents are recognized risk factors for the development of respiratory symptoms and illness in children. Most measurements of exposure have relied upon stationary indoor monitors (SIMs), overlooking the role of resuspended PM. To improve exposure characterization to resuspended aerosol PM, a recently developed methodology has been employed. The goal of this study was to characterize the resuspendable fraction of house dust and early childhood exposures to PM and its constituents in the child's home and compare conventional SIM and the Pre-toddler Inhalable Particulate Environmental Robotic (PIPER), an innovative mobile sampler. The study seeks to demonstrate that PIPER provides a more relevant estimate of exposure from inhalable particulate matter through improved correlation with respiratory symptoms in young children. Seventy-five households with children between 3 and 59 months of age were recruited from clinics in central New Jersey. Demographic information, and responses to a health questionnaire based upon that used by the International Study of Allergies and Asthma in Childhood (ISAAC), and household data were collected. Household exposures to inhalable PM (PM100) and endotoxin were determined with simultaneous SIM and mobile (PIPER) sampling. Univariate and multivariate analyses were carried out. History of wheeze ("recent" (<1 year) and "ever"), cough, asthma and eczema was evaluated. Multivariate analysis models included PM100 and endotoxin levels by tertiles of exposure. Risk of asthma for the highest tertile of PM100, as measured by PIPER (odds ratio=4.2; 95% confidence interval 0.7-24.0), was compared with measurements by SIM (odds ratio=0.7; 95% confidence interval 0.2-2.6). Measurements of PM and its constituents with PIPER are more strongly associated with asthma, eczema and wheeze compared with measurements using SIMs. Application of this methodology may provide useful insights into early childhood exposures related to the etiology of childhood illnesses associated with inhalation exposures. PMID:24802555

Ramagopal, Maya; Wang, Zuocheng; Black, Kathleen; Hernandez, Marta; Stambler, Adam A; Emoekpere, Osiloke H; Mainelis, Gediminas; Shalat, Stuart L

2014-07-01

89

Piper betel leaf extract: anticancer benefits and bio-guided fractionation to identify active principles for prostate cancer management.  

PubMed

Plant extracts, a concoction of bioactive non-nutrient phytochemicals, have long served as the most significant source of new leads for anticancer drug development. Explored for their unique medicinal properties, the leaves of Piper betel, an evergreen perennial vine, are a reservoir of phenolics with antimutagenic, antitumor and antioxidant activities. Here, we show that oral feeding of betel leaf extract (BLE) significantly inhibited the growth of human prostate xenografts implanted in nude mice compared with vehicle-fed controls. To gain insights into the 'active principles', we performed a bioactivity-guided fractionation of methanolic BLE employing solvents of different polarity strengths using classical column chromatography. This approach yielded 15 fractions, which were then pooled to 10 using similar retention factors on thin-layer chromatographs. Bioactivity assays demonstrated that one fraction in particular, F2, displayed a 3-fold better in vitro efficacy to inhibit proliferation of prostate cancer cells than the parent BLE. The presence of phenols, hydroxychavicol (HC) and chavibetol (CHV), was confirmed in F2 by nuclear magnetic resonance, high-performance liquid chromatography and mass spectroscopy. Further, the HC containing F2 subfraction was found to be ~8-fold more potent than the F2 subfraction that contained CHV, in human prostate cancer PC-3 cells as evaluated by the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide assay. Removing CHV from F2 remarkably decreased the IC50 of this fraction, indicating that HC is perhaps the major bioactive constituent, which is present to an extent of 26.59% in BLE. These data provide evidence that HC is a potential candidate for prostate cancer management and warrants further preclinical evaluation. PMID:23430955

Paranjpe, Rutugandha; Gundala, Sushma R; Lakshminarayana, N; Sagwal, Arpana; Asif, Ghazia; Pandey, Anjali; Aneja, Ritu

2013-07-01

90

Cytotoxic, mutagenic and genotoxic evaluation of crude extracts and fractions from Piper jericoense with trypanocidal action.  

PubMed

The current Chagas disease treatment is based on two drugs, nifurtimox and benznidazole, which is considered unsatisfactory, not only because of the narrow therapeutic range but also because of the associated toxicity. Natural products are considered an important source of biologically active compounds against various infectious organisms. Numerous Piper species are used in traditional medicine to treat parasitic diseases. In this paper, we study the activity of extracts and fractions obtained from Piper jericoense plant against epimastigote, trypomastigote and amastigote forms of Trypanosoma cruzi. In addition, we evaluated the cytotoxic, mutagenic and genotoxic activities of the F4 fraction obtained from one of the more promising extracts. We obtained four extracts, one of which presented low toxicity and high trypanocidal activity. This extract was separated into eight fractions, and the F4 fraction presented better results than the other extracts and had a higher selectivity index than the reference drug, benznidazole. This fraction was not cytotoxic, mutagenic or genotoxic. PMID:24361641

Hamedt, A L; Ortiz, I C; García-Huertas, P A; Sáenz, J; de Araujo, A Caldeira; De Mattos, J C P; Rodríguez-Gazquez, M A; Triana-Chávez, O

2014-03-01

91

Bioefficacy of methanolic root extract of Piper longum L. against isolated strains of Keratinophilic fungi  

PubMed Central

A total of 9 species belonging to 3 genera of keratinophillic fungi were recovered from twelve soil samples collected from different sites in shivamogga using the hair-baiting technique. Most of the fungal species isolated are known to be agents of human and animal infection. The methanolic root extract of Piper longum was evaluated for antifungal activity against the isolated strains to determine the active. It was observed that the extract was effective in inhibiting species with zone of inhibition ranging between 3 mm and 11 mm but the extract showed no zone of inhibition for Chrysosporium keratirophilum. The results indicate that the methanolic root extract of Piper longum might be exploited as natural drug for the treatment of several infection caused by these organisms

Prassanna, Kodagikere Palakshappa; Naika, Raja; Ganapathy, Pasura Subbaiah Sujan

2011-01-01

92

Benzoic acid derivatives from Piper species and their fungitoxic activity against Cladosporium cladosporioides and C. sphaerospermum.  

PubMed

Piper crassinervium, P. aduncum, P. hostmannianum, and P. gaudichaudianum contain the new benzoic acid derivatives crassinervic acid (1), aduncumene (8), hostmaniane (18), and gaudichaudianic acid (20), respectively, as major secondary metabolites. Additionally, 19 known compounds such as benzoic acids, chromenes, and flavonoids were isolated and identified. The antifungal activity of these compounds was evaluated by bioautographic TLC assay against Cladosporium cladosporioides and C. sphaerospermum. PMID:15568762

Lago, João Henrique G; Ramos, Clécio Sousa; Casanova, Diego Campos C; Morandim, Andreia de A; Bergamo, Debora Cristina B; Cavalheiro, Alberto J; Bolzani, Vanderlan da S; Furlan, Maysa; Guimarães, Elsie F; Young, Maria Claudia M; Kato, Massuo J

2004-11-01

93

Studies on the genus Piper. Part IV. Long peppers of Indian commerce  

Microsoft Academic Search

Summary  A review of the literature on the history, uses, and chemical constituents of long pepper is presented. The long peppers of\\u000a Indian commerce are derived from five different species of the genusPiper. Data concerning the geographical sources, cultivation, collection and commerce of each is presented. Distinguishing features\\u000a of the fruits derived from the several species are described. Substantial quantities of

C. K. Atal; J. N. Ojha

1965-01-01

94

Views of Astronaut (Col.) Joe Engle and son Jon with L-5 Piper Cub  

NASA Technical Reports Server (NTRS)

Views of Astronaut (Col.) Joe Engle and son Jon with L-5 Piper Cub at Clover Airport. Photos includes Jon Engle sitting on side door frame working on portion of wing. Joe Engle is behind him working on a wing strut (34329); Joe Engle works on tightening bolt (34330); Jon Engle works on portion of wing which connects to the cockpit. Joe Engle works on connecting strut to wing (34331).

1981-01-01

95

Amygdalin in Prunus leaves  

Microsoft Academic Search

The cyanogenic diglucoside amygdalin was found for the first time in the leaves of mature trees of several Prunus taxa: P. serotina and P. virginiana cv. Schubert of subg. Padus and P. ilicifolia and P. lyonii of subg. Laurocerasus. Leaves of other taxa in both subgenera contained only the monoglucoside prunasin. Amygdalin production was inherited in hybrids between P. padus

Frank S. Santamour

1998-01-01

96

Types of Compound Leaves  

NSDL National Science Digital Library

This illustrated guide is designed to help students recognize and learn the different types of compound leaves. The single Web page can be easily printed for use at field sites. Along with a short description, an illustration that identifies a leaflet and petiole is included for four types of compound leaves.

97

Look At Those Leaves!  

NSDL National Science Digital Library

In this lesson, students will observe, measure, and sort tree leaves. They will examine leaves individually, in groups, and in relationship to the entire tree. As they observe attributes, they will group the leaves according to these attributes and consider any patterns that emerge. In addition, they will communicate what they have learned about leaves in quantitative terms. The activities in this lesson will challenge students to consider how standard units of measurement help clarify for others what they are trying to convey. In the second part of the lesson, students will become more familiar with the seasonal changing of leaves. They will realize that these and other changes repeat themselves and that these patterns of change are called cycles and are part of our environment.

98

Insecticidal activity of piper essential oils from the amazon against the fire ant Solenopsis saevissima (Smith) (Hymenoptera: Formicidae).  

PubMed

Pepper plants in the genus Piper (Piperales: Piperaceae) are common in the Brazilian Amazon and many produce compounds with biological activity against insect pests. We evaluated the insecticidal effect of essential oils from Piper aduncum, Piper marginatum (chemotypes A and B), Piper divaricatum and Piper callosum against workers of the fire ant Solenopsis saevissima (Smith) (Hymenoptera: Formicidae), as well as their chemical composition by gas chromatography and gas chromatography-mass spectrometry. The lowest median lethal concentration (LC50) in 48 h was obtained with the oil of P. aduncum (58.4 mg/L), followed by the oils of P. marginatum types A (122.4 mg/L) and B (167.0 mg/L), P. divaricatum (301.7 mg/L), and P. callosum (312.6 mg/L). The major chemical constituents were dillapiole (64.4%) in the oil of P. aduncum; p-mentha-1(7),8-diene (39.0%), 3,4-methylenedioxypropiophenone (19.0%), and (E)-?-ocimene (9.8%) in P. marginatum chemotype A and (E)-isoosmorhizole (32.2%), (E)-anethole (26.4%), isoosmorhizole (11.2%), and (Z)-anethole (6.0%) in P. marginatum chemotype B; methyleugenol (69.2%) and eugenol (16.2%) in P. divaricatum; and safrole (69.2%), methyleugenol (8.6%), and ?-pinene (6.2%) in P. callosum. These chemical constituents have been previously known to possess insecticidal properties. PMID:23949677

Souto, R N P; Harada, A Y; Andrade, E H A; Maia, J G S

2012-12-01

99

A chromene and prenylated benzoic acid from Piper aduncum  

Microsoft Academic Search

In addition to nerolidol, 2?,6?-dihydroxy-4?-methoxydihydrochalcone, methyl 2,2-dimethyl-8-(3?-methyl-2?-butenyl)-2H-1-chromene-6-carboxylate, methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate and methyl 8-hydroxy-2,2-dimethyl-2H-1-chromene-6-carboxylate, two new natural products were isolated from the leaves of Piperaduncum, 2,2-dimethyl-2H-1-chromene-6-carboxylic acid and 3-(3?,7?-dimethyl-2?,6?-octadienyl)-4-methoxybenzoic acid. The structures of the isolates were established based on analysis of spectroscopic data, including ES–MS. The DNA-damaging activity of the isolated compounds was also investigated against mutant strains of Saccharomyces cerevisiae.

Debora Cristina Baldoqui; Massuo Jorge Kato; Alberto José Cavalheiro; Vanderlan da Silva Bolzani; Maria Claudia M. Young; Maysa Furlan

1999-01-01

100

Falling for Clay Leaves.  

ERIC Educational Resources Information Center

Describes an art project that integrated science and art education. Explains that students create ceramic bowls by using real leaves. Discusses the process of creating the ceramic bowls, including how to glaze the bowls. Includes a list of materials. (CMK)

Kernan, Christine

2002-01-01

101

Different plants produce different leaves  

NSDL National Science Digital Library

Plants produce leaves to gather sunlight and exchange gases in the environment around them. Plants produce leaves unique to that particular plant species. Leaves can have many different shapes, sizes, and colors.

Olivia Worland (Purdue University;Biological Sciences)

2008-06-30

102

Identifying sequences potentially related to resistance response of Piper tuberculatum to Fusarium solani f. sp. piperis by suppression subtractive hybridization.  

PubMed

Piper tuberculatum is an exotic Piper from the Amazon region that shows resistance to infection by Fusarium solani f. sp. piperis, causal agent of Fusarium disease in black pepper (Piper nigrum L.). In this work we aimed to study the interaction between P. tuberculatum and F. solani f. sp. piperis at a molecular level, using suppression subtractive hybridization to identify genes potentially related to Fusarium disease resistance. Comparative sequence analysis confirmed that clones isolated here show a high identity with genes coding for proteins that have a known role in plant defense response mechanisms, such as peroxidase, hydroxyproline-rich glycoprotein and CBL-interacting protein kinase. The present study constitutes the first effort to understand the molecular basis of this plant-pathogen interaction, identifying genes which may be used in the future genetic improvement of black pepper. PMID:20001904

Nascimento, Soelange Bezerra; Cascardo, Júlio Cezar de Mattos; Menezes, Ilmarina Campos de; Duarte, Maria de Lourdes Reis; Darnet, Sylvain; Harada, Maria Lúcia; Souza, Cláudia Regina Batista de

2009-01-01

103

[Studies on the chemical constituents of Piper macropodum C.DC].  

PubMed

Piper macropodum is used in Chinese folk medicine for the treatment of rheumatism, toothache, epilepsy and stomach ache. From the ethanolic extract of the viny stem of this plant five components were isolated, a new compound and four known compounds. On the basis of spectroscopic analysis (IR, UV, MS, 1HNMR and 13CNMR) the structure of this new compound was elucidated as (2E,4E)-N-isobutyl-2,4-icosadienamide (I). The other four compounds were identified as piperine (II), piperyline (III), daucosterol (IV) and beta-sitosterol (V). All of them were isolated from this species for the first time. PMID:2618672

Hou, C Y; Zhang, J Q; Zhang, Y M; Liu, Y L

1989-01-01

104

Leaves: Nature's Solar Collectors  

ERIC Educational Resources Information Center

One of the most captivating things about plants is the way they capture the Sun's energy, but this can be a difficult topic to cover with elementary students. Therefore, to help students to make a concrete connection to this abstract concept, this series of solar-energy lessons focuses on leaves and how they act as "solar collectors." As students…

Isabelle, Aaron D.; de Groot, Cornelis

2009-01-01

105

Maternity Leave in Taiwan  

PubMed Central

Using the first nationally representative birth cohort study in Taiwan, this paper examines the role that maternity leave policy in Taiwan plays in the timing of mothers returning to work after giving birth, as well as the extent to which this timing is linked to the amount of time mothers spend with their children and their use of breast milk versus formula. We found that the time when mothers returned to work coincided with the duration of guaranteed leave. In particular, mothers with a labor pension plan resumed work significantly earlier than mothers with no pension plan, and mothers with no pension plan returned to work significantly later than those with pension plans. The short leave of absence guaranteed under existing policies translated into mothers spending less time with their children and being more likely to exclusively use formula by 6 months after birth. In contrast, mothers who resumed work later than 6 months after birth were more likely to have not worked before birth or to have quit their jobs during pregnancy. Implications and recommendations for parental leave policy in Taiwan are discussed.

Feng, Joyce Yen; Han, Wen-Jui

2011-01-01

106

Legacies and Leaving Home.  

ERIC Educational Resources Information Center

Explores the role that mothers' and grandmothers' legacies have in the home-leaving transition of adolescent girls from a rural setting. Results suggest issues that school counselors might explore using the concept of legacy, including: distance from home; attachment to families; adolescent girls' interpretation of what it means to be a woman; and…

Daigneault, Susan Dahlgren

1999-01-01

107

Levodopa reversible loss of the Piper frequency oscillation component in Parkinson's disease  

PubMed Central

OBJECTIVES—Although Parkinson's disease is typically characterised by bradykinesia, rigidity, and rest tremor, the possibility that two additional motor deficits are manifest during small hand muscle activity was explored—namely, weakness and abnormal physiological tremor.?METHODS—A paradigm previously used in normal subjects reliably records the strength, tremor and surface EMG of index finger abducting contractions against a compliant (elastic) resistance. In addition to the well known physiological tremor at around 10 Hz, there are other co existing peak tremor frequencies at around 20 and 40 Hz; the last of these frequencies corresponds to the range of EMG Piper rhythm. The same technique was used to study parkinsonian patients while on and off dopaminergic medication.?RESULTS—The maximum strength of finger abduction produced by first dorsal interosseous contraction was considerably lower when patients were off medication (mean (SD) 6.27 (1.49) N when off v 12.33(3.64) N when on). There was also a marked reduction in the power of Piper frequency finger tremor (p<0.0005) and EMG (p<0.0005) oscillations that did not simply result from weaker contraction.?CONCLUSION—As the components of physiological tremor at higher frequencies are thought to derive from CNS oscillations important in motor control, their loss in parkinsonism in association with severe off symptoms may represent an important pathophysiological link between dopaminergic depletion and parkinsonian motor deficits.??

McAuley, J; Corcos, D; Rothwell, J; Quinn, N; Marsden, C

2001-01-01

108

The complete genome sequence of Piper yellow mottle virus (PYMoV).  

PubMed

This study reports the first complete genome sequence of Piper yellow mottle virus (PYMoV, KC808712) identified in black pepper. The genome is 7,622 nucleotides long, possessing four open reading frames (ORFs). ORF1, ORF2 and ORF4 of PYMoV are reported as hypothetical proteins of unknown function with a predicted molecular mass of 15.7, 17.1 and 17.9 kDa, respectively. ORF3 of PYMoV encodes a polyprotein of 218.6 kDa and consists of a viral movement protein (MP), trimeric dUTPase, zinc finger, retropepsin, RT-LTR, and RNAse H. Detailed PYMoV genome analysis confirmed that it is a member of the family Caulimoviridae, genus Badnavirus. Fragments of two additional novel sequences resembling those found in members of the family Caulimoviridae were also identified in the black pepper sample, and the viruses from which they were derived were tentatively named Piper DNA virus 1 and 2. PMID:24005374

Hany, U; Adams, I P; Glover, R; Bhat, A I; Boonham, N

2014-02-01

109

Chemical composition of essential oils from four Vietnamese species of piper (piperaceae).  

PubMed

The chemical composition of essential oils from four Piper species, Piper retrofractum Vahl., P. boehmeriaefolium (Miq.) C. DC., P. sarmentosum Roxb., and P. maclurei Merr., were analysed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Nineteen to sixty-four compounds representing 92.0%-98.4% of the total contents were identified in the oil samples. The major constituents identified in P. retrofractum leaf oil were benzyl benzoate (14.4%), myrcene (14.4%), bicycloelemene (9.9%), bicyclogermacrene (7.0%) and ?-caryophyllene (5.3%). On the other hand, the main constituents of P. boehmeriaefolium were ?-copaene (28.3%), ?-pinene (7.4%) and 1, 8-cineole (5.7%). P. sarmentosum showed a very different chemical profile characterized mainly by aromatic compounds and devoid of monoterpene hydrocarbons. The major constituents were benzyl benzoate (49.1%), benzyl alcohol (17.9%), 2-hydroxy-benzoic acid phenylmethyl ester (10.0%) and 2-butenyl-benzene (7.9%). The leaf of P. maclurei was characterized by higher amount of (E)-cinnamic acid (37.4%) and (E)-nerolidol (19.4%). Moreover, (Z)-9-octadecanoic acid methyl ester (28.0%), (E)-cinnamyl acetate (17.2%), phytol (12.2%) and (E)-cinnamaldehyde (8.8%) were the major compounds identified in the stem oil. PMID:24712088

Hieu, Le D; Thang, Tran D; Hoi, Tran M; Ogunwande, Isiaka A

2014-01-01

110

Analysis of plant extracts by NIRS: simultaneous determination of kavapyrones and water in dry extracts of Piper methysticum Forst  

Microsoft Academic Search

A near-infrared reflection spectroscopy (NIRS) method was developed to determine the total content of kavapyrones, kavain and water in dry extracts of Piper methysticum Forst. (kava kava, Piperaceae). Based on the recorded spectra and the reference data, performed by HPLC and Karl Fischer titration, a chemometrical analysis was calculated using PLS 2 algorithm. In general, good calibration statistics are obtained

M. Gaub; Ch. Roeseler; G. Roos; K.-A. Kovar

2004-01-01

111

Soil seed banks and growth rates of an invasive species, Piper aduncum, in the lowlands of Papua New Guinea  

Microsoft Academic Search

Secondary fallow vegetation in parts of the Papua New Guinea lowlands is dominated by the shrub Piper aduncum L. that originates from South America. Here we report on its seed bank, growth rate and biomass accumulation. P. aduncum accounted for 69 % (408 m[minus sign]2) of the seed bank in the forest and 53 % (1559 m[minus sign]2) of the

Howard M. Rogers; Alfred E. Hartemink

2000-01-01

112

Aircraft Accident Report - Las Vegas Airlines Flight 88, Piper PA-31-350, Grand Canyon, Arizona, August 17, 1983.  

National Technical Information Service (NTIS)

On August 17, 1983, Las Vegas Airlines Flight 88, a Piper PA-31-350, N88LV, was being operated as a scheduled Grand Canyon sightseeing flight from Las Vegas, Nevada, to Tusayan, Arizona. Weather conditions precluded the pilot of Las Vegas 88 from flying o...

1984-01-01

113

Geographic Variation in Host-Specificity and Parasitoid Pressure of an Herbivore (Geometridae) Associated with the Tropical Genus Piper (Piperaceae)  

PubMed Central

The extraordinary diversity of tropical herbivores may be linked to hostplant specialization driven in part by variation in pressure from natural enemies. We quantified levels of host-specificity and parasitoid attack for the specialist herbivore, Eois (Geometridae). The goals of this research were to examine: 1) whether Eois are specialized on the genus Piper (Piperaceae) and if hostplant specialization varies geographically; 2) whether Eois are equally vulnerable to parasitoid attack across different geographic regions and by the same parasitoid families; and 3) whether parasitism levels vary with precipitation and elevation. Based on over 15,000 rearings, we found Eois caterpillars feeding exclusively on Piper. However, we did not detect geographic differences in host-specificity; each Eois species fed on an average of two Piper species. Parasitism levels of Eois varied significantly with climate and topography; Eois were most vulnerable to parasitoid attack in moist versus dry and wet forests and at low versus high elevations. The diversity of parasitoid families reared from Eois was greater in Ecuador and Costa Rica than in Panama, where parasitoids were primarily in the family Braconidae. The quantitative evidence for host-specificity provides support for the hypothesis that Eois are specialized on Piper. Our results also reveal that Eois are exposed to a mosaic of potential selective pressures due to variation in parasitoid attack over a large spatial scale.

Connahs, Heidi; Rodriguez-Castaneda, Genoveva; Walters, Toni; Walla, Thomas; Dyer, Lee

2009-01-01

114

Dynamic stomatal behavior and its role in carbon gain during lightflecks of a gap phase and an understory Piper species acclimated to high and low light  

Microsoft Academic Search

Steady-state and dynamic stomatal and assimilation responses to light transients were characterized in sun- and shade-acclimated plants of Piper auritum, a pioneer tree, and Piper aequale a shade-tolerant shrub from a tropical forest at Los Tuxtlas, Veracruz, México. Despite essentially identical steady-state responses of stomatal conductance to PFD of P. aequale and P. auritum shade plants, the dynamic responses to

Clara Tinoco-Ojanguren; Robert W. Pearcy

1992-01-01

115

Parental leave and child health  

Microsoft Academic Search

This study investigates whether rights to parental leave improve pediatric health. Aggregate data are used for 16 European countries over the 1969 through 1994 period. More generous paid leave is found to reduce deaths of infants and young children. The magnitudes of the estimated effects are substantial, especially where a causal effect of leave is most plausible. In particular, there

Christopher J. Ruhm

2000-01-01

116

Placing the origin of two species-rich genera in the late cretaceous with later species divergence in the tertiary: a phylogenetic, biogeographic and molecular dating analysis of Piper and Peperomia (Piperaceae)  

Microsoft Academic Search

Nearly all of the species diversity in Piperaceae is encompassed within Piper and Peperomia. Both genera are pan-tropical with areas of diversification in the Neotropics and Southeast Asia. Piperaceae are less diverse\\u000a in Africa with only two native species of Piper. This study examines the distribution of both Piper and Peperomia with representative samples from the Neotropics, Asia, Pacific Islands,

James F. Smith; Angela C. Stevens; Eric J. Tepe; Chris Davidson

2008-01-01

117

Preventable disasters in the offshore oil industry: from Piper Alpha to Deepwater Horizon.  

PubMed

This article compares two industrial disasters in the offshore oil industry, the explosion and fire on Piper Alpha off the coast of Scotland in 1988, the world's worst offshore disaster, and the blowout and explosions on Deepwater Horizon in the Gulf of Mexico in 2010. It attempts to answer a simple question: Given the enormity of the first tragedy and the careful analysis of its circumstances and causes, why were the lessons of previous failure not learned by this globally organized industry, in the very heartland in the United States? The answer tells us much about the ability of corporate capital to configure regulatory regimes in its own interests and to do so in a manner that continues to threaten the safety and well-being of its employees and the wider environment. PMID:23384815

Woolfson, Charles

2012-01-01

118

Antileishmanial activities of dihydrochalcones from piper elongatum and synthetic related compounds. Structural requirements for activity.  

PubMed

Two dihydrochalcones (1 and 2) were isolated from Piper elongatum Vahl by activity-guided fractionation against extracellular promastigotes of Leishmania braziliensis in vitro. Their structures were elucidated by spectral analysis, including homonuclear and heteronuclear correlation NMR experiments. Derivatives 3-7 and 20 synthetic related compounds (8-27) were also assayed to establish the structural requirements for antileishmanial activity. Compounds 1-11 that proved to be more active that ketoconazol, used as positive control, were further assayed against promastigotes of Leishmania tropica and Leishmania infantum. Compounds 7 and 11, with a C(6)-C(3)-C(6) system, proved to be the most promising compounds, with IC(50) values of 2.98 and 3.65 microg/mL, respectively, and exhibited no toxic effect on macrophages (around 90% viability). Correlation between the molecular structures and antileishmanial activity is discussed in detail. PMID:12927858

Hermoso, Alicia; Jiménez, Ignacio A; Mamani, Zulma A; Bazzocchi, Isabel L; Piñero, José E; Ravelo, Angel G; Valladares, Basilio

2003-09-01

119

Evaluation of Piper aduncum Linn. Essential Oil (Fam:Piperaceae) against Periplaneta americana (L.)  

PubMed Central

Background: The efficacy of Piper aduncum essential oil was evaluated against Periplaneta americana adults and nymphs in the laboratory. Methods: The plant essential oil at varying concentrations ranging between 10,000 to 80,000 ppm were placed inside glass beakers, rolled horizontally to ensure the essential oil covers all sides of the beakers and exposed to adults and nymphs of P. americana. Resigen (R) 1ppm was used as positive control and distilled water as negative control. The LT50 and LT90 was obtained using Log Probit programme. Results: Exposure of essential oil to females P. americana at concentrations between 10,000 to 80,000 ppm indicated the LT50 and LT90 values between 5.31 h–189.19 h and 14.90 h–2105.31 h, respectively. Treatment with the same concentrations against males P. americana ,the LT50 and LT90 were 2.08 h–181.73 h and 5.4 h–8460.51 h, respectively. Treatment against the nymphal stage with the same range of concentrations indicated the LT50 and LT 90 of 4.68 h–381.02 h and 28.71 h–5313.36 h, respectively.The nymphs and males were more susceptible than the females cockroaches. Treatment with Resigen (R) at 1ppm indicated much lower LT 50 and LT 90 values of 2.54 h–9.47 h for the females, 1.47 h–4.22 h for the males and 4.69 h–8.92 h for the nymphs.The negative control indicated no mortality for all stages of the cockroach. Conclusion: Piper aduncum essential oil can be used as an alternative natural product for controlling the cockroach Peripatetic americana.

Ling A, I; Sulaiman, S; Othman, H

2009-01-01

120

Antioxidant activity of some phenolic constituents from green pepper ( Piper nigrum L.) and fresh nutmeg mace ( Myristica fragrans)  

Microsoft Academic Search

Antioxidant potential of phenolic compounds from green pepper (Piper nigrum L.) and lignans from fresh mace (Myristica fragrans) were evaluated for their ability to scavenge 1,1?-diphenyl-2-picrylhydrazyl (DPPH) radical, inhibit lipid peroxidation and protect plasmid DNA damage upon exposure to gamma radiation. EC50 values of the major phenolic compounds of green pepper namely, 3,4-dihydroxyphenyl ethanol glucoside, 3,4-dihydroxy-6-(N-ethylamino) benzamide and phenolic acid

Suchandra Chatterjee; Zareena Niaz; S. Gautam; Soumyakanti Adhikari; Prasad S. Variyar; Arun Sharma

2007-01-01

121

Development and in-home testing of the Pretoddler Inhalable Particulate Environmental Robotic (PIPER Mk IV) sampler.  

PubMed

Exposure and dose estimation are essential to understanding the etiology of environmentally linked childhood diseases. The behavior of resuspended particulate matter (PM) suggests that stationary measurements may underestimate household exposures in young children (ages 6-36 months). Because of the size and weight of the sampling equipment, use of personal samplers in this age group is either difficult or impossible. The Pretoddler Inhalable Particulate Environmental Robotic (PIPER Mk IV) sampler has been developed to provide a surrogate method to ascertain personal exposures to PM for this age group. As part of a study of childhood asthma, 55 homes in central New Jersey were tested. Simultaneous sampling for inhalable PM using stationary (110 cm height) and PIPER mobile sampler were carried out. In homes with bare floors (N=21), the absolute difference was 3.9 ?g/m3 (SE=3.01; p=0.217) and relative difference (PIPER/Stationary) was 1.12 (linearized SE=0.11). On carpets (N=34), the absolute difference was 54.1 ?g/m3 (SE=13.50; p=0.0003), and the relative difference was 2.30 (linearized SE=0.34). The results confirm the importance of understanding the personal dust cloud caused by children's activity in a room, particularly when rugs or carpets are present. PMID:21351766

Shalat, Stuart L; Stambler, Adam A; Wang, Zuocheng; Mainelis, Gediminas; Emoekpere, Osiloke H; Hernandez, Marta; Lioy, Paul J; Black, Kathleen

2011-04-01

122

Who leaves against medical advice?  

PubMed

Patients who leave hospitals against medical advice (AMA) frustrate physicians and may put themselves at medical risk. A case-control study was conducted to characterize the factors associated with AMA discharges from an impatient medical service. Logistic regression analysis indicated that not having a primary care physician and previous AMA discharge were significantly associated with leaving AMA. The patients most often stated that they were leaving because they "felt better" or had personal or financial obligations. However, the patients leaving AMA were more likely to return for care within the next week than were the control patients. PMID:7472691

Jeremiah, J; O'Sullivan, P; Stein, M D

1995-07-01

123

Parental Leave Policies and Parents' Employment and Leave-Taking  

ERIC Educational Resources Information Center

We describe trends in maternal employment and leave-taking after birth of a newborn and analyze the extent to which these behaviors are influenced by parental leave policies. Data are from the June Current Population Survey (CPS) Fertility Supplements, merged with other months of the CPS, and cover the period 1987 to 1994. This time span is one…

Han, Wen-Jui; Ruhm, Christopher; Waldfogel, Jane

2009-01-01

124

Intrinsic anticarcinogenic effects of Piper sarmentosum ethanolic extract on a human hepatoma cell line  

PubMed Central

Background Piper sarmentosum, locally known as kaduk is belonging to the family of Piperaceae. It is our interest to evaluate their effect on human hepatoma cell line (HepG2) for the potential of anticarcinogenic activity. Results The anticarcinogenic activity of an ethanolic extract from Piper sarmentosum in HepG2 and non-malignant Chang's liver cell lines has been previously determined using (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) (MTT) assays, where the IC50 value was used as a parameter for cytotoxicity. The ethanolic extract that showed anticarcinogenic properties in HepG2 cells had an IC50 of 12.5 ?g mL-1, while IC50 values in the non-malignant Chang's liver cell line were greater than 30 ?g mL-1. Apoptotic morphological changes in HepG2 cells were observed using an inverted microscope and showed chromatin condensation, cell shrinkage and apoptotic bodies following May-Grunwald-Giemsa's staining. The percentage of apoptotic cells in the overall population (apoptotic index) showed a continuously significant increase (p < 0.05) in 12.5 ?g mL-1 ethanolic extract-treated cells at 24, 48 and 72 hours compared to controls (untreated cells). Following acridine orange and ethidium bromide staining, treatment with 10, 12 and 14 ?g mL-1 of ethanolic extracts caused typical apoptotic morphological changes in HepG2 cells. Molecular analysis of DNA fragmentation was used to examine intrinsic apoptosis induced by the ethanolic extracts. These results showed a typical intrinsic apoptotic characterisation, which included fragmentation of nuclear DNA in ethanolic extract-treated HepG2 cells. However, the non-malignant Chang's liver cell line produced no DNA fragmentation. In addition, the DNA genome was similarly intact for both the untreated non-malignant Chang's liver and HepG2 cell lines. Conclusion Therefore, our results suggest that the ethanolic extract from P. sarmentosum induced anticarcinogenic activity through an intrinsic apoptosis pathway in HepG2 cells in vitro.

Zainal Ariffin, Shahrul Hisham; Wan Omar, Wan Haifa Haryani; Zainal Ariffin, Zaidah; Safian, Muhd Fauzi; Senafi, Sahidan; Megat Abdul Wahab, Rohaya

2009-01-01

125

See the Colors in Leaves  

NSDL National Science Digital Library

Learners use chromatography to separate and analyze the mixture of pigments in leaves. Use this activity to discuss photosynthesis as well as why leaves change color in autumn. Safety note: Nail polish remover is flammable; do not use near heat. It also is harmful if ingested. Adult supervision recommended.

Museum Of Science And Industry, Chicago

2012-01-01

126

Thermographic measurements on plant leaves  

Microsoft Academic Search

An important process of plant physiology is the transpiration of plant leaves. It is actively controlled by pores (stomata) in the leaf and the governing feature for vital factors such as gas exchange and water transport affixed to which is the nutrient transport from the root to the shoot. Because of its importance, the transpiration and water transport in leaves

Christoph Garbe; Ulrich Schurr; Bernd Jaehne

2002-01-01

127

Learning from the Piper Alpha accident: A postmortem analysis of technical and organizational factors  

SciTech Connect

The accident that occurred on board the offshore platform Piper Alpha in July 1988 killed 167 people and cost billions of dollars in property damage. It was caused by a massive fire, which was not the result of an unpredictable act of God' but of an accumulation of errors and questionable decisions. Most of them were rooted in the organization, its structure, procedures, and culture. This paper analyzes the accident scenario using the risk analysis framework, determines which human decision and actions influenced the occurrence of the basic events, and then identifies the organizational roots of these decisions and actions. These organizational factors are generalizable to other industries and engineering systems. They include flaws in the design guidelines and design practices (e.g., tight physical couplings or insufficient redundancies), misguided priorities in the management of the tradeoff between productivity and safety, mistakes in the management of the personnel on board, and errors of judgement in the process by which financial pressures are applied on the production sector (i.e., the oil companies' definition of profit centers) resulting in deficiencies in inspection and maintenance operations. This analytical approach allows identification of risk management measures that go beyond the purely technical (e.g., add redundancies to a safety system) and also include improvements of management practices. 18 refs., 4 figs.

Pate-Cornell, M.E. (Stanford Univ., CA (United States))

1993-04-01

128

Nephroprotective effect of Kabab chini (Piper cubeba) in gentamycin-induced nephrotoxicity.  

PubMed

Kabab chini (KC) (Piper cubeba) is an important drug in Unani Medicine, widely described to be effective in renal diseases, and physicians are using it as a protective and curative agent in various renal disorders from ancient times. The present study was designed to evaluate the nephroprotective effect of KC against gentamycin-induced nephrotoxicity in Wistar rats. This was studied in two different sets of tests, in which both the protective as well as the curative effects were evaluated in groups of albino rats. The powder of the test drug was administered orally in a dose of 810 mg/kg and 1220 mg/kg, in suspension form, in the pre- and post-treated models. The nephroprotective effect was assessed on the basis of biochemical estimation of serum urea and creatinine levels and histopathological examination of the treated kidney. The effect observed in the pre-treated and post-treated groups was compared with plain as well as negative control groups using one-way ANOVA with Dunnett's multiple pair comparison test. The findings of the two tests demonstrated that KC produced a significant nephroprotective effect in both pre-treated and post-treated groups. The results of our study indicate that KC possesses significant benefit against gentamycin-induced nephrotoxicity. PMID:22805390

Ahmad, Qazi Zaid; Jahan, Nasreen; Ahmad, Ghufran

2012-07-01

129

Chemistry and in vitro antioxidant activity of volatile oil and oleoresins of black pepper (Piper nigrum).  

PubMed

Essential oil and oleoresins (ethanol and ethyl acetate) of Piper nigrum were extracted by using Clevenger and Soxhlet apparatus, respectively. GC-MS analysis of pepper essential oil showed the presence of 54 components representing about 96.6% of the total weight. beta-Caryophylline (29.9%) was found as the major component along with limonene (13.2%), beta-pinene (7.9%), sabinene (5.9%), and several other minor components. The major component of both ethanol and ethyl acetate oleoresins was found to contain piperine (63.9 and 39.0%), with many other components in lesser amounts. The antioxidant activities of essential oil and oleoresins were evaluated against mustard oil by peroxide, p-anisidine, and thiobarbituric acid. Both the oil and oleoresins showed strong antioxidant activity in comparison with butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) but lower than that of propyl gallate (PG). In addition, their inhibitory action by FTC method, scavenging capacity by DPPH (2,2'-diphenyl-1-picrylhydrazyl radical), and reducing power were also determined, proving the strong antioxidant capacity of both the essential oil and oleoresins of pepper. PMID:19456163

Kapoor, I P S; Singh, Bandana; Singh, Gurdip; De Heluani, Carola S; De Lampasona, M P; Catalan, Cesar A N

2009-06-24

130

Synergistic effects of three Piper amides on generalist and specialist herbivores.  

PubMed

The tropical rainforest shrub Piper cenocladum, which is normally defended against herbivores by a mutualistic ant, contains three amides that have various defensive functions. While the ants are effective primarily against specialist herbivores, we hypothesized that these secondary compounds would be effective against a wider range of insects, thus providing a broad array of defenses against herbivores. We also tested whether a mixture of amides would be more effective against herbivores than individual amides. Diets spiked with amides were offered to five herbivores: a naïve generalist caterpillar (Spodoptera frugiperda), two caterpillar species that are monophagous on P. cenocladum (Eois spp.), leaf-cutting ants (Atta cephalotes), and an omnivorous ant (Paraponera clavata). Amides had negative effects on all insects, whether they were naïve, experienced, generalized, or specialized feeders. For Spodoptera, amide mixtures caused decreased pupal weights and survivorship and increased development times. Eois pupal weights, larval mass gain, and development times were affected by additions of individual amides, but increased parasitism and lower survivorship were caused only by the amide mixture. Amide mixtures also deterred feeding by the two ant species, and crude plant extracts were strongly deterrent to P. clavata. The mixture of all three amides had the most dramatic deterrent and toxic effects across experiments, with the effects usually surpassing expected additive responses, indicating that these compounds can act synergistically against a wide array of herbivores. PMID:14682530

Dyer, L A; Dodson, C D; Stireman, J O; Tobler, M A; Smilanich, A M; Fincher, R M; Letourneau, D K

2003-11-01

131

Chemical variation in Piper aduncum and biological properties of its dillapiole-rich essential oil.  

PubMed

The essential oils of the specimens of Piper aduncum that occur in deforested areas of Brazilian Amazon, North Brazil, are rich in dillapiole (35-90%), a derivative of phenylpropene, to which are attributed biological properties. On the other hand, the oils of the specimens with occurrence in the Atlantic Forest, and Northeastern and Southeastern Brazil, do not contain dillapiole, but only terpene compounds such as (E)-nerolidol and linalool. One specimen existing in the Amazon was hydrodistilled. The obtained oil was fractioned on a silica chromatographic column, resulting in fractions rich in dillapiole (95.0-98.9%) utilized for analyses by GC and GC/MS, structural characterization by NMR, confirmation of their biological properties, and to obtain the isomer isodillapiole. Dillapiole showed a fungicide action against the fungus Clinipellis perniciosa (witches' broom) by inhibition of its basidiospores, in concentrations ranging from 0.6 to 1.0 ppm. The larvicide and insecticide actions of dillapiole were tested against the larvae and the adult insects of Anopheles marajoara and Aedes aegypti (malaria and dengue mosquitoes), resulting in mortality of the larvae (48 h, 100%) at a concentration of 100 ppm, and mortality of the insects (30 min, 100%) at a concentration of 600 ppm. The isomeric isodillapiole showed no significant activity in the same biological tests. PMID:19774604

de Almeida, Roseli R P; Souto, Raimundo N P; Bastos, Cleber N; da Silva, Milton H L; Maia, José G S

2009-09-01

132

Selective Effect of 2?,6?-Dihydroxy-4?-Methoxychalcone Isolated from Piper aduncum on Leishmania amazonensis  

PubMed Central

2?,6?-Dihydroxy-4?-methoxychalcone (DMC) was purified from the dichloromethane extract of Piper aduncum inflorescences. DMC showed significant activity in vitro against promastigotes and intracellular amastigotes of Leishmania amazonensis, with 50% effective doses of 0.5 and 24 ?g/ml, respectively. Its inhibitory effect on amastigotes is apparently a direct effect on the parasites and is not due to activation of the nitrogen oxidative metabolism of macrophages, since the production of nitric oxide by both unstimulated and recombinant gamma interferon-stimulated macrophages was decreased rather than increased with DMC. The phagocytic activity of macrophages was functioning normally even with DMC concentrations as high as 80 ?g/ml, as seen by electron microscopy and by the uptake of fluorescein isothiocyanate-labeled beads. Ultrastructural studies also showed that in the presence of DMC the mitochondria of promastigotes were enlarged and disorganized. Despite destruction of intracellular amastigotes, no disarrangement of macrophage organelles were observed, even at 80 ?g of DMC/ml. These observations suggest that DMC is selectively toxic to the parasites. Its simple structure may well enable it to serve as a new lead compound for the synthesis of novel antileishmanial drugs.

Torres-Santos, Eduardo Caio; Moreira, Davyson Lima; Kaplan, Maria Auxiliadora C.; Meirelles, Maria Nazareth; Rossi-Bergmann, Bartira

1999-01-01

133

Repellency of essential oil of Piper aduncum against Aedes albopictus in the laboratory.  

PubMed

The repellent activity of Piper aduncum essential oil against Aedes albopictus was investigated under laboratory conditions with human volunteers. The lowest median effective dose (ED50) value was 1.5 microg/cm2 at 60 sec of exposure when compared to 90 sec (2.1 microg/cm2) and 120 sec (1.8 microg/cm2) of exposure. At 0.4 g, the essential oil gave a high protection (95.2%) against Ae. albopictus bites or landing at 2 h postapplication. The percentage of protection was reduced to 83.3% after 4 h, 64.5% after 6 h, and 51.6% after 8 h postapplication. As a comparison, treatment with 10% deet gave 100% protection against mosquito biting/landing for 4 h postapplication. There was no significant difference in percentage protection reduction between the plant extract and the commercial product deet, respectively (P = 0.739). The essential oil, which was not as good as deet, still gave moderate protection against Ae. albopictus biting even until 4 h postapplication. In conclusion, the P. aduncum essential oil has the potential to be used as a repellent against the dengue/dengue hemorrhagic fever vector, Ae. albopictus. PMID:20099591

Misni, Norashiqin; Sulaiman, Sallehudin; Othman, Hidayatulfathi; Omar, Baharudin

2009-12-01

134

Selective effect of 2',6'-dihydroxy-4'-methoxychalcone isolated from Piper aduncum on Leishmania amazonensis.  

PubMed

2',6'-Dihydroxy-4'-methoxychalcone (DMC) was purified from the dichloromethane extract of Piper aduncum inflorescences. DMC showed significant activity in vitro against promastigotes and intracellular amastigotes of Leishmania amazonensis, with 50% effective doses of 0.5 and 24 micrograms/ml, respectively. Its inhibitory effect on amastigotes is apparently a direct effect on the parasites and is not due to activation of the nitrogen oxidative metabolism of macrophages, since the production of nitric oxide by both unstimulated and recombinant gamma interferon-stimulated macrophages was decreased rather than increased with DMC. The phagocytic activity of macrophages was functioning normally even with DMC concentrations as high as 80 micrograms/ml, as seen by electron microscopy and by the uptake of fluorescein isothiocyanate-labeled beads. Ultrastructural studies also showed that in the presence of DMC the mitochondria of promastigotes were enlarged and disorganized. Despite destruction of intracellular amastigotes, no disarrangement of macrophage organelles were observed, even at 80 micrograms of DMC/ml. These observations suggest that DMC is selectively toxic to the parasites. Its simple structure may well enable it to serve as a new lead compound for the synthesis of novel antileishmanial drugs. PMID:10223942

Torres-Santos, E C; Moreira, D L; Kaplan, M A; Meirelles, M N; Rossi-Bergmann, B

1999-05-01

135

Simultaneous estimation of hydroxychavicol and chlorogenic acid from Piper betel L. through RP-HPLC.  

PubMed

A RP-HPLC method was developed (? (max)?=280) to quantify hydroxychavicol and chlorogenic acid in Piper betel Linn. The method was validated for linearity, limit of detection (LOD=3:1?/S), limit of quantification (LOQ=10:1?/S), precision, accuracy and ruggedness. The response was linear with good correlation between concentration and mean peak area through a coefficient of determinants (r (2)) of 0.9940, y=1.98e?+004x?+5.19e?+004 and 0.9945, y=2.76e+004x+1.40e+005 with LOD 1.6 µg mL(-1), 1.0 µg mL(-1) and LOQ 5.0 µg mL(-1) and 3.0 µg mL(-1), respectively, for hydroxychavicol (28.56% w/w) and chlorogenic acid (0.40% w/w). The %RSD of precision and recovery of hydroxychavicol and chlorogenic acid were <2.0%. The proposed method was simple, accurate, specific, precise and reproducible. PMID:21923622

Maity, Niladri; Nema, Neelesh K; Sellamuthu, Mythies K; Sarkar, Birendra K; Mukherjee, Pulok K

2012-01-01

136

Structural and sensory characterization of key pungent and tingling compounds from black pepper (Piper nigrum L.).  

PubMed

To gain a more comprehensive knowledge on whether, besides the well-known piperine, other compounds are responsible for the pungent and tingling oral impression imparted by black pepper, an ethanol extract prepared from black pepper (Piper nigrum L.) was screened for its key sensory-active nonvolatiles by application of taste dilution analysis (TDA). Purification of the compounds perceived with the highest sensory impact, followed by LC-MS and 1D/2D NMR experiments as well as synthesis, led to the structure determination of 25 key pungent and tingling phytochemicals, among which the eight amides 1-(octadeca-2E,4E,13Z-trienyl)piperidine, 1-(octadeca-2E,4E,13Z-trienyl)pyrrolidine, (2E,4E,13Z)-N-isobutyl-octadeca-2,4,13-trienamide, 1-(octadeca-2E,4E,12Z-trienoyl)-pyrrolidine, 1-(eicosa-2E,4E,15Z-trienyl)piperidine, 1-(eicosa-2E,4E,15Z-trienyl)pyrrolidine, (2E,4E,15Z)-N-isobutyl-eicosa-2,4,15-trienamide, and 1-(eicosa-2E,4E,14Z-trienoyl)-pyrrolidine were not yet reported in literature. Sensory studies by means of a modified half-tongue test revealed recognition thresholds ranging from 3.0 to 1150.2 nmol/cm² for pungency and from 520.6 to 2162.1 nmol/cm² for the tingling orosensation depending on their chemical structure. PMID:22352449

Dawid, Corinna; Henze, Andrea; Frank, Oliver; Glabasnia, Anneke; Rupp, Mathias; Büning, Kirsten; Orlikowski, Diana; Bader, Matthias; Hofmann, Thomas

2012-03-21

137

Effects of Piper hispidinervum on spermatogenesis and histochemistry of ovarioles of Spodoptera frugiperda.  

PubMed

Abstract The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), not only damages crops, but controlling its population also requires synthetic insecticides, which leads to selection of resistant populations and environmental contamination. Essential oils are an alternative for controlling this insect. There are few studies of the effects of these oils on the insect's reproductive system. We evaluated the effects of the long pepper, Piper hispidinervum, essential oil on the gonads of the armyworm and tested its possible influence on the fertility of this insect. Dosages of 30 and 50 mg/ml were tested in 3(rd) instar caterpillars using the leaf immersion method. Testes and ovarioles were collected, fixed with 10% formalin and embedded in Historesin. The sections were stained with toluidine blue and Mallory trichrome to detect connective tissue, periodic acid-Schiff to detect neutral carbohydrates, and bromophenol blue to detect proteins. We found that the long pepper essential oil affected negatively the spermatogenesis and altered the histochemistry of the ovarioles of S. frugiperda. The effects of long pepper oil suggest that it is a promising tool for controlling the armyworm pest. PMID:24106972

Alves, Tjs; Cruz, Gs; Wanderley-Teixeira, V; Teixeira, Aac; Oliveira, Jv; Correia, Aa; Câmara, Cag; Cunha, Fm

2014-05-01

138

[Potential allelopathic effects of Piper nigrum, Mangifera indica and Clausena lansium].  

PubMed

With Piper nigrum, Mangifera indica and Clausena lansium as the donators, this paper studied their potential allelopathic effects on the germination and growth of Zea mays, Glycine max, Cucurbita moschata, Arachis hypogaea, Raphanus sativus, Echinochloa crusgalli, Digitaria sanguinalis and Stylosanthes guianensis. The results showed that the aqueous extracts of these donators could inhibit the germination and growth of Z. mays, G. max, C. moschata, E. crus-galli and D. sanguinalis at high concentration, but stimulate them at low concentration. In rhizosphere soil of P. nigrum and M. indica, the germination and growth of Z. mays L was stimulated, while A. hypogaea was inhibited. The aqueous extracts of the donators were extracted by ethyl acetate and n-butanol, respectively, and the inhibitory activity of both aqueous and n-butanol fractions from P. nigrum and M. indica on Z. mays, R. sativus and S. guianensis was stronger than that of ethyl acetate fraction, indicating that P. nigrum and M. indica contained the allelochemicals with high polarity. PMID:17147171

Yan, Guijun; Zhu, Chaohua; Luo, Yanping; Yang, Ye; Wei, Jinju

2006-09-01

139

Paralytic effect of alcoholic extract of Allium sativum and Piper longum on liver amphistome, Gigantocotyle explanatum  

PubMed Central

Objective: To investigate the effects of alcoholic extract of Allium sativum and Piper longum on the muscular activity of a parasitic amphistome, Gigantocotyle explanatum. Materials and Methods: Amphistomes were isometrically mounted to record the spontaneous muscular activity by using Chart 4 software program (Power Lab, AD Instruments, Australia) and to examine the effects of cumulative doses (100, 300, 1000, and 3000 ?g/ml) of the plant extracts on the amplitude (g), frequency (per 10 min), and baseline tension (g) of the spontaneous muscular activity of the amphistome. Results: Alcoholic extract of A. sativum produced significant reduction in the frequency and amplitude of contractile activity of the amphistome at 1000 and 3000 ?g/ml bath concentrations. Complete paralysis of the amphistome was observed after 15 min of addition of 3000 ?g/ml concentration. Alcoholic extract of P. longum also caused paralysis following 15-20 min exposure of the amphistome to 3000 ?g/ml concentration. In both the cases the amphistomes did not recover from paralysis following 2-3 washes. Conclusion: The observations demonstrate the paralytic effect of alcoholic extract of A. sativum and P. longum on G. explanatum.

Singh, T.U.; Kumar, D.; Tandan, S.K.

2008-01-01

140

Who leaves against medical advice?  

Microsoft Academic Search

Patients who leave hospitals against medical advice (AMA) frustrate physicians and may put themselves at medical risk. A case—control\\u000a study was conducted to characterize the factors associated with AMA discharges from an inpatient medical service. Logistic\\u000a regression analysis indicated that not having a primary care physician and previous AMA discharge were significantly associated\\u000a with leaving AMA. The patients most often

Jennifer Jeremiah; Patricia O’Sullivan; Michael D. Stein

1995-01-01

141

The antioxidant activity of allylpyrocatechol is mediated via decreased generation of free radicals along with escalation of antioxidant mechanisms.  

PubMed

Allylpyrocatechol (APC) is responsible for the antiinflammatory activity exhibited by the methanolic extract of leaves of Piper betle. As antiinflammatory compounds may display antioxidant properties and vice versa, we investigated the antioxidant effect of APC. APC effectively reduced phorbol-myristate-acetate-induced generation of reactive oxygen species and superoxide in murine peritoneal macrophages as well as inhibited Escherichia-coli-induced phagocytic activity of macrophages. Furthermore, pBluescript SK(+) plasmid DNA damage induced by addition of sodium ascorbate was attenuated by APC as it inhibited transformation of the supercoiled form to a relaxed form. In addition, APC increased the enzymatic (catalase) and nonenzymatic (GSH) antioxidant components of murine macrophages. Taken together, APC exhibited an antioxidant activity which was mediated both via decreased generation of free radicals along with increase in cellular antioxidants. PMID:22585425

Sarkar, Debjani; Kundu, Sunanda; De, Soumita; Hariharan, Chellaram; Saha, Piu; Manna, Alak; Chattopadhyay, Subrata; Chatterjee, Mitali

2013-03-01

142

Piper sarmentosum inhibits ICAM-1 and Nox4 gene expression in oxidative stress-induced human umbilical vein endothelial cells  

Microsoft Academic Search

Background  Aqueous extract of Piper sarmentosum (AEPS) is known to possess antioxidant and anti-atherosclerotic activities but the mechanism responsible for it remains unclear.\\u000a In early part of atherosclerosis, nuclear factor-kappa B (NF-?B) induces the expression of cellular adhesion molecules such\\u000a as vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1) and E-selectin. NADPH oxidase 4\\u000a (Nox4) is the predominant source of

Azizah Ugusman; Zaiton Zakaria; Chua Kien Hui; Nor Anita Megat Mohd Nordin

2011-01-01

143

Fatigue in Brazilian cancer patients, caregivers, and nursing students: a psychometric validation study of the Piper Fatigue Scale-Revised  

Microsoft Academic Search

Goals of work  The objective of this study was to validate the Piper Fatigue Scale-Revised (PFS-R) for use in Brazilian culture.\\u000a \\u000a \\u000a \\u000a Patients and methods  Translation of the PFS-R into Portuguese and validity and reliability tests were performed. Convenience samples in Brazil\\u000a we as follows: 584 cancer patients (mean age 57?±?13 years; 51.3% female); 184 caregivers (mean age 50?±?12.7 years; 65.8%\\u000a female); and 189 undergraduate

Dálete D. C. F. Mota; Cibele A. M. Pimenta; Barbara F. Piper

2009-01-01

144

5 CFR 630.1004 - Application to become a leave contributor and leave bank member.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Application to become a leave contributor and leave bank member...Program § 630.1004 Application to become a leave contributor and leave bank member...application to the leave bank board to become a leave contributor. The...

2009-01-01

145

5 CFR 630.1004 - Application to become a leave contributor and leave bank member.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Application to become a leave contributor and leave bank member...Program § 630.1004 Application to become a leave contributor and leave bank member...application to the leave bank board to become a leave contributor. The...

2010-01-01

146

Antidiabetic and antihyperlipidemic activity of Piper longum root aqueous extract in STZ induced diabetic rats  

PubMed Central

Background The available drugs for diabetes, Insulin or Oral hypoglycemic agents have one or more side effects. Search for new antidiabetic drugs with minimal or no side effects from medicinal plants is a challenge according to WHO recommendations. In this aspect, the present study was undertaken to evaluate the antihyperglycemic and antihyperlipidemic effects of Piper longum root aqueous extract (PlrAqe) in streptozotocin (STZ) induced diabetic rats. Methods Diabetes was induced in male Wister albino rats by intraperitoneal administration of STZ (50 mg/kg.b.w). Fasting blood glucose (FBG) levels were measured by glucose-oxidase & peroxidase reactive strips. Serum biochemical parameters such as glycosylated hemoglobin (HbA1c), total cholesterol (TC), triglycerides (TG), very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol were estimated. The activities of liver and kidney functional markers were measured. The statistical analysis of results was carried out using Student t-test and one-way analysis (ANOVA) followed by DMRT. Results During the short term study the aqueous extract at a dosage of 200 mg/kg.b.w was found to possess significant antidiabetic activity after 6 h of the treatment. The administration of aqueous extract at the same dose for 30 days in STZ induced diabetic rats resulted in a significant decrease in FBG levels with the corrections of diabetic dyslipidemia compared to untreated diabetic rats. There was a significant decrease in the activities of liver and renal functional markers in diabetic treated rats compared to untreated diabetic rats indicating the protective role of the aqueous extract against liver and kidney damage and its non-toxic property. Conclusions From the above results it is concluded that the plant extract is capable of managing hyperglycemia and complications of diabetes in STZ induced diabetic rats. Hence this plant may be considered as one of the potential sources for the isolation of new oral anti hypoglycemic agent(s).

2013-01-01

147

Post-test analysis of PIPER-ONE PO-IC-2 experiment by RELAP5/MOD3 codes  

SciTech Connect

RELAP5/MOD3.1 was applied to the PO-IC-2 experiment performed in PIPER-ONE facility, which has been modified to reproduce typical isolation condenser thermal-hydraulic conditions. RELAP5 is a well known code widely used at the University of Pisa during the past seven years. RELAP5/MOD3.1 was the latest version of the code made available by the Idaho National Engineering Laboratory at the time of the reported study. PIPER-ONE is an experimental facility simulating a General Electric BWR-6 with volume and height scaling ratios of 1/2,200 and 1./1, respectively. In the frame of the present activity a once-through heat exchanger immersed in a pool of ambient temperature water, installed approximately 10 m above the core, was utilized to reproduce qualitatively the phenomenologies expected for the Isolation Condenser in the simplified BWR (SBWR). The PO-IC-2 experiment is the flood up of the PO-SD-8 and has been designed to solve some of the problems encountered in the analysis of the PO-SD-8 experiment. A very wide analysis is presented hereafter including the use of different code versions.

Bovalini, R.; D`Auria, F.; Galassi, G.M.; Mazzini, M. [Univ. of Pisa (Italy)

1996-11-01

148

Photopyroelectric Microscopy of Plant Leaves  

NASA Astrophysics Data System (ADS)

The use of photothermal microscopy to obtain superficial and in-depth images, by means of the interaction of a thermal wave with the analyzed material, has reached great interest due to its numerous applications. The application of the photopyroelectric microscopy technique to obtain images of plant leaves is presented in this article. In the experimental setup, a pyroelectric sensor and linear micro-positioners were used to obtain the photothermal signal at each point of the sample. Then it is possible to obtain images of plant leaves through their differences in local thermal properties and thickness.

Briseño-Tepepa, B. R.; Jiménez-Peréz, J. L.; Saavedra, R.; González-Ballesteros, R.; Suaste, E.; Cruz-Orea, A.

2008-12-01

149

Aroma compound analysis of Piper nigrum and Piper guineense essential oils from Cameroon using solid-phase microextraction-gas chromatography, solid-phase microextraction-gas chromatography-mass spectrometry and olfactometry.  

PubMed

The investigation of aroma compounds of the essential oils of dried fruits of black pepper (Piper nigrum) and black and white "Ashanti pepper" (Piper guineense) from Cameroon by means of solid-phase microextraction (SPME) was carried out for the first time to identify the odorous target components responsible for the characteristic odor of these valuable spices and food flavoring products. By means of GC-flame ionization detection (FID) and GC-MS (using different polar columns) the main compounds (concentration >3.0%, calculated as area of GC-FID analysis using a non-polar fused-silica open tubular RSL-200 column) of the SPME headspace samples of P. nigrum (black) and P. guineense (black and white) were found to be: P. nigrum (black)--germacrene D (11.01%), limonene (10.26%), beta-pinene (10.02%), alpha-phellandrene (8.56%), beta-caryophyllene (7.29%), alpha-pinene (6.40%) and cis-beta-ocimene (3.19%); P. guineense (black)--beta-caryophyllene (57.59%), beta-elemene (5.10%), bicyclogermacrene (5.05%) and alpha-humulene (4.86%); and P. guineense (white)--beta-caryophyllene (51.75%), cis-beta-ocimene (6.61%), limonene (5.88%), beta-pinene (4.56%), linalool (3.97%) and alpha-humulene (3.29%). The most intense odor impressions of the essential oils of the various dried pepper fruits were given byprofessional perfumers as follows: P nigrum (black)--fine, pleasant black pepper note; P. guineense (black)--black pepper top-note; and P. guineense (white)--pleasant white pepper note. These analytical results for the SPME headspace samples of three different pepper species from Cameroon are in accordance with the olfactoric data of the corresponding essential oils. A GC-sniffing technique was used to correlate the single odor impression of the identified SPME headspace volatiles of the three investigated pepper samples with the following results: themain compounds such as beta-caryophyllene, germacrene D, limonene, beta-pinene, alpha-phellandrene and alpha-humulene, as well as minor constituents such as delta-carene, beta-phellandrene, isoborneol, alpha-guaiene, sarisan, elemicin, calamenene, caryophyllene alcohol, isoelemicin, T-muurolol, cubenol and bulnesol, are of greatest importance for the characteristic pepper odor notes of these three Piper samples. Further aroma impressions can be attributed to mono- and sesquiterpenes, hexane, octane and nonane derivatives. PMID:12462618

Jirovetz, Leopold; Buchbauer, Gerhard; Ngassoum, Martin Benoit; Geissler, Margit

2002-11-01

150

Compound Specific Extraction of Camptothecin from Nothapodytes nimmoniana and Piperine from Piper nigrum Using Accelerated Solvent Extractor.  

PubMed

Effects of varying temperatures with constant pressure of solvent on extraction efficiency of two chemically different alkaloids were studied. Camptothecin (CPT) from stem of Nothapodytes nimmoniana (Grah.) Mabb. and piperine from the fruits of Piper nigrum L. were extracted using Accelerated Solvent Extractor (ASE). Three cycles of extraction for a particular sample cell at a given temperature assured complete extraction. CPT and piperine were determined and quantified by using a simple and efficient UFLC-PDA (245 and 343?nm) method. Temperature increased efficiency of extraction to yield higher amount of CPT, whereas temperature had diminutive effect on yield of piperine. Maximum yield for CPT was achieved at 80°C and for piperine at 40°C. Thus, the study determines compound specific extraction of CPT from N. nimmoniana and piperine from P. nigrum using ASE method. The present study indicates the use of this method for simple, fast, and accurate extraction of the compound of interest. PMID:24527258

Upadhya, Vinayak; Pai, Sandeep R; Sharma, Ajay K; Hegde, Harsha V; Kholkute, Sanjiva D; Joshi, Rajesh K

2014-01-01

151

Insecticidal activity of isobutylamides derived from Piper nigrum against adult of two mosquito species, Culex pipiens pallens and Aedes aegypti.  

PubMed

The insecticidal activity of Piper nigrum fruit-derived piperidine alkaloid (piperine) and N-isobutylamide alkaloids (pellitorine, guineensine, pipercide and retrofractamide A) against female adults of Culex pipiens pallens and Aedes aegypti was examined. On the basis of 24-h LD(50) values, the compound most toxic to female C. pipiens pallens was pellitorine (0.4?µg/?) followed by guineensine (1.9?µg/?), retrofractamide A (2.4?µg/?) and pipercide (3.2?µg/?). LD(50) value of chlorpyrifos was 0.03?µg/?. Against female A. aegypti, the insecticidal activity was more pronounced in pellitorine (0.17?µg/?) than in retrofractamide A (1.5?µg/?), guineensine (1.7?µg/?), and pipercide (2.0?µg/?). LD(50) value of chlorpyrifos was 0.0014?µg/?. PMID:22010905

Park, Il-Kwon

2012-01-01

152

LC-MS/MS Based Identification of Piperine Production by Endophytic Mycosphaerella sp. PF13 from Piper nigrum.  

PubMed

Piper nigrum is very remarkable for its medicinal properties due to the presence of metabolites like piperine. Emerging understanding on the biosynthetic potential of endophytic fungi suggests the possibility to have piperine producing fungi in P. nigrum. In the current study, endophytic fungi isolated from P. nigrum were screened for the presence of piperine by liquid chromatography-tandem mass spectrometry (LC-MS/MS). This resulted in the identification of a Mycosphaerella sp. with the ability to produce piperine extracellularly. The biosynthesis of piperine (C17H19NO3) by the endophytic fungal isolate was confirmed by the presence of m/z 286.1 (M + H(+)) in the LC-MS/MS analysis using positive mode ionization. This was further supported by the presence of specific fragment ions with masses 135, 143, 171 and 201 formed due to the fragmentation of piperine present in the fungal extract. PMID:24691878

Chithra, S; Jasim, B; Anisha, C; Mathew, Jyothis; Radhakrishnan, E K

2014-05-01

153

A member of the U.S. Women's World Cup Soccer Team is greeted by Stefanyshyn-Piper  

NASA Technical Reports Server (NTRS)

A member of the U.S. Women's World Cup Soccer Team is greeted by NASA Astronaut Heidemarie M. Stefanyshyn-Piper (left) upon her arrival at the Skid Strip at Cape Canaveral Air Station to view the launch of Space Shuttle mission STS-93. Liftoff is scheduled for 12:36 a.m. EDT July 20. Much attention has been generated over the launch due to Commander Eileen M. Collins, the first woman to serve as commander of a Shuttle mission. The primary payload of the five-day mission is the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes.

1999-01-01

154

Muscodor albus MOW12 an Endophyte of Piper nigrum L. (Piperaceae) Collected from North East India Produces Volatile Antimicrobials.  

PubMed

Muscodor albus MOW12, an endophytic fungus isolated from Piper nigrum in Mawlong, Meghalaya, India, resembles some cultural and hyphal characteristics of previous isolates of Muscodor sp. In addition, it possesses about 99 % similarity in its ITS rDNA with other M. albus isolates and thus is nicely centered within the genetic tree to other Muscodor spp. This xylariaceae fungus effectively inhibits and kills certain plant pathogenic fungi by virtue of a mixture of volatile compounds that it produces. The majority of these compounds were identified by gas chromatography/mass spectrometry as small molecular weight esters, alcohols, and acids. The main ester components of this isolate of M. albus in its volatile mixture are acetic acid, ethyl ester; propanoic acid, 2-methyl-, methyl ester and acetic acid, 2-methylpropyl ester. This appears to be the first report of any M. albus strain from India. PMID:24426163

Banerjee, Debdulal; Pandey, Akhil; Jana, Maloy; Strobel, Gary

2014-03-01

155

Arsenic Sorption in Dried Leaves  

NASA Astrophysics Data System (ADS)

Biosorption is the retention of metal ions from aqueous solutions by biomasses. This phenomenon can be helpful in the design of alternative filters for the depollution of industrial and mining waste waters. The recovery of filtered metal ions can also be commercially interesting. Although many studies about the sorptive capacity of biomasses have been done for different metals, few have investigated sorption sites and mechanisms in these systems. We studied the retention of arsenic ions from aqueous solutions using dried lettuce leaves (L. sativa) as biomass. The toxic arsenic forms As(III) and As(V) are commonly found in mining waste waters. Early studies have shown that lettuce leaves have a good sorptive capacity for copper and iron ions, comparable to other sorbents such as activated carbon or ionic-exchange resins. Arsenic sorption by lettuce dried leaves was not found to be effective when in natura biomass was used. Sorptive capacity was improved and became comparable to the sorption of the other ions studied when the biomass was charged with Fe(III). The sorption mechanism of arsenic in Fe-charged biomass must be similar to the one proposed for As sorption by mineral clays, where As ions bind to Fe(III) atoms in the clay structure.

Silva, Gabriela C.; de Carvalho, Regina P.; Duarte, Grazielle; Santos, Mércia H.

2005-10-01

156

Strong spatial genetic structure in five tropical Piper species: should the Baker-Fedorov hypothesis be revived for tropical shrubs?  

PubMed Central

Fifty years ago, Baker and Fedorov proposed that the high species diversity of tropical forests could arise from the combined effects of inbreeding and genetic drift leading to population differentiation and eventually to sympatric speciation. Decades of research, however have failed to support the Baker–Fedorov hypothesis (BFH), and it has now been discarded in favor of a paradigm where most trees are self-incompatible or strongly outcrossing, and where long-distance pollen dispersal prevents population drift. Here, we propose that several hyper-diverse genera of tropical herbs and shrubs, including Piper (>1,000 species), may provide an exception. Species in this genus often have aggregated, high-density populations with self-compatible breeding systems; characteristics which the BFH would predict lead to high local genetic differentiation. We test this prediction for five Piper species on Barro Colorado Island, Panama, using Amplified Fragment Length Polymorphism (AFLP) markers. All species showed strong genetic structure at both fine- and large-spatial scales. Over short distances (200–750 m) populations showed significant genetic differentiation (Fst 0.11–0.46, P < 0.05), with values of spatial genetic structure that exceed those reported for other tropical tree species (Sp = 0.03–0.136). This genetic structure probably results from the combined effects of limited seed and pollen dispersal, clonal spread, and selfing. These processes are likely to have facilitated the diversification of populations in response to local natural selection or genetic drift and may explain the remarkable diversity of this rich genus.

Lasso, E; Dalling, J W; Bermingham, E

2011-01-01

157

Exploring Why Career Changers Leave Teaching  

ERIC Educational Resources Information Center

Survey data were used to explore the current teaching status and reasons for leaving or considering leaving teaching for 154 career changers who all graduated from a Master of Arts in Teaching (MAT) program over a 9-year time period. Respondents provided information about reasons for leaving teaching, indicating personal/family, career, and school…

Cuddapah, Jennifer L.; Beaty-O'Ferrall, Mary Ellen; Masci, Frank J.; Hetrick, Monica

2011-01-01

158

Why Leaves Aren't Trees  

NSDL National Science Digital Library

The Physical Review Focus article describes the controversy over the structure of networks that optimize transport of nutrients through the veins in leaves. Images show how vein networks in leaves can provide protection against damage to part of the network. Also, videos show how colored dye moves through the veins of the leaves.

2010-07-30

159

Parental Leave and Productivity. Current Research.  

ERIC Educational Resources Information Center

This report consists of papers, commissioned by the Family Work Institute, by expert policy makers in the area of parental leave. The report consists of eight papers: (1) "The Impact of Childbearing on Employment" (James T. Bond); (2) "Fathers and Parental Leave: A Perspective" (Joseph H. Pleck); (3) Parental Leave and Productivity: The…

Friedman, Dana E., Ed.; And Others

160

Resource capture by single leaves  

SciTech Connect

Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.

Long, S.P.

1992-05-01

161

Genotoxic and Non-genotoxic Effects of Betel Quid Ingredients on Oral Mucosal Fibroblasts in vitro  

Microsoft Academic Search

To understand the role of betel quid (BQ) in the pathogenesis of oral submucous fibrosis (OSF) and oral cancer, we used DNA damage, cytotoxicity, and cell proliferation assays to study the pathobiological effects of aqueous extracts of three BQ constituents [betel nut (Areca catechu, BN), inflorescence of Piper betle (IPB), and lime], one BN alkaloid (arecoline), and one BN polyphenol

J. H. Jeng; M. L. Kuo; L. J. Hahn; M. Y. P. Kuo

1994-01-01

162

Phytic acid in green leaves.  

PubMed

Phytic acid or phytate, the free-acid form of myo-inositolhexakiphosphate, is abundant in many seeds and fruits, where it represents the major storage form of phosphorus. Although also known from other plant tissues, available reports on the occurrence of phytic acid, e.g. in leaves, have never been compiled, nor have they been critically reviewed. We found 45 published studies with information on phytic acid content in leaves. Phytic acid was almost always detected when studies specifically tried to detect it, and accounted for up to 98% of total P. However, we argue that such extreme values, which rival findings from storage organs, are dubious and probably result from measurement errors. Excluding these high values from further quantitative analysis, foliar phytic acid-P averaged 2.3 mg·g(-1) , and represented, on average, 7.6% of total P. Remarkably, the ratio of phytic acid-P to total P did not increase with total P, we even detected a negative correlation of the two variables within one species, Manihot esculenta. This enigmatic finding warrants further attention. PMID:24341824

Hadi Alkarawi, H; Zotz, G

2014-07-01

163

Thermographic measurements on plant leaves  

NASA Astrophysics Data System (ADS)

An important process of plant physiology is the transpiration of plant leaves. It is actively controlled by pores (stomata) in the leaf and the governing feature for vital factors such as gas exchange and water transport affixed to which is the nutrient transport from the root to the shoot. Because of its importance, the transpiration and water transport in leaves have been extensively studied. However, current measurement techniques provide poor spatial and temporal resolution. With the use of one single low-NETD infrared camera important parameter of plant physiology such as transpiration rates, heat capacity per unit area of the leaf and the water flow velocity can be measured to high temporal and special resolution by techniques presented in this paper. The latent heat flux of a plant, which is directly proportional to the transpiration rate, can be measured with passive thermography. Here use is made of the linear relationship between the temperature difference between a non transpiring reference body and the transpiring leaf and the latent heat flux. From active thermography the heat capacity per unit area of the leaf can be measured. This method is termed active, because the response of the leaf temperature to an imposed energy flux is measured. Through the use of digital image processing techniques simultaneous measurements of the velocity field and temporal change of heated water parcels traveling through the leaf can be estimated from thermal image sequences.

Garbe, Christoph; Schurr, Ulrich; Jaehne, Bernd

2002-03-01

164

Edible Leaves of the Tropics (2nd Edition).  

National Technical Information Service (NTIS)

Contents: The principal edible green leaf herbs of the tropics; Some fruits, vegetables, and ornamental plants that also bear edible leaves; Common weeds with edible green leaves; Tropical trees with edible green leaves; Tropical leaves as spices and teas...

F. W. Martin R. M. Ruberte

1979-01-01

165

Hojas Comestibles del Tropico (Edible Leaves of the Tropics).  

National Technical Information Service (NTIS)

Contents: The principal edible green leaf herbs of the tropics; Some fruits, vegetables, and ornamental plants that also bear edible leaves; Common weeds with edible green leaves; Tropical trees with edible green leaves; Tropical leaves as spices and teas...

F. W. Martin R. M. Ruberte

1975-01-01

166

Antinociceptive properties of conocarpan and orientin obtained from Piper solmsianum C. DC. var. solmsianum (Piperaceae).  

PubMed

The antinociceptive properties of some fractions and two pure compounds, conocarpan and orientin, obtained from P. solmsianum leaves were investigated in several models of pain in mice. The results indicated that this plant exhibits a promising antinociceptive profile, as it produces active principles which are several times more active than some reference drugs used for comparison. The main compound tested, orientin, caused potent and dose-dependent effects against acetic acid-induced writhing and capsaicin- and glutamate-induced nociception, being more effective against the first one, with an ID(50) value of 6.5 mg/kg (14.5 micromol/kg). Orientin was about 20-fold more potent than acetylsalicylic acid and 3.5-fold more active than indomethacin. The antinociceptive effects of this plant may be attributed, at least partially, to the presence of conocarpan and, in particular, to the flavonoid orientin. PMID:20473574

Da Silva, Rosi Zanoni; Yunes, Rosendo Augusto; de Souza, Márcia Maria; Delle Monache, Franco; Cechinel-Filho, Valdir

2010-10-01

167

Ion exchanger from chemically modified banana leaves.  

PubMed

Cation exchangers from chemically modified banana leaves have been prepared. Banana leaves were treated with different molarities of KMnO4 and cross linked with epichlorohydrin and their effect on metal ion adsorption was investigated. Phosphorylation of chemically modified banana leaves was also studied. The metal ion uptake by these modified banana leaves was clarified. Effect of different varieties, e.g. activation of produced cation exchanger, concentration of metal ions was also investigated. Characterization of the prepared ion exchangers by using infrared and thermal analysis was also taken in consideration. PMID:23768590

El-Gendy, Ahmed A; Mohamed, Samar H; Abd-Elkader, Amal H

2013-07-25

168

Paid Sick Leave and Job Stability  

PubMed Central

A compelling, but unsubstantiated, argument for paid sick leave legislation is that workers with leave are better able to address own and family member health needs without risking a voluntary or involuntary job separation. This study tests that claim using the Medical Expenditure Panel Survey and regression models controlling for a large set of worker and job characteristics, as well as with propensity score techniques. Results suggest that paid sick leave decreases the probability of job separation by at least 2.5 percentage points, or 25%. The association is strongest for workers without paid vacation leave and for mothers.

Hill, Heather D.

2013-01-01

169

Biological activities of Zingiber officinale (Zingiberaceae) and Piper cubeba (Piperaceae) essential oils against pulse beetle, Callosobruchus chinensis (Coleoptera: Bruchidae).  

PubMed

Zingiber officinale (Zingiberaceae) and Piper cubeba (Piperaceae) was essential oils were investigated for repellent, insecticidal, antiovipositional, egg hatching, persistence of its insecticidal activities against pulse beetle, Callosobruchus chinensis (Coleoptera: Bruchidae). Essential oil vapours repelled bruchid adults significantly as oviposition was found reduced in choice oviposition assay. Z. officinale and P. cubeba essential oils caused both fumigant and contact toxicity in C. chinensis adults. In fumigation toxicity assay, median lethal concentrations (LC50) were 0.34 and 0.27 microL cm(-3) for Z. officinale and P. cubeba essential oils, respectively, while in contact toxicity assay, LC50 were 0.90 and 0.66 microL cm(-2) for Z. officinale and P. cubeba essential oils, respectively. These two essential oils reduced oviposition in C. chinensis adults when treated with sublethal concentrations by fumigation and contact method. Oviposition inhibition was more pronounced when adults come in contact than in vapours. Both essential oils significantly reduced egg hatching rate when fumigated. Persistence in insecticidal efficiency of both essential oils decreased with time. P. cubeba showed less persistence than Z. officinale essential oil because no mortality was observed in C. chinensis adults after 36 h of treatment with P. cubeba and after 48 h of treatment of Z. officinale essential oil. Fumigation with these essential oils has no effect on the germination of the cowpea seeds. Findings of the study suggest that Z. officinale and P. cubeba essential oils can be useful as promising agent in insect pest management programme. PMID:24498820

Chaubey, Mukesh Kumar

2013-06-01

170

Accelerated Stability and Chemical Kinetics of Ethanol Extracts of Fruit of Piper sarmentosum Using High Performance Liquid Chromatography  

PubMed Central

The extracts of Piper sarmentosum, a medicinal plant, are being used to prepare phytopharmaceuticals while the information about chemical kinetics of constituents of the extract is unavailable to assign precise shelf life (t90) and find optimum storage conditions of the product for patient safety, and to avoid economic repercussions of launching an unstable product. The extract was exposed to three different conditions of high temperature and relative humidity (RH) for six months. The samples were then analyzed at 0, 1, 2, 4 and 6 months by high performance liquid chromatography (HPLC) using pellitorine, sarmentine and sarmentosine as markers. Different chemical kinetic parameters of the markers were evaluated by Arrhenius equation to predict shelf life (t90) at different storage conditions and at room temperature. The markers in the extract followed the zero order degradation, and the activation energy, pre exponential factor and rate constant of the reaction of the markers were found to be varying in samples stored at different conditions. The contents of the markers were found to be decreasing at high temperature and humidity with the passage of time. The predicted shelf life (t90) of the markers at room temperature was found to be 16 months approximately. Results of this study indicate that extracts of the plant are stable at room temperature for 16 months. Moreover, the chemical kinetic data of the markers and the analytical method used to quantify the markers may be useful for phytopharmaceutical industry to produce efficacious and stable products from extracts of the plant.

Khalid, Hussain; Zhari, Ismail; Amirin, Sadikun; Pazilah, Ibrahim

2011-01-01

171

In situ biosynthesis of Ag, Au and bimetallic nanoparticles using Piper pedicellatum C.DC: green chemistry approach.  

PubMed

The synthesis of Ag, Au and Ag-Au bimetallic nanoparticles using Piper pedicellatum C.DC leaf extract is demonstrated here. The rapid formation of stable Ag and Au nanoparticles has been found using P. pedicellatum C.DC leaf extract in aqueous medium at normal atmospheric condition. Competitive reduction of Ag(+) and Au(3+) ions present simultaneously in solution during exposure to P. pedicellatum C.DC leaf extract leads to the synthesis of bimetallic Ag-Au nanoparticles in solution. Transmission electron microscopy (TEM) analysis revealed that the Ag nanoparticles predominantly form spherical in shape with the size range of 2.0±0.5-30.0±1.2 nm. In case of Au nanoparticles, the particles are spherical in shape along with few triangular, hexagonal and pentagonal shaped nanoparticles also observed. X-ray diffraction (XRD) studies revealed that the nanoparticles were face centered cubic (fcc) in shape. Fourier transform infrared spectroscopy (FTIR) showed nanoparticles were capped with plant compounds. The chemical constituents, viz. catechin, gallic acid, courmaric acid and protocatechuic acid of the leaf extract were identified which may act as a reducing, stabilizing and capping agent. The expected reaction mechanism in the formation of Ag and Au nanoparticles is also reported. PMID:23107941

Tamuly, Chandan; Hazarika, Moushumi; Borah, Sarat Ch; Das, Manash R; Boruah, Manas P

2013-02-01

172

Toxicity of Piper aduncum L. (Piperales: Piperaceae) from the Amazon forest for the cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).  

PubMed

The mortality of 14-21-day-old Rhipicephalus (Boophilus) microplus larvae, and the mortality and fertility of groups of engorged adult females exposed to different concentrations of hexane, ethyl acetate and ethanol extracts of spiked pepper (Piper aduncum) were evaluated, using a completely randomized design with five treatment groups, two control groups, and two replicates for the larvae and five replicates for the adult females. Similar methodology was used to investigate the toxicity of the essential oil hydro-distillate (94.84% dillapiole) obtained from the P. aduncum crude hexane extract. The LC(50) of the hexane extract was 9.30 mg ml(-1) for larvae and the reproduction reduction ranged from 12.48% to 54.22%, while 0.1mg/ml(-1) of the essential oil induced 100% mortality in larvae. Literature reports on natural products active against R. microplus were listed and compared with the results presented here. These results indicate that P. aduncum extracts, and particularly its essential oil, are potential alternative control agents for R. microplus. PMID:19573994

Silva, Wilson Castro; Martins, João Ricardo de Souza; de Souza, Hellen Emília Menezes; Heinzen, Horacio; Cesio, Maria Verônica; Mato, Mauricio; Albrecht, Francine; de Azevedo, João Lúcio; de Barros, Neiva Monteiro

2009-10-14

173

Three new phenylpropanoids from the roots of Piper taiwanense and their inhibitory activities on platelet aggregation and Mycobacterium tuberculosis.  

PubMed

Bioassay-guided fractionation of the active AcOEt-soluble fraction from the roots of Piper taiwanense has led to the isolation of two new phenylpropanoids, taiwanensols A and B (1 and 2, resp.), a new natural product, taiwanensol C (3), and 3-acetoxy-4-hydroxy-1-allylbenzene (4). The compounds were obtained as two isomer mixtures (1/2 and 3/4, resp.). Their structures were elucidated by spectroscopic analyses, including 1D- and 2D-NMR spectroscopy and mass spectrometry, and by the comparison of their NMR data with those of related compounds. Compounds 1-4 were evaluated for their antiplatelet and antitubercular activities. The mixtures 1/2 and 3/4 showed potent inhibitory activities against platelet aggregation induced by collagen, with IC50 values of 35.2 and 8.8 ?M, respectively. In addition, 1/2 and 3/4 showed antitubercular activities against Mycobacterium tuberculosis H37Rv, with MIC values of 30.0 and 48.0 ?g/ml, respectively. PMID:24827689

Chen, Si; Cheng, Ming-Jen; Wu, Chin-Chung; Peng, Chien-Fang; Huang, Hung-Yi; Chang, Hsun-Shuo; Wang, Chyi-Jia; Chen, Ih-Sheng

2014-05-01

174

Jamu Gendong, a kind of traditional medicine in Indonesia: the microbial contamination of its raw materials and endproduct.  

PubMed

An examination on the microbiological quality of seven kinds of Jamu Gendong (JG) and their raw materials has been conducted according to the requirements of microbial contamination in traditional medicine, issued by the Department of Health of Indonesia in 1986. Samples of JG and their raw materials were taken from producers in three districts of Surabaya. The samples were subject to the following examinations: total plate count (TPC), MPN coliform, the enumeration of molds and yeasts, the presence or absence of Staphylococcus aureus, Salmonella and Vibrio. Each time the JG samples were taken from different producers together with their raw materials. The results of this investigation showed that most of the JG samples were heavily contaminated with bacteria, yeasts and molds. For bacteria, taken from the TPC results, their numbers were ranging from 7.7 x 10(2) microorganisms/ml to too many to count (TMTC). For yeasts and molds the numbers showed variations from 0 microorganisms/ml to TMTC. Contamination with Coliform in 1 ml of JG were ranged from 0 to > 2.4 x 10(6) microorganisms. In most of the samples pathogenic Staphylococci, Salmonella sp. and Vibrio sp. were not detected, so that a conclusion can be drawn that most of the contamination in JG are saprophytic, only a few pathogenic. The results also show that it is possible to have JG which fulfill the government's requirements. Similar results were obtained with the plant material constituents of JG such as rhizomes, leaves, herbs and fruits of Piper nigrum and Piper retrofractum, with the exception of Piper betle leaves and P. retrofractum fruits, both showing low contamination of Coliform bacteria. However, the fruits of Citrus aurantifolia and Morinda citrifolia were less contaminated, just like seeds of Oryza sativa, Parkia roxburghii, bulbs of Allium sativum and the pulp of Tamarindus indica. With these plant constituents of JG, it might be of interest to screen their antibacterial and antifungal activities. PMID:10030724

Limyati, D A; Juniar, B L

1998-12-01

175

Fed Leaves Interest Rates Alone  

NSDL National Science Digital Library

This week's In the News looks at the recent Federal Reserve Board decision to leave interest rates unchanged. The eight resources discussed provide background information on interest rates and inflation, Federal Reserve news, and current US economic data. With the stock market at record highs and global economic crises fading, the Federal Reserve Board (FRB) showed increased concern about the risk of inflation this month at a May 18, 1999 meeting of the Federal Open Market Committee (FOMC). Although committee members ultimately decided not to raise the rate at which banks lend to each other, they cited a "tight" domestic labor market and "ongoing strength in demand in excess of productivity gains" as possible reasons for future rate hikes. Wall Street reacted to the Fed news with a 100 point Dow Jones Industrial Average fall on May 18 but recovered by the end of the day down just 16.52, and many market watchers expressed optimism over the FOMC action. Irwin Kellner, chief economist at CBS.MarketWatch.com, for example, deemed the decision "great" and praised the Fed for a flexible policy that is not locked into a particular course of action should the economy change unexpectedly.

Waters, Megan.

176

When and Why Dropouts Leave High School  

ERIC Educational Resources Information Center

Teens may leave school because of academic failure, disciplinary problems, or employment opportunities. In this article, the authors test whether the reasons dropouts leave school differ by grade level and age. We compare dropout rates and reasons across grade levels and ages for all high school students, ethnic groups, and gender groups. Across…

Stearns, Elizabeth; Glennie, Elizabeth J.

2006-01-01

177

A photoacoustic study of water infiltrated leaves  

Microsoft Academic Search

Photoacoustic measurements of photosynthetic energy storage were conducted on water infiltrated pea and sugar maple leaves. The samples were vacuum infiltrated with pure water or with a suitable buffer. The use of such methodology permitted an accurate determination of the energy storage parameter at low modulation frequencies, where in non-infiltrated leaves oxygen evolution dominates the photoacoustic signal and does not

Shmuel Malkin; Marc Charland; Roger M. Leblanc

1992-01-01

178

Resilience and Young People Leaving Care  

ERIC Educational Resources Information Center

How do we promote the resilience of young people leaving care? This article explores this question by bringing together research findings on the resilience of young people from disadvantaged family backgrounds with research studies on young people leaving care. These findings are applied to young people during their journey to adulthood: their…

Stein, Mike

2008-01-01

179

Subcellular Metabolite Levels in Spinach Leaves 1  

PubMed Central

The alterations of subcellular metabolite levels during the day in spinach leaves have been investigated using nonaqueous density gradient centrifugation to separate chloroplasts, cytosol, and vacuole. The results provide direct evidence for the role of sucrose phosphate synthase and cytosolic fructose 1,6-bisphosphatase in regulating sucrose synthesis in leaves and also show that the phosphate translocator is kinetically limiting in vivo.

Gerhardt, Richard; Stitt, Mark; Heldt, Hans W.

1987-01-01

180

Changes in spectral properties of detached leaves  

NASA Technical Reports Server (NTRS)

If leaf senescence can be delayed for several days without significant changes in spectral properties, then samples of leaves at remote test sites could be prepared and shipped to laboratories to measure spectral properties. The changes in spectral properties of detached leaves were determined. Leaves from red birch and red pine were immersed in water or 0.001 M benzylaminopurine (BAP) and stored in plastic bags in the dark at either 5 or 25 C. Total directional-hemispherical reflectance and transmittance of the adaxial surface of birch leaves were measured over the 400 to 1100 nm wavelength region with a spectroradiometer and integrating sphere. Pine needles were taped together and reflectance of the mat of needles was measured. Spectral properties changed less than 5% of initial values during the first week when leaves were stored at 5 C. Storage at 25 C promoted rapid senescence and large changes in spectral properties. BAP delayed, but did not stop, senescence at 25 C.

Daughtry, C. S. T.; Biehl, L. L.

1984-01-01

181

Ribonucleic acids from barley leaves  

PubMed Central

1. The total RNA and the RNA present in 27000g pellet (probably composed of chloroplasts, nuclei and mitochondria) and in 27000g supernatant (probably composed of microsomes and soluble proteins) fractions (separated by centrifugation at 27000g of a leaf homogenate prepared in 0·5m-sucrose–0·02m-tris–HCl, pH7·6) of barley leaves were extracted by phenol–sodium lauryl sulphate and their elution profiles on Sephadex G-200 and on ECTEOLA-cellulose anion-exchanger were examined and their nucleotide compositions and the melting curves were determined. 2. The pellet and the supernatant fractions contained respectively about 55% and 20% of the total RNA, whereas 25% of the total RNA was lost during homogenization of the leaf tissue with sucrose–buffer. 3. The total RNA or the RNA from pellet or supernatant fractions, which by its behaviour on Sephadex G-200 columns was found to be predominantly of high molecular weight (i.e. of ribosomal origin), produced about 13 peaks on ECTEOLA-cellulose columns. The RNA species in the pellet and supernatant fractions probably resembled each other in molecular size or secondary structure or both. However, they were present in relatively different amounts in these fractions. 4. The Tm (i.e. the temperature at which 50% of the maximal increase in extinction had occurred) of total RNA and of RNA from pellet fraction was 64·5° whereas Tm of RNA from the supernatant fraction was 73°. The total RNA and the RNA from pellet fraction also resembled each other in nucleotide composition, and the RNA from the supernatant fraction in accordance with its high Tm had a high GMP+CMP content.

Srivastava, B. I. Sahai

1965-01-01

182

A flight investigation of the ultra-deep-stall descent and spin recovery characteristics of a 1/6 scale radiocontrolled model of the Piper PA38 Tomahawk  

NASA Technical Reports Server (NTRS)

Ultradeep stall descent and spin recovery characteristics of a 1/6 scale radio controlled model of the Piper PA38 Tomahawk aircraft was investigated. It was shown that the full scale PA38 is a suitable aircraft for conducting ultradeep stall research. Spin recovery was accomplished satisfactorily by entry to the ultradeep stall mode, followed by the exit from the ultradeep stall mode. It is concluded that since the PA38 has excellent spin recovery characteristics using normal recovery techniques (opposite rudder and forward control colum pressure), recovery using ultradeep stall would be beneficial only if the pilot suffered from disorientation.

Blanchard, W. S., Jr.

1981-01-01

183

[Modeling polarimetric BRDF of leaves surfaces].  

PubMed

The purpose of the present paper is to model a physical polarimetric bidirectional reflectance distribution function (pBRDF), which can character not only the non-Lambertian but also the polarized features in order that the pBRDF can be applied to analyze the relationship between the degree of polarization and the physiological and biochemical parameters of leaves quantitatively later. Firstly, the bidirectional polarized reflectance distributions from several leaves surfaces were measured by the polarized goniometer developed by Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences. The samples of leaves include two pieces of zea mays L. leaves (young leaf and mature leaf) and a piece of E. palcherrima wild leaf. Non-Lambertian characteristics of directional reflectance from the surfaces of these three leaves are obvious. A Cook-Torrance model was modified by coupling the polarized Fresnel equations to simulate the bidirectional polarized reflectance properties of leaves surfaces. The three parameters in the modified pBRDF model, such as diffuse reflectivity, refractive index and roughness of leaf surface were inversed with genetic algorithm (GA). It was found that the pBRDF model can fit with the measured data well. In addition, these parameters in the model are related with both the physiological and biochemical properties and the polarized characteristics of leaves, therefore it is possible to build the relationships between them later. PMID:21322232

Xie, Dong-Hui; Wang, Pei-Juan; Zhu, Qi-Jiang; Zhou, Hong-Min

2010-12-01

184

Influence of pesticides on yeasts colonizing leaves.  

PubMed

The effect of nine different pesticides on the growth of yeasts isolated from the leaves of fruit and forest trees was investigated. Four insecticides (with the active ingredients: thiacloprid, deltamethrin, lambdacyhalothrin, and thiamethoxam) and five fungicides (with the effective substances: bitertanol, kresoxim-methyl, mancozeb, trifloxystrobin, and cupric oxychloride) were tested. The concentrations of chemicals were those recommended by the manufacturers for the spraying of trees. The yeast strains isolated from the leaves of fruit trees were not sensitive to any of the insecticides. The majority of yeast strains isolated from the leaves of forest trees were either not sensitive or only to a small extent. While Rhodotorula mucilaginosa and Pichia anomala were not affected by any insecticide, the strains of Cryptococcus laurentii and Rhodotorula glutinis showed the highest sensitivity. The effects of fungicides on the growth of isolated yeasts were more substantial. The fungicide Dithane DG (mancozeb) completely inhibited the growth of all yeasts. All strains isolated from fruit tree leaves were more resistant to the tested fungicides than those isolated from the leaves of forest trees. The most resistant strains from the leaves of fruit trees belonged to the species Metschnikowia pulcherrima, Pichia anomala, and Saccharomyces cerevisiae, whereas Cryptococcus albidus and C. laurentii, originating from the leaves of forest trees, showed the highest sensitivity to fungicides. PMID:22351984

Vadkertiová, Renata; Sláviková, Elena

2011-01-01

185

Piper sarmentosum as an antioxidant on oxidative stress in human umbilical vein endothelial cells induced by hydrogen peroxide*  

PubMed Central

Endothelial cell death due to increased reactive oxygen species (ROS) may contribute to the initial endothelial injury, which promotes atherosclerotic lesion formation. Piper sarmentosum (PS), a natural product, has been shown to have an antioxidant property, which is hypothesized to inhibit production of ROS and prevent cell injury. Thus, the present study was designed to determine the effects of PS on the hydrogen peroxide (H2O2)-induced oxidative cell damage in cultured human umbilical vein endothelial cells (HUVECs). In this experiment, HUVECs were obtained by collagenase perfusion of the large vein in the umbilical cord and cultured in medium M200 supplemented with low serum growth supplementation (LSGS). HUVECs were treated with various concentrations of H2O2 (0–1000 µmol/L) and it was observed that 180 µmol/L H2O2 reduced cell viability by 50% as denoted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Using the above concentration as the positive control, the H2O2-induced HUVECs were concomitantly treated with various concentrations (100, 150, 250 and 300 µg/ml) of three different extracts (aqueous, methanol and hexane) of PS. Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) levels showed a significant increase (P<0.05) in HUVECs compared to the negative control. However, PS extracts showed a protective effect on HUVECs from H2O2-induced cell apoptosis with a significant reduction in MDA, SOD, CAT and GPX levels (P<0.05). Furthermore, PS had exhibited ferric reducing antioxidant power with its high phenolic content. Hence, it was concluded that PS plays a beneficial role in reducing oxidative stress in H2O2-induced HUVECs.

Hafizah, Abdul Hamid; Zaiton, Zakaria; Zulkhairi, Amom; Mohd Ilham, Adenan; Nor Anita, Megat Mohd Nordin; Zaleha, Abdullah Mahdy

2010-01-01

186

Antioxidant activity of Piper nigrum L. essential oil extracted by supercritical CO? extraction and hydro-distillation.  

PubMed

The aim of this study was to optimize the antioxidant activity of Piper nigrum L. essential oil extracted using the supercritical carbon dioxide (SC-CO?) technique. Response surface methodology was applied using a three-factor central composite design to evaluate the effects of three independent extraction variables: pressure of 15-30 MPa, temperature of 40-50 °C and dynamic extraction time of 40-80 min. The DPPH radical scavenging method was used to evaluate the antioxidant activity of the extracts. The results showed that the best antioxidant activity was achieved at 30 MPa, 40 °C and 40 min. The extracts were analyzed by GC-FID and GC-MS. The main components extracted using SC-CO? extraction in optimum conditions were ?-caryophyllene (25.38 ± 0.62%), limonene (15.64 ± 0.15%), sabinene (13.63 ± 0.21%), 3-carene (9.34 ± 0.04%), ?-pinene (7.27 ± 0.05%), and ?-pinene (4.25 ± 0.06%). The essential oil obtained through this technique was compared with the essential oil obtained using hydro-distillation. For the essential oil obtained by hydro-distillation, the most abundant compounds were ?-caryophyllene (18.64 ± 0.84%), limonene (14.95 ± 0.13%), sabinene (13.19 ± 0.17%), 3-carene (8.56 ± 0.11%), ?-pinene (9.71 ± 0.12%), and ?-pinene (7.96 ± 0.14%). Radical scavenging activity of the extracts obtained by SC-CO? and hydro-distillation showed an EC?? of 103.28 and 316.27 µg mL(-1) respectively. PMID:24607131

Bagheri, Hossein; Abdul Manap, Mohd Yazid Bin; Solati, Zeinab

2014-04-01

187

Herbicide Uptake by Leaves and Cells  

NSDL National Science Digital Library

This animation describes how herbicides are taken up by leaves and illustrates how physico-chemical characteristics alter their movement across cuticles. Passive and active mechanisms of herbicide absorption across plant membranes into cells are shown as well.

188

Pharmacognostical studies on Zanthoxylum armatum leaves  

PubMed Central

The present study deals with the Pharmacognostical investigations on the leaves of Zanthoxylum armatum along with fluorescence characteristics ash and extractive values with an aim to identify and differentiate if from its possible adulterants and / or substitutes.

Verma, Nitin; Khosa, R. L.

2009-01-01

189

Characteristics of photosynthesis in peach leaves  

Microsoft Academic Search

Seasonal photosynthetic patterns of Loring peach (Prunus persica (L). Batsch) leaves were monitored throughout the 1974 growing season. Using leaves on detached branches, CO2 exchange was measured under controlled light and temperature conditions. Net photosynthesis rate varied from 9 to 12.4 mg CO2 dm-2 leaf area h-1 and was correlated with fruit development, with the highest values occurring during the

C. E. Crews; S. L. Williams; H. M. Vines

1975-01-01

190

5 CFR 630.911 - Restoration of transferred annual leave.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Restoration of transferred annual leave. 630.911 Section 630.911 Administrative...MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Voluntary Leave Transfer Program § 630.911 Restoration of...

2009-01-01

191

5 CFR 630.911 - Restoration of transferred annual leave.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Restoration of transferred annual leave. 630.911 Section 630.911 Administrative...MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Voluntary Leave Transfer Program § 630.911 Restoration of...

2010-01-01

192

5 CFR 630.906 - Transfer of annual leave.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Transfer of annual leave. 630.906 Section 630.906 Administrative...MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Voluntary Leave Transfer Program § 630.906 Transfer of...

2010-01-01

193

5 CFR 550.1207 - Recrediting annual leave.  

Code of Federal Regulations, 2010 CFR

... 2009-01-01 false Recrediting annual leave. 550.1207 Section 550.1207 Administrative...Lump-Sum Payment for Accumulated and Accrued Annual Leave § 550.1207 Recrediting annual leave. (a) When an employee pays a full...

2009-01-01

194

5 CFR 630.906 - Transfer of annual leave.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Transfer of annual leave. 630.906 Section 630.906 Administrative...MANAGEMENT CIVIL SERVICE REGULATIONS ABSENCE AND LEAVE Voluntary Leave Transfer Program § 630.906 Transfer of...

2009-01-01

195

Chemopreventive and Antilipidperoxidative Efficacy of Piper longum (Linn.) on 7,12-dimethylbenz (a) anthracene (DMBA) Induced Hamster Buccal Pouch Carcinogenesis  

NASA Astrophysics Data System (ADS)

Aim of the present study was to find out the chemopreventive efficacy of Piper longum, a plant having diverse medicinal properties, in 7,12-dimethyl benz (a) anthracene (DMBA) induced oral carcinogenesis. The mechanistic pathway for its chemopreventive potential was analysed by measuring lipid peroxidation and antioxidants status in DMBA induced oral cancer. DMBA painting in hamster buccal pouch three times per week for 14 weeks resulted in well developed, well differentiated squamous cell carcinoma. Elevated lipid peroxidation and decline in antioxidants were noticed in tumor bearing hamsters as compared to control animals. Oral administration of ethanolic extract of Piper longum dried fruits (PLEFet) on alternate days to DMBA painting significantly prevented the tumor incidence, volume and burden and restored the status of lipid peroxidation and antioxidants in DMBA painted hamsters. Our results indicate that the dried fruits of P. longum has suppressing effects on cell proliferation, which is probably due to its antilipid peroxidative and antioxidative potential during DMBA induced oral carcinogenesis.

Senthil, Namasivayam; Manoharan, Shanmugam; Balakrishnan, Subramanian; Rajmani Ramachandran, Cinnamanoor; Muralinaidu, Radhakrishnan

196

More Manganese Accumulates in Maple Sun Leaves than in Shade Leaves 1  

PubMed Central

Nuclear magnetic resonance and neutron activation analysis were used to measure manganese concentrations in leaves of Acer platanoides. Mn was found to accumulate in both the vacuoles and the chloroplasts, with more Mn (per unit area) in sun leaves than in shade leaves. No Mn was lost at senescence. Different seasonal patterns of Mn accumulation were found in sun and shade leaves. The quantity of chloroplast reserve Mn (bound to the outer surface of thylakoid membranes) increased rapidly in sun leaves from bud-break through midsummer, and then remained approximately constant through senescence. In shade leaves, however, the quantity of reserve Mn increased slowly, and at approximately a constant rate throughout the growing season.

McCain, Douglas C.; Markley, John L.

1989-01-01

197

Complete chloroplast genome sequences of Drimys, Liriodendron, andPiper: Implications for the phylogeny of magnoliids and the evolution ofGC content  

SciTech Connect

The magnoliids represent the largest basal angiosperm clade with four orders, 19 families and 8,500 species. Although several recent angiosperm molecular phylogenies have supported the monophyly of magnoliids and suggested relationships among the orders, the limited number of genes examined resulted in only weak support, and these issues remain controversial. Furthermore, considerable incongruence has resulted in phylogenies supporting three different sets of relationships among magnoliids and the two large angiosperm clades, monocots and eudicots. This is one of the most important remaining issues concerning relationships among basal angiosperms. We sequenced the chloroplast genomes of three magnoliids, Drimys (Canellales), Liriodendron (Magnoliales), and Piper (Piperales), and used these data in combination with 32 other completed angiosperm chloroplast genomes to assess phylogenetic relationships among magnoliids. The Drimys and Piper chloroplast genomes are nearly identical in size at 160,606 and 160,624 bp, respectively. The genomes include a pair of inverted repeats of 26,649 bp (Drimys) and 27,039 (Piper), separated by a small single copy region of 18,621 (Drimys) and 18,878 (Piper) and a large single copy region of 88,685 bp (Drimys) and 87,666 bp (Piper). The gene order of both taxa is nearly identical to many other unrearranged angiosperm chloroplast genomes, including Calycanthus, the other published magnoliid genome. Comparisons of angiosperm chloroplast genomes indicate that GC content is not uniformly distributed across the genome. Overall GC content ranges from 34-39%, and coding regions have a substantially higher GC content than non-coding regions (both intergenic spacers and introns). Among protein-coding genes, GC content varies by codon position with 1st codon > 2nd codon > 3rd codon, and it varies by functional group with photosynthetic genes having the highest percentage and NADH genes the lowest. Across the genome, GC content is highest in the inverted repeat due to the presence of rRNA genes and lowest in the small single copy region where most NADH genes are located. Phylogenetic analyses using maximum parsimony and maximum likelihood methods were performed on DNA sequences of 61 protein-coding genes. Trees from both analyses provided strong support for the monophyly of magnoliids and two strongly supported groups were identified, the Canellales/Piperales and the Laurales/Magnoliales. The phylogenies also provided moderate to strong support for the basal position of Amborella, and a sister relationship of magnoliids to a clade that includes monocots and eudicots. The complete sequences of three magnoliid chloroplast genomes provide new data from the largest basal angiosperm clade. Evolutionary comparisons of these new genome sequences, combined with other published angiosperm genome, confirm that GC content is unevenly distributed across the genome by location, codon position, and functional group. Furthermore, phylogenetic analyses provide the strongest support so far for the hypothesis that the magnoliids are sister to a large clade that includes both monocots and eudicots.

Zhengqiu, C.; Penaflor, C.; Kuehl, J.V.; Leebens-Mack, J.; Carlson, J.; dePamphilis, C.W.; Boore, J.L.; Jansen, R.K.

2006-06-01

198

The extraction of characteristic wavebands for radish leaves and rice leaves based on LCTF imaging method  

NASA Astrophysics Data System (ADS)

In order to identify and classify horticultural crops rapidly, it is great importance of selecting effective characteristic wavebands from a large number of imaging data. Extracting effective characteristic wavebands can nearly represent holistic information of the research target from rich imaging spectral data, mainly used for rapid characteristic identification, cluster analysis and establishing database, especially in high spectral sensing to recognize targets for a long distance. The experiment chooses radish leaves and rice leaves as research samples so as to obtain spectral information from the surface of samples by interval of 5nm based on LCTF imaging; then, the standard deviation and correlation coefficient of the gray images are calculated for these two kinds of leaves; next, we calculate the value of waveband index according to standard deviation and correlation coefficient, and extract the effective characteristic wavebands for radish leaves and rice leaves through the sorting of waveband index. By those, the experimental results show there are six ideal wavebands at 530nm, 550nm, 555nm, 715nm, 510nm and 565nm for radish leaves, 645nm, 675nm, 685nm, 670nm, 690nm and 660nm for rice leaves separately. Further, according to the principle of Euclidean distance, we also give an assessment of classification accuracy for these two samples by comparing characteristic wavebands with full wavebands, and the classification accuracy of radish leaves and rice leaves is 80.00% and 86.67% respectively. Therefore, choosing these wavebands can be used as effective characteristic wavebands for radish leaves and rice leaves.

Cao, Peng-fei; Feng, Jie; Li, Hong-ning

2013-08-01

199

Maize Leaves Turn Away from Neighbors1  

PubMed Central

In commercial crops, maize (Zea mays) plants are typically grown at a larger distance between rows (70 cm) than within the same row (16–23 cm). This rectangular arrangement creates a heterogeneous environment in which the plants receive higher red light (R) to far-red light (FR) ratios from the interrow spaces. In field crops, the hybrid Dekalb 696 (DK696) showed an increased proportion of leaves toward interrow spaces, whereas the experimental hybrid 980 (Exp980) retained random leaf orientation. Mirrors reflecting FR were placed close to isolated plants to simulate the presence of neighbors in the field. In addition, localized FR was applied to target leaves in a growth chamber. During their expansion, the leaves of DK696 turned away from the low R to FR ratio signals, whereas Exp980 leaves remained unaffected. On the contrary, tillering was reduced and plant height was increased by low R to FR ratios in Exp980 but not in DK696. Isolated plants preconditioned with low R/FR-simulating neighbors in a North-South row showed reduced mutual shading among leaves when the plants were actually grouped in North-South rows. These observations contradict the current view that phytochrome-mediated responses to low R/FR are a relic from wild conditions, detrimental for crop yield.

Maddonni, Gustavo Angel; Otegui, Maria Elena; Andrieu, Bruno; Chelle, Michael; Casal, Jorge J.

2002-01-01

200

Catabolism of Adenine Derivatives in Leaves  

PubMed Central

The in vivo activity of xanthine dehydrogenase (E.C. 1.2.1.37) was followed in leaf discs excised from illuminated or darkened plants. In cotyledons of Pharbitis nil, 24 hours of darkness enhanced the in vivo activity of xanthine dehydrogenase which increased between 2 to 5-fold depending on the concentration of hypoxanthine of the solution where cotyledon discs were incubated. The same effect occurred in leaves of several other species, in plants with both high and low ureide content. However, the effect of light was not observed in leaves of Zea mays, Pennisetum americanum and Atriplex spongiosa, whereas, it appeared very clearly in other C4 plants such as Sorghum sudanense and Portulaca oleracea. This enzymic activity in chlorophyll-deficient tobacco leaves was the same both for illuminated and darkened plants. In addition, the in vivo activity of xanthine dehydrogenase in roots of Pharbitis nil was not dependent upon the light conditions applied to leaves. In cotyledons of Pharbitis nil, the level of the in vivo activity of xanthine dehydrogenase was influenced by the energy of light and the duration of illumination. The supply of carbohydrates to darkened cotyledons had the same effect as light on the in vivo activity of xanthine dehydrogenase. It is proposed that the effect of light on the in vivo activity of xanthine dehydrogenase in leaves is mainly due to the production of photosynthates which changes the osmotic state of leaf tissue and thus modifies the level of the in vivo activity of xanthine dehydrogenase.

Nguyen, Jacqueline

1980-01-01

201

Gene Expression in Autumn Leaves1  

PubMed Central

Two cDNA libraries were prepared, one from leaves of a field-grown aspen (Populus tremula) tree, harvested just before any visible sign of leaf senescence in the autumn, and one from young but fully expanded leaves of greenhouse-grown aspen (Populus tremula × tremuloides). Expressed sequence tags (ESTs; 5,128 and 4,841, respectively) were obtained from the two libraries. A semiautomatic method of annotation and functional classification of the ESTs, according to a modified Munich Institute of Protein Sequences classification scheme, was developed, utilizing information from three different databases. The patterns of gene expression in the two libraries were strikingly different. In the autumn leaf library, ESTs encoding metallothionein, early light-inducible proteins, and cysteine proteases were most abundant. Clones encoding other proteases and proteins involved in respiration and breakdown of lipids and pigments, as well as stress-related genes, were also well represented. We identified homologs to many known senescence-associated genes, as well as seven different genes encoding cysteine proteases, two encoding aspartic proteases, five encoding metallothioneins, and 35 additional genes that were up-regulated in autumn leaves. We also indirectly estimated the rate of plastid protein synthesis in the autumn leaves to be less that 10% of that in young leaves.

Bhalerao, Rupali; Keskitalo, Johanna; Sterky, Fredrik; Erlandsson, Rikard; Bjorkbacka, Harry; Birve, Simon Jonsson; Karlsson, Jan; Gardestrom, Per; Gustafsson, Petter; Lundeberg, Joakim; Jansson, Stefan

2003-01-01

202

Piper sarmentosum inhibits ICAM-1 and Nox4 gene expression in oxidative stress-induced human umbilical vein endothelial cells  

PubMed Central

Background Aqueous extract of Piper sarmentosum (AEPS) is known to possess antioxidant and anti-atherosclerotic activities but the mechanism responsible for it remains unclear. In early part of atherosclerosis, nuclear factor-kappa B (NF-?B) induces the expression of cellular adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1) and E-selectin. NADPH oxidase 4 (Nox4) is the predominant source of superoxide in the endothelial cells whereas superoxide dismutase 1 (SOD1), catalase (CAT) and glutathione peroxidase (GPx) are the antioxidant enzymes responsible for inactivating reactive oxygen species. The present study aimed to investigate the effects of AEPS on the gene expression of NF-?B, VCAM-1, ICAM-1, E-selectin, Nox4, SOD1, CAT and GPx in cultured human umbilical vein endothelial cells (HUVECs). Methods HUVECs were divided into four groups:- control; treatment with 180 ?M hydrogen peroxide (H2O2); treatment with 150 ?g/mL AEPS and concomitant treatment with AEPS and H2O2 for 24 hours. Total RNA was extracted from all the groups of HUVEC using TRI reagent. Subsequently, qPCR was carried out to determine the mRNA expression of NF-?B, VCAM-1, ICAM-1, E-selectin, Nox4, SOD1, CAT and GPx. The specificity of the reactions was verified using melting curve analysis and agarose gel electrophoresis. Results When stimulated with H2O2, HUVECs expressed higher level of ICAM-1 (1.3-fold) and Nox4 (1.2-fold) mRNA expression. However, AEPS treatment led to a reduction in the mRNA expression of ICAM-1 (p < 0.01) and Nox4 (p < 0.05) in the H2O2-induced HUVECs. AEPS also upregulated the mRNA expression of SOD1 (p < 0.05), CAT (p < 0.01) and GPx (p < 0.05) in oxidative stress-induced HUVECs. There was no significant change in the mRNA expression of VCAM-1 and E-selectin. Conclusion The expressional suppression of ICAM-1 and Nox4 and induction of antioxidant enzymes might be an important component of the vascular protective effect of AEPS.

2011-01-01

203

School Involvement Leave: Providing Leave for Parental Involvement in School Activities. Policy Briefing Series. Issue 18  

ERIC Educational Resources Information Center

One of the most important factors in school performance is parental involvement. However, many parents do not have the flexibility in their work schedules or the leave policies necessary to attend school functions. As a result, legislators are creating policies to address this issue. School involvement leave policies provide parents with…

Curlew, Mary; Weber, Julie

2009-01-01

204

University Students Leaving Relationships (USLR): Scale Development and Gender Differences in Decisions to Leave Romantic Relationships  

ERIC Educational Resources Information Center

The University Students Leaving Relationships scale was developed to identify student concerns when contemplating dissolution of romantic relationships. Participants included 1,106 students who rated the importance of issues when deciding to leave relationships. Factor analysis produced three dimensions: Missing the Relationship, Social…

Hendy, Helen M.; Can, S. Hakan; Joseph, Lauren J.; Scherer, Cory R.

2013-01-01

205

Phenolic profile of Cydonia oblonga Miller leaves.  

PubMed

Cydonia oblonga Miller leaves phenolic compounds were analyzed by reversed-phase HPLC/DAD and HPLC/UV. Qualitative and quantitative analysis of phenolics were carried out in a total of 36 samples of quince leaves from three different geographical origins of Northern (Bragança and Carrazeda de Ansiães) and Central Portugal (Covilhã) and three collection months (June, August, and October of 2006). These leaves presented a common phenolic profile composed by nine compounds: 3- O-, 4- O- and 5- O-caffeoylquinic acids, 3,5- O-dicaffeoylquinic acid, quercetin-3- O-galactoside, quercetin-3- O-rutinoside, kaempferol-3- O-glycoside, kaempferol-3- O-glucoside, and kaempferol-3- O-rutinoside. 5- O-caffeoylquinic acid was the major phenolic compound (36.2%), followed by quercetin 3- O-rutinoside (21.1%). Quince leaves are characterized by higher relative contents of kaempferol derivatives than fruits (pulps, peels, and seeds), especially in what concerns kaempferol-3- O-rutinoside (12.5%). C. oblonga leaves total phenolic content was very high, varying from 4.9 to 16.5 g/kg dry matter (mean value of 10.3 g/kg dry matter), indicating that these leaves can be used as a good and cheap source of bioactive constituents. Significantly differences were observed in 3- O-caffeoylquinic and 3,5- O-dicaffeoylquinic acids contents, according to geographical provenance and harvesting month, suggesting a possible use of these compounds as geographical origin and/or maturity markers. PMID:17711340

Oliveira, Andreia P; Pereira, José A; Andrade, Paula B; Valentão, Patrícia; Seabra, Rosa M; Silva, Branca M

2007-09-19

206

29 CFR 825.120 - Leave for pregnancy or birth.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Leave for pregnancy or birth. 825.120 Section 825...Medical Leave Act § 825.120 Leave for pregnancy or birth. (a) General rules. ...employees are entitled to FMLA leave for pregnancy or birth of a child as follows:...

2010-07-01

207

29 CFR 825.120 - Leave for pregnancy or birth.  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 false Leave for pregnancy or birth. 825.120 Section 825...Medical Leave Act § 825.120 Leave for pregnancy or birth. (a) General rules. ...employees are entitled to FMLA leave for pregnancy or birth of a child as follows:...

2009-07-01

208

Piper guineense on on on on on the reproductive function of adult male rats the reproductive function of adult male rats the reproductive function of adult male rats the reproductive function of adult male rats the reproductive function of adult male rats  

Microsoft Academic Search

Objective: To study the effect of the aqueous extract of Piper guineense (Piperaceae) on male reproductive function in Wistar rats. Materials and Methods: Male rats, 3 months old, weighing 180-210 g were administered (by gas- tric intubation) the aqueous extract of dry fruits of Piper guineense at two doses, 122.5 and 245 mg\\/ kg for 8 days and 122.5 mg\\/kg

F. G. Y. Mbongue; P. Kamtchouing; O. J. L. Essame; P. M. Yewah; T. Dimo; D. Lontsi

209

The geometry of unfolding tree leaves  

PubMed Central

Leaves of hornbeam (Carpinus betulus) and beech (Fagus sylvaticus) were modelled to a first approximation as plane surfaces, with straight parallel folds, using numerical methods. In both species the lateral veins, when the leaves are outstretched, are angled at 30 to 50 degrees from the centre vein. A higher angle allows the leaf to be folded more compactly within the bud, but it takes longer to expand. This may allow the plant to optimize the timing of leaf deployment with ecological and physiological conditions.

Kobayashi, H.; Kresling, B.; Vincent, J. F. V.

1998-01-01

210

Practical Approaches for Teaching Leave No Trace.  

ERIC Educational Resources Information Center

As participation in outdoor recreation grows, natural resources suffer a variety of environmental and social impacts. A minimum-impact back country educational program first developed during the 1970s, Leave No Trace (LNT), has been revitalized by the National Outdoor Leadership School, six federal agencies, and members of the outdoor products…

Attarian, Aram

211

MINERAL COMPOSITION OF AVOCADO LEAVES IN FLORIDA  

Microsoft Academic Search

Avocado (Persea Americana Mill.) leaves of 'Tonnage' trees growing on sand, muck, and calcareous rock soils and 'Lula,' 'Taylor,' and 'Booth 8' trees on sand and rock were collected in 1974 and 1975 and analyzed for concns of N, P, K, Ca, Mg, Mn, Cu, Zn, and Fe. Differences, in levels of the 9 elements occurred with differences in soil

T. W. Young

212

Employing Linear Regression in Regression Tree Leaves  

Microsoft Academic Search

. The advantage of using linear regressionin the leaves of a regression tree is analysed in thepaper. It is carried out how this modification affectsthe construction, pruning and interpretation of a regressiontree. The modification is tested on artificialand real-life domains. The results show that the modificationis beneficial as it leads to smaller classificationerrors of induced regression trees. Keywords: machinelearning, TDIDT,

Aram Karalic

1992-01-01

213

Ecojustice in Science Education: Leaving the Classroom  

ERIC Educational Resources Information Center

Eduardo Dopico and Eva Garcia-Vazquez's article enriched the ecojustice literature with an interesting metaphor of leaving the classroom, which I argue for here. Glasson and Boggs help to highlight the challenges and fortitude of working ecojustice perspectives in science education and the ways that a dialogical conversation addresses the world at…

Mueller, Michael P.

2011-01-01

214

Leaving Care: The Need to Make Connections  

ERIC Educational Resources Information Center

For too many years the phrase "after care, an after thought" summed up the lack of attention given to preparing young people in care for adult life and to the development of leaving-care and aftercare services. That stance has changed in the United Kingdom, however, and indeed has shifted positively and dramatically over the last decade. In 2010…

Coyle, Deirdre; Pinkerton, John

2012-01-01

215

Paid Educational Leave: A Partnership Approach.  

ERIC Educational Resources Information Center

Humberside (England) City Council and Hull University collaborated on a project to offer paid educational leave to manual and lower-grade white-collar council staff. The program was aimed at those who had derived little benefit from formal education and provided a supportive environment for working class women who made up the bulk of the…

Somerton, Michael

1994-01-01

216

[Polyphenolic substances of Cynara scolymus L. leaves].  

PubMed

From the leaves of Cynara scolymus the following substances where isolated: apigenin, luteolin, luteolin-4'-glucoside, cynaroside, scolimoside, cosmoside, quercetin, rutin, chlorogenic acid, caffeic acid, isochlorogenic acid, luteolin-7-gentiobioside, along with the more uncommon scopoletin, hesperitin, hesperidoside, esculetin-6-O-beta-glucoside; more over maritimein was for the first time isolated and identified in the genus. PMID:2610472

Hinou, J; Harvala, C; Philianos, S

1989-01-01

217

Why Nannies Leave Their Employing Families.  

ERIC Educational Resources Information Center

The position of nanny as a career option for child care/child development/early childhood education graduates is examined. This study surveyed nannies randomly selected from the 1991 International Nanny Association Directory to determine why nannies leave their employing families. Surveys were mailed to 160 nannies; 62 (39%) nannies responded.…

Olsen, Glenn

218

Leaving Welfare: Independence or Continued Vulnerability?  

ERIC Educational Resources Information Center

Interviews with seven women before and 6 months after leaving welfare revealed barriers to self-sufficiency (low wages, lack of advancement opportunities in jobs, confusion about program regulations) and survival strategies (continued reliance on income and family support, banking of care benefits under the 5-year limit as a safety net). (SK)

Litt, Jacquelyn; Gaddis, Barbara J.; Fletcher, Cynthia Needles; Winter, Mary

2000-01-01

219

The Pied Piper  

NSDL National Science Digital Library

An unusually thorough British pest identification website loaded with general arthropod information, most of it well illustrated. Sections dedicated to chemicals, and miscellaneous home intruders are especially nice additions. They also include a bit of their work ethic, which contributes nicely to the overall quality.

0002-11-30

220

Developmental studies on microbodies in wheat leaves  

Microsoft Academic Search

1.In etiolated wheat (Triticum aestivum L.) leaves, the development of the microbody enzymes catalase, hydroxypyruvate reductase, and glycolate oxidase was specifically stimulated by short treatments of the seedlings with red light, although the increases were less than observed after treatment with continuous white light. A comparison of the effects of short red and far-red exposures indicated the involvement of phytochrome.2.Continuous

J. Feierabend

1975-01-01

221

Inhibitors of osteoclastogenesis from Lawsonia inermis leaves.  

PubMed

Ten phenolic compounds (1-10) were isolated from a methanol extract of Lawsonia inermis leaves including two new ones, lawsoniasides A (1) and B (2). Their structures were elucidated by spectroscopic methods (NMR and FTICRMS) in combination with acid hydrolysis and GC analyses. Compounds 4 and 5 showed a significant inhibition on receptor activator for nuclear factor-kappaB ligand-induced osteoclast formation in murine bone-marrow macrophages. PMID:20634065

Cuong, Nguyen Xuan; Nhiem, Nguyen Xuan; Thao, Nguyen Phuong; Nam, Nguyen Hoai; Dat, Nguyen Tien; Anh, Hoang Le Tuan; Huong, Le Mai; Kiem, Phan Van; Minh, Chau Van; Won, Ji-Hee; Chung, Won-Yoon; Kim, Young Ho

2010-08-15

222

Sick leave patterns in common musculoskeletal disorders - a study of doctor prescribed sick leave  

PubMed Central

Background Comparative data on sick leave within musculoskeletal disorders (MSDs) is limited. Our objective was to give a descriptive overview of sick leave patterns in different MSDs. Methods Using electronic medical records, we collected information on dates and diagnostic codes for all available sick leave certificates, during 2 years (2009–2010), in the North Western part of the Skåne region in Sweden (22 public primary health care centres and two general hospitals). Using the International Classification of Diseases (ICD) 10 codes on the certificates we studied duration, age and sex distribution and recurrent periods of sick leave for six strategically chosen MSDs; low back pain (M54) disc disorders (M51), knee osteoarthritis (M17) hip osteoarthritis (M16) rheumatoid arthritis (M05-M06) and myalgia (M79). Results All together 20 251 sick leave periods were issued for 16 673 individuals 16–64 years of age (53% women). Out of the selected disorders, low back pain and myalgia had the shortest sick leave periods, with a mean of 26 and 27 days, respectively, while disc disorders and rheumatoid arthritis had the longest periods with a mean of 150 and 147 days. For low back pain and myalgia 27% and 26% of all sick leave was short (8–14 days) and only 11% and 13%, were long (?90 days). For the other selected MSDs, less than 5% of the periods were short. For disc disorders, hip osteoarthritis and rheumatoid arthritis, more than 60% of the periods were long (p?>?0.001). For back disorders and myalgia most periods were issued in the age groups between 40–49, with similar patterns for women and men. Osteoarthritis and rheumatoid arthritis had most periods in the age groups of 50–64, and patterns for women and men differed. Low back pain, rheumatoid arthritis and myalgia had the greatest share of recurrent sick leave (31%, 34% and 32% respectively). Conclusion Duration, age and sex distribution and numbers of recurrent sick leave varies considerably between different MSDs. This underscores the importance of using specified diagnosis, in sick leave research as well as in planning of treatment and rehabilitation and evaluation of prognosis.

2014-01-01

223

Carbon Fluxes in Mature Peach Leaves  

PubMed Central

The turnover and transport of sugars are described in peach (Prunus persica L. Batsch), a species exporting both sucrose and sorbitol. Apparent export rate was slower in peach leaves than in leaves of herbaceous species. Sorbitol was the major soluble end product of photosynthesis and the major soluble carbohydrate in the leaf (higher than sucrose). Carbon fluxes were described using 14C labeling, radioactivity loss curves, and compartmental analysis during the second half of the photoperiod when chemical steady state was reached for soluble carbohydrates. The measured specific radioactivity of sucrose was typical of a primary product. The delayed decrease in specific radioactivity of sorbitol indicated that part of it was secondarily synthesized. Sucrose is proposed to be the carbon source for the delayed synthesis of sorbitol in the light. The sorbitol to sucrose ratio was higher in the petiole than in the leaf tissues. In phloem sap, obtained using stylectomy of aphids and collected from the main stem between source leaves and apex, this ratio was lower than in the petiole, suggesting a preferential sorbitol demand by sinks.

Moing, Annick; Carbonne, Francis; Rashad, Mohamed H.; Gaudillere, Jean-Pierre

1992-01-01

224

Enumerating All Rooted Trees Including k Leaves  

NASA Astrophysics Data System (ADS)

This paper presents an efficient algorithm to generate all (unordered) rooted trees with exactly n vertices including exactly k leaves. There are known results on efficient enumerations of some classes of graphs embedded on a plane, for instance, biconnected and triconnected triangulations [3], [6], and floorplans [4]. On the other hand, it is difficult to enumerate a class of graphs without a fixed embedding. The paper is on enumeration of rooted trees without a fixed embedding. We already proposed an algorithm to generate all “ordered” trees with n vertices including k leaves [11], while the algorithm cannot seem to efficiently generate all (unordered) rooted trees with n vertices including k leaves. We design a simple tree structure among such trees, then by traversing the tree structure we generate all such trees in constant time per tree in the worst case. By repeatedly applying the algorithm for each k=1,2,...,n-1, we can also generate all rooted trees with exactly n vertices.

Ishikawa, Masanobu; Yamanaka, Katsuhisa; Otachi, Yota; Nakano, Shin-Ichi

225

Isocitrate Lyase in Green Leaves 1  

PubMed Central

Isocitrate lyase (EC 4.1.3.1) has been demonstrated in crude dialyzed extracts of healthy spinach (Spinacia oleracea) leaves from commercial sources and wheat (Triticum aestivum) and maize (Zea mays) leaves stored in darkness in the cold room for 1 week. The products of the reaction were identified as glyoxylate and succinate, the former by its phenylhydrazone, and the latter traced by isotopic labeling and cochromatography. Fresh spinach extracts contain a mixture of at least two endogenous inhibitors of isocitrate lyase activity and one of them is proteinaceous. The endogenous inhibitor(s) is thermostable and retains 50% of its inhibitory effect even after boiling for 10 minutes. Dark starvation of the leaves removes the inhibition, due possibly to autolysis of the inhibitor(s). The inhibitor(s) can also be removed by filtration through Sephadex gels. The crude extract from spinach shows double pH optima in phosphate buffer at pH 7.4 and pH 8.0. The apparent Km at pH 7.4 was 0.1 mm. Oxaloacetate, dl-malate, succinate, 3-phosphoglycerate, and glycolate at 10 mm concentration inhibited, but ribulose 1,5-diphosphate activated enzymic activity. Images

Godavari, H. R.; Badour, S. S.; Waygood, E. R.

1973-01-01

226

48 CFR 752.7031 - Leave and holidays.  

Code of Federal Regulations, 2013 CFR

...Holidays for Contractor employees serving overseas should take into consideration local practices and shall be established in collaboration with the Mission Director. (e) Military leave. Military leave of not more than 15 calendar days in any...

2013-10-01

227

46 CFR 502.68 - Motion for leave to intervene.  

Code of Federal Regulations, 2013 CFR

... 9 2013-10-01 2013-10-01 false Motion for leave to intervene. 502.68 Section...PRACTICE AND PROCEDURE Proceedings; Pleadings; Motions; Replies § 502.68 Motion for leave to intervene. (a) Filing....

2013-10-01

228

Self-Funded Leave and Life Role Development  

ERIC Educational Resources Information Center

Self-funded leave is an employee benefit that provides a time resource to those who wish to develop interests and other life roles. Semistructured interviews were used for this qualitative study to explore the motivations for enrolling in the self-funded leave program, how the leave contributed to work-life balance through development of other…

Furbish, Dale S.

2009-01-01

229

29 CFR 825.200 - Amount of leave.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Amount of leave. 825.200 Section 825.200 Labor Regulations...DEPARTMENT OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993 Employee Leave Entitlements Under the Family and Medical...

2010-07-01

230

29 CFR 825.200 - Amount of leave.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Amount of leave. 825.200 Section 825.200 Labor Regulations...DEPARTMENT OF LABOR OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993 Employee Leave Entitlements Under the Family and Medical...

2009-07-01

231

Physically Based Real-Time Translucency for Leaves  

Microsoft Academic Search

This paper presents a new shading model for real-time rendering of plant leaves that reproduces all important attributes of a leaf and allows for a large number of leaves to be shaded. In particular, we use a physically based model for accurate subsurface scattering on the translucent side of directly lit leaves. For real-time rendering of this model, we formulate

Ralf Habel; Alexander Kusternig; Michael Wimmer

2007-01-01

232

Parents' Workplace Situation and Fathers' Parental Leave Use  

ERIC Educational Resources Information Center

This study examines how the workplace situation of both parents affects fathers' parental leave use. We used parental leave-taking register data from Statistics Sweden for dual-earner couples who resided in Stockholm and had children in 1997 (n=3,755). The results indicate that fathers shorten their parental leave if their workplaces are such that…

Bygren, Magnus; Duvander, Ann-Zofie

2006-01-01

233

Tannin Composition Affects the Oxidative Activities of Tree Leaves  

Microsoft Academic Search

We examined whether tannin composition plays an important role in explaining the oxidative activities of tree leaves of Acer saccharum (sugar maple) and Quercus rubra (red oak). Sugar maple leaves contained substantial amounts of ellagitannins, condensed tannins, and galloyl glucoses, whereas red oak leaves contained almost exclusively condensed tannins. Oxidative activities of the crude phenolics from both species, and the

Raymond V. Barbehenn; Christopher P. Jones; Maarit Karonen; Juha-Pekka Salminen

2006-01-01

234

Factors Predicting Staff's Intentions to Leave the University.  

ERIC Educational Resources Information Center

The survey of University of Bergen (Norway) teaching staff (N=601) found the leading reason for intending to leave the institution was collegial relations. Other reasons predicting intention to leave were in the area of general job satisfaction with staff who found their work less intrinsically satisfying more likely to plan on leaving.…

Manger, Terje; Eikeland, Ole-Johan

1990-01-01

235

29 CFR 825.200 - Amount of leave.  

Code of Federal Regulations, 2013 CFR

...OTHER LAWS THE FAMILY AND MEDICAL LEAVE ACT OF 1993 Employee...Entitlements Under the Family and Medical Leave Act § 825.200 Amount...State which has a family and medical leave statute. The State...or an employer closing the plant for retooling or...

2013-07-01

236

Early School Leaving and the Cultural Geography of High Schools.  

ERIC Educational Resources Information Center

States early school leaving is a protracted educational problem throughout the world. Examines early school leaving from the position of young Australians (n=209) who left school or were considering leaving. Provides tentative theorizing traversing aspects of the cultural geography of high school as partial explanation of what is occurring. (BT)

Smyth, John; Hattam, Robert

2002-01-01

237

Teachers' Professional Identity and Job-Leaving Inclination.  

ERIC Educational Resources Information Center

This study focused on the intrinsic motives that account for teachers leaving their profession. Former teachers in the Haifa area of Israel participated in interviews, giving reasons for leaving teaching that correlated with those found in a study of the literature. The most frequently mentioned reasons for leaving teaching were: (1) burnout and…

Kremer, Lya; Hofman, John E.

238

Genotoxic andNon-genotoxic Effects ofBetel QuidIngredients onOral Mucosal Fibroblasts invitrol  

Microsoft Academic Search

Tounderstand therole ofbetel quid(BQ)inthe pathogenesis oforal submucous fibrosis (OSF) andoral cancer, we used DNAdamage, cytotoxicity, andcell proliferation assays to study thepathobiological effects ofaqueous extracts ofthree BQ constituents (betel nut(Areca catechu, BN), inflorescence ofPiper betle (IPB), andlime), oneBNalkaloid (arecoline), andoneBN polyphenol ((+)-catechinl oncultured oral mucosal fibroblasts. Extracts ofBNandIPBinduced DNAstrand break formation ina dose-dependent manner. Extracts ofBNandIPB, (+)-catechin, and arecoline decreased cell

J. H. Jeng; M. L. Kuo; L. J. Hahn; Y. P. Kuo

239

Effects of garlic, turmeric and betel leaf against gastrointestinal nematodes in cattle  

Microsoft Academic Search

The experiment was conducted in the Department of Pharmacology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, for a period of 28 days to study the effects of garlic (Allium sativum, Linn., @100mg\\/kg bwt.), turmeric (Curcuma longa, Linn., @100mg\\/kg bwt.) and betel leaf (Piper betle, Linn., @100mg\\/kg bwt.) against natural gastrointestinal nematodes in cattle. The effects of garlic, turmeric and

M. R. Amin; M. Mostofa; M. A. Awal; M. A. Sultana

2008-01-01

240

Molluscicidal saponins from leaves of Hedera canariensis.  

PubMed

Activity-guided fractionation of the methanol extract of Hedera canariensis (var. Gloire de Maringo) Wild leaves afforded five saponins 1-5. Chemical and spectral methods (MS, 1HNMR, 13CNMR) showed that they are glycosides of hederagenin and oleanolic acid. The results showed that 4,5 exhibited molluscicidal properties, compound 1 was inactive. Mortality rate of exposed snails increased by increasing plant extract concentration. Lymnaea cailliaudi was more sensitive to plant extract than Biomphalaria alexandrina. The histopathological study revealed distinct damage in the structure of the stomach and ovotestis of treated L. cailliaudi snails. Saponin content was determined in term of haemolytic index. PMID:19143139

Abdel Rahman, E H; Hassan, Soad E

2008-04-01

241

Bioactive terpenoids from sunflower leaves cv. Peredovick.  

PubMed

The CH(2)Cl(2) extract of dried leaves of Helianthus annuus L. cv. Peredovick(R) has yielded, in addition to the known sesquiterpene lactones annuolide E and leptocarpin, and the sesquiterpenes heliannuols A, C, D, F, G, H, I, the new bisnorsesquiterpene, annuionone E, and the new sesquiterpenes heliannuol L, helibisabonol A and helibisabonol B. Structural elucidation was based on extensive spectral (one and two-dimensional NMR experiments) and theoretical studies. The sesquiterpenes heliannuol A and helibisabonol A and the sesquiterpene lactone leptocarpin inhibited the growth of etiolated wheat coleoptiles. PMID:12423890

Macías, Francisco A; Torres, Ascensión; Galindo, José L G; Varela, Rosa M; Alvarez, José A; Molinillo, José M G

2002-11-01

242

Amino Acid Metabolism of Pea Leaves  

PubMed Central

In the young leaves of pea (Pisum sativum L.) plants, there was a diurnal variation in the levels of amino acids. In the light, total amino nitrogen increased for the first few hours, then stabilized; in the dark, there was a transient decrease followed by a gradual recovery. Asparagine, homoserine, alanine, and glutamine accounted for much of these changes. The incorporation of 15N into various components of the young leaves was followed after supply of 15N-nitrate. 15N appeared most rapidly in ammonia, due to reduction in the leaf, and this process took place predominantly in the light. A large proportion of the primary assimilation took place through the amide group of glutamine, which became labeled and turned over rapidly; labeling of glutamic acid and alanine was also rapid. Asparagine (amide group) soon became labeled and showed considerable turnover. Slower incorporation and turnover were found for aspartic acid, ?-aminobutyric acid, and homoserine. Synthesis and turnover of all of the amino acids continued at a low rate in the dark. ?-Aminobutyric acid was the only compound found to label more rapidly in the dark than in the light.

Bauer, Alfred; Urquhart, Aileen A.; Joy, Kenneth W.

1977-01-01

243

Antibacterial compounds from Siraitia grosvenorii leaves.  

PubMed

Luo Han Guo (LHG) fruits (Siraitia grosvenorii Swingle) have been used as traditional medicine in China for centuries to treat sore throats and coughs. However, LHG leaves are seldom used and minimal scientific information is available on them. In our recent study on the leaves of S. grosvenorii, the bioactive compounds ?-amyrin (2), aloe emodin (5), aloe-emodin acetate (6), 5?,8?-epidioxy-24(R)-methylcholesta-6,22-dien-3?-ol (7) and p-hydroxyl benzyl acid (8), accompanied by n-hexadecaoic acid (1), 12-methyltetradecanoic acid (3), ?-sitosterol (4) and daucosterol (9) were first obtained. Their structures have been identified on the basis of spectroscopic studies. The activities of these compounds were evaluated in vitro against the growth of oral bacterial species Streptococcus mutans, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum and the yeast Candida albicans, and their minimum inhibition concentrations were determined. Furthermore, the activity against S. mutans is likely to be due to the inhibition of glucosyltransferase. The experimental data provide important information on bioactive phytochemicals in the leaf of S. grosvenorii, which shows that the leaf can be a new resource as an antibacterial agent. PMID:21547839

Zheng, Yan; Huang, Wen; Yoo, Jae-Gil; Ebersole, Jeffrey L; Huang, Chifu Brad

2011-05-01

244

Intention to leave, anticipated reasons for leaving, and 12-month turnover of child care center staff  

Microsoft Academic Search

Job turnover among a sample of 169 child care workers from rural and semi-rural parts of Pennsylvania was examined in relation to demographic, work related and nonwork related factors. Findings indicate that the perceived choice of other jobs and job tenure both have an impact on intention to leave, as well as on actual 12 month turnover. Turnover in this

Elizabeth E. Manlove; Jacqueline R. Guzell

1997-01-01

245

Metabolic Regulation in Diseased Leaves II. Changes in Nicotinamide Nucleotide Coenzymes in Barley Leaves Infected With Powdery Mildew 1  

PubMed Central

Nicotinamide nucleotide coenzymes were estimated spectrophotometrically in noninfected barley leaves and leaves infected with Erysiphe graminis var hordei (powdery mildew). Amounts of NADH, NADP+ and NADPH were not altered by infection. In contrast, the NAD+ content rose sharply and at 144 hours was 100% greater than in noninfected leaves. The respiratory rate was increased in infected leaves and the pattern of this increase was similar to that of NAD+. The effect of infection on the intracellular distribution of NADP+ was examined by fractionating lyophilized leaves in a nonaqueous medium. In noninfected leaves almost all of the NADP+ was localized in the chloroplasts. In infected leaves where some chloroplast breakdown occurs, about 60% of the NADP+ was detected in the nonchloroplast part of the cell. This intracellular redistribution of NADP+ is discussed in relation to the increased pentose-P pathway activity occuring after infection.

Ryrie, I. J.; Scott, K. J.

1968-01-01

246

HPLC assisted chemobiological standardization of alpha-glucosidase-I enzyme inhibitory constituents from Piper longum Linn-An Indian medicinal plant.  

PubMed

Formulations of traditional medicines are usually made up of complex mixture of herbs. However, effective quality control methods in order to select right quality materials are lacking. Though Piper longum is a widely used herb in several Ayurvedic formulations prescribed for various diseases, there is no analytical method in the literature so far which can help in selecting the right quality material with proper proportions of the active ingredients (alpha-glucosidase-I enzyme inhibitory principles). We employed a systematic bioassay guided fractionation method and isolated pipataline, pellitorine, sesamin, brachystamide B and guineensine as active principles. A reversed-phase high-performance liquid chromatography method was developed to quantify these active principles in the plant material, which can serve as an effective quality control tool. The separation was carried out using a Discovery HS F5 C-18 (ODS) column and the solvent system used was a gradient comprising of (A) acetonitrile and (B) water with a flow rate of 1 ml/min. The detection was performed using a PDA detector. Regression equation pertaining to all the bioactive isolates revealed a linear relationship (r2 > 0.9995). The detection limits (S/N = 3) ranged from 0.005 to 0.001 microg/ml. Of all the active isolates, sesamin was identified to be present in maximum quantities (0.91%) where as brachystamide B was found in minimum quantity (0.01%). PMID:16872768

Pullela, Srinivas V; Tiwari, Ashok K; Vanka, UmaMaheswara S; Vummenthula, Anuradha; Tatipaka, Hari B; Dasari, Krishna R; Khan, Ikhlas A; Janaswamy, Madhusudana R

2006-12-01

247

The effect of Piper aduncum Linn. (Family: Piperaceae) essential oil as aerosol spray against Aedes aegypti (L.) and Aedes albopictus Skuse.  

PubMed

The bioefficacy of Piper aduncum L. essential oil formulated in aerosol cans was evaluated against Aedes aegypti and Aedes albopictus in a simulated room. The aerosol spray test was based on the Malaysian test standard for aerosol (MS 1221:1991UDC 632.982.2 modified from WHO 2009 methodology) and examined the knockdown effect within 20 minutes of exposure. Mortality rate after 24 hour of holding period was also determined. A commercial aerosol spray (0.09% prallethrin 0.05% d-phenothrin) was also tested as a comparison. Our results showed that the knockdown effect of the commercial aerosol spray and P. aduncum essential oil spray (8% and 10% concentrations) was significantly higher in Ae. albopictus adult females, when compared with that of Ae. aegypti adult females (P<0.05). There was a significant difference in knockdown between commercial aerosol spray and essential oil spray for both Aedes spp. (P<0.05). The essential oil induced significantly higher mortality in Ae. aegypti (80%) than in Ae. albopictus (71.6%) (P<0.05). The commercial aerosol spray caused 97.7% and 86.5% mortality against Ae. aegypti and Ae. albopictus respectively (P<0.05). Based on these data, P. aduncum essential oil has the potential to be used as an aerosol spray against Aedes spp. PMID:22041743

Misni, Norashiqin; Othman, Hidayatulfathi; Sulaiman, Sallehudin

2011-08-01

248

Safety assessment of Zanthoxylum alatum Roxb. essential oil, its antifungal, antiaflatoxin, antioxidant activity and efficacy as antimicrobial in preservation of Piper nigrum L. fruits.  

PubMed

The investigation deals with antifungal, antiaflatoxin and antioxidant efficacy of Zanthoxylum alatum Roxb. essential oil (EO), its two major constituents and their comparison with five commonly used organic acid preservatives. The chemical profile of EO, characterized through GC and GC-MS analysis, revealed linalool (56.10%) and methyl cinnamate (19.73%) as major components. The EO, linalool and methyl cinnamate completely inhibited the growth of a toxigenic strain of A. flavus (LHP-10) as well as aflatoxin B(1) secretion at different concentrations. Methyl cinnamate was found to be more efficacious than EO, linalool and five organic acid preservatives, showing antifungal and antiaflatoxigenic efficacy at a low concentration (0.6 ?l/ml) and the nature of its toxicity was fungicidal. However, EO showed strong antioxidant activity with an IC(50) value at 5.6 ?l/ml. Moreover, EO was found to have negligible mammalian toxicity as its LD(50) value, determined through oral administration on mice, was calculated to be 6124?l/kg body weight during safety profile assessment. During in vivo investigation on fruit systems, the Zanthoxylum EO, when tested as fumigant, provided 66.27% and 86.33% protection respectively at 1.25 ?l/ml and 2.5 ?l/ml against fungi infesting Piper nigrum L. fruits demonstrating its practical efficacy as a plant based antimicrobial for post harvest application. PMID:22137251

Prakash, Bhanu; Singh, Priyanka; Mishra, Prashant Kumar; Dubey, N K

2012-02-01

249

Quantification of kavalactones and determination of kava (Piper methysticum) chemotypes using near-infrared reflectance spectroscopy for quality control in vanuatu.  

PubMed

Kava ( Piper methysticum Forst f., Piperaceae) has anxiolytic properties and the ability to promote a state of relaxation without the loss of mental alertness. The rapid growth of the nutraceutical market between 1998 and 2000 has been stopped by a ban in Europe and Australia because of some suspicion of liver toxicity. It is now important to develop a fast, cheap, and reliable quality test to control kava exports. The aim of this study is to develop a calibration of the near-infrared reflectance spectroscopy (NIRS) using partial least-squares (PLS) regression. Two hundred thirty-six samples of kava roots, stumps, and basal stems were collected from the Vanuatu Agricultural Research and Technical Centre germplasm collection and from four villages. These samples, representing 45 different varieties, were analyzed using NIRS to record their absorption spectra between 400 and 2500 nm. A set of 101 selected samples was analyzed for their kavalactone content using HPLC. The results were used for PLS calibration of the NIRS. The NIRS prediction of the kavalactone content and the dry matter were in agreement with the HPLC results. There were good correlations between these two series of results, and coefficients ( R (2)) were all close to 1. The measurements were reproducible and had repeatability on par with the HPLC method. The NIRS system has been calibrated for the six major kavalactone content measurements, and it is suggested that this method could be used for quality control in Vanuatu. PMID:18540613

Lasme, Privat; Davrieux, Fabrice; Montet, Didier; Lebot, Vincent

2008-07-01

250

Environmental controls over methanol emission from leaves  

NASA Astrophysics Data System (ADS)

Methanol is found throughout the troposphere, with average concentrations second only to methane among atmospheric hydrocarbons. Proposed global methanol budgets are highly uncertain, but all agree that at least 60% of the total source arises from the terrestrial biosphere and primary emissions from plants. However, the magnitude of these emissions is also highly uncertain, and the environmental factors which control them require further elucidation. Using a temperature-controlled leaf enclosure, we measured methanol emissions from leaves of six plant species by proton transfer reaction mass spectrometry, with simultaneous measurements of leaf evapotranspiration and stomatal conductance. Rates of emission at 30°C varied from 0.3 to 38 ?g g (dry mass)-1 h-1, with higher rates measured on young leaves, consistent with the production of methanol via pectin demethylation in expanding foliage. On average, emissions increased by a factor of 2.4 for each 10°C increase in leaf temperature. At constant temperature, emissions were also correlated with co-varying incident photosynthetic photon flux density and rates of stomatal conductance. The data were analyzed using the emission model developed by Niinemets and Reichstein (2003a, b), with the incorporation of a methanol production term that increased exponentially with temperature. It was concluded that control of emissions, during daytime, was shared by leaf temperature and stomatal conductance, although rates of production may also vary diurnally in response to variations in leaf growth rate in expanding leaves. The model, which generally provided reasonable simulations of the measured data during the day, significantly overestimated emissions on two sets of measurements made through the night, suggesting that production rates of methanol were reduced at night, perhaps because leaf growth was reduced or possibly through a direct effect of light on production. Although the short-term dynamics of methanol emissions can be successfully modeled only if stomatal conductance and compound solubility are taken into account, emissions on longer time scales will be determined by rates of methanol production, controls over which remain to be investigated.

Harley, P.; Greenberg, J.; Niinemets, Ü.; Guenther, A.

2007-08-01

251

Environmental controls over methanol emission from leaves  

NASA Astrophysics Data System (ADS)

Methanol is found throughout the troposphere, with average concentrations second only to methane among atmospheric hydrocarbons. Proposed global methanol budgets are highly uncertain, but all agree that at least 60% of the total source arises from the terrestrial biosphere and primary emissions from plants. However, the magnitude of these emissions is also highly uncertain, and the environmental factors which control them require further elucidation. Using a temperature-controlled leaf enclosure, we measured methanol emissions from leaves of six plant species by proton transfer reaction mass spectrometry, with simultaneous measurements of leaf evapotranspiration and stomatal conductance. Rates of emission at 30°C varied from 0.2 to 38 ?g g (dry mass)-1 h-1, with higher rates measured on young leaves, consistent with the production of methanol via pectin demethylation in expanding foliage. On average, emissions increased by a factor of 2.3 for each 10°C increase in leaf temperature. At constant temperature, emissions were also correlated with co-varying incident photosynthetic photon flux density and rates of stomatal conductance. The data were analyzed using the emission model developed by Niinemets and Reichstein (2003a, b), with the incorporation of a methanol production term that increased exponentially with temperature. It was concluded that control of emissions, during daytime, was shared by leaf temperature and stomatal conductance, although rates of production may also vary diurnally in response to variations in leaf growth rate in expanding leaves. The model, which generally provided reasonable simulations of the measured data during the day, significantly overestimated emissions on two sets of measurements made through the night, suggesting that production rates of methanol were reduced at night, perhaps because leaf growth was reduced or possibly through a direct effect of light on production. Although the short-term dynamics of methanol emissions can be successfully modeled only if stomatal conductance and compound solubility are taken into account, emissions on longer time scales will be determined by rates of methanol production, controls over which remain to be investigated.

Harley, P.; Greenberg, J.; Niinemets, É.; Guenther, A.

2007-12-01

252

Evolutionary biology. Chewed leaves reveal ancient relationship.  

PubMed

On page 291, researchers describe a new beetle fossil based not on traces of the insect skeleton but on the distinctive gouges the beetles left when they munched on 11 ginger leaves many millions of years ago. The chew marks of the newly described Cephaloleichnites strongi prove that leaf beetles underwent rapid evolution and diversification more than 65 million years ago, possibly taking advantage of (and perhaps influencing) the rapid diversification among flowering plants occurring at the same time. What's more, C. strongi represents the earliest known rolled-leaf beetle species, hundreds of which today still prefer just one of the ginger- and heliconia-like plants in the Zingiberales order. PMID:10917840

Pennisi, E

2000-07-14

253

Flavonoids from mango leaves with antibacterial activity  

Microsoft Academic Search

Five flavonoids, viz. (-)-epicatechin-3-O-?-glucopyranoside (1), 5-hy- droxy-3-(4-hydroxylphenyl)pyrano(3,2-g)chromene-4(8H)-one (2), 6-(p-hyd- roxybenzyl)taxifolin-7-O-?-D-glucoside (tricuspid) (3), quercetin-3-O-?-glu- copyranosyl-(1?2)-?-glucopyranoside (4) and (-)-epicatechin(2-(3,4-dihyd- roxyphenyl)-3,4-dihydro-2H-chromene-3,5,7-triol) (5), were isolated from the leaves of mango (Mangifera indica L.). The antibacterial activity of different concentrations of these flavonoids (100, 300, 500, 700, 900 and 1000 ppm) was evaluated against four bacterial species, namely Lactobacillus sp., Escherichia coli, Azospirillium lipoferum and

Qudsia Kanwal; Ishtiaq Hussain; HAMID LATIF SIDDIQUI; Arshad Javaid

2009-01-01

254

Antioxidant and immunomodulatory constituents of henna leaves.  

PubMed

The immunomodulatory bioassay-guided fractionation of the methanolic extract of henna (Lawsonia inermis L.; syn. Lawsonia alba L.) leaves resulted in the isolation of seven compounds; three have been isolated for the first time from the genus, namely p-coumaric acid, 2-methoxy-3-methyl-1,4-naphthoquinone and apiin, along with the previously isolated compounds: lawsone, apigenin, luteolin, and cosmosiin. Structural elucidation of the isolated compounds was based upon their physical, chemical as well as spectroscopic characters. Their immuomodulatory profile was studied using an in vitro immunoassay, the lymphocyte transformation assay. The ABTS [2,2'-azino-bis (3-ethyl benzthiazoline-6-sulfonic acid)], free radical scavenging assay depicted that all isolated compounds exhibited antioxidant activity comparable to that of ascorbic acid. PMID:15813363

Mikhaeil, Botros R; Badria, Farid A; Maatooq, Galal T; Amer, Mohamed M A

2004-01-01

255

Medicinal properties of neem leaves: a review.  

PubMed

Azadirachta indica, commonly known as neem, has attracted worldwide prominence in recent years, owing to its wide range of medicinal properties. Neem has been extensively used in Ayurveda, Unani and Homoeopathic medicine and has become a cynosure of modern medicine. Neem elaborates a vast array of biologically active compounds that are chemically diverse and structurally complex. More than 140 compounds have been isolated from different parts of neem. All parts of the neem tree- leaves, flowers, seeds, fruits, roots and bark have been used traditionally for the treatment of inflammation, infections, fever, skin diseases and dental disorders. The medicinal utilities have been described especially for neem leaf. Neem leaf and its constituents have been demonstrated to exhibit immunomodulatory, anti-inflammatory, antihyperglycaemic, antiulcer, antimalarial, antifungal, antibacterial, antiviral, antioxidant, antimutagenic and anticarcinogenic properties. This review summarises the wide range of pharmacological activities of neem leaf. PMID:15777222

Subapriya, R; Nagini, S

2005-03-01

256

Buckling cascade in thin sheets and leaves  

NASA Astrophysics Data System (ADS)

The edge of torn plastic sheet displays a fractal pattern composed of superimposed wrinkles at different scales, like the edges of some leaves do (lettuce for example). We show that in the plastic sheet, this pattern is self-similar with up to 6 generations of waves and is due to the very large plastic deformations in the sheet when torn : the distances on the sheet are redefined, the edge being as much as twice longer as before. This actually defines a new metric that is similar to that of the hyperbolic plane. Because the sheet is thin, the equilibrium shape (elastic energy minimization) will satisfy the metric at the cost of bending energy that is preferred to costy in-plane stretching energy. But imposing such metric is a very strong constraint, that may not have solution in physical space. It is known for example that the hyperbolic plane is not imbedable as a whole in euclidean space E^3. These geometric constraints make it necessary a superposition of wavelength. It is interesting to note that similar metrics can be the result of other phenomena, for example the growth of biological tissue. Simple growth law, (for example, a growth rate proportional to the cell density) will give such an hyperbolic metric. This suggests that the very complex pattern observed in leaves, for example in lettuce can be the result of an extremely simple process (growth law), and not of a complex process of construction after very large quantity of information stored in DNA. Said differently, there is no need to store the complex and exhaustive map of the lettuce shape in its genetic information, elasticity can construct it out of a simple growth law.

Roman, Benoît

2003-03-01

257

[Chemical constituents from leaves of Nelumbo nucifera].  

PubMed

To study the chemical constituents, twenty-seven compounds were isolated from the 70% ethanol extract from leaves of Nelumbo nucifera by modern chromatographic techniques. Their structures were identified as 10-octacosanol (1), beta-sitosterol (2), 1-undecanol (3), 1-eicosanol (4), daucosterol (5), 6'-hydroxy-4,4'-dimethoxychalcone (6), 3,7,8-trimethoxy-1-hydroxy-xanthone (7), rhamnetin-3-O-beta-D-glucopyranoside (8), chrysoeriol-7-O-beta-D-glucoside (9), quercetin-3-O-beta-D-glucopyranoside (10), quercetin-3-O-alpha-L-rhamnopyranosyl (11), hyperoside (12), quercetin-3-O-rutinoside (13), astragalin (14), isorhamnetin-3-O-alpha-L-rhamnopyranosyl-(1--> 6)-[alpha-D-lyxopyranosyl-(1 --> 2) -beta-D-glucopyranoside] (15), isorhamnetin-3-O-alpha-D-lyxopyranosyl-(1 --> 2) -beta-D-glucopyranoside (16), isorhamnetin-3-O-beta-D-glucopyranoside (17), isorhamnetin-3-O-alpha-L-rhamnopyranosyl-(1 --> 6)-beta-D-glucopyranoside (18), quercetin (19), kaempferol (20), dehydronuciferine (21), roemerine (22), stigmast-7-en-3-O-beta-D-glucopyranoside (23), stigmast-7-en-3beta-ol (24), and benzene-1,2-diol (25) on the basis of spectral data analysis. Compounds 1, 6, 7, 8, 24 and 25 were isolated from this plant for the first time, and compounds 15-18 were isolated from the leaves for the first time. Compounds 6, 8, 10, 11, 13 and 15 showed inhibitory activities against beta amyloid (1-42) by A-beta aggregation method with inhibition rates of (63.99 +/- 24.29)%, (79.61 +/- 4.49)%, (49.96 +/- 12.61)%, (101.19 +/- 8.19)%, (88.41+/-6.76)% and (72.48 +/- 8.97)%, respectively. PMID:23724680

Zhao, Xiao-Liang; Wang, Zhi-Min; Ma, Xiao-Jun; Jing, Wen-Guang; Liu, An

2013-03-01

258

Adolescent home-leaving and the transition to adulthood  

PubMed Central

Home-leaving is considered an important marker of the transition to adulthood and is usually framed as an individual decision. We move beyond this limited assumption to examine a broader conceptualization that might better illuminate home-leaving among youth in impoverished circumstances. We adopt the Problem Behavior Theory-framework to investigate the association of home-leaving with behavioral and psychosocial variables and with other transitions. We use data on adolescents aged 14–22 years from a three-wave study conducted between 2007 and 2010. We used variable- and person-centered cross-sectional analyses, as well as predictive analysis of home-leaving by subsequent waves. Parental controls protection predicted home-leaving by subsequent waves. Overall, protective factors moderated the association of problem behavior involvement with leaving home in Nairobi’s slums.

Egondi, Thaddaeus; Kabiru, Caroline; Beguy, Donatien; Kanyiva, Muindi; Jessor, Richard

2013-01-01

259

5 CFR 630.403 - Substitution of sick leave for unpaid family and medical leave to care for a covered servicemember.  

...leave for unpaid family and medical leave to care for a covered servicemember. 630.403...leave for unpaid family and medical leave to care for a covered servicemember. The...S.C. 6382(a)(3) for leave to care for a covered servicemember may...

2014-01-01

260

Growth correlations in Bryophyllum leaves and exogenous growth regulators  

Microsoft Academic Search

Growth correlations in leaves ofBryophyllum may be recognized by the development of marginal shoots varying in their particular lamina regions, the correlative inhibition\\u000a increasing from the top to the base. Cytokinins extend their promoting action inB. crenatum leaves farther in the apical than in the basal direction. In the uppermost leaves ofB. daigremontianum they evoke the development of marginal shoots

R. Dostál

1970-01-01

261

Evidence on paid sick leave: Observations in times of crisis  

Microsoft Academic Search

A large number of governments in all regions of the world have recognised the need for paid sick leave although the benefit\\u000a schedules vary widely. International data show that the incidence of paid sick leave is closely associated with overall economic\\u000a developments. What are the patterns of paid sick leave and its incidence around the world, and how have these

Xenia Scheil-Adlung; Lydia Sandner

2010-01-01

262

Extraction of tannin from fresh and preserved leaves.  

PubMed

The extractability of tannin from fresh, lyophilized, and dried leaves collected at various times in the growing season was determined using the radial diffusion assay for protein-precipitating phenolics. The amount of tannin extracted depended on the method of leaf preservation and on the maturity of the leaf. Early in the season, more tannin was extracted from lyophilized leaves than from fresh leaves, but late in the season more tannin was extracted from fresh leaves. At all times, more tannin was extracted with aqueous acetone than with aqueous or acidic methanol. PMID:24275992

Hagerman, A E

1988-02-01

263

Hepatoprotective effect of feeding celery leaves mixed with chicory leaves and barley grains to hypercholesterolemic rats  

PubMed Central

Celery, chicory leaves, and barley grains are valuable in weight loss diets and regulate lipid metabolism. They may reduce risk of fatty liver. The present study aimed to investigate the effect of diet supplementation with celery, chicory, and barley powder on liver enzymes and blood lipids in rats fed with cholesterol-enriched diet. This study used four groups of rats fed with 3% cholesterol were supplemented diet to induce hypercholesterolemia and one group was fed on cholesterol-free basal diet. The dry powder of celery leaves, chicory leaves, and barley grains was separately added to the basal diet at 10% concentration or in combination of three plants at 15% for four weeks. Biochemical analyses of serum liver enzymes and blood lipids as well as histopathological examination of liver were performed. Feeding of diet supplemented with 10% of celery, 10% chicory, and 10% of barley lowered the elevated serum level of liver enzymes and blood lipids in rats. Feeding plant combination of celery, chicory, and barley at 15% concentration (5% from each) was more effective in decreasing the elevation of liver enzymes (aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase) and blood lipids. The histopathological lesions seen in the livers of hypercholesterolemic rats were ameliorated by feeding this plant mixture. This study recommends that dietary intake of plant mixture of celery; chicory, and barley at 15% (5% of each) concentration can be beneficial to patients suffering from hypercholesterolemia and liver diseases.

Abd El-Mageed, Nehal M.

2011-01-01

264

Work-family balance after childbirth: the association between employer-offered leave characteristics and maternity leave duration.  

PubMed

Early return to work after childbirth has been increasing among working mothers in the US. We assessed the relationship between access to employer-offered maternity leave (EOML) (both paid and unpaid) and uptake and duration of maternity leave following childbirth in a socio-economically diverse sample of full-time working women. We focus on California, a state that has long provided more generous maternity leave benefits than those offered by federal maternity leave policies through the State Disability Insurance program. The sample included 691 mothers who gave birth in Southern California in 2002-2003. Using weighted logistic regression, we examined the EOML-maternity leave duration relationship, controlling for whether the leave was paid, as well as other occupational, personality and health-related covariates. Compared with mothers who were offered more than 12 weeks of maternity leave, mothers with <6 weeks of EOML and those offered 6-12 weeks had five times higher odds of returning to work within 12 weeks; those offered no leave had six times higher odds of an early return. These relationships were similar after controlling for whether the leave was paid and after controlling for other occupational and health characteristics. Access to and duration of employer-offered maternity leave significantly determine timing of return to work following childbirth, potentially affecting work-family balance. Policy makers should recognize the pivotal role of employers in offering job security during and after maternity leave and consider widening the eligibility criteria of the Family and Medical Leave Act. PMID:23504130

Guendelman, Sylvia; Goodman, Julia; Kharrazi, Martin; Lahiff, Maureen

2014-01-01

265

Parental leave for residents and pediatric training programs.  

PubMed

The American Academy of Pediatrics (AAP) is committed to the development of rational, equitable, and effective parental leave policies that are sensitive to the needs of pediatric residents, families, and developing infants and that enable parents to spend adequate and good-quality time with their young children. It is important for each residency program to have a policy for parental leave that is written, that is accessible to residents, and that clearly delineates program practices regarding parental leave. At a minimum, a parental leave policy for residents and fellows should conform legally with the Family Medical Leave Act as well as with respective state laws and should meet institutional requirements of the Accreditation Council for Graduate Medical Education for accredited programs. Policies should be well formulated and communicated in a culturally sensitive manner. The AAP advocates for extension of benefits consistent with the Family Medical Leave Act to all residents and interns beginning at the time that pediatric residency training begins. The AAP recommends that regardless of gender, residents who become parents should be guaranteed 6 to 8 weeks, at a minimum, of parental leave with pay after the infant's birth. In addition, in conformance with federal law, the resident should be allowed to extend the leave time when necessary by using paid vacation time or leave without pay. Coparenting, adopting, or fostering of a child should entitle the resident, regardless of gender, to the same amount of paid leave (6-8 weeks) as a person who takes maternity/paternity leave. Flexibility, creativity, and advanced planning are necessary to arrange schedules that optimize resident education and experience, cultivate equity in sharing workloads, and protect pregnant residents from overly strenuous work experiences at critical times of their pregnancies. PMID:23359582

2013-02-01

266

Maltose Biochemistry and Transport in Plant Leaves  

SciTech Connect

Transitory starch builds up in photosynthesizing leaves during the day and is then degraded each night. It has recently been shown through mutant analysis and genetically engineered plants that transitory starch is required for maximal rates of photosynthesis, especially in high carbon dioxide atmospheres. Understanding the pathway by which carbon is exported from chloroplasts at night is limited. Previous work has shown that starch conversion to sucrose at night involves maltose export from chloroplasts. This pathway for carbon export from chloroplasts normally does not occur during the day. The regulation of maltose formation, the transporters that allow export of maltose from the chloroplast, and the cytosolic reactions by which maltose is converted to sucrose remain obscure. Genomic and biochemical approaches are proposed here to address maltose metabolism and transport. The research will cover three areas (1) how are hydrolytic and phosphorylytic starch degradation regulated, (2) how is maltose exported from chloroplasts, and (3) how is maltose converted to sucrose in the cytosol? It is expected that this research will lead to new insights about photosynthesis at high carbon dioxide levels, how carbon is partitioned in plants, and how partitioning can be altered to adapt plants to human needs.

Weber, Andreas P.M.

2008-04-25

267

Amino Acid Metabolism of Pea Leaves  

PubMed Central

Short term (2-hour) incorporation of nitrogen from nitrate, glutamine, or asparagine was studied by supplying them as unlabeled (14N) tracers to growing pea (Pisum sativum L.) leaves, which were previously labeled with 15N, and then following the elimination of 15N from various amino components of the tissue. Most components had active and inactive pools. Ammonia produced from nitrate was assimilated through the amide group of glutamine. When glutamine was supplied, its nitrogen was rapidly transferred to glutamic acid, asparagine, and other products, and there was some transfer to ammonia. Nitrogen from asparagine was widely distributed into ammonia and amino compounds. There was a rapid direct transfer to glutamine, which did not appear to involve free ammonia. Alanine nitrogen could be derived directly from asparagine, probably by transamination. Homoserine was synthesized in substantial amounts from all three nitrogen sources. Homoserine appears to derive nitrogen more readily from asparagine than from free aspartic acid. A large proportion of the pool of ?-aminobutyric acid turned over, and was replenished with nitrogen from all three supplied sources.

Bauer, Alfred; Joy, Kenneth W.; Urquhart, Aileen A.

1977-01-01

268

Photosynthetic strategies in leaves and stems of Egeria densa  

Microsoft Academic Search

Photosynthetic mechanisms have been compared in leaves and, separately, in stems of Egeria densa Planch. In order to correlate the structural and functional characteristics of the two organs (1) the ultrastructural features of leaves and stems have been studied and (2) their photosynthetic activity has been evaluated by measuring in vivo both oxygen evolution and the kinetics of chlorophyll fluorescence.

Nicoletta Rascio; Paola Mariani; Emanuela Tommasini; Maria Bodner; Walter Larcher

1991-01-01

269

Multitasking Is Multitaxing: Why Special Educators Are Leaving the Field  

ERIC Educational Resources Information Center

The purpose of the study was to provide insight into the inability to retain qualified special education teachers. Why do special educators say they want to leave? What conditions would encourage them to stay? Nearly half of the teachers reported they planned to leave the field in the next 5 years. They cited three areas of concern: administrative…

Kaff, Marilyn S.

2004-01-01

270

SOME PHARMACOGNOSTICAL CHARACTERISTICS OF MORINGA OLEIFERA LAM. LEAVES  

PubMed Central

The macroscopic character of the leaflets ash values extractive values by different solvent extractive behavior on treatment with different chemical reagents fluorescence characters by treatment with different chemical reagents of the powdered leaves of Maoringa oleifera lam (fam moringaceae) were studied to fix some pharmacognostical parameters, chemical group test of different extracts of the leaves were also performed.

Pal, Saroj K.; Mukherjee, Pulok K.; Saha, Kakali; Pal, M.; Saha, B.P

1996-01-01

271

Reasons that Orthodontic Faculty Teach and Consider Leaving Teaching.  

ERIC Educational Resources Information Center

Surveyed full-time (FT) and part-time (PT) orthodontic faculty about reasons for considering leaving academia. About 38 percent FT and 25 percent PT were currently considering leaving. The factors most important for FT were work-related: salary support, financial support of department, and control over work or destiny. For PTs, the reasons were:…

Kula, Katherine; Glaros, Alan; Larson, Brent; Tuncay, Orhan

2000-01-01

272

Life-history strategies affect aphid preference for yellowing leaves  

PubMed Central

According to the nutrient-translocation hypothesis, yellowing tree leaves are colonized by aphids at the end of the growing season owing to improved availability of nutrients in the phloem sap after chlorophyll degradation. We measured aphid densities on potted Betula pendula seedlings in a field site where a small proportion of foliage rapidly turned yellow before normal autumn coloration as a consequence of root anoxia. The number of adults and nymphs of the birch-feeding specialist aphids Euceraphis betulae, Betulaphis brevipilosa and Callipterinella tuberculata were counted from leaves on each of the 222 plants. Aphids were detected on 19 per cent of green leaves and on 41 per cent of yellow leaves. There was no indication of aphid avoidance of yellow leaves, and the number of winged (alate) viviparous E. betulae adults and their nymphs were significantly higher on yellow leaves than on green leaves, while the numbers of apterous B. brevipilosa and C. tuberculata did not differ between the leaf colour types. Our result suggests that only aphid species with alate generation during colour change can take advantage of yellowing leaves. This may explain the exceptional abundance of E. betulae compared with other aphid species on birches.

Holopainen, Jarmo K.; Semiz, Gurkan; Blande, James D.

2009-01-01

273

Early School-Leaving in Spain: Evolution, Intensity and Determinants  

ERIC Educational Resources Information Center

Spain has one of the highest levels of early school leaving and educational failure of the European Union. The purpose of this paper is to analyse the anatomy of early school leaving in Spain and its characteristics. In order to do so, in the first part we discuss the measurement problems related with this concept and the evolution of drop-out…

Fernandez-Macias, Enrique; Anton, Jose-Ignacio; Brana, Francisco-Javier; De Bustillo, Rafael Munoz

2013-01-01

274

Genotoxicity of Nicotiana tabacum leaves on Helix aspersa  

PubMed Central

Tobacco farmers are routinely exposed to complex mixtures of inorganic and organic chemicals present in tobacco leaves. In this study, we examined the genotoxicity of tobacco leaves in the snail Helix aspersa as a measure of the risk to human health. DNA damage was evaluated using the micronucleus test and the Comet assay and the concentration of cytochrome P450 enzymes was estimated. Two groups of snails were studied: one fed on tobacco leaves and one fed on lettuce (Lactuca sativa L) leaves (control group). All of the snails received leaves (tobacco and lettuce leaves were the only food provided) and water ad libitum. Hemolymph cells were collected after 0, 24, 48 and 72 h. The Comet assay and micronucleus test showed that exposure to tobacco leaves for different periods of time caused significant DNA damage. Inhibition of cytochrome P450 enzymes occurred only in the tobacco group. Chemical analysis indicated the presence of the alkaloid nicotine, coumarins, saponins, flavonoids and various metals. These results show that tobacco leaves are genotoxic in H. aspersa and inhibit cytochrome P450 activity, probably through the action of the complex chemical mixture present in the plant.

da Silva, Fernanda R.; Erdtmann, Bernardo; Dalpiaz, Tiago; Nunes, Emilene; Ferraz, Alexandre; Martins, Tales L.C.; Dias, Johny F.; da Rosa, Darlan P.; Porawskie, Marilene; Bona, Silvia; da Silva, Juliana

2013-01-01

275

Flavonoid variation in the leaves of Glycyrrhiza glabra  

Microsoft Academic Search

Genistein, pinocembrin, prunetin, 6-prenylnaringenin, licoflavanone and wighteone were isolated from the leaves of Glycyrrhiza glabra collected on the west coast of Anatolia, whereas lupiwighteone was found only in the leaves of G. glabra growing in middle or east Anatolia. The G. glabra plants growing in different areas of Turkey could be classified into two types according to the occurrence of

Hiroaki Hayashi; Miyako Yasuma; Noboru Hiraoka; Yasumasa Ikeshiro; Hirobumi Yamamoto; Erdem Ye?ilada; Ekrem Sezik; Gisho Honda; Mamoru Tabata

1996-01-01

276

Carbon monoxide photoproduction from rice and maize leaves  

NASA Astrophysics Data System (ADS)

We investigated CO photoproduction from intact leaves of rice ( Oryza sativa L.) and maize ( Zea mays L.) by laboratory experiments. CO photoproduction showed positive correlation with light intensity and was positively dependent on oxygen concentration. The average CO photoproduction was 2.6±0.3×10 10 molecules cm -2 s -1 from rice leaves and 2.2±0.1×10 10 molecules cm -2 s -1 from maize leaves ( n=5) at a radiation intensity of 49 mW cm -2. CO photoproduction from senescent rice leaves was 9 times greater (25.7±1.5×10 10 molecules cm -2 s -1, n=2) at the same radiation intensity than from live leaves, and responded slowly to changes in oxygen concentration and light intensity. CO photoproduction showed no correlation with CO 2 concentration or humidity. This indicates that CO photoproduction in leaves is not directly controlled by carbon metabolism or stomatal conductance. The lack of dependence on stomatal conductance leads to the conclusion that the diffusion of CO from inside the leaves to the atmosphere is not a controlling factor for CO photoproduction from rice and maize leaves.

Yonemura, S.; Morokuma, M.; Kawashima, S.; Tsuruta, H.

277

Identification of Factors Influencing Vocational Agriculture Teachers to Leave Teaching.  

ERIC Educational Resources Information Center

Personal interviews were conducted with 26 former teachers (agricultural education graduates of the University of Nebraska) to identify reasons for leaving the teaching profession. Sixteen factors were given as the number one reason for leaving. Factors relating to the opportunity to begin farming and ranching accounted for the majority of the…

Dillon, Roy D.

1978-01-01

278

Iron distribution in vine leaves with HCO3 induced chlorosis  

Microsoft Academic Search

The objective of the investigation was to examine whether iron chlorosis in grape vine grown on calcareous soils was related to the Fe distribution in the leaf.Leaf samples collected from three different sites showed in most cases higher Fe contents in the chlorotic leaves as compared with healthy leaves. The solubility of leaf Fe in diluted HC1, however, was lower

K. Mengel; W. Bubl; H. W. Scherer

1984-01-01

279

Light-dependent modification of Photosystem II in spinach leaves  

Microsoft Academic Search

In dark-adapted spinach leaves approximately one third of the Photosystem II (PS II) reaction centers are impaired in their ability to transfer electrons to Photosystem I. Although these ‘inactive’ PS II centers are capable of reducing the primary quinone acceptor, QA, oxidation of QA- occurs approximately 1000 times more slowly than at ‘active’ centers. Previous studies based on dark-adapted leaves

Kevin Oxborough; Ladislav Nedbal; Roger A. Chylla; John Whitmarsh

1996-01-01

280

Leave Tracker for the Cancer Prevention Fellowship Program Home Page  

Cancer.gov

Skip to Main Content Log In Leave Tracker for The Cancer Prevention Fellowship Program Leave Tracker is intended for use by fellows in the Cancer Prevention Fellowship Program. If you are not a fellow in this program but are a NIH employee, please see

281

Volatile oils in leaves of Bauhinia (Fabaceae Caesalpinioideae)  

Microsoft Academic Search

Leaves of seven species of Bauhinia (B. aculeata, B. alata, B. brevipes, B. forficata, B. longifolia, B. outimouta, B. pentandra, B. rufa and B. variegata) were submitted to volatile oil extraction by steam distillation. B. alata and B. outimouta, both of subgenus Phanera, failed to yield detectable volatile oils. Among the other species, all of subgenus Bauhinia, leaves of B.

Joaquim M Duarte-Almeida; Giuseppina Negri; Antonio Salatino

2004-01-01

282

Evaluation of the Danish Leave Schemes. Summary of a Report.  

ERIC Educational Resources Information Center

An evaluation examined how the Danish leave schemes, an offer to employed and unemployed persons who qualify for unemployment benefits, were functioning and to what extent the objectives have been achieved. It was found that 60 percent of those taking leave had previously been unemployed; women accounted for two-thirds of those joining the scheme;…

Andersen, Dines; Appeldorn, Alice; Weise, Hanne

283

Wisconsin Maternity Leave and Fringe Benefits: Policies, Practices and Problems.  

ERIC Educational Resources Information Center

The study examines the economic implications in Wisconsin of the 1972 Equal Employment Opportunity Commission guideline which requires employers to treat maternity leave as a temporary disability. First, the static cost of the maternity leave guideline to employers is estimated for the State of Wisconsin. Second, some examination of the economic…

Gerner, Jennifer

284

The Meaning of Korean Women's Career-Leaving Experience  

ERIC Educational Resources Information Center

What is the meaning of Korean women's career-leaving experience? To answer this question, this study adopted a hermeneutic phenomenology approach. My intention was to search for the deeper meaning of Korean women's career-leaving experience from their perspective. Ten Korean women who had left their careers due to their domestic roles in their…

Lee, Yu-Jin

2010-01-01

285

Genotoxicity of Nicotiana tabacum leaves on Helix aspersa.  

PubMed

Tobacco farmers are routinely exposed to complex mixtures of inorganic and organic chemicals present in tobacco leaves. In this study, we examined the genotoxicity of tobacco leaves in the snail Helix aspersa as a measure of the risk to human health. DNA damage was evaluated using the micronucleus test and the Comet assay and the concentration of cytochrome P450 enzymes was estimated. Two groups of snails were studied: one fed on tobacco leaves and one fed on lettuce (Lactuca sativa L) leaves (control group). All of the snails received leaves (tobacco and lettuce leaves were the only food provided) and water ad libitum. Hemolymph cells were collected after 0, 24, 48 and 72 h. The Comet assay and micronucleus test showed that exposure to tobacco leaves for different periods of time caused significant DNA damage. Inhibition of cytochrome P450 enzymes occurred only in the tobacco group. Chemical analysis indicated the presence of the alkaloid nicotine, coumarins, saponins, flavonoids and various metals. These results show that tobacco leaves are genotoxic in H. aspersa and inhibit cytochrome P450 activity, probably through the action of the complex chemical mixture present in the plant. PMID:23885210

da Silva, Fernanda R; Erdtmann, Bernardo; Dalpiaz, Tiago; Nunes, Emilene; Ferraz, Alexandre; Martins, Tales L C; Dias, Johny F; da Rosa, Darlan P; Porawskie, Marilene; Bona, Silvia; da Silva, Juliana

2013-07-01

286

Predicting Turnover: Validating the Intent to Leave Child Welfare Scale  

ERIC Educational Resources Information Center

A number of proxies have been used in child welfare workforce research to represent actual turnover; however, there have been no psychometric studies to validate a scale specifically designed for this purpose. The Intent to Leave Child Welfare Scale is a proxy for actual turnover that measures workers' intention to leave. This scale was…

Auerbach, Charles; Schudrich, Wendy Zeitlin; Lawrence, Catherine K.; Claiborne, Nancy; McGowan, Brenda G.

2014-01-01

287

Factors Influencing Year 9 Students' Intentions to Leave School.  

ERIC Educational Resources Information Center

A study was conducted in Victoria, Australia, to examine the factors that influence Year 9 students' intentions to leave secondary school. Discriminant function analysis was used to determine the effects of family background variables, school characteristics, significant others, personal assessments, and attitudes on school-leaving intentions of…

Schrom, Linda K.

288

Efflux of sucrose from minor veins of tobacco leaves  

Microsoft Academic Search

Mature leaves import limited amounts of nutrient when darkened for prolonged periods. We tested the hypothesis that import is restricted by the apoplast-phloem loading mechanism, ie., as sucrose exits the phloem of minor veins it is retrieved by the same tissue, thus depriving the mesophyll of nutrient. When single, attached, mature leaves of tobacco (Nicotiana tabacum L.) plants were darkened,

Robert Turgeon

1984-01-01

289

Energy budgets and temperatures of nyctinastic leaves on freezing nights.  

PubMed

Temperatures of exposed horizontal and vertical soybean leaves (Glycine max [L.] Merr. var. Chippewa) were measured on calm, clear nights with temperatures near freezing. Average leaf-air temperature differences for 5 nights were -1.5 C and -1.0 C for horizontal and vertical leaves respectively. The horizontal leaves were cooler than the vertical leaves. The mean of all observed horizontal-vertical leaf temperature differences was -0.5 C with a maximum average for 1 night of -0.8 C, while maximum differences theoretically attainable in similar leaves were calculated to be -1.7 C. No differences were observed in the extent of frost damage in horizontal and vertical leaves. The apparent reduction in frost damage in vertical leaves observed by Charles Darwin was probably caused by his method of using corks to hold the horizontal leaves and not by leaf orientation. Theoretical considerations and the experimental results indicate that nyctinastic leaf movements probably do not provide significant protection from frost for any plants. PMID:16657763

Schwintzer, C R

1971-08-01

290

Evaluation of in vitro aldose reductase inhibitory potential of alkaloidal fractions of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera.  

PubMed

Abstract Background: Aldose reductase is primarily involved in development of long-term diabetic complications due to increased polyol pathway activity. The synthetic aldose reductase inhibitors are not very successful clinically. Therefore, the natural sources may be exploited for safer and effective aldose reductase inhibitors. Methods: In the present study, the aldose reductase inhibitory potential of hydroalcoholic and alkaloidal extracts of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera was evaluated. The hydroalcoholic and alkaloidal extracts of the selected plants were prepared. The different concentrations of hydroalcoholic and alkaloidal extracts of these plants were evaluated for their goat lens aldose reductase inhibitory activity using dl-glyceraldehyde as substrate. The aldose reductase inhibitory potential of extracts was assessed in terms of their IC50 value. Results: Amongst the hydroalcoholic extracts, the highest aldose reductase inhibitory activity was shown by P. nigrum (IC50 value 35.64±2.7 ?g/mL) followed by M. koenigii (IC50 value 45.67±2.57 ?g/mL), A. mexicana (IC50 value 56.66±1.30 ?g/mL), and N. nucifera (IC50 value 59.78±1.32 ?g/mL). Among the alkaloidal extracts, highest inhibitory activity was shown by A. mexicana (IC50 value 25.67±1.25 ?g/mL), followed by N. nucifera (IC50 value 28.82±1.85 ?g/mL), P. nigrum (IC50 value 30.21±1.63 ?g/mL), and M. koenigii (IC50 value 35.66±1.64 ?g/mL). Conclusions: It may be concluded that the alkaloidal extracts of these plants possess potent aldose reductase inhibitory activity and may be therapeutically exploited in diabetes-related complications associated with increased activity of aldose reductase. PMID:24127538

Gupta, Sakshi; Singh, Nirmal; Jaggi, Amteshwar Singh

2014-05-01

291

Tissue distribution profiles of three antiparkinsonian alkaloids from Piper longum L. in rats determined by liquid chromatography-tandem mass spectrometry.  

PubMed

The alkaloids of Piper longum L. (PLA) improved motor dysfunction and dopamine depletion in a rat model of Parkinson's disease induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. A rapid, accurate, simple, and high-performance liquid chromatography-mass spectrometry method was developed and fully validated to simultaneously detect three P. longum L. antiparkinsonian alkaloids (piperine (PPR), piperlonguminine (PPL), and ??,?-dihydropiperlonguminine (DPPL)) in rat plasma, heart, liver, spleen, lung, kidney, and brain tissues. Rat plasma and tissue homogenates were pretreated with methanol/acetonitrile (1:1, v/v) using a simple protein precipitation method. Chromatographic separation was achieved on a Phenomenex Gemini C18 column (50mm×2.00mm, 5?m) with a gradient mobile phase containing 0.1% (v/v) formic acid in water or acetonitrile. The elution was pumped at a flow rate of 0.4ml/min, and the injection volume was 10?l with a total running time of 4min. The analysis was performed by selected reaction monitoring of the transitions m/z 285.9?201.1, m/z 274.3?209.9, and m/z 276.2?134.9 for PPR, PPL, and DPPL, respectively. All three analytes showed good linearity (R>0.995) in plasma and tissue homogenates, and the lower limit of quantification was 0.20ng/ml. The distribution of PPR, PPL and DPPL in all 7 tissues was examined. The highest concentrations for PPR and PPL were observed in the liver, while the highest DPPL concentration was observed in the kidney. Following oral administration, the highest levels of PPR, PPL and DPPL in different tissues were found at approximately 2h. PPR, PPL and DPPL could cross the blood-brain barrier. The present study provides evidences for that PPR, PPL and DPPL may play roles in improving motor dysfunction and dopamine depletion. PMID:23603295

Liu, Haolong; Luo, Rong; Chen, Xiaoqing; Liu, Junhui; Bi, Ying; Zheng, Li; Wu, Xia

2013-06-01

292

Response of the Succulent Leaves of Peperomia magnoliaefolia to Dehydration  

PubMed Central

Relative water content, solute concentrations, and osmolality were determined in the water storage tissue (hydrenchyma) and the assimilatory tissue (chlorenchyma) of the succulent leaves of Peperomia magnoliaefolia (Jac) (Piperaceae) during slow desiccation. Relative water loss was significantly greater for the hydrenchyma than for the chlorenchyma. When whole leaves had lost 50% of their initial water content, the concomitant decrease of the relative water content of the hydrenchyma was 75 to 85%, but of the chlorenchyma only 15 to 25%. In spite of this differential water loss, the osmolality in both tissues increased to the same extent, indicating solute flow from the hydrenchyma to the chlorenchyma during desiccation. Solute translocation appeared to be unspecific, probably reflecting symplastic mass flow from one tissue to the other. The observed volume preservation of the chlorenchyma stabilized photosynthesis of Peperomia magnoliaefolia (Jac) leaves, which was less inhibited by a given decrease of the relative water content of the whole leaves than in nonsucculent leaves.

Schmidt, Jutta E.; Kaiser, Werner M.

1987-01-01

293

The Effects of California's Paid Family Leave Program on Mothers' Leave-Taking and Subsequent Labor Market Outcomes  

ERIC Educational Resources Information Center

This analysis uses March Current Population Survey data from 1999 to 2010 and a differences-in-differences approach to examine how California's first in the nation paid family leave (PFL) program affected leave-taking by mothers following childbirth, as well as subsequent labor market outcomes. We obtain robust evidence that the California program…

Rossin-Slater, Maya; Ruhm, Christopher J.; Waldfogel, Jane

2013-01-01

294

Conserved host-pathogen PPIs. Globally conserved inter-species bacterial PPIs based conserved host-pathogen interactome derived novel target in C. pseudotuberculosis, C. diphtheriae, M. tuberculosis, C. ulcerans, Y. pestis, and E. coli targeted by Piper betel compounds.  

PubMed

Although attempts have been made to unveil protein-protein and host-pathogen interactions based on molecular insights of important biological events and pathogenesis in various organisms, these efforts have not yet been reported in Corynebacterium pseudotuberculosis (Cp), the causative agent of Caseous Lymphadenitis (CLA). In this study, we used computational approaches to develop common conserved intra-species protein-protein interaction (PPI) networks first time for four Cp strains (Cp FRC41, Cp 316, Cp 3/99-5, and Cp P54B96) followed by development of a common conserved inter-species bacterial PPI using conserved proteins in multiple pathogens (Y. pestis, M. tuberculosis, C. diphtheriae, C. ulcerans, E. coli, and all four Cp strains) and E. Coli based experimentally validated PPI data. Furthermore, the interacting proteins in the common conserved inter-species bacterial PPI were used to generate a conserved host-pathogen interaction (HP-PPI) network considering human, goat, sheep, bovine, and horse as hosts. The HP-PPI network was validated, and acetate kinase (Ack) was identified as a novel broad spectrum target. Ceftiofur, penicillin, and two natural compounds derived from Piper betel were predicted to inhibit Ack activity. One of these Piper betel compounds found to inhibit E. coli O157:H7 growth similar to penicillin. The target specificity of these betel compounds, their effects on other studied pathogens, and other in silico results are currently being validated and the results are promising. PMID:23288366

Barh, Debmalya; Gupta, Krishnakant; Jain, Neha; Khatri, Gourav; León-Sicairos, Nidia; Canizalez-Roman, Adrian; Tiwari, Sandeep; Verma, Ankit; Rahangdale, Sachin; Shah Hassan, Syed; dos Santos, Anderson Rodrigues; Ali, Amjad; Guimarães, Luis Carlos; Thiago Jucá Ramos, Rommel; Devarapalli, Pratap; Barve, Neha; Bakhtiar, Marriam; Kumavath, Ranjith; Ghosh, Preetam; Miyoshi, Anderson; Silva, Artur; Kumar, Anil; Misra, Amarendra Narayan; Blum, Kenneth; Baumbach, Jan; Azevedo, Vasco

2013-03-01

295

Acetaldehyde and Ethanol Biosynthesis in Leaves of Plants 1  

PubMed Central

Leaves of terrestrial plants are aerobic organs, and are not usually considered to possess the enzymes necessary for biosynthesis of ethanol, a product of anaerobic fermentation. We examined the ability of leaves of a number of plant species to produce acetaldehyde and ethanol anaerobically, by incubating detached leaves in N2 and measuring headspace acetaldehyde and ethanol vapors. Greenhouse-grown maize and soybean leaves produced little or no acetaldehyde or ethanol, while leaves of several species of greenhouse-grown woody plants produced up to 241 nanograms per milliliter headspace ethanol in 24 hours, corresponding to a liquid-phase concentration of up to 3 milligrams per gram dry weight. When leaves of 50 plant species were collected in the field and incubated in N2, all higher plants produced acetaldehyde and ethanol, with woody plants generally producing greater amounts (up to 1 microgram per milliliter headspace ethanol concentration). Maize and soybean leaves from the field produced both acetaldehyde and ethanol. Production of fermentation products was not due to phylloplane microbial activity: surface sterilized leaves produced as much acetaldehyde and ethanol as did unsterilized controls. There was no relationship between site flooding and foliar ethanol biosynthesis: silver maple and cottonwood from upland sites produced as much acetaldehyde and ethanol anaerobically as did plants from flooded bottomland sites. There was no relationship between flood tolerance of a species and ethanol biosynthesis rates: for example, the flood intolerant species Quercus rubra and the flood tolerant species Quercus palustris produced similar amounts of ethanol. Cottonwood leaves produced more ethanol than did roots, in both headspace and enzymatic assays. These results suggest a paradox: that the plant organ least likely to be exposed to anoxia or hypoxia is rich in the enzymes necessary for fermentation.

Kimmerer, Thomas W.; MacDonald, Robert C.

1987-01-01

296

Resveratrols in Grape Berry Skins and Leaves in Vitis Germplasm  

PubMed Central

Background Resveratrol is an important stilbene that benefits human health. However, it is only distributed in a few species including grape and is very expensive. At present, grape has been an important source resveratrol. However, the details are scarce on resveratrol distribution in different Vitis species or cultivars. Methodology/Principal Finding The composition and content of resveratrols were investigated by HPLC for assessing genotypic variation in berry skins and leaves of 75 grape cultivars, belonging to 3 species and 7 interspecific hybrids. Trans-resveratrol, cis-piceid and trans-piceid were detected in berry skins and leaves, but cis-resveratrol was not. Resveratrol content largely varied with genetic background as well as usage. In most cultivars, total resveratrol including the above three compounds was higher in berry skins than leaves. In berry skins of most cultivars and leaves of almost all cultivars, cis-piceid was the most abundant resveratrol; trans-resveratrol and trans-piceid were minor components. Some specific cultivars were found with extremely high levels of trans-resveratrol, cis- piceid, trans-piceid or total resveratrols in berry skins or leaves. In skins and leaves, rootstock cultivars had a higher content of total resveratrols, and the cultivated European type cultivars and their hybrids with V. labrusca had relatively low totals. There were no significant correlations of the amounts of total resveratrols or any individual resveratrol between berry skins and leaves. All 75 cultivars can be divided into four groups based on the composition of resveratrols and their concentration by principal component analysis. Conclusion Resveratrol content of grape berries and leaves varied largely with their genetic background and usage. Rootstock cultivars had a higher content of total resveratrols than the other germplasm. Total resveratrols were lower in leaves than berry skins in most cultivars. Cis-piceid was the most abundant resveratrol in most cultivars, and trans-res and trans-pd were minor components.

Wang, Lijun; Xu, Man; Liu, Chunyan; Wang, Junfang; Xi, Huifen; Wu, Benhong; Loescher, Wayne; Duan, Wei; Fan, Peige; Li, Shaohua

2013-01-01

297

Plantlet regeneration from cultured leaves of Cydonia oblonga L. (quince).  

PubMed

Adventitious shoots of Cydonia oblonga Quince A were obtained from leaves cultured on MS-N6 medium containing thidiazuron (TDZ) and ?-naphthaleneacetic acid (NAA). The frequency of regeneration was high (78% of the cultured leaves with 3.2 shoots per regenerating leaf) at 32 ?M TDZ plus 0.3 ?M NAA on young leaves obtained from micropropagated shoots. Shoots were rooted by culturing them first on medium containing 5 ?M NAA for one week and then on auxinfree medium for four weeks. The regeneration protocol may be useful for selection of somaclonal variants with increased tolerance to low Fe and for transformation mediated by Agrobacterium. PMID:24221587

Dolcet-Sanjuan, R; Mok, D W; Mok, M C

1991-08-01

298

Huygens space probe ready to leave Europe  

NASA Astrophysics Data System (ADS)

Over the past year, the Huygens probe has been integrated and extensively tested at the facilities of Daimler Benz Aerospace Dornier Satellitensysteme in Ottobrunn near Munich. It was designed and developed for ESA by a European industrial consortium led by Aerospatiale (F) as prime contractor. The European activities have been successfully completed and this is to be formalised by the Flight Acceptance Review which will release the probe for shipment to the USA. To mark this important milestone a press briefing is scheduled for Wednesday, 26 March at 10.00 hours at Daimler-Benz Aerospace Dornier Satellitensysteme in Ottobrunn. The detailed programme of the press briefing is attached. If you wish to attend the press briefing, please complete the attached accreditation form and return it, preferably by fax, to : Daimler Benz Aerospace Dornier Satellitensysteme Mr. Mathias Pikelj, Fax. + 49 7545 8 5589, Tel. + 49 7545 8 9123 NOTE FOR THE EDITORS: Background facts about the Cassini Huygens mission Huygens is a medium-sized mission of ESA's Horizons 2000 programme for space science, and a contribution to the joint NASA ESA Cassini mission. Christiaan Huygens discovered Saturn s moon Titan in 1655, and the mission named after him aims to land a 343 kilogram probe on Titan carrying a package of scientific instruments through the atmosphere. Six sets of instruments will analyse the chemical composition of the atmosphere, observe the weather and topography of Titan, and examine the nature of its surface. Titan is larger than the planet Mercury, and its unique atmosphere, rich in nitrogen and hydrocarbons, may resemble the atmosphere of the primitive Earth, before life began. Nominal dates for the Huygens mission are as follows: * launch, 6 October 1997 * arrival at Saturn, 1 July 2004 * release of Huygens, 6 November 2004 * entry into Titan's atmosphere, 27 November 2004. The Saturn Orbiter, the other element in the Cassini mission, will relay the signals from Huygens to the Earth, before settling down to prolonged observations of Saturn and its rings and moons. European and American scientists are partners in all the experiments, both in the Orbiter and in the Huygens Probe. Farthest out for Europe Huygens will travel to a greater distance from the Sun than any previous ESA mission, out to the orbit of Saturn at 1400 million kilometres, or nearly ten times the Sun Earth distance. For comparison, the farthest ranging mission at present is Ulysses, orbiting over the poles of the Sun and out to the orbit of Jupiter, 800 million kilometres from the Sun. As no other mission planned or contemplated by ESA at present will go as far as Saturn, Huygens is likely to hold the European record for many years. HUYGENS READY TO LEAVE EUROPE PRESS BRIEFING Wednesday 26 March, 10:00 hrs. Location : Daimler-Benz Aerospace/ Dornier Satellitensysteme Gate 2, Building 5.1 Ludwig-B>lkow-Allee Ottobrunn (Munich) Programme: 10h00 Registration of press 10h15 Huygens video introduction 10h20 Welcoming addresses: Klaus Ensslin, President, Dornier Satellitensysteme Roger Bonnet, Director of Science, ESA Michel Delaye, President, Aerospatiale Espace & Defense 10h30 NASA News and Cassini status Wesly T. Huntress, Associate Administrator of Space Science, NASA Richard Spehalski, Head of Cassini Project, NASA/JPL 10h40 The Huygens Project: Hamid Hassan, Head of the Huygens Project, ESA/ESTEC Hans-Joachim Hoffman, Head of the Huygens Project, Dornier Satellitensysteme Gerard Huttin, Head of the Huygens Project, Aerospatiale 11h00 The Huygens Scientific Programme: Jean-Pierre Lebreton, Huygens Project Scientist, ESA supported by European and American scientists. 11h15 The ESA Science programme, current and future missions Roger Bonnet, Director of Science, ESA 11h25 Question and Answer session 11h55 Visit to the Huygens spacecraft (access inside the clean room limited to photographers and TV teams only). 12h45 Buffet lunch 14h00 End of activties HUYGENS READY TO LEAVE EUROPE PRESS BRIEFING Wednesday 26 March, 10:00 hrs. Location : Daimler-Benz Aerospace

1997-03-01

299

Nurse manager job satisfaction and intent to leave.  

PubMed

An electronic survey was used to collect data from 291 nurse managers working in U.S. hospitals. Seventy percent were satisfied or very satisfied with their jobs and 68% were either likely or very likely to recommend nursing management as a career choice. Seventy-two percent of these nurse managers were also planning to leave their positions in the next 5 years. The four most common reasons reported for intent to leave included burnout, career change, retirement, and promotion. Burnout was the most common reason cited by the entire sample but the fourth most common reason for leaving cited by those nurse managers who were planning to leave and also satisfied or very satisfied with their positions. Recommendations for nursing leaders include evaluating the workload of nurse managers, providing career counseling, and developing succession plans. PMID:24689156

Warshawsky, Nora E; Havens, Donna S

2014-01-01

300

GENERAL VIEW LOOKING WEST DOWN RIVER AT BARGES LEAVING THE ...  

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

GENERAL VIEW LOOKING WEST DOWN RIVER AT BARGES LEAVING THE LOCKS. - Wilson Dam & Hydroelectric Plant, Navigation Lock, Spanning Tennessee River at Wilson Dam Road (Route 133), Muscle Shoals, Colbert County, AL

301

Antioxidant properties of extracts from Ginkgo biloba leaves in meatballs.  

PubMed

The aim was to determine the effect of Ginkgo leaf extracts on the stability of lipids and cholesterol in pork meatballs over 21days of refrigerated storage. The antioxidants used were characterized by their antioxidant activity towards lipids and cholesterol. Extracts were prepared from green and yellow leaves from Ginkgo biloba L. trees. Water, acetone and ethanol were used as extractants. The extracts showed stabilizing effects on both lipid and cholesterol oxidation processes. The lipid oxidation process of pork meatballs was mostly inhibited by the aqueous and ethanolic extracts of the yellow leaves. Their antioxidant activity was higher than that of BHT. All the extracts had a stabilizing effect on cholesterol and most of them inhibited the formation of oxidized derivatives. The acetone and ethanol extracts of green leaves and the ethanol extract of yellow leaves inhibited the formation of cholesterol oxidation products formation most effectively. PMID:24583325

Kobus-Cisowska, Joanna; Flaczyk, Ewa; Rudzi?ska, Magdalena; Kmiecik, Dominik

2014-06-01

302

Pharmacognostical studies on leaves of commiphora caudata (wight & arn) engl.  

PubMed

Commiphora caudata (Wight & Arn) is a potential medicinal plant used for its antispasmodic activity, cytotoxic activity and hypothermic activity. Owing to its medicinal importance, macroscopic and microscopic characters of leaves of Commiphora caudata were studied. PMID:22557220

Latha, S; Selvamani, P; Pal, T K; Gupta, J K; Ghosh, L K

2006-07-01

303

PHARMACOGNOSTICAL STUDIES ON LEAVES OF COMMIPHORA CAUDATA (WIGHT & ARN) ENGL  

PubMed Central

Commiphora caudata (Wight & Arn) is a potential medicinal plant used for its antispasmodic activity, cytotoxic activity and hypothermic activity. Owing to its medicinal importance, macroscopic and microscopic characters of leaves of Commiphora caudata were studied.

Latha, S.; Selvamani, P.; Pal, T.K.; Gupta, J.K.; Ghosh, L.K.

2006-01-01

304

Detail view of gauges that record pressure of gas leaving ...  

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

Detail view of gauges that record pressure of gas leaving the engine house. - Burnsville Natural Gas Pumping Station, Saratoga Avenue between Little Kanawha River & C&O Railroad line, Burnsville, Braxton County, WV

305

Implications for Reducing Sick Leave through Improved Managerial Practices.  

National Technical Information Service (NTIS)

The study demonstrated significant relationships between specific managerial practices and sick leave use and other personnel indicators of organizational effectiveness. The research used a nation-wide sample of approximately 1500 employees in 235 work gr...

R. L. Ellison D. G. Fox K. E. Coray M. T. King

1986-01-01

306

Morphogenesis of Simple and Compound Leaves: A Critical Review  

PubMed Central

The leaves of seed plants evolved from a primitive shoot system and are generated as determinate dorsiventral appendages at the flanks of radial indeterminate shoots. The remarkable variation of leaves has remained a constant source of fascination, and their developmental versatility has provided an advantageous platform to study genetic regulation of subtle, and sometimes transient, morphological changes. Here, we describe how eudicot plants recruited conserved shoot meristematic factors to regulate growth of the basic simple leaf blade and how subsets of these factors are subsequently re-employed to promote and maintain further organogenic potential. By comparing tractable genetic programs of species with different leaf types and evaluating the pros and cons of phylogenetic experimental procedures, we suggest that simple and compound leaves, and, by the same token, leaflets and serrations, are regulated by distinct ontogenetic programs. Finally, florigen, in its capacity as a general growth regulator, is presented as a new upper-tier systemic modulator in the patterning of compound leaves.

Efroni, Idan; Eshed, Yuval; Lifschitz, Eliezer

2010-01-01

307

Don't Let the Warm Weather Leave You Snakebitten  

MedlinePLUS

... please enable JavaScript. Don't Let the Warm Weather Leave You Snakebitten If bitten, call 911 but ... the bite. A large number of bites are dry -- with no venom injected -- or are from nonpoisonous ...

308

25 CFR 38.12 - Leave system for education personnel.  

Code of Federal Regulations, 2011 CFR

...system for education personnel. (a) Full-time school-term employees. Employees on a full-time school-term contract are authorized the...appointments should be scheduled after instructional time. (i) Sick leave shall accrue at...

2011-04-01

309

A Postdoc's Guide to Pregnancy and Maternity Leave  

NSDL National Science Digital Library

This guide provides general information on pregnancy and maternity leave for postdocs, including tips for keeping your research going and talking with your supervisor. This guide is intended primarily for postdoc women who are pregnant or are planning for pregnancy.

Kathleen Flint Ehm (National Postdoctoral Association)

2011-10-05

310

Stress May Leave You Heading to The Cookie Jar  

MedlinePLUS

... sharing features on this page, please enable JavaScript. Stress May Leave You Heading to the Cookie Jar ... July 14, 2014 Related MedlinePlus Pages Body Weight Stress Women's Health MONDAY, July 14, 2014 (HealthDay News) -- ...

311

Induced fluctuations of electric potentials in the apoplast of leaves  

Microsoft Academic Search

Extracellular recordings of electrical potential in leaves of different species by means of band-pass amplifiers showed the\\u000a occurrence of fast, small changes (spikes) with an amplitude below 1 mV. Local illumination of leaves induced temporal patterns\\u000a of spikes outside the illuminated region. The light-induced patterns recorded by a given electrode in a particular experimental\\u000a setup were similar for successive illuminations.

K. Glebicki; Z. Hejnowicz; A. Pijanowski

1989-01-01

312

Nutritional Composition of Water Spinach (Ipomoea aquatica Forsk.) Leaves  

Microsoft Academic Search

Analyses of the nutritional composition of water spinach (Ipomoea aquatica) Forsk leaves were carried out using standard methods of food analysis. The proximate composition as well as mineral elements were determined. The leaves were found on dry weight basis to have high moisture (72.83±0.29%), ash (10.83±0.80%), crude lipid (11.00±0.50%), crude fibre (17.67±0.35%) and available carbohydrate (54.20±0.68%), but low in crude

K. J. Umar; L. G. Hassan; S. M. Dangoggo; M. J. Ladan

2007-01-01

313

Plant regeneration from leaves of sweet and sour cherry cultivars  

Microsoft Academic Search

Leaves excised from shoot cultures of sweet cherry (Prunus avium L.) cv. ‘Burlat’, ‘Hedelfinger’, ‘Napoleon’ and ‘Schneiders’ and sour cherry (Prunus cerasus L.) cv. ‘Beutal Spacher Rexelle’ and ‘Morellenfeuer’ developed shoots on Lloyd and McCown woody plant medium (WPM) supplemented with 2mgl?1 benzylaminopurine (BAP) and 0.5–1mgl?1 ?-naphthaleneacetic acid (NAA). After cutting the leaves into three segments perpendicular to the midrib

Haoru Tang; Zhenglong Ren; Göts Reustle; Gabi Krczal

2002-01-01

314

The mechanism of kinetin-induced transport in corn leaves  

Microsoft Academic Search

1.Kinetin-induced transport of P32 in detached corn leaves is shown to be limited to the axial direction of the leaves, i.e. along the axis of the vascular bundles. It is not apparently dependent on the water flow in the xylem, and it can be blocked by steam-killed zones or by metabolic inhibitors. It is concluded that kinetin-induced redistribution of phosphates

K. Müller; A. C. Leopold

1966-01-01

315

Antibacterial Activity of Leaves of Cadaba trifoliata (Roxb.) Wt. & Arn  

PubMed Central

Antibacterial activity of aqueous and ethanol leaf extracts of Cadaba trifoliata was evaluated by cup plate method against bacterial strains such as Staphylococcus aureus, Bacillus subtilis, Acinetobacter, Enterobacter aerogenes, Erwinia and Escherichia coli. The ethanol extract of the leaves demonstrated a high degree of activity against all the tested bacterial strains except Erwinia and Acinetobacter, whereas the aqueous extract of the leaves showed moderate activity against E. coli, B. subtilis and Staph. aureus and Enterobacter aerogenes.

Mythreyi, R.; Sasikala, E.; Geetha, A.; Madhavan, V.

2009-01-01

316

Antibacterial Activity of Leaves of Cadaba trifoliata (Roxb.) Wt. & Arn.  

PubMed

Antibacterial activity of aqueous and ethanol leaf extracts of Cadaba trifoliata was evaluated by cup plate method against bacterial strains such as Staphylococcus aureus, Bacillus subtilis, Acinetobacter, Enterobacter aerogenes, Erwinia and Escherichia coli. The ethanol extract of the leaves demonstrated a high degree of activity against all the tested bacterial strains except Erwinia and Acinetobacter, whereas the aqueous extract of the leaves showed moderate activity against E. coli, B. subtilis and Staph. aureus and Enterobacter aerogenes. PMID:20336203

Mythreyi, R; Sasikala, E; Geetha, A; Madhavan, V

2009-03-01

317

Volatiles From Leaves and Flowers of Borage (Borago officinalis L.)  

Microsoft Academic Search

The essential oils obtained from the fresh leaves and flowers of Borago officinalis collected in the region of Amdoun (northwestern Tunisia) were examined by GC and GC\\/MS. Twenty-three volatile compounds were identified. The oil yields expressed on a dry weight basis were 0.14% and 0.24% for the leaves and flowers, respectively. The main compound determined in flower and leaf oil

Baya Mhamdi; Wissem A. Wannes; Wissal Dhiffi; Brahim Marzouk

2009-01-01

318

Negative regulation of KNOX expression in tomato leaves  

Microsoft Academic Search

Leaves of seed plants can be described as simple, where the leaf blade is entire, or dissected, where the blade is divided\\u000a into distinct leaflets. Both simple and dissected leaves are initiated at the flanks of a pluripotent structure termed the\\u000a shoot apical meristem (SAM). In simple-leafed species, expression of class I KNOTTED1-like homeobox (KNOX) proteins is confined\\u000a to the

Sophie Jasinski; Hardip Kaur; Alexander Tattersall; Miltos Tsiantis

2007-01-01

319

Phytochemical and Nutrient Evaluation of Spondias Mombin Leaves  

Microsoft Academic Search

Sample of Spondias Mombin leaves was analyzed for the phytochemical composition, vitamins and minerals constituents. Phytochemical screening and subsequent quantification revealed the presence of bioactive compounds tannins 3.82%; Saponins 7.60%; Flavonoids 3.00%, alkaloids 6.00% and phenols 1.00%. Vitamin results showed the plant leaves contained ascorbic acid 19.35mg100 g; Niaci n -1 3.75mg100 g. Riboflavin 0.25 mg100 g and Thiamine 0.05

P. C. Njoku; M. I. Akumefula

2007-01-01

320

Contrasts among bidirectional reflectance of leaves, canopies, and soils  

NASA Technical Reports Server (NTRS)

Simple models are presented for predicting the bidirectional reflectance distribution functions (BRDFs) for soils and plant canopies viewed from various directions. BRDFs are predicted for bare soil, individual leaves, and plant canopies, and the results are compared with measurements and a three coefficient empirical equation. BRDF measurements for corn and soybean leaves are presented to contrast with canopy and soil distributions. Estimates of the soil, canopy, and leaf BRDFs are combined into a model called Cupid to predict BRDFs for complex natural surfaces.

Norman, J. M.; Walter, E. A.; Welles, J. M.

1985-01-01

321

1-Methylcyclopropene prevents ethylene induced yellowing of rocket leaves  

Microsoft Academic Search

Fully expanded rocket (Eruca sativa Mill.) leaves were treated with 1-methylcyclopropene (1-MCP, SmartFresh™) at a concentration of 0.5?ll?1 for 4h at 10°C before storage for 10 days in air or in air with ethylene (1?ll?1). The untreated leaves stored in air showed a progressive yellowing during storage, resulting in a shelf life of about 10 days. The presence of exogenous

Athanasios Koukounaras; Anastasios S. Siomos; Evangelos Sfakiotakis

2006-01-01

322

Subcellular volumes and metabolite concentrations in barley leaves  

Microsoft Academic Search

Metabolite concentrations in subcellular compartments from mature barley (Hordeum vulgare L. cv. Apex) leaves after 9 h of illumination and 5 h of darkness were determined by nonaqueous fractionation and by the stereological evaluation of cellular and subcellular volumes from light and electron micrographs. Twenty one-day-old primary leaves of barley with a total leaf volume of 902 µL per mg

Heike Winter; David G. Robinson; Hans Walter Heldt

1993-01-01

323

Protective Effect of Hexane and Ethanol Extract of Piper Longum L. on Gentamicin-Induced Hair Cell Loss in Neonatal Cultures  

PubMed Central

Objectives Gentamicin (GM) is a commonly used aminoglycoside antibiotic that generates free oxygen radicals within the inner ear, which can cause vestibulo-cochlear toxicity and permanent damage to the sensory hair cells and neurons. Piper longum L. (PL) is a well-known spice and traditional medicine in Asia and Pacific islands, which has been reported to exhibit a wide spectrum of activity, including antioxidant activity. In this study, we evaluated the effect of hexane:ethanol (2:8) PL extract (subfraction of PL [SPL] extract) on GM-induced hair cell loss in basal, middle and apical regions in a neonatal cochlea cultures. Methods The protective effects of SPL extract were measured by phalloidin staining of cultures from postnatal day 2-3 mice with GM-induced hair cell loss. The anti-apoptosis activity of SPL extract was measured using double labeling by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and myosin-7a staining. The radical-scavenging activity of SPL extract was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Results SPL extract at a concentration of 1 µg/mL significantly inhibited GM-induced hair cell loss at basal and middle region of cochlea, while 5 µg/mL was effective against apical region hair cell loss. The protective effect of SPL extract was concentration dependent and hair cells retained their stereocilia in explants treated with SPL extract prior to treatment with 0.3 mM GM. SPL extract decreased GM-induced apoptosis of hair cells as assessed by TUNEL staining. The outer hair and inner hair counts were not decreased in SPL extract treated groups in compare to GM treated explants. Additionally, SPL extract showed concentration dependent radical scavenging activity in a DPPH assay. Conclusion An anti-apoptosis effect and potent radical scavenger activity of SPL extract protects from GM-induced hair cell loss at basal, middle and apical regions in neonatal cochlea cultures.

Yadav, Mukesh Kumar; Choi, June

2014-01-01

324

76 FR 63354 - Proposed Information Collection (Trainee Request for Leave) Activity: Comment Request  

Federal Register 2010, 2011, 2012, 2013

...Information Collection (Trainee Request for Leave) Activity: Comment Request AGENCY: Veterans...needed to evaluate a trainee's request for leave from Vocational Rehabilitation and Employment...technology. Title: Trainee Request for Leave--Chapter 31, Title 38, U. S....

2011-10-12

325

5 CFR 630.1105 - Application to become an emergency leave recipient.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Application to become an emergency leave recipient. 630...Program § 630.1105 Application to become an emergency leave recipient. ...application to his or her employing agency to become an emergency leave recipient. If...

2009-01-01

326

5 CFR 630.1105 - Application to become an emergency leave recipient.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Application to become an emergency leave recipient. 630...Program § 630.1105 Application to become an emergency leave recipient. ...application to his or her employing agency to become an emergency leave recipient. If...

2010-01-01

327

Spectra of normal and nutrient-deficient maize leaves  

NASA Technical Reports Server (NTRS)

Reflectance, transmittance and absorptance spectra of normal and six types of nutrient-deficient (N, P, K, S, Mg, and Ca) maize (Zea mays L.) leaves were analyzed at 30 selected wavelengths from 500 to 2600 nm. The analysis of variance showed significant differences in reflectance, transmittance and absorptance in the visible wavelengths among leaf numbers 3, 4, and 5, among the seven treatments, and among the interactions of leaf number and treatments. In the infrared wavelengths only treatments produced significant differences. The chlorophyll content of leaves was reduced in all nutrient-deficient treatments. Percent moisture was increased in S-, Mg-, and N-deficiencies. Polynomial regression analysis of leaf thickness and leaf moisture content showed that these two variables were significantly and directly related. Leaves from the P- and Ca-deficient plants absorbed less energy in the near infrared than the normal plants; S-, Mg-, K-, and N-deficient leaves absorbed more than the normal. Both S- and N-deficient leaves had higher temperatues than normal maize leaves.

Al-Abbas, A. H.; Barr, R.; Hall, J. D.; Crane, F. L.; Baumgardner, M. F.

1973-01-01

328

Light absorption by anthocyanins in juvenile, stressed, and senescing leaves.  

PubMed

The optical properties of leaves from five species, Norway maple (Acer platanoides L.), cotoneaster (Cotoneaster alaunica Golite), hazel (Corylus avellana L.), Siberian dogwood (Cornus alba L.), and Virginia creeper (Parthenocissus quinquefolia (L.) Planch.), differing in pigment composition and at different stages of ontogenesis, were studied. Anthocyanin absorption maxima in vivo, as estimated with spectrophotometry of intact anthocyanic versus acyanic leaves and microspectrophotometry of vacuoles in the leaf cross-sections, were found between 537 nm and 542 nm, showing a red shift of 5-20 nm compared with the corresponding maxima in acidic water-methanol extracts. In non-senescent leaves, strong anthocyanin absorption was found between 500 nm and 600 nm (with a 70-80 nm apparent bandwidth). By and large, absorption by anthocyanin in leaves followed a modified form of the Lambert-Beer law, showing a linear trend up to a content of nearly 50 nmol cm(-2), and permitting thereby a non-invasive determination of anthocyanin content. The apparent specific absorption coefficients of anthocyanins at 550 nm showed no substantial dependence on the species. Anthocyanin contribution to total light absorption at 550 nm was followed in maple leaves in the course of autumn senescence. Photoprotection by vacuolar anthocyanins is discussed with special regard to their distribution within a leaf; radiation screening by anthocyanins predominantly localized in the epidermal cells in A. platanoides and C. avellana leaves was also evaluated. PMID:18796701

Merzlyak, Mark N; Chivkunova, Olga B; Solovchenko, Alexei E; Naqvi, K Razi

2008-01-01

329

Stress Induction of Mitochondrial Formate Dehydrogenase in Potato Leaves1  

PubMed Central

In higher plants formate dehydrogenase (FDH, EC 1.2.1.2.) is a mitochondrial, NAD-dependent enzyme. We previously reported that in potato (Solanum tuberosum L.) FDH expression is high in tubers but low in green leaves. Here we show that in isolated tuber mitochondria FDH is involved in formate-dependent O2 uptake coupled to ATP synthesis. The effects of various environmental and chemical factors on FDH expression in leaves were tested using the mitochondrial serine hydroxymethyltransferase as a control. The abundance of FDH transcripts is strongly increased under various stresses, whereas serine hydroxymethyltransferase transcripts decline. The application of formate to leaves strongly enhances FDH expression, suggesting that it might be the signal for FDH induction. Our experiments using glycolytic products suggest that glycolysis may play an important role in formate synthesis in leaves in the dark and during hypoxia, and in tubers. Of particular interest is the dramatic accumulation of FDH transcripts after spraying methanol on leaves, as this compound is known to increase the yields of C3 plants. In addition, although the steady-state levels of FDH transcript increase very quickly in response to stress, protein accumulation is much slower, but can eventually reach the same levels in leaves as in tubers.

Hourton-Cabassa, Cecile; Ambard-Bretteville, Francoise; Moreau, Francois; de Virville, Jacques Davy; Remy, Rene; Colas des Francs-Small, Catherine

1998-01-01

330

Comparative antioxidant effect of aqueous extracts of curry leaves, fenugreek leaves and butylated hydroxytoluene in raw chicken patties.  

PubMed

Antioxidant properties and use of aqueous extracts of curry leaves (Murraya koenigii) and fenugreek leaves (Trigonella foenum-graecum) as source of natural antioxidant in raw chicken meat were evaluated. Four treatments viz., I. Control (meat +2% salt), II.BHT (meat +2% salt +0.1% BHT), III. CLE (meat +2% salt +2% curry leaves extract) and IV. FLE (meat +2% salt +2% fenugreek leaves extract) were compared for lipid oxidation during eight days refrigerated storage. The average phenolic content was 59.2 and 52.8 mg/g gallic acid equivalent in CLE and FLE respectively. Free radical scavenging activity was 61.4 and 64.2% in CLE and FLE, respectively. CLE had significantly (P?leaves and fenugreek leaves could be explored as natural antioxidants in poultry meat and meat products. PMID:24293699

Devatkal, Suresh K; Thorat, Pramod R; Manjunatha, M; Anurag, Rahul K

2012-12-01

331

Drying kinetics of dill leaves in a convective dryer  

NASA Astrophysics Data System (ADS)

Thin layer drying characteristics of dill leaves under fixed, semi-fluidized, and fluidized bed conditions were studied at air temperatures of 30, 40, 50, and 60°C. In order to find a suitable drying curve, 12 thin layer-drying models were fitted to the experimental data of the moisture ratio. Among the applied mathematical models, the Midilli et al. model was the best for drying behavior prediction in thin layer drying of dill leaves. To obtain the optimum network for drying of dill leaves, various numbers of multilayer feed-forward neural networks were made and tested with different numbers of hidden layers and neurons. The best neural network feed-forward back-propagation topology for the prediction of drying of dill leaves (moisture ratio and drying rate) was the 3-45-2 structure with the training algorithm trainlm and threshold functions logsig and purelin. The coefficient of determination for this topology for training, validation, and testing patterns was 0.9998, 0.9981, and 0.9990, respectively. Effective moisture diffusivity of dill leaves during the drying process in different bed types was found to be in the range from 7.10 10-12 to 1.62 10-10 m2 s-1. Also, the values of activation energy were determined to be between 75.435 and 80.118 kJ mol-1

Motevali, A.; Younji, S.; Chayjan, R. Amiri; Aghilinategh, N.; Banakar, A.

2013-01-01

332

Proteomic analysis of strawberry leaves infected with Colletotrichum fragariae.  

PubMed

Understanding the defense mechanisms used by anthracnose-resistant strawberries against Colletotrichum infection is important for breeding purposes. To characterize cell responses to Colletotrichum infection, proteomes from strawberry seedling leaves that had or had not been infected with Colletotrichum fragariae were characterized at different time points post infection by 2-DE and by MALDI-TOF/TOF MS/MS and database-searching protein identification. Mass spectrometry identified 49 differentially expressed proteins with significant intensity differences (>1.5-fold, p<0.05) in mock- and C. fragariae-infected leaves at least at one time point. Notably, 2-DE analysis revealed that C. fragariae infection increased the expression of well-known and novel pathogen-responsive proteins whose expression patterns tended to correlate with physiological changes in the leaves. Quantitative real-time PCR was used to examine the transcriptional profiles of infected and uninfected strawberry leaves, and western blotting confirmed the induction of ?-1,3-glucanase and a low-molecular-weight heat shock protein in response to C. fragariae infection. During the late phase of infection, proteins involved in the Calvin cycle and glycolysis pathway had suppressed expression. The abundance changes, putative functions, and participation in physiological reactions for the identified proteins produce a pathogen-responsive protein network in C. fragariae-infected strawberry leaves. Together, these findings increase our knowledge of pathogen resistance mechanisms, especially those found in non-model plant species. PMID:22634039

Fang, Xianping; Chen, Wenyue; Xin, Ya; Zhang, Hengmu; Yan, Chengqi; Yu, Hong; Liu, Hui; Xiao, Wenfei; Wang, Shuzhen; Zheng, Guizhen; Liu, Hongbo; Jin, Liang; Ma, Huasheng; Ruan, Songlin

2012-07-16

333

Intercellular Diffusion Limits to CO2 Uptake in Leaves 1  

PubMed Central

We studied plants of five species with hypostomatous leaves, and six with amphistomatous leaves, to determine the extent to which gaseous diffusion of CO2 among the mesophyll cells limits photosynthetic carbon assimilation. In helox (air with nitrogen replaced by helium), the diffusivities of CO2 and water vapor are 2.3 times higher than in air. For fixed estimated CO2 pressure at the evaporating surfaces of the leaf (pi), assimilation rates in helox ranged up to 27% higher than in air for the hypostomatous leaves, and up to 7% higher in the amphistomatous ones. Thus, intercellular diffusion must be considered as one of the processes limiting photosynthesis, especially for hypostomatous leaves. A corollary is that CO2 pressure should not be treated as uniform through the mesophyll in many leaves. To analyze our helox data, we had to reformulate the usual gas-exchange equation used to estimate CO2 pressure at the evaporating surfaces of the leaf; the new equation is applicable to any gas mixture for which the diffusivities of CO2 and H2O are known. Finally, we describe a diffusion-biochemistry model for CO2 assimilation that demonstrates the plausibility of our experimental results.

Parkhurst, David F.; Mott, Keith A.

1990-01-01

334

Changes in the vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and c-reactive protein following administration of aqueous extract of piper sarmentosum on experimental rabbits fed with cholesterol diet  

PubMed Central

Background Inflammation process plays an important role in the development of atherosclerosis. Hypercholesterolemia is one of the major risk factors for atherosclerosis. The present study aimed to evaluate the effect of aqueous extract of Piper sarmentosum (P.s) on inflammatory markers like vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and C-reactive protein (CRP). Methods Forty two male New Zealand white rabbits were divided equally into seven groups; (i) C- control group fed normal rabbit chow (ii) CH- cholesterol diet (1%cholesterol) (iii) X1- 1% cholesterol with water extract of P.s (62.5 mg/kg) (iv) X2- 1% cholesterol with water extract of P.s (125 mg/kg (v) X3- 1% cholesterol with water extract of P.s (250 mg/kg) (vi) X4- 1% cholesterol with water extract of P.s (500 mg/kg) and (vii) SMV group fed with 1% cholesterol supplemented with simvistatin drug (1.2 mg/kg). All animals were treated for 10 weeks. Blood serum was taken for observing the inflammatory markers at the beginning and end of the experiment. Results Rabbits fed with 1% cholesterol diet (CH) showed significant increase in the level of VCAM-1, ICAM-1 and CRP compared to the C group. The levels of VCAM-1, ICAM-1 and CRP in the 1% cholesterol group and supplemented with P.s (500 mg/kg) were significantly reduced compared to the cholesterol group. Similar results were also reported with simvistatin group. Conclusion These results suggest that the supplementation of Piper sarmentosum extract could inhibit inflammatory markers which in turn could prevent atherosclerosis.

2011-01-01

335

Falling Leaves, Flapping Flight, and Making a Virtual Insect  

NASA Astrophysics Data System (ADS)

Insects are fascinating to watch but difficult to catch, so are falling leaves. The diverse maneuver executed by insects and the flutter and tumbling motion of leaves are manifestations of complex interactions between the moving surfaces and the surrounding unsteady air. Despite the long tradition in fluid dynamics, relatively few quantitative descriptions and basic mechanisms are known about these two everyday phenomena. In this talk, I will describe some of the lessons we learned by analyzing them. In particular, I will show 1)a basic two dimensional mechanism of insect hovering and the associated vortical flow and forces, 2) the use of drag in insect hovering, in contrast to helicopter,3) the rise of falling leaves and the lift mechanism which is responsible for the center of mass elevation, 4) a model of fluid forces, different from the classical theory, for falling objects in fluid, and 5) computer experiments of three dimensional elastic flapping wings driven by muscles.

Wang, Z. Jane

2004-03-01

336

Antimicrobial activity of extracts from Tamarindus indica L. leaves  

PubMed Central

Tamarindus indica L. leaves are reported worldwide as antibacterial and antifungal agents; however, this observation is not completely accurate in the case of Cuba. In this article, decoctions from fresh and sun dried leaves, as well as fluid extracts prepared with 30 and 70% ethanol-water and the pure essential oil from tamarind leaves were microbiologically tested against Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Pseudomona aeruginosa and Candida albicans. Aqueous and fluid extracts were previously characterized by spectrophotometric determination of their total phenols and flavonoids, while the essential oil was chemically evaluated by gas chromatography/mass spectroscopy (GC/MS). Experimental data suggest phenols as active compounds against B. subtilis cultures, but not against other microorganisms. On the other hand, the essential oil exhibited a good antimicrobial spectrum when pure, but its relative low concentrations in common folk preparations do not allow for any good activity in these extracts.

Escalona-Arranz, Julio Cesar; Peres-Roses, Renato; Urdaneta-Laffita, Imilci; Camacho-Pozo, Miladis Isabel; Rodriguez-Amado, Jesus; Licea-Jimenez, Irina

2010-01-01

337

[Maternity leave and experience of working mothers in Lebanon].  

PubMed

We conducted a cross-sectional study of 802 Lebanese mothers to evaluate effect of rapid return to work on their health and that of their child. Breastfeeding practices were also assessed. The duration of maternity leave was insufficient for 72.8% of the women. Rapid return to work could cause physical and psychological problems depending on the type of work. The average length of breastfeeding was 4.7 months and while the average desired length was 10.9 months. Breastfeeding depended on the duration of the maternity leave, the possibility of breaks for breastfeeding and the presence of nurseries at work. Urgent interventions are necessary to prolong maternity leave and promote breastfeeding among working women. PMID:21222323

Saadé, N; Barbour, B; Salameh, P

2010-09-01

338

Physicochemical characterization of cellulose from perennial ryegrass leaves (Lolium perenne).  

PubMed

In this study, we investigated the physicochemical properties of the cellulosic preparations obtained from both untreated perennial ryegrass leaves and de-juiced leaves. It was found that treatment at 22 degrees C with 18% NaOH and 18% KOH for 2h, and 10% NaOH and 10% KOH for 16 h yielded 28.2%, 28.8%, 22.7%, 23.4%, respectively, of 'cellulose' residue from untreated ryegrass leaves and 35.7%, 36.8%, 32.8% and 34.6%, respectively, from the de-juiced leaves. For each cellulosic fraction, the glucose content was 71.6%, 69.6%, 67.8%, 66.7%, 69.7%, 68.6%, 63.9% and 61.7%, respectively. The structure of the cellulose samples was examined using FTIR and CP/MAS (13)C NMR spectroscopy and X-ray diffraction. The cellulosic preparations were free of bound lignin except for noticeable amounts of residual hemicelluloses (28.4-38.3%), and had intrinsic viscosities between 275.1 and 361.0 mL/g, along with molecular weights from 144,130 to 194,930 g/mol. This study found that the cellulose samples isolated from both de-juiced ryegrass leaves and the untreated leaves had a much lower percent crystallinity (33.0-38.6%) than that from wood-based fibres (60-70%) and had much shorter fibres (0.35-0.49 mm) than those of either cereal straws, bagasse or wood. In addition, a partial disruption of the hydrogen bonds and microfibrils may occur during the de-juicing process by mechanical activity, which results in a decreased cellulose crystallinity and fibre length. These findings are significant in relation to hydrolysing ryegrass cellulose for bio-ethanol production. PMID:16934239

Liu, C F; Xu, F; Sun, J X; Ren, J L; Curling, S; Sun, R C; Fowler, P; Baird, M S

2006-11-27

339

Induced fluctuations of electric potentials in the apoplast of leaves.  

PubMed

Extracellular recordings of electrical potential in leaves of different species by means of band-pass amplifiers showed the occurrence of fast, small changes (spikes) with an amplitude below 1 mV. Local illumination of leaves induced temporal patterns of spikes outside the illuminated region. The light-induced patterns recorded by a given electrode in a particular experimental setup were similar for successive illuminations. The patterns recorded at different sites on the same leaf were different. Locally repetitive patterns of spikes at the electrode outside the illuminated region indicate the occurrence of some signals transmitted from this region to the cells in the neighborhood of the electrode. PMID:24201837

Glebicki, K; Hejnowicz, Z; Pijanowski, A

1989-12-01

340

Fungal diversity on fallen leaves of Ficus in northern Thailand* §  

PubMed Central

Fallen leaves of Ficus altissima, F. virens, F. benjamina, F. fistulosa and F. semicordata, were collected in Chiang Mai Province in northern Thailand and examined for fungi. Eighty taxa were identified, comprising 56 anamorphic taxa, 23 ascomycetes and 1 basidiomycete. Common fungal species occurring on five host species with high frequency of occurrence were Beltraniella nilgirica, Lasiodiplodia theobromae, Ophioceras leptosporum, Periconia byssoides and Septonema harknessi. Colletotrichum and Stachybotrys were also common genera. The leaves of different Ficus species supported diverse fungal taxa, and the fungal assemblages on the different hosts showed varying overlap. The fungal diversity of saprobes at the host species level is discussed.

Wang, Hong-kai; Hyde, Kevin D.; Soytong, Kasem; Lin, Fu-cheng

2008-01-01

341

G-MG How many leaves on a tree?  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Amy and Greg are raking up leaves from a large maple tree in their yard and Amy remarks "I'll bet this tree has a million leaves." Greg is skeptical an...

342

Phytochemical investigation and antimicrobial activity of Psidium guajava L. leaves  

PubMed Central

Psidium guajava L. leaves were subjected to extraction, fractionation and isolation of the flavonoidal compounds. Five flavonoidal compounds were isolated which are quercetin, quercetin-3-O-?-L-arabinofuranoside, quercetin-3-O-?-D-arabinopyranoside, quercetin-3-O-?-D-glucoside and quercetin-3-O-?-D-galactoside. Quercetin-3-O-?-D-arabinopyranoside was isolated for the first time from the leaves. Fractions together with the isolates were tested for their antimicrobial activity. The antimicrobial studies showed good activities for the extracts and the isolated compounds.

Metwally, A. M.; Omar, A. A.; Harraz, F. M.; El Sohafy, S. M.

2010-01-01

343

Degree of polarization model for leaves and discrimination between pea and rice types leaves for estimation of leaf area index  

NASA Astrophysics Data System (ADS)

It is difficult to estimate leaf area index(LAI) by measuring spectral reflectance from nadir view only. BRDF might help to estimate LAI in some sense. It is still difficult to estimate LAI precisely. Shape of pea and rice types of leaves is different. It might be helpful to descriminate between both. Meanwhile, degree of polarization is different between both so that it is possible to descriminate each other by using degree of polarization. Model of degree of polarization of leaves is proposed. Theoretical background of degree of polarization of leaves is described followed by some examples of simulation studies. Experimental degree of polarization is described to show a validity of the proposed model followed by estimation accuracy of leaf area index.

Arai, Kohei

344

Fluorescence emission spectra of plant leaves and plant constituents  

Microsoft Academic Search

Summary The UV-B radiation (e.g. 337 nm) induced blue fluorescence (BF) and red chlorophyll fluorescence spectra (RF) of green leaves from plants with different leaf structure were determined and the possible nature and candidates of the blue fluorescence emission investigated. The blue fluorescence BF is characterized by a main maximum in the 450 nm region and in most cases by

M. Lang; F. Stober; H. K. Lichtenthaler

1991-01-01

345

Polyphenols in Strawberry (Fragaria × ananassa) Leaves Induced by Plant Activators.  

PubMed

Strawberry leaves contain high amounts of diverse phenolic compounds potentially possessing defensive activities against microbial pathogens and beneficial properties for human health. In this work, young strawberry plants were treated with two plant activators, S-methylbenzo-1,2,3-thaidiazole-7-carbothiate (BTH) and birch wood distillate. Phenolic compounds from activator-treated and control leaves were subjected to quantitative analyses by HPLC-DAD, HPLC-ESI-MS, and microQTOF ESI-MS. Thirty-two different phenolic compounds were detected and characterized, and 21 different ellagitannins constituted the largest group of compounds in the strawberry leaves (37.88-45.82 mg/g dry weight, 47.0-54.3% of total phenolics). Treatment with BTH resulted in higher levels of individual ellagitannins, whereas treatment with birch wood distillate strongly increased the levels of chlorogenic acid in strawberry leaves compared with the control. The results suggest that different plant activators may be useful tools for the activation of different branches in the phenylpropanoid biosynthesis in strawberry. PMID:24819677

Kårlund, Anna; Salminen, Juha-Pekka; Koskinen, Piia; Ahern, Jeffrey R; Karonen, Maarit; Tiilikkala, Kari; Karjalainen, Reijo O

2014-05-21

346

When the Leader Leaves: Sustaining Success at Romero High School  

ERIC Educational Resources Information Center

This case study asks readers to consider what leadership actions might help to sustain success for immigrant students in a small urban high school when the leader leaves. Principal Michael Perez, the founding principal of Romero High School, has been recruited to become the superintendent of a first-ring suburban district with rapidly changing…

Johnson, Lauri; Sillman, Kathryn

2012-01-01

347

Physical aspects of the internal water relations of plant leaves  

Microsoft Academic Search

Relations between the water potential, osmotic potential, pressure potential, and relative water content have been derived on the basis of 2 simple assumptions. Measurements of these quantities were made on leaves of cotton, sunflower, pepper, and birdsfoot trefoil to test the validity of these relations. Within the precision of the data, the assumption that the osmotic potential is inversely proportional

W. R. Gardner; C. F. Ehlig

1965-01-01

348

Leaving Care: Retrospective Reports by Alumni of Israeli Group Homes  

ERIC Educational Resources Information Center

This study examines the retrospective reports of alumni of Israeli group homes on their experiences of leaving care, taking into account possible gender differences as well as associations with their experiences while in care. The reports of 94 alumni (38 men and 56 women) interviewed by phone revealed major difficulties associated with the…

Schiff, Miriam

2006-01-01

349

Growth and regeneration of waxes on the leaves of Eucalyptus  

Microsoft Academic Search

The relationships of wax morphology to wax chemistry and the effects of light intensity on wax development were investigated using rubbing techniques to produce nearly wax free cuticular surfaces. Wax regeneration took place rapidly on leaves which were in their exponential stage of expansion, but only slowly on those that had fully expanded. The pattern of wax development suggested that

N. D. Hallam

1970-01-01

350

Einstein's Tea Leaves and Pressure Systems in the Atmosphere  

ERIC Educational Resources Information Center

Tea leaves gather in the center of the cup when the tea is stirred. In 1926 Einstein explained the phenomenon in terms of a secondary, rim-to-center circulation caused by the fluid rubbing against the bottom of the cup. This explanation can be connected to air movement in atmospheric pressure systems to explore, for example, why low-pressure…

Tandon, Amit; Marshall, John

2010-01-01

351

Why Some Students Leave College during Their Senior Year  

ERIC Educational Resources Information Center

Although many studies have examined college student attrition, no extant literature examines the phenomenon of undergraduates who discontinue their enrollment in college during a semester of their senior year. This study used both institutional and self-reported survey data to examine the rationale behind seniors' decision to leave college during…

Hunt, Patricia F.; Boyd, Vivian S.; Gast, Linda K.; Mitchell, Alice; Wilson, Wendy

2012-01-01

352

Strong Electrical Currents Leave the Primitive Streak of Chick Embryos  

Microsoft Academic Search

The electrical fields above chick embryos were explored with a vibrating probe. These fields indicate that steady currents with exit densities of the order of 100 microamperes per square centimeter leave the whole streak and return elsewhere through the epiblast. The epicenter of these strong exit currents lies near Hensen's node. They are probably pumped into the intraembryonic space by

Lionel F. Jaffe; Claudio D. Stern

1979-01-01

353

Voices from the Darkness: A House of Leaves Experience  

Microsoft Academic Search

House of Leaves is both a love letter to the written word and a demonstration of its inadequacies, a cautionary tale, a horror story, a romance, a bildungsroman, an eloquent mockery of literary criticism, and much else besides. It incorporates postmodern poly-vocal framing techniques, which are sort of a literary version of Russian nesting dolls, if the dolls all talked

Waltman Melanie

2009-01-01

354

Indole alkaloids from leaves and twigs of Rauvolfia verticillata.  

PubMed

Seven new indole alkaloids, rauverines A-G (1-7), and 19 known indole alkaloids were isolated from the leaves and twigs of Rauvolfia verticillata. All compounds showed no cytotoxicity against five human cancer cell lines, human myeloid leukemia (HL-60), hepatocellular carcinoma (SMMC-7721), lung cancer (A-549), breast cancer (MCF-7), and colon cancer (SW480) cells. PMID:24266393

Zhang, Bing-Jie; Peng, Lei; Wu, Zhi-Kun; Bao, Mei-Fen; Liu, Ya-Ping; Cheng, Gui-Guang; Luo, Xiao-Dong; Cai, Xiang-Hai

2013-01-01

355

Child health: An underplayed variable in parental leave policy debates?  

Microsoft Academic Search

This paper examines parental leave policy from the perspective of infant and young child health. Factors assisting the successful integration of breastfeeding and maternal employment are outlined. Health effects of day care attendance are also explored as an integral component of this assessment. It is suggested that the potential health disadvantages associated with lack of, or inability to access, parental

Judith Galtry

2002-01-01

356

Distribution of Peltate Glandular Trichomes on Developing Leaves of Peppermint  

Microsoft Academic Search

The pattern of peltate glandular trichome initiation and ontogeny on expanding peppermint (Mentha 3 piperita) leaves was defined by surveying the populations of peltate glands in each of seven developmental stages within sampling areas of leaf apical, mid-, and basal zones for both abaxial and adaxial surfaces. It was shown that new peltate glands continue to form until leaf expansion

Glenn W. Turner; Jonathan Gershenzon; Rodney B. Croteau

2000-01-01

357

Regulation of Monoterpene Accumulation in Leaves of Peppermint  

Microsoft Academic Search

Plants synthesize numerous classes of natural products that ac- cumulate during development and are thought to function as con- stitutive defenses against herbivores and pathogens. However, little information is available about how the levels of such defenses are regulated. We measured the accumulation of monoterpenes, a model group of constitutive defenses, in peppermint (Mentha 3 piperita L.) leaves and investigated

Jonathan Gershenzon; Marie E. McConkey; Rodney B. Croteau

2000-01-01

358

Distribution of cadmium in leaves of Thlaspi caerulescens  

Microsoft Academic Search

Knowledge of the intracellular distribution of Cd in leaves is necessary in order to understand the mech- anisms of hyperaccumulation in Thlaspi caerulescens. Ganges and Prayon, two ecotypes accumulating Cd to different levels, were grown in nutrient medium containing varying concentrations (0, 5, 10, 50, and 100 lM) of Cd. Several different approaches were com- bined in this study to

Claudia Cosio; Laura DeSantis; Beat Frey; Saliou Diallo; Catherine Keller

2005-01-01

359

Management of Sick Leave due to Musculoskeletal Disorders  

Microsoft Academic Search

Musculoskeletal disorders are a common problem that may lead to func-Ational limitations and (work) disability. It is not clear yet how improvement in Apain or functional limitations is related to return to work after an episode of sick Aleave. Furthermore, several physicians are involved in the treatment and man-Aagement of a patient is on sick leave. In the Netherlands a

E. Faber

2007-01-01

360

Characteristics of Opiate Users Leaving Detoxification Treatment Against Medical Advice  

Microsoft Academic Search

Substance-dependent patients leaving against medical advice (AMA) pose a unique challenge to detoxification programs. Most notably, AMA patients fail to access residential or outpatient treatment needed after detoxification and often return to detoxification treatment multiple times which has deleterious results for the patient and is taxing to the healthcare system. Using retrospective data from 89 daily opiate-using detoxification patients completing

Deric R. Kenne; Alec P. Boros; Rebecca L. Fischbein

2010-01-01

361

Why do student nurses leave? Suggestions from a Delphi Study  

Microsoft Academic Search

The high dropout rate of nursing students is a major concern. However, there is little research available about the reasons why students leave. Universities collect some information from ‘exit’ interviews but, due to ethical sensitivities, it is not made available for research analysis. The purpose of this study was to establish a consensus view of the reasons why student nurses

Paul Fulbrook

2003-01-01

362

Fluoride content in khat ( Catha edulis) chewing leaves  

Microsoft Academic Search

Khat (qat) leaves are chewed for their psychostimulative effects; there is an unconfirmed suggestion that they contain a high concentration of fluoride (F). Khat samples from Yemen were suspended in deionized water, spun, and the supernatants exposed to a chelator that decomplexes F, which was assayed with an F?-electrode coupled to an ion analyser. F released into whole saliva after

Faiez N Hattab; Birgit Angmar-Månsson

2000-01-01

363

Toxicological evaluation of a tea from leaves of Vernonia condensata  

Microsoft Academic Search

Teas of Vernonia condensata Baker (Asteraceae) are widely used in Brazil for gastro-intestinal disorders and to treat several other diseases. In this study, we evaluated the acute toxicity, embryotoxicity and mutagenicity of a lyophilized aqueous extract (LAE) from V. condensata leaves. Single doses of LAE, up to 5000 mg\\/kg body weight, were given orally or intraperitoneally to male and female

M. H. D. Monteiro; M. R. Gomes-Carneiro; I. Felzenszwalb; I. Chahoud; F. J. R. Paumgartten

2001-01-01

364

Spectral characteristics of normal and nutrient-deficient maize leaves  

NASA Technical Reports Server (NTRS)

Reflectance, transmittance and absorbance spectra of normal and six types of mineral-deficient (N,P,K,S,Mg and Ca) maize (Zea mays L.) leaves were analyzed at 30 selected wavelengths along the electromagnetic spectrum from 500 to 2600 nm. Chlorophyll content and percent leaf moisture were also determined. Leaf thermograms were obtained for normal, N- and S- deficient leaves. The results of the analysis of variance showed significant differences in reflectance, transmittance and absorbance in the visible wavelengths among leaf numbers 3, 4, and 5, among the seven nutrient treatments, and among the interactions of leaves and treatments. In the reflective infrared wavelengths only treatments produced significant differences. The chlorophyll content of leaves was reduced in all deficiencies in comparison to controls. Percent moisture was increased in S-, Mg- and N- deficiencies. Positive correlation (r = 0.707) between moisture content and percent absorption at both 1450 and 1930 nm were obtained. Polynomial regression analysis of leaf thickness and leaf moisture content showed that these two variables were significantly and directly related (r = 0.894).

Al-Abbas, A. H.; Barr, R.; Hall, J. D.; Crane, F. L.; Baumgardner, M. F.

1972-01-01

365

Oviposition by butterflies on young leaves: Investigation of leaf volatiles  

Microsoft Academic Search

Summary Various butterflies select young foliage on which to lay their eggs; volatiles emitted by young and old leaves have been compared (by sorption enrichment, followed by GC-MS) to gauge possible qualitative and quantitative differences between the two age groups. The plants investigated are cabbage (Brassica oleracea), two milkweeds (Asclepias syriaca andA. curassavica), the bitter orange (Citrus aurantium) and the

Gunnar Bergström; Miriam Rothschild; Inga Groth; Cathy Crighton

1994-01-01

366

Tannin composition affects the oxidative activities of tree leaves.  

PubMed

We examined whether tannin composition plays an important role in explaining the oxidative activities of tree leaves of Acer saccharum (sugar maple) and Quercus rubra (red oak). Sugar maple leaves contained substantial amounts of ellagitannins, condensed tannins, and galloyl glucoses, whereas red oak leaves contained almost exclusively condensed tannins. Oxidative activities of the crude phenolics from both species, and the phenolic fractions from sugar maple, were measured with electron paramagnetic resonance (EPR) spectrometry and UV-visible spectrophotometry. The two assays produced similar results: (1) sugar maple phenolics produced larger semiquinone radical concentrations,and higher semiquinone decay rates and browning rates than did red oak phenolics; (2) ellagitannin levels were positively associated with the three measures of oxidative activity; and (3) condensed tannin and galloyl glucose levels were negatively associated with these measures. The negative relationship between condensed tannin levels and oxidative activity resulted from the antioxidant effects of condensed tannins on hydrolyzable tannins; several purified condensed tannins significantly decreased the concentrations of semiquinone radicals and browning rates of pedunculagin (an ellagitannin) and pentagalloyl glucose. As expected, whole-leaf extracts from sugar maple produced elevated levels of semiquinone radicals, but none were observed in red oak extracts when the two species were compared with an EPR time-course assay. We conclude that the oxidative activities of tree leaves may be affected by tannin composition, and that the prooxidant activity of ellagitannins may be decreased by co-occurring condensed tannins. PMID:17031601

Barbehenn, Raymond V; Jones, Christopher P; Karonen, Maarit; Salminen, Juha-Pekka

2006-10-01

367

COLOR CHANGE KINETICS OF CELERY LEAVES UNDERGOING MICROWAVE HEATING  

Microsoft Academic Search

The aim of this study was to investigate the effect of microwave output power and sample amount on color change kinetics of celery leaves (Apium graveolens L.) during microwave heating. The color parameters of the materials were quantified by the Hunter Lab system. These values were also used for calculation of the total color change, chroma, hue angle, and browning

Elçin Dem?rhan; Belma Özbek

2011-01-01

368

Evaluation of Alstonia scholaris leaves for broncho-vasodilatory activity  

Microsoft Academic Search

The present study demonstrates that the ethanol extract of Alstonia scholaris (Apocynaceae) leaves induced pronounced bronchodilatory activity in anaesthetized rats with the probable involvement of prostaglandins. However, in vitro preparations of guinea-pig trachea did not confirm this property, indicating that bronchodilation is not due to the direct tracheal smooth muscle relaxation. The vasodilatory activity of the extract was independent of

Shabana Channa; Ahsana Dar; Shakeel Ahmed; Atta-ur-Rahman

2005-01-01

369

Beginning Teachers: Are They Still Leaving the Profession?  

ERIC Educational Resources Information Center

Examines attitudes of beginning teachers toward their current support systems and compares those attitudes with factors previously identified as predictors of attrition. Notes that this sample of teachers is not predisposed to leaving the profession. Suggests that administrators should strongly support teachers' new ideas. (RS)

Marlow, Leslie; And Others

1997-01-01

370

The evolution, morphology, and development of fern leaves  

PubMed Central

Leaves are lateral determinate structures formed in a predictable sequence (phyllotaxy) on the flanks of an indeterminate shoot apical meristem. The origin and evolution of leaves in vascular plants has been widely debated. Being the main conspicuous organ of nearly all vascular plants and often easy to recognize as such, it seems surprising that leaves have had multiple origins. For decades, morphologists, anatomists, paleobotanists, and systematists have contributed data to this debate. More recently, molecular genetic studies have provided insight into leaf evolution and development mainly within angiosperms and, to a lesser extent, lycophytes. There has been recent interest in extending leaf evolutionary developmental studies to other species and lineages, particularly in lycophytes and ferns. Therefore, a review of fern leaf morphology, evolution and development is timely. Here we discuss the theories of leaf evolution in ferns, morphology, and diversity of fern leaves, and experimental results of fern leaf development. We summarize what is known about the molecular genetics of fern leaf development and what future studies might tell us about the evolution of fern leaf development.

Vasco, Alejandra; Moran, Robbin C.; Ambrose, Barbara A.

2013-01-01

371

Optimal vein density in artificial and real leaves  

PubMed Central

The long evolution of vascular plants has resulted in a tremendous variety of natural networks responsible for the evaporatively driven transport of water. Nevertheless, little is known about the physical principles that constrain vascular architecture. Inspired by plant leaves, we used microfluidic devices consisting of simple parallel channel networks in a polymeric material layer, permeable to water, to study the mechanisms of and the limits to evaporation-driven flow. We show that the flow rate through our biomimetic leaves increases linearly with channel density (1/d) until the distance between channels (d) is comparable with the thickness of the polymer layer (?), above which the flow rate saturates. A comparison with the plant vascular networks shows that the same optimization criterion can be used to describe the placement of veins in leaves. These scaling relations for evaporatively driven flow through simple networks reveal basic design principles for the engineering of evaporation–permeation-driven devices, and highlight the role of physical constraints on the biological design of leaves.

Noblin, X.; Mahadevan, L.; Coomaraswamy, I. A.; Weitz, D. A.; Holbrook, N. M.; Zwieniecki, M. A.

2008-01-01

372

Isolation and Characterization of Phosphatidyl Choline from Spinach Leaves.  

ERIC Educational Resources Information Center

This inexpensive but informative experiment for undergraduate biochemistry students involves isolating phosphatidyl choline from spinach leaves. Emphasis is on introducing students to techniques of lipid extraction, separation of lipids, identification using thin layer chromatography, and identification of fatty acids. Three periods of three hours…

Devor, Kenneth A.

1979-01-01

373

Leaving Teaching in the UK: A Duration Analysis  

Microsoft Academic Search

In this paper, the authors analyze the decision by teachers to leave the profession. Their results affirm the importance of relative earnings in the tenure and turnover decisions of teachers. The econometric modeling approach used yields important insights into the appropriateness of adopting a flexible, semiparametric specification of the duration dependence structure and of the unobserved heterogeneity distribution in duration

Peter J Dolton; Wilbert van der Klaauw

1995-01-01

374

LEAVES AS INDICATORS OF EXPOSURE TO AIRBORNE VOLATILE ORGANIC COMPOUNDS  

EPA Science Inventory

The concentration of volatile organic compounds (VOCs) in leaves is primarily a product of airborne exposures and dependent upon bioconcentration factors and release rates. The bioconcentration factors for VOCs in grass are found to be related to their partitioning between octan...

375

"Hello, Goodbye": Exploring the Phenomenon of Leaving Teaching Early  

ERIC Educational Resources Information Center

High teacher attrition rates hinder schools in their ability to provide quality instruction. This study seeks to understand why teachers leave early in their careers (within the first 5 years) using a mixed methods approach that combined 50 in-depth interviews with 15 public and 10 Catholic school teachers in the United States who left early with…

Torres, Aubrey Scheopner

2012-01-01

376

Trace Element Conient ol Leaves of Desert Shrubs in  

Microsoft Academic Search

lntroduclion Measurements of the mineral content of leaves of desett shrubs gtowing io the shrub steppe region of south-central Vashington have generally centered upon mineral cycling behavior (Mack 1977, Rickard 1965, Rickard and Keough 1968, Cline and Rickard 1974) and have been mostly coocerned with the behavior of maclooutrient elemeots and sodium rather than trace metals. In lecent years considerable

T. R. Garland

377

Carolina "Takes It or Leaves It" then "Gives It Up."  

ERIC Educational Resources Information Center

Describes the "Take It or Leave It" (now the "Give It Up") program at the University of South Carolina, in which the materials generated by students moving out of campus housing for the summer, rather than being disposed of as trash, are collected and recycled or donated to local charities. (EV)

Koman, Michael

2003-01-01

378

Photosynthetic pigments and mineral composition of iron deficient pear leaves  

Microsoft Academic Search

A decrease in the pigment content of pear (Pyrus communis L.) leaves, thought to be related to Fe deficiency, occurs in northeastern Spain where is usually called “pear yellowness”;. A nutritional study has been carried out on a pear orchard affected by this physiological “disease”; and growing in the medium Jalón river valley. Total Fe contents were high both in

Anunciación Abadía; Manuel Sanz; Javier de las Rivas; Javier Abadía

1989-01-01

379

Ethical capital: 'what's a poor man got to leave?'.  

PubMed

For those of little or no means, leaving one's mark through financial assets, social connections, and human investment is difficult. Using secondary analysis of transcripts from face-to-face interviews with 33 terminally-ill patients from an outpatient clinic at a public hospital serving the disadvantaged in the southern United States, we examine the legacy participants wish to leave behind. As part of this process, participants assess life circumstances to try and generate a legacy allowing them to remain personally relevant to loved ones after death. For the low-SES terminally ill persons in this study, the desire to leave a material legacy and the means to do so are not congruous. In the absence of economic resources to bequeath loved ones, participants describe their desire to leave loved ones some form of ethical currency to facilitate interactions with others and protect them against social marginalisation. We call this concept ethical capital. We then argue ethical capital is a way for disadvantaged people to find dignity and to affirm their lives. PMID:20633241

Williams, Beverley; Woodby, Lesa; Drentea, Patricia

2010-09-01

380

Challenges in implementation of the maternity leave in Kosovo  

Microsoft Academic Search

This study aims to analyze the implementation of Labor Law in Kosovo, with a particular attention towards Article 49th which regulates the issue of maternity leave. Labor Law in Kosovo has been in force only for a year, and as such it has been a matter of discussion because of the challenges that have hampered its successful implementation. The study

Argjiro Ramosaj

2012-01-01

381

Maintenance Carbon Cycle in Crassulacean Acid Metabolism Plant Leaves 1  

PubMed Central

The reciprocal relationship between diurnal changes in organic acid and storage carbohydrate was examined in the leaves of three Crassulacean acid metabolism plants. It was found that depletion of leaf hexoses at night was sufficient to account quantitatively for increase in malate in Ananas comosus but not in Sedum telephium or Kalanchoë daigremontiana. Fructose and to a lesser extent glucose underwent the largest changes. Glucose levels in S. telephium leaves oscillated diurnally but were not reciprocally related to malate fluctuations. Analysis of isolated protoplasts and vacuoles from leaves of A. comosus and S. telephium revealed that vacuoles contain a large percentage (>50%) of the protoplast glucose, fructose and malate, citrate, isocitrate, ascorbate and succinate. Sucrose, a major constituent of intact leaves, was not detectable or was at extremely low levels in protoplasts and vacuoles from both plants. In isolated vacuoles from both A. comosus and S. telephium, hexose levels decreased at night at the same time malate increased. Only in A. comosus, however, could hexose metabolism account for a significant amount of the nocturnal increase in malate. We conclude that, in A. comosus, soluble sugars are part of the daily maintenance carbon cycle and that the vacuole plays a dynamic role in the diurnal carbon assimilation cycle of this Crassulacean acid metabolism plant.

Kenyon, William H.; Severson, Ray F.; Black, Clanton C.

1985-01-01

382

Control of Chlorophyll Production in Rapidly Greening Bean Leaves 1  

PubMed Central

The possible involvement of nucleic acid and protein synthesis in light-regulated chlorophyll formation by rapidly greening leaves has been studied. Removing leaves from illumination during the phase of rapid greening results in a reduction in the rate of pigment synthesis; cessation occurs within 2 to 4 hours. Etiolated leaves which exhibit a lag in pigment synthesis when first placed in the light do not show another lag after a 4 hour interruption of illumination during the phase of rapid greening. Actinomycin D, chloramphenicol, and puromycin inhibit chlorophyll synthesis when applied before or during the phase of rapid greening. Application of ?-amino-levulinic acid partially relieves the inhibition by chloramphenicol. It is suggested that light regulates chlorophyll synthesis by controlling the availability of ?-aminolevulinic acid, possibly by mediating the formation of an enzyme of ?-aminolevulinate synthesis. This process may result from gene activation or derepression; the involvement of RNA synthesis of some sort is suggested by the inhibitory effect of actinomycin D on chlorophyll production by rapidly greening leaves.

Gassman, Merrill; Bogorad, Lawrence

1967-01-01

383

Is Your Sick Leave Bank in Good Health?  

ERIC Educational Resources Information Center

Sick leave banks are a common staple of teacher contracts. Although these banks may benefit employees, they expose school districts to a variety of complications and unintended consequences, including administrative complexity, potential cash flow implications, cost disparities, increased absenteeism, instructional instability, privacy issues, and…

Hoover, James P.

2012-01-01

384

Expedition Five crew is ready to leave KSC for Houston  

NASA Technical Reports Server (NTRS)

KENNEDY SPACE CENTER, FLA. -- The Expedition Five crew are ready to leave KSC for Houston. From left are Science Officer Peggy Whitson, Commander Valery Korzun and Flight Engineer Sergei Treschev. The three returned to Earth on Endeavour Dec. 7, with the STS-113 crew, after six months on the International Space Station.

2002-01-01

385

Modeling photosynthesis in olive leaves under drought conditions.  

PubMed

We quantified parameters for a model of leaf-level photosynthesis for olive, and tested the model against an independent dataset. Specific temperature-dependence parameters of the model for olive leaves were measured, as well as the relationship of the model parameters with area-based leaf nitrogen (N) content. The effect of soil water deficit on leaf photosynthesis was examined by applying two irrigation treatments to 29-year-old trees growing in a plantation: drip irrigation sufficient to meet the crop water requirements (I) and dry-farming (D). In both treatments, leaves had a higher photosynthetic capacity in April than in August. In August, photosynthetic capacity was lower in D trees than in I trees. Leaf photosynthetic capacity was linearly and positively related to leaf N content on an area basis (N(a)) and to leaf mass per unit area (LMA), and the regression slope varied with irrigation treatment. The seasonal reduction in N(a) was used in the model to predict photosynthesis under drought conditions. Olive leaves showed a clear limitation of photosynthesis by triose phosphate utilization (TPU) even at 40 degrees C, and the data suggest that olive invests fewer resources in TPU than other species. The seasonal decrease in photosynthetic capacity moderated the stomatal limitation to carbon dioxide (CO(2)) fixation as soil water deficit increased. Further, it enabled leaves to operate close to the transition point between photosynthetic limitation due to RuBP carboxylation capacity and that due to RuBP regeneration capacity, and resulted in a near constant value of internal CO(2) concentration from April to August. Under well watered conditions, N-use efficiency of the olive leaves was enhanced at the expense of reduced water-use efficiency. PMID:16877329

Díaz-Espejo, A; Walcroft, A S; Fernández, J E; Hafridi, B; Palomo, M J; Girón, I F

2006-11-01

386

Radiative properties of hardwood leaves to ultraviolet irradiation  

NASA Astrophysics Data System (ADS)

Spectral reflectance and transmittance of leaves to ultraviolet irradiation were determined under laboratory conditions for seven species of hardwood trees, namely red oak ( Quercus rubra, L), black oak ( Q. velutina, Lamarch), white oak ( Q. alba, L.), sugar maple ( Acer saccharum), Norway maple ( A. plantanoides), hickory ( Carya tomemtosa), sweetgum ( Liquidambar styraciflua), and black oak litter. The experimental system consisted of a solar simulator, an integrating sphere, and a spectroradiometer. Experiments were repeated three to five times for both adaxial and abaxial surfaces of fresh leaves chosen at randomly. The spectral distributions and simple averages of the radiative properties in the wavelength ranges of ultraviolet-B (UV-B, 280 320 nm) and ultraviolet-A (UV-A, 320 400 nm) were determined. The spectral distributions of reflectance were similar between adaxial and abaxial surfaces, although the magnitude varied among tree species. Leaf reflectance was very low for the ultraviolet spectrum in general and varied among species and between adaxial and abaxial surfaces. It was generally higher over the UV-A waveband compared to UV-B, and higher on the abaxial than adaxial surface. The broadband reflectance in the UV-A range (over all species) was 5.0 and 3.9% for abaxial and adaxial surface, respectively, compared to 3.5 and 2.8% in UV-B. The transmittance through leaves was extremely small in the UV-B (<0.1%) and nearly zero in the UV-A spectral range. Consequently, the absorptance of ultraviolet radiation by leaves, as determined from the measured reflectance and transmittance, was quite high, being more than 90% for all the combinations of species and wavebands examined. The reported results are useful for studies requiring spectral radiative properties of the examined leaves with respect to ultraviolet irradiation.

Yang, Xiusheng; Heisler, Gordon M.; Montgomery, Michael E.; Sullivan, Joseph H.; Whereat, Edward B.; Miller, David R.

1995-06-01

387

Why Leaves Turn Red in Autumn. The Role of Anthocyanins in Senescing Leaves of Red-Osier Dogwood  

Microsoft Academic Search

Why the leaves of many woody species accumulate anthocyanins prior to being shed has long puzzled biologists because it is unclear what effects anthocyanins may have on leaf function. Here, we provide evidence for red-osier dogwood (Cornus stolonifera) that anthocyanins form a pigment layer in the palisade mesophyll layer that decreases light capture by chloroplasts. Measurements of leaf absorbance demonstrated

Taylor S. Feild; David W. Lee; N. Michele Holbrook

2001-01-01

388

Movement of water from old to young leaves in three species of succulents.  

PubMed

A hypothetical adaptive response of succulent plants to drought-stress is the redistribution of water from old to young leaves. We examined the effects of possible movement of water from old to young leaves in three succulent species, Carpobrotus edulis (weak CAM-inducible), Kalanchoe tubiflora (CAM) and Sedum spectabile (possibly a CAM-cycler or CAM-inducible). Old leaves were removed from plants, and photosynthesis, transpiration, f. wt : d. wt ratios, diurnal acid fluctuations, stomatal conductance and internal CO2 concentrations of the remaining young leaves were measured during drought-stress. Comparison was made with plants retaining old leaves. There was no evidence that water moved from old to young leaves during drought-stress as previously hypothesized. Only in drought-stressed plants of K. tubiflora, were photosynthetic and transpiration rates of young leaves greater on shoots with old leaves removed compared with attached. There was a trend in all species for greater fluctuations in acidity in young leaves on shoots that lacked older leaves. For two of the three species studied, the f. wt : d. wt ratios of young leaves were greater under drought-stress, on shoots with old leaves removed than with them attached. Absence of old leaves may reduce competition for water with young leaves, which consequently have higher water content and greater photosynthetic rates. PMID:12907468

Rabas, A R; Martin, C E

2003-10-01

389

Histone Deacetylases and ASYMMETRIC LEAVES2 Are Involved in the Establishment of Polarity in Leaves of Arabidopsis[W  

PubMed Central

We show that two Arabidopsis thaliana genes for histone deacetylases (HDACs), HDT1/HD2A and HDT2/HD2B, are required to establish leaf polarity in the presence of mutant ASYMMETRIC LEAVES2 (AS2) or AS1. Treatment of as1 or as2 plants with inhibitors of HDACs resulted in abaxialized filamentous leaves and aberrant distribution of microRNA165 and/or microRNA166 (miR165/166) in leaves. Knockdown mutations of these two HDACs by RNA interference resulted in phenotypes like those observed in the as2 background. Nuclear localization of overproduced AS2 resulted in decreased levels of mature miR165/166 in leaves. This abnormality was abolished by HDAC inhibitors, suggesting that HDACs are required for AS2 action. A loss-of-function mutation in HASTY, encoding a positive regulator of miRNA levels, and a gain-of-function mutation in PHABULOSA, encoding a determinant of adaxialization, suppressed the generation of abaxialized filamentous leaves by inhibition of HDACs in the as1 or as2 background. AS2 and AS1 were colocalized in subnuclear bodies adjacent to the nucleolus where HDT1/HD2A and HDT2/HD2B were also found. Our results suggest that these HDACs and both AS2 and AS1 act independently to control levels and/or patterns of miR165/166 distribution and the development of adaxial-abaxial leaf polarity and that there may be interactions between HDACs and AS2 (AS1) in the generation of those miRNAs.

Ueno, Yoshihisa; Ishikawa, Takaaki; Watanabe, Keiro; Terakura, Shinji; Iwakawa, Hidekazu; Okada, Kiyotaka; Machida, Chiyoko; Machida, Yasunori

2007-01-01

390

Using excised leaves to screen lucerne for salt tolerance  

PubMed Central

Salinity affects many physiological processes at all levels of plant structural organization. Being a physiologically and genetically complex trait, salinity tolerance implies a coordinated contribution of multiple mechanisms, making plant screening for salt tolerance extremely difficult. In this work, we show how the use of excised leaves can fulfill that task. We argue that, by adding NaCl directly to the transpiration stream, the protective effects of several mechanisms regulating Na+ delivery to the shoot are eliminated, enhancing PSII exposure to salinity treatment and resulting in a significant decline in leaf photochemistry (Fv/Fm characteristics). We suggest that measuring Fv/Fm characteristics on excised salt-treated leaves provides an opportunity to evaluate the efficiency of vacuolar Na+ compartmentation, arguably the most important feature for salt tolerance. We also explain the observed decline in Fv/Fm values as salt-induced structural damage to chloroplasts caused by oxidative stress.

Smethurst, Christiane F; Gill, Warwick M

2009-01-01

391

Underground leaves of Philcoxia trap and digest nematodes  

PubMed Central

The recently described genus Philcoxia comprises three species restricted to well lit and low-nutrient soils in the Brazilian Cerrado. The morphological and habitat similarities of Philcoxia to those of some carnivorous plants, along with recent observations of nematodes over its subterranean leaves, prompted the suggestion that the genus is carnivorous. Here we report compelling evidence of carnivory in Philcoxia of the Plantaginaceae, a family in which no carnivorous members are otherwise known. We also document both a unique capturing strategy for carnivorous plants and a case of a plant that traps and digests nematodes with underground adhesive leaves. Our findings illustrate how much can still be discovered about the origin, distribution, and frequency of the carnivorous syndrome in angiosperms and, more generally, about the diversity of nutrient-acquisition mechanisms that have evolved in plants growing in severely nutrient-impoverished environments such as the Brazilian Cerrado, one of the world's 34 biodiversity hotspots.

Pereira, Caio G.; Almenara, Daniela P.; Winter, Carlos E.; Fritsch, Peter W.; Lambers, Hans; Oliveira, Rafael S.

2012-01-01

392

Phenolic compounds analysis of root, stalk, and leaves of nettle.  

PubMed

Types of nettles (Urtica dioica) were collected from different regions to analyze phenolic compounds in this research. Nettles are specially grown in the coastal part. According to this kind of properties, nettle samples were collected from coastal part of (Mediterranean, Aegean, Black sea, and Marmara) Turkey. Phenolic profile, total phenol compounds, and antioxidant activities of nettle samples were analyzed. Nettles were separated to the part of root, stalk, and leaves. Then, these parts of nettle were analyzed to understand the difference of phenolic compounds and amount of them. Nettle (root, stalk and leaves) samples were analyzed by using High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) to qualitative and quantitative determination of the phenolic compounds. Total phenolic components were measured by using Folin-Ciocalteu method. The antioxidant activity was measured by using DPPH (2,2-diphenyl-1-picrylhydrazyl) which is generally used for herbal samples and based on single electron transfer (SET). PMID:22593694

Otles, Semih; Yalcin, Buket

2012-01-01

393

Bioactive molecules in Kalanchoe pinnata leaves: extraction, purification, and identification.  

PubMed

Kalanchoe pinnata (Lam.) Pers. (syn. Bryophyllum pinnatum; family Crassulaceae) is a popular plant used in traditional medicine in many temperate regions of the world and particularly in South America. In Guyana, the leaves are traditionally used as an anti-inflammatory and antiseptic to treat coughs, ulcers, and sores. The purpose of this study was to implement a method for targeting and identifying molecules with antimicrobial activity, which could replace chemical preservatives in cosmetic applications. The leaves were extracted by a method based on pressurized liquid extraction (PLE), using different solvents. A study of antimicrobial activity and cytotoxicity tests were performed to select the most interesting extract. To isolate one or more active molecules, the selected crude extract was fractionated by centrifugal partition chromatography (CPC) and then antimicrobial activity and cytotoxicity of each fraction were tested under the same procedure. The last step consisted of identifying the main compounds in the most active fraction by LC-MS/MS. PMID:20714893

El Abdellaoui, Saïda; Destandau, Emilie; Toribio, Alix; Elfakir, Claire; Lafosse, Michel; Renimel, Isabelle; André, Patrice; Cancellieri, Perrine; Landemarre, Ludovic

2010-10-01

394

A new diterpene from the leaves of Andrographis paniculata Nees.  

PubMed

Phytochemical investigation of the methanolic extract of the leaves of Andrographis paniculata Nees yielded a minor, new diterpene, 21-nor-3,19-isopropylidine-14-deoxy-ent-labda-8(17),13-dien-16,15-olide (1), together with five known labdane type diterpenes, andrographolide 3, 14-deoxyandrographolide 4, 14-deoxy-12-hydroxyandrographolide 5, 14-deoxy-11,12-dihydroandrographolide 6, neoandrographolide 7, and two acids, cinnamic acid 8, and ferulic acid 9. The chemical structures were established by spectroscopic analyses, including 1D- and 2D-NMR spectroscopic experiments, and on the basis of HR-ESI MS analyses. The methanolic extract of the leaves exhibited moderate antibacterial and antifungal activities at a dose of 200 microg/mL in comparison with the reference standards. PMID:22574448

Radhika, Parvataneni; Prasad, Yejella Rajendra; Sowjanya, Kattupalli

2012-04-01

395

Fractal Structures of Zinc Metal Leaves Grown by Electrodeposition  

Microsoft Academic Search

Zinc metal leaves are grown two-dimensionally by electrodeposition. The structures clearly remind us of the random patterns simulated by computer according to the Witten-Sander diffusion-limited-aggregation model. The scale invariance is tested by computing the density-density correlation function for the digitized patterns of the photographs. The Hausdorff dimension averaged over many examples is D=1.66+\\/-0.03, which is in excellent agreement with that

M. Matsushita; M. Sano; Y. Hayakawa; H. Honjo; Y. Sawada

1984-01-01

396

New phenolic compounds from Camellia sinensis L. fermented leaves.  

PubMed

Two new phenolic compounds (1 and 2, named as teasperol and teasperin, respectively) were isolated from fermented tea (Camellia sinensis L.) products, together with known phenolic compounds. Teasperol (1) was isolated from Chinese traditional post-fermented tea leaves (Liu-pao tea) and teasperin (2) was from a Japanese tea product which was selectively fermented with Aspergillus sp. The chemical structures of 1 and 2 were elucidated based on the analyses of their spectroscopic data. PMID:22972630

Kanegae, Ayaka; Sakamoto, Arisa; Nakayama, Hideyuki; Nakazono, Yoko; Yakashiro, Ichiro; Matsuo, Yosuke; Tanaka, Takashi; Ishimaru, Kanji

2013-07-01

397

Microwave drying characteristics of coriander ( Coriandrum sativum L.) leaves  

Microsoft Academic Search

Effect of microwave power output on effective moisture diffusivity, colour parameters and rehydration characteristics of coriander leaves (Coriandrum sativum L.) was investigated by using a microwave drier. Within the range of microwave power values, 180–360W, effective moisture diffusivities were found to be 6.3×10?11–2.19×10?10m2\\/s and the result could successfully be presented with the model suggested by Midilli et al. No significant

Ayse Sarimeseli

2011-01-01

398

IEQ and the impact on employee sick leave  

SciTech Connect

When selecting minimum ventilation rates, employers should balance the well-recognized energy costs of providing higher minimum ventilation rates with the expected, but less well quantified, health benefits from a higher ventilation rate. This is a summary of the paper by Milton, et al. that found low employee sick leave associated with high ventilation rates in a set of buildings located in Massachusetts. A simple cost-benefit analysis also is presented.

Kumar, Satish; Fisk, William J.

2002-08-01

399

Phenylpropanoid glycosides from the leaves of Paulownia coreana.  

PubMed

Study on the water soluble fraction from the leaves of Paulownia coreana led to the isolation of verbascoside (1), isoverbascoside (2), campneoside II (3), and a new phenylpropanoid glycoside, (R,S)-7-hydroxy-7-(3,4-dihydroxyphenyl)-ethyl-O-alpha-L-rhamnopyranosyl(1 --> 3)-beta-d-(6-O-caffeoyl)-glucopyranoside (4). The structures of these compounds were established on the basis of spectroscopic evidence. PMID:18266154

Kim, Jin-Kyu; Si, Chuan-Ling; Bae, Young-Soo

2008-02-15

400

Dried leaves — Novel reductant for acid leaching of manganese ore  

Microsoft Academic Search

In the present investigation results on the use of dried leaves as a reductant for manganese ore leaching is reported. A complete\\u000a flow-sheet consisting of steps such as reductive acid leaching, enrichment of leach solution by recycling, iron removal and\\u000a crystallization has been developed for the preparation of manganese sulphate monohydrate from manganese ore of Gujarat Mineral\\u000a Development Corporation (GMDC),

D. Hariprasad; M. K. Ghosh; S. Anand

2009-01-01

401

New triterpenoids from the leaves of Cyclocarya paliurus.  

PubMed

Six new triterpenoids including four new secodammarane triterpenoid glycosides (1-4), an epoxydammarane triterpenoid glycoside (5), and a new secodammarane triterpenoid (6) were isolated from the ethanolic extract of the leaves of Cyclocarya paliurus. The structures of these compounds were elucidated by spectroscopic analysis methods. Compounds 1-6 were evaluated for their inhibitory activities against ?-glucosidase, lipase, DPP-IV, and aldose reductase. PMID:22161740

Li, Shuai; Cui, Baosong; Liu, Quan; Tang, Li; Yang, Yongchun; Jin, Xiangju; Shen, Zhufang

2012-02-01

402

Triterpenes and triterpenoid saponins from the leaves of Ilex kudincha.  

PubMed

One new triterpene, kudinchalactone A (1), and four new triterpenoid saponins, ilekudinchosides A-D (2- 5), were isolated from the leaves of Ilex kudincha C.?J. Tseng along with eight known triterpenoids. These new compounds were elucidated by spectroscopic methods including 1D and 2D NMR, HR-TOF-MS, and CD spectra. Compounds 2, 3, 12, and 13 showed antibacterial activities against Staphylococcus aureus (SA) and methicillin-resistant Staphylococcus aureus (MRSA). PMID:21870320

Zuo, Wen-Jian; Dai, Hao-Fu; Chen, Jing; Chen, Hui-Qin; Zhao, You-Xing; Mei, Wen-Li; Li, Xian; Wang, Jin-Hui

2011-11-01

403

Cadinane sesquiterpenes from the leaves of Eupatorium adenophorum.  

PubMed

Four new cadinane sesquiterpenes (1- 4), including a dimeric cadinane derivative (2) and a peroxide cadinane analogue (3), have been isolated from the leaves of Eupatorium adenophorum. Their structures including absolute configurations were determined on the basis of spectroscopic data interpretation and single-crystal X-ray crystallography. Compound 4 showed in vitro cytotoxicity against the HCT-8, Bel-7402, and A2780 cancer cell lines. PMID:18620454

He, Lan; Hou, Jing; Gan, Maoluo; Shi, Jiangong; Chantrapromma, Suchada; Fun, Hoong-Kun; Williams, Ian D; Sung, Herman H-Y

2008-08-01

404

In vitro Evaluation of Anthelmintic Activity of Nauclea orientalis Leaves  

PubMed Central

Antianthelmintic activity of successive extracts (chloroform, acetone, ethanol and aqueous) of Nauclea orientalis leaves were evaluated separately on adult Indian earthworm (Pheretima posthuma) and compared with that of albendazole. It was found that the extracts exhibited, respectively dose-dependent action and inhibition of spontaneous motility (paralysis) and death of earthworms. The results indicated that the chloroform, ethyl acetate and ethanol extracts were more potent.

Raghavamma, S. T. V.; Rao, N. Rama

2010-01-01

405

Membrane concentration of antioxidants from Castanea sativa leaves aqueous extracts  

Microsoft Academic Search

Aqueous extraction of Castanea sativa leaves (CsL) was scaled up and the extract was processed in a series of two UF membranes (5 and 10kDa) with the aim of concentrating the active phenolic compounds with antioxidant activity. Due to the occurrence of adsorptive fouling of the phenolic compounds found in one membrane's configuration assayed (Configuration I), batch dilution of the

Beatriz Díaz-Reinoso; Andrés Moure; Herminia Domínguez; Juan Carlos Parajó

2011-01-01

406

Transcriptome Analysis of Cytokinin Response in Tomato Leaves  

PubMed Central

Tomato is one of the most economically and agriculturally important Solanaceous species and vegetable crops, serving as a model for examination of fruit biology and compound leaf development. Cytokinin is a plant hormone linked to the control of leaf development and is known to regulate a wide range of genes including many transcription factors. Currently there is little known of the leaf transcriptome in tomato and how it might be regulated by cytokinin. We employ high throughput mRNA sequencing technology and bioinformatic methodologies to robustly analyze cytokinin regulated tomato leaf transcriptomes. Leaf samples of two ages, 13d and 35d were treated with cytokinin or the solvent vehicle control dimethyl sulfoxide (DMSO) for 2 h or 24 h, after which RNA was extracted for sequencing. To confirm the accuracy of RNA sequencing results, we performed qPCR analysis of select transcripts identified as cytokinin regulated by the RNA sequencing approach. The resulting data provide the first hormone transcriptome analysis of leaves in tomato. Specifically we identified several previously untested tomato orthologs of cytokinin-related genes as well as numerous novel cytokinin-regulated transcripts in tomato leaves. Principal component analysis of the data indicates that length of cytokinin treatment and plant age are the major factors responsible for changes in transcripts observed in this study. Two hour cytokinin treatment showed a more robust transcript response indicated by both greater fold change of induced transcripts and the induction of twice as many cytokinin-related genes involved in signaling, metabolism, and transport in young vs. older leaves. This difference in transcriptome response in younger vs. older leaves was also found to a lesser extent with an extended (24 h) cytokinin treatment. Overall data presented here provides a solid foundation for future study of cytokinin and cytokinin regulated genes involved in compound leaf development or other developmental processes in tomato.

Shi, Xiuling; Gupta, Sarika; Lindquist, Ingrid E.; Cameron, Connor T.; Mudge, Joann; Rashotte, Aaron M.

2013-01-01

407

Two new tirucallane triterpenoids from the leaves of Aquilaria sinensis.  

PubMed

Two new tirucallane triterpenoids, aquilacallanes A-B (1-2), together with 15 known compounds (3-17) were isolated from the leaves of Aquilaria sinensis. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analyses. All compounds were evaluated for their cytotoxic activity against five human cancer cell lines. The known compounds, ursolic acid (7) and 5,7,4'-trimethoxyflavone (14), exhibited weak cytotoxic activity against some cells. PMID:23508744

Cheng, Jin Tang; Han, Ya Qiong; He, Juan; De Wu, Xing; Dong, Liao Bin; Peng, Li Yan; Li, Yan; Zhao, Qin Shi

2013-09-01

408

[Constituents of the leaves of Daphne pseudo-mezereum].  

PubMed

Three new phenolic compounds were isolated from methanol extracts of the leaves of Daphne pseudo-mezereum (Thymelaeaceae) and characterized as (-)-pinoresinol di-O-glucoside (1), 5-hydroxy-7-methoxy coumarin 8-O-beta-D-glucoside (2), diosmetin 7-O-beta-D-xylopyranosyl (1-->6) beta-D-glucopyranoside (3), respectively, together with six known compounds, using 1H- and 13C-NMR spectra. PMID:8229666

Konishi, T; Wada, S; Kiyosawa, S

1993-09-01

409

Extraction of nettle leaves using synthetic esters of fatty acids  

Microsoft Academic Search

The extractive power of synthetic esters of higher fatty acids, widely used as emollients in cosmetics, has been studied.\\u000a Three popular emollients — isopropyl myristate (IPM), capryl-caprinic triglycerides (CCT) and soybean oil (SO) — were used\\u000a to isolate biologically active substances from nettle leaves (Folia urtica). The qualitative compositions of lipophilic biologically active compounds in all extracts have proved to

A. V. Belyakova; V. A. Vainshtein; K. V. Markova; Yu. T. Demchenko; T. H. Chibilyaev

2005-01-01

410

Auxin Control of Protein-Levels in Detached Autumn Leaves  

Microsoft Academic Search

IT is well established that when mature leaves are detached from the plant the protein-level in the blade falls1. It has also been demonstrated by both Vickery, Pucher, Wakeman and Leavenworth2 and Mothes and Engelbrecht3 that an external supply of carbohydrate or of nitrogenous substances such as nitrates, ammonium salts or urea, will only slow down the rate of the

Daphne J. Osborne

1960-01-01

411

Variegation in Arum italicum leaves. A structural-functional study.  

PubMed

The presence of pale-green flecks on leaves (speckling) is a frequent character among herbaceous species from shady places and is usually due to local loosening of palisade tissue (air space type of variegation). In the winter-green Arum italicum L. (Araceae), dark-green areas of variegated leaf blades are ca. 400 ?m thick with a chlorophyll content of 1080 mg m?² and a palisade parenchyma consisting of a double layer of oblong cells. Pale-green areas are 25% thinner, have 26% less chlorophyll and contain a single, loose layer of short palisade cells. Full-green leaves generally present only one compact layer of cylindrical palisade cells and the same pigment content as dark-green sectors, but the leaf blade is 13% thinner. A spongy parenchyma with extensive air space is present in all leaf types. Green cells of all tissues have normal chloroplasts. Assays of photosynthetic activities by chlorophyll fluorescence imaging and O? exchange measurements showed that variegated pale-green and dark-green sectors as well as full-green leaves have comparable photosynthetic activities on a leaf area basis at saturating illumination. However, full-green leaves require a higher saturating light with respect to variegated sectors, and pale-green sectors support relatively higher photosynthesis rates on a chlorophyll basis. We conclude that i) variegation in this species depends on number and organization of palisade cell layers and can be defined as a "variable palisade" type, and ii) the variegated habit has no limiting effects on the photosynthetic energy budget of A. italicum, consistent with the presence of variegated plants side by side to full-green ones in natural populations. PMID:22078376

La Rocca, Nicoletta; Rascio, Nicoletta; Pupillo, Paolo

2011-12-01

412

Bioactive limonoids from the leaves of Azaridachta indica (Neem).  

PubMed

Eight new limonoids (1-8) and one new phenol glycoside (9), along with six known compounds, were isolated from the leaves of Azaridachta indica. The structures of 1-9 were elucidated on the basis of spectroscopic data analysis. Compounds isolated were assayed for their cytotoxicity against different cancer cell lines. Moreover, their ability to interact with the molecular chaperone Hsp90, affecting its biological activity, was tested. PMID:24499352

Gualtieri, Maria J; Malafronte, Nicola; Vassallo, Antonio; Braca, Alessandra; Cotugno, Roberta; Vasaturo, Michele; De Tommasi, Nunziatina; Dal Piaz, Fabrizio

2014-03-28

413

Quantitative determination of phenolic compounds in Mentha piperita leaves  

Microsoft Academic Search

A spectrophotometric method using a dual-wavelength Firordt method that enabled simultaneous determination of the flavonoid\\u000a and phenolic-acid contents was developed for quantitative analysis of phenolic compounds in Mentha piperita L. (Lamiaceae) leaves. Hesperidin and rosmaric acid were used as standards. The optimal extraction parameters of the phenolic\\u000a compounds were determined. Metrological analysis of the developed method was performed. It was

D. N. Olennikov; L. M. Tankhaeva

2010-01-01

414

Antioxidant and Antifungal Activity of Verbena officinalis L. Leaves  

Microsoft Academic Search

The scavenging activity against DPPH (1,1-diphenil-2-picrylhydrazyl) radical and the antifungal effect against chloroform,\\u000a ethyl acetate and 50% methanolic extracts of Verbena officinalis leaves were investigated. The activity of different fractions of 50% methanolic extract and some isolated compounds were\\u000a also investigated. The results suggest that 50% methanolic extract and caffeoyl derivatives could potentially be considered\\u000a as excellent and readily available

E. Casanova; J. M. García-Mina; M. I. Calvo

2008-01-01

415

Characterization of a cadmium-binding complex of cabbage leaves  

Microsoft Academic Search

The chemical nature of a principle, inducible cadmium-binding complex which accumulates in cabbage leaves was studied and compared with that of animal metallothionein and copper-binding proteins isolated from various organisms. The apparent molecular weight of native cabbage complex and carboxymethylated ligand of the complex under native conditions as determined by gel filtration was about 10,000 daltons. Under denaturing conditions their

G. J. Wagner

1984-01-01

416

Systemic signalling of environmental cues in Arabidopsis leaves  

Microsoft Academic Search

Light intensity and atmospheric CO2 partial pressure are two environmental signals known to regulate stomatal numbers. It has previously been shown that if a mature Arabidopsis leaf is supplied with either elevated CO2 (750 ppm instead of ambient at 370 ppm) or reduced light levels (50 lmol m22 s21 instead of 250 lmol m22 s21), the young, developing leaves that

S. A. Coupe; B. G. Palmer; J. A. Lake; S. A. Overy; K. Oxborough; F. I. Woodward; J. E. Gray; W. P. Quick

2010-01-01

417

Diuretic activity of the leaves of Coleus aromaticus Benth.  

PubMed

The aqueous and ethanolic extract of leaves of Coleus aromaticus was evaluated for diuretic activity. Both extracts were evaluated by determination of urine volume and electrolyte concentration in albino rats. Results revealed that both the aqueous and ethanolic extract at dose 500mgl kg showed significant diuretic activity by increasing the total volume of urine and concentration electrolyte. Furosamide (10 mg/kg) was used as reference drug while normal saline (0.9%) solution was used as control. PMID:22557339

Choudhary, G P

2009-07-01

418

Diuretic activity of the leaves of Coleus aromaticus Benth  

PubMed Central

The aqueous and ethanolic extract of leaves of Coleus aromaticus was evaluated for diuretic activity. Both extracts were evaluated by determination of urine volume and electrolyte concentration in albino rats. Results revealed that both the aqueous and ethanolic extract at dose 500mgl kg showed significant diuretic activity by increasing the total volume of urine and concentration electrolyte. Furosamide (10 mg/kg) was used as reference drug while normal saline (0.9%) solution was used as control.

Choudhary, G.P.

2009-01-01

419

Characterization of the epidermis from barley primary leaves  

Microsoft Academic Search

The cation and anion distribution between the epidermis and mesophyll of primary leaves of 10-d-old barley (Hordeum vulgare L.) seedlings was studied in relation to growth conditions. A new method was employed to isolate epidermal protoplasts. The following observations were made: (i) Under standard hydroponic growth conditions, K+ was the dominant cation and NO33-the predominant anion, both in epidermal and

K. J. Dietz; M. Schramm; B. Lang; A. Lanzl-Schramm; C. Dürr; E. Martinoia

1992-01-01

420

Acetogenins in Annona muricata L. (annonaceae) leaves are potent molluscicides.  

PubMed

An ethanolic extract of the leaves of Annona muricata was shown to be toxic to adult forms of the snail Biomphalaria glabrata (LC50 9.32 microg mL(-1)) and to larvae of the brine shrimp Artemia salina (LC50 0.49 microg mL(-1)). Activity-guided fractionation of the extract gave rise to a sample with high molluscicidal activity that contained the acetogenins, annonacin (90%), isoannonacin (6%) and goniothalamicin (4%). PMID:16401556

Luna, J De S; De Carvalho, J M; De Lima, M R F; Bieber, L W; Bento, Edson De S; Franck, X; Sant'ana, A E G

2006-03-01

421

Two new triterpenoid isomers from Nerium oleander leaves  

Microsoft Academic Search

Two new triterpenoid isomers ?-neriursate (1) and ?-neriursate (2) have been isolated from the fresh, uncrushed leaves of Nerium oleander and their structures elucidated as 3?-acetophenoxy-urs-12-en-28-oic acid and 3?-acetophenoxy-urs-12-en-28-oic acid, respectively. The structure elucidation is based on spectroscopic methods, including 1D (H NMR, C NMR) and 2D (H-H COSY, NOESY, HMQC, HMBC and J-resolved) NMR data and chemical transformation.

Bina S. Siddiqui; Nasima Khatoon; Sabira Begum; Saima A. Durrani

2009-01-01

422

An Assessment of Wound Healing Potential of Argyreia speciosa Leaves  

PubMed Central

In North India, poultice of young unfolded leaves of Argyreia speciosa Linn. (Convolvulaceae) is used for healing wounds. In order to find scientific evidence for the traditional utilization of leaves of A. speciosa in wound healing, this investigation was carried out. A linear incision wound of about 3?cm in length and 2?mm in depth and circular excision wound of 177?mm2 full thickness were made on the dorsal region of separate groups (n = 5) of anesthetized Swiss albino mice. A simple ointment, developed by including ethanol, ethanol-water, and water extracts (10% each, separately) of A. speciosa, was applied topically to mice once daily for 14 days after wounding. To evaluate the effect of each extract, wound contraction, epithelization period, wound breaking strength, and hydroxyproline content were determined. The water extract of A. speciosa showed accelerated wound healing activity as evidenced by fast wound contraction (96.30 ± 0.52%; P < 0.01), rapid epithelization period (11.40 ± 0.60 days; P < 0.001), greater wound breaking strength (376.56 ± 21.16?g; P < 0.001), and higher hydroxyproline content (16.49 ± 1.12?mg/g; P < 0.05) of granulation tissue. The present report supports the traditional use of Argyreia speciosa leaves for wound healing and signify its relevant therapeutic potential.

Yadav, Narayan Prasad; Rawat, Bindu; Rai, Vineet Kumar; Shanker, Karuna; Venkateswara Rao, Chandana

2014-01-01

423

Phloem Unloading in Developing Leaves of Sugar Beet 1  

PubMed Central

Phloem unloading in developing leaves of Beta vulgaris L. (`Klein E' multigerm) occurred from successively higher order branches of veins as leaves matured. Phloem unloading was studied in autoradiographs of leaf samples taken at various times during the arrival of a pulse of 14C-labeled photoassimilate. Extension of mass flow of sieve element contents into leaf vein branches was determined from the high level of radiolabel in veins soon after first arrival of the pulse. Rapid entry, indicative of mass flow through open sieve pores, occurred down to the fourth division of veins in young, importing leaves and to the fifth or terminal branch in importing regions near the zone of transition from sink to source. The rate of unloading decreased with leaf age, as evidenced by the increased time required for the vein-mesophyll demarcation to become obscured. The rate of import per unit leaf area, measured by steady state labeling with 14CO2 also decreased as a leaf matured. The decline in import appeared to result from progressive changes that increased resistance to unloading of sieve elements and eventually terminated phloem unloading. Images Fig. 1 Fig. 2

Schmalstig, J. Gougler; Geiger, Donald R.

1987-01-01

424

Chloroplast DNA in mature and senescing leaves: a reappraisal.  

PubMed

The fate of plastid DNA (ptDNA) during leaf development has become a matter of contention. Reports on little change in ptDNA copy number per cell contrast with claims of complete or nearly complete DNA loss already in mature leaves. We employed high-resolution fluorescence microscopy, transmission electron microscopy, semithin sectioning of leaf tissue, and real-time quantitative PCR to study structural and quantitative aspects of ptDNA during leaf development in four higher plant species (Arabidopsis thaliana, sugar beet [Beta vulgaris], tobacco [Nicotiana tabacum], and maize [Zea mays]) for which controversial findings have been reported. Our data demonstrate the retention of substantial amounts of ptDNA in mesophyll cells until leaf necrosis. In ageing and senescent leaves of Arabidopsis, tobacco, and maize, ptDNA amounts remain largely unchanged and nucleoids visible, in spite of marked structural changes during chloroplast-to-gerontoplast transition. This excludes the possibility that ptDNA degradation triggers senescence. In senescent sugar beet leaves, reduction of ptDNA per cell to ?30% was observed reflecting primarily a decrease in plastid number per cell rather than a decline in DNA per organelle, as reported previously. Our findings are at variance with reports claiming loss of ptDNA at or after leaf maturation. PMID:24668747

Golczyk, Hieronim; Greiner, Stephan; Wanner, Gerhard; Weihe, Andreas; Bock, Ralph; Börner, Thomas; Herrmann, Reinhold G

2014-03-01

425

Inhibition of rat platelet aggregation by Urtica dioica leaves extracts.  

PubMed

Platelet hyperactivity plays an important role in arterial thrombosis and atherosclerosis. The present study was undertaken to investigate the effects of different extracts of Urtica dioica leaves on platelet aggregation. Rat platelets were prepared and incubated in vitro with different concentrations of the tested extracts and aggregation was induced by different agonists including thrombin (0.5 U/mL), ADP (10 microm), epinephrine (100 microm) and collagen (5 mg/mL). The crude aqueous extract inhibited thrombin-induced platelet aggregation in a dose-dependent manner. At 1 mg/mL, the percent inhibition was 17.1 +/- 4.2%. Soxhlet extraction of the plant leaves with different successive solvents showed that the ethyl acetate extract exhibited the most antiaggregant effect with an inhibition of 76.8 +/- 6.1% at 1 mg/mL. Flavonoids isolated from the plant leaves, produced a strong inhibitory effect on thrombin-induced platelet aggregation with an IC(50) of 0.25 +/- 0.05 and 0.40 +/- 0.04 mg/mL for genins and heterosidic flavonoids, respectively. Flavonoids also markedly inhibited platelet aggregation induced by ADP, collagen and epinephrine. It is concluded that Urtica dioica has an antiplatelet action in which flavonoids are mainly implicated. These results support the traditional use of Urtica dioica in the treatment and/or prevention of cardiovascular disease. PMID:16619332

El Haouari, Mohammed; Bnouham, Mohamed; Bendahou, Mourad; Aziz, Mohammed; Ziyyat, Abderrahim; Legssyer, Abdelkhaleq; Mekhfi, Hassane

2006-07-01

426

Antifreeze Proteins in Winter Rye Leaves Form Oligomeric Complexes1  

PubMed Central

Antifreeze proteins (AFPs) similar to three pathogenesis-related proteins, a glucanase-like protein (GLP), a chitinase-like protein (CLP), and a thaumatin-like protein (TLP), accumulate during cold acclimation in winter rye (Secale cereale) leaves, where they are thought to modify the growth of intercellular ice during freezing. The objective of this study was to characterize the rye AFPs in their native forms, and our results show that these proteins form oligomeric complexes in vivo. Nine proteins were separated by native-polyacrylamide gel electrophoresis from apoplastic extracts of cold-acclimated winter rye leaves. Seven of these proteins exhibited multiple polypeptides when denatured and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After isolation of the individual proteins, six were shown by immunoblotting to contain various combinations of GLP, CLP, and TLP in addition to other unidentified proteins. Antisera produced against individual cold-induced winter rye GLP, CLP, and TLP all dramatically inhibited glucanase activity in apoplastic extracts from cold-acclimated winter rye leaves, and each antiserum precipitated all three proteins. These results indicate that each of the polypeptides may be exposed on the surface of the protein complexes. By forming oligomeric complexes, AFPs may form larger surfaces to interact with ice, or they may simply increase the mass of the protein bound to ice. In either case, the complexes of AFPs may inhibit ice growth and recrystallization more effectively than the individual polypeptides.

Yu, Xiao-Ming; Griffith, Marilyn

1999-01-01

427

Characteristics of opiate users leaving detoxification treatment against medical advice.  

PubMed

Substance-dependent patients leaving against medical advice (AMA) pose a unique challenge to detoxification programs. Most notably, AMA patients fail to access residential or outpatient treatment needed after detoxification and often return to detoxification treatment multiple times which has deleterious results for the patient and is taxing to the healthcare system. Using retrospective data from 89 daily opiate-using detoxification patients completing detoxification and 95 patients leaving AMA, we sought to identify patient characteristics useful in predicting AMA discharges from detoxification. Bivariate analyses indicated that AMA patients reported drug use did not impair their health, were injection drug users, younger and had fewer previous treatment admissions. Binomial logistic regression indicated that AMA patients were more likely to be unemployed and report that drug use did not impair their health. Patients completing detoxification were less likely to be injection drug users and less likely to be self-referred to treatment. Identifying patients at risk of leaving AMA provides an opportunity for clinicians to intervene in an effort to increase treatment engagement for these patients. PMID:20635287

Kenne, Deric R; Boros, Alec P; Fischbein, Rebecca L

2010-07-01

428

Evolution of asexual reproduction in leaves of the genus Kalanchoë.  

PubMed

Plant somatic cells have the remarkable ability to regenerate an entire organism. Many species in the genus Kalanchoë, known as "mother of thousands," develop plantlets on the leaf margins. Using key regulators of organogenesis (STM) and embryogenesis (LEC1 and FUS3) processes, we analyzed asexual reproduction in Kalanchoë leaves. Suppression of STM abolished the ability to make plantlets. Here, we report that constitutive plantlet-forming species, like Kalanchoë daigremontiana, form plantlets by coopting both organogenesis and embryogenesis programs into leaves. These species have a defective LEC1 gene and produce nonviable seed, whereas species that produce plantlets only upon stress induction have an intact LEC1 gene and produce viable seed. The latter species are basal in the genus, suggesting that induced-plantlet formation and seed viability are ancestral traits. We provide evidence that asexual reproduction likely initiated as a process of organogenesis and then recruited an embryogenesis program into the leaves in response to loss of sexual reproduction within this genus. PMID:17893341

Garcês, Helena M P; Champagne, Connie E M; Townsley, Brad T; Park, Soomin; Malhó, Rui; Pedroso, Maria C; Harada, John J; Sinha, Neelima R

2007-09-25

429

Chlorophyll breakdown and chlorophyll catabolites in leaves and fruit†  

PubMed Central

Chlorophyll metabolism probably is the most visible manifestation of life. Total annual turnover of chlorophyll has been estimated to involve more than 1000 million tons. Surprisingly, chlorophyll catabolism has remained an enigma until less than twenty years ago, when a colorless chlorophyll catabolite from senescent plant leaves was identified and its structure was elucidated. In the meantime, chlorophyll breakdown products have been identified in a variety of plant leaves and their structural features have been elucidated. Most recently, chlorophyll breakdown products have also been identified in some ripening fruit. Chlorophyll breakdown in vascular plants only fleetingly involves enzyme-bound colored intermediates. The stage of fluorescent catabolites is also passed rapidly, as these isomerize further to colorless nonfluorescent tetrapyrrolic catabolites. The latter accumulate in the vacuoles of de-greened leaves and are considered the final products of controlled chlorophyll breakdown. The same tetrapyrroles are also found in ripening fruit and are effective antioxidants. Chlorophyll breakdown leads to tetrapyrroles that appear to have physiologically beneficial chemical properties, and it may thus not merely be a detoxification process.

Krautler, Bernhard

2010-01-01

430

Photosynthetic energy storage in aquatic leaves measured by photothermal deflection.  

PubMed

In a study of photosynthetic energy storage efficiency (ES), the adaxial surface of the leaves of Vallisneria americana exhibited the highest ES values (22%) of the four aquatic plants examined. V. americana leaves have a dispersed structure and it was possible to measure the energy storage properties of the epidermal cells independently of the rest of the leaf. The abaxial epidermis had a higher value of ES at zero light fluence than the adaxial epidermis but ES in the abaxial epidermis declined much more rapidly with light fluence. Thus the abaxial epidermis is more suited to lower light fluences than the adaxial epidermis. ES declined as the pH rose from 4.0 to 8.0 at a constant dissolved inorganic carbon concentration. This paralleled the change from carbon dioxide to bicarbonate and suggests that these leaves utilise CO2 more efficiently than bicarbonate. ES increased by about 50% at pH 8.0 as leaf sections further from the leaf tip were examined which demonstrates that the older epidermal cells are less well able to use bicarbonate. Exposure to 30 min of a saturating light fluence caused the epidermal chloroplasts to move from the periclinal walls to the anticlinal walls. This decreased the photothermal signal by increasing the thermal diffusion distance and lowering the light fluence due to greater chloroplast shading. The latter effect increased ES. It appears that chloroplast movement could assist the epidermis to survive harmful light fluences. PMID:24301482

Sinclair, J; Hall, C E

1995-08-01

431

Cellular proton dynamics in Elodea canadensis leaves induced by cadmium.  

PubMed

Our earlier investigations showed that Elodea canadensis shoots, grown in the presence of cadmium (Cd), caused basification of the surrounding medium. The present study was aimed to examine the proton dynamics of the apoplastic, cytosolic and vacuolar regions of E. canadensis leaves upon Cd exposure and to establish possible linkage between cellular pH changes and the medium basification. The changes in cytosolic calcium [Ca(2+)]cyt was also investigated as the [Ca(2+)]cyt and [pH]cyt homeostasis are closely linked. The cellular H(+) and Ca(2+) concentrations were monitored by fluorescence microscopy and ion-specific fluorescent dyes. Cadmium concentration of leaf-cell walls was measured after plant cultivation at different fixed levels of starting pH. The protoplasts from E. canadensis leaves were isolated by use of a newly developed enzymatic method. Upon Cd addition, both cytosolic and vacuolar pH of leaf protoplasts increased with a concomitant rise in the cytosolic Ca(2+) concentration. Time course studies revealed that changes in [Ca(2+)]cyt and [pH]cyt followed similar dynamics. Cadmium (0.5 ?M) exposure decreased the apoplastic pH by 0.85 units. The maximum cell wall bound Cd-contents were obtained in plants grown at low starting pH. It is concluded that Cd treatment causes apoplastic acidosis in E. canadensis leaves associated with enhanced Cd binding to the cell walls and, consequently, reduced Cd influx into the cytosol. PMID:24525352

Tariq Javed, M; Lindberg, Sylvia; Greger, Maria

2014-04-01

432

Regulation of Monoterpene Accumulation in Leaves of Peppermint1  

PubMed Central

Plants synthesize numerous classes of natural products that accumulate during development and are thought to function as constitutive defenses against herbivores and pathogens. However, little information is available about how the levels of such defenses are regulated. We measured the accumulation of monoterpenes, a model group of constitutive defenses, in peppermint (Mentha × piperita L.) leaves and investigated several physiological processes that could regulate their accumulation: the rate of biosynthesis, the rate of metabolic loss, and the rate of volatilization. Monoterpene accumulation was found to be restricted to leaves of 12 to 20 d of age, the period of maximal leaf expansion. The rate of monoterpene biosynthesis determined by 14CO2 incorporation was closely correlated with monoterpene accumulation, as determined by gas chromatographic analysis, and appeared to be the principal factor controlling the monoterpene level of peppermint leaves. No significant catabolic losses of monoterpenes were detected throughout leaf development, and monoterpene volatilization was found to occur at a very low rate, which, on a monthly basis, represented less than 1% of the total pool of stored monoterpenes. The composition of volatilized monoterpenes differed significantly from that of the total plant monoterpene pool, suggesting that these volatilized products may arise from a separate secretory system. With the demonstration that the rate of biosynthesis is the chief process that determines monoterpene accumulation in peppermint, efforts to improve production in this species can now focus on the genes, enzymes, and cell differentiation processes that regulate monoterpene biosynthesis.

Gershenzon, Jonathan; McConkey, Marie E.; Croteau, Rodney B.

2000-01-01

433

Revising Himself : Walt Whitman and Leaves of Grass  

NSDL National Science Digital Library

An impressive feat of literary collation, the Library of Congress presents this exhibition on Walt Whitman, probably America's first superstar author, and Whitman's book of poetry, _Leaves of Grass_. Initially published in 1855, _Leaves of Grass_ contained 12 poems. Whitman continuously revised it until his death in 1892, when it contained 400 poems. The poet added new poems, renamed older ones, reworded lines, changed punctuation, and regrouped poems (through the 1881 edition), as well as inventing typography, and posing for frontispiece portraits wearing various styles of clothing and props. (front and back views of a cardboard butterfly that Whitman posed with in 1877 are included in the show). The exhibition traces this evolution of _Leaves of Grass_ and Whitman's life, as a poet and a person, from the first appearance of the lines "I am the poet of the body, And I am the poet of the soul" in a notebook dating 1847-1950s, to the final "Deathbed edition" of 1891-1892. A wealth of interesting biographical material on Whitman, his friends and associates, his work as a teacher, tending the wounded during the Civil War, and for the federal government, also appears in the exhibit.

434

An assessment of wound healing potential of Argyreia speciosa leaves.  

PubMed

In North India, poultice of young unfolded leaves of Argyreia speciosa Linn. (Convolvulaceae) is used for healing wounds. In order to find scientific evidence for the traditional utilization of leaves of A. speciosa in wound healing, this investigation was carried out. A linear incision wound of about 3 cm in length and 2 mm in depth and circular excision wound of 177 mm(2) full thickness were made on the dorsal region of separate groups (n = 5) of anesthetized Swiss albino mice. A simple ointment, developed by including ethanol, ethanol-water, and water extracts (10% each, separately) of A. speciosa, was applied topically to mice once daily for 14 days after wounding. To evaluate the effect of each extract, wound contraction, epithelization period, wound breaking strength, and hydroxyproline content were determined. The water extract of A. speciosa showed accelerated wound healing activity as evidenced by fast wound contraction (96.30 ± 0.52%; P < 0.01), rapid epithelization period (11.40 ± 0.60 days; P < 0.001), greater wound breaking strength (376.56 ± 21.16 g; P < 0.001), and higher hydroxyproline content (16.49 ± 1.12 mg/g; P < 0.05) of granulation tissue. The present report supports the traditional use of Argyreia speciosa leaves for wound healing and signify its relevant therapeutic potential. PMID:24688387

Yadav, Kuldeep Singh; Yadav, Narayan Prasad; Rawat, Bindu; Rai, Vineet Kumar; Shanker, Karuna; Venkateswara Rao, Chandana

2014-01-01

435

Are environmental characteristics in the municipal eldercare, more closely associated with frequent short sick leave spells among employees than with total sick leave: a cross-sectional study  

PubMed Central

Background It has been suggested that frequent-, short-term sick leave is associated with work environment factors, whereas long-term sick leave is associated mainly with health factors. However, studies of the hypothesis of an association between a poor working environment and frequent short spells of sick leave are few and results are inconsistent. Therefore, we aimed to explore associations between self-reported psychosocial work factors and workplace-registered frequency and length of sick leave in the eldercare sector. Methods Employees from the municipal eldercare in Aarhus (N?=?2,534) were included. In 2005, they responded to a work environment questionnaire. Sick leave records from 2005 were dichotomised into total sick leave days (0–14 and above 14 days) and into spell patterns (0–2 short, 3–9 short, and mixed spells and 1–3 long spells). Logistic regression models were used to analyse associations; adjusted for age, gender, occupation, and number of spells or sick leave length. Results The response rate was 76%; 96% of the respondents were women. Unfavourable mean scores in work pace, demands for hiding emotions, poor quality of leadership and bullying were best indicated by more than 14 sick leave days compared with 0–14 sick leave days. For work pace, the best indicator was a long-term sick leave pattern compared with a non-frequent short-term pattern. A frequent short-term sick leave pattern was a better indicator of emotional demands (1.62; 95% CI: 1.1-2.5) and role conflict (1.50; 95% CI: 1.2-1.9) than a short-term non-frequent pattern. Age (=?40 years) statistically significantly modified the association between the 1–3 long-term sick leave spell pattern and commitment to the workplace compared with the 3–9 frequent short-term pattern. Conclusions Total sick leave length and a long-term sick leave spell pattern were just as good or even better indicators of unfavourable work factor scores than a frequent short-term sick leave pattern. Scores in commitment to the workplace and quality of leadership varied with sick leave pattern and age. Thus, different sick leave measures seem to be associated with different work environment factors. Further studies on these associations may inform interventions to improve occupational health care.

2013-01-01

436

Mineral Composition of Two Populations of Leaves - Green and Iron Chlorotic - of the Same Age All from the Same Tree.  

National Technical Information Service (NTIS)

Since carefully washed Fe chlorotic leaves often contain more total Fe on the dry weight basis than do green leaves, a population of leaves of the same age representing chlorotic leaves from each of two lemon trees and green leaves also of the same age an...

J. Procopiou A. Wallace

1981-01-01

437

NADH-Nitrate Reductase Inhibitor from Soybean Leaves 1  

PubMed Central

A NADH-nitrate reductase inhibitor has been isolated from young soybean (Glycine max L. Merr. Var. Amsoy) leaves that had been in the dark for 54 hours. The presence of the inhibitor was first suggested by the absence of nitrate reductase activity in the homogenate until the inhibitor was removed by diethylaminoethyl (DEAE)-cellulose chromatography. The inhibitor inactivated the enzyme in homogenates of leaves harvested in the light. Nitrate reductases in single whole cells isolated through a sucrose gradient were equally active from leaves grown in light or darkness, but were inhibited by addition of the active inhibitor. The NADH-nitrate reductase inhibitor was purified 2,500-fold to an electrophoretic homogeneous protein by a procedure involving DEAE- cellulose chromatography, Sephadex G-100 filtration, and ammonium sulfate precipitation followed by dialysis. The assay was based on nitrate reductase inhibition. A rapid partial isolation procedure was also developed to separate nitrate reductase from the inhibitor by DEAE-cellulose chromatography and elution with KNO3. The inhibitor was a heat-labile protein of about 31,000 molecular weight with two identical subunits. After electrophoresis on polyacrylamide gel two adjacent bands of protein were present; an active form and an inactive form that developed on standing. The active factor inhibited leaf NADH-nitrate reductase but not NADPH-nitrate reductase, the bacterial nitrate reductase or other enzymes tested. The site of inhibition was probably at the reduced flavin adenine dinucleotide-NR reaction, since it did not block the partial reaction of NADH-cytochrome c reductase. The inhibitor did not appear to be a protease. Some form of association of the active inhibitor with nitrate reductase was indicated by a change of inhibitor mobility through Sephadex G-75 in the presence of the enzyme. The inhibition of nitrate reductase was noncompetitive with nitrate but caused a decrease in Vmax. The isolated inhibitor was inactivated in the light, but after 24 hours in the dark full inhibitory activity returned. Equal amounts of inhibitor were present in leaves harvested from light or darkness, except that the inhibitor was at first inactive when rapidly isolated from leaves in light. Photoinactivation of yellow impure inhibitor required no additional components, but inactivation of the purified colorless inhibitor required the addition of flavin. Preliminary evidence and a procedure are given for partial isolation of a component by DEAE-cellulose chromatography that stimulated nitrate reductase. The data suggest that light-dark changes in nitrate reductase activity are regulated by specific protein inhibitors and stimulators.

Jolly, S. Omata; Tolbert, N. E.

1978-01-01

438

Radioactivity of Tobacco Leaves and Radiation Dose Induced from Smoking  

PubMed Central

The radioactivity in tobacco leaves collected from 15 different regions of Greece and before cigarette production was studied in order to find out any association between the root uptake of radionuclides from soil ground by the tobacco plants and the effective dose induced to smokers from cigarette tobacco due to the naturally occurring primordial radionuclides, such as 226Ra and 210Pb of the uranium series and 228Ra of the thorium series and/or man-made radionuclides, such as 137Cs of Chernobyl origin. Gamma-ray spectrometry was applied using Ge planar and coaxial type detectors of high resolution and high efficiency. It was concluded that the activities of the radioisotopes of radium, 226Ra and 228Ra in the tobacco leaves reflected their origin from the soil by root uptake rather than fertilizers used in the cultivation of tobacco plants. Lead-210 originated from the air and was deposited onto the tobacco leaves and trapped by the trichomes. Potassium-40 in the tobacco leaves was due to root uptake either from soil or from fertilizer. The cesium radioisotopes 137Cs and 134Cs in tobacco leaves were due to root uptake and not due to deposition onto the leaf foliage as they still remained in soil four years after the Chernobyl reactor accident, but were absent from the atmosphere because of the rain washout (precipitation) and gravitational settling. The annual effective dose due to inhalation for adults (smokers) for 226Ra varied from 42.5 to 178.6 ?Sv/y (average 79.7 ?Sv/y), while for 228Ra from 19.3 to 116.0 ?Sv/y (average 67.1 ?Sv/y) and for 210Pb from 47.0 to 134.9 ?Sv/y (average 104.7 ?Sv/y), that is the same order of magnitude for each radionuclide. The sum of the effective doses of the three radionuclides varied from 151.9 to 401.3 ?Sv/y (average 251.5 ?Sv/y). The annual effective dose from 137Cs of Chernobyl origin was three orders of magnitude lower as it varied from 70.4 to 410.4 nSv/y (average 199.3 nSv/y).

Papastefanou, Constantin

2009-01-01

439

Influence of harvest season on antioxidant activity and constituents of rabbiteye blueberry ( Vaccinium ashei ) leaves.  

PubMed

To select rabbiteye blueberry leaves from an appropriate harvest season to develop functional foods, this paper studied the bioactive secondary metabolites and the antioxidant capacity of rabbiteye blueberry leaves from May, September, and November. The results showed the leaves from May had the highest content of total flavonoids (114.21 mg/g) and the leaves from November had the highest content of total polyphenols and proanthocyanidins (425.24 and 243.29 mg/g, respectively). It was further found that blueberry leaves from different seasons have similar bioactive constituents, but their contents are obviously different by HPLC. The rabbiteye blueberry leaves from November had the highest antioxidant capacity, which was well correlated with their highest proanthocyanidin content. The results clarify that the blueberry leaves from different seasons have different contents of bioactive secondary metabolites and different antioxidant activities, which implied that leaves from November should be selected first for utilization in functional foods. PMID:24175648

Zhu, Liancai; Liu, Xi; Tan, Jun; Wang, Bochu

2013-11-27

440

29 CFR 2590.701-8 - Interaction With the Family and Medical Leave Act. [Reserved  

Code of Federal Regulations, 2010 CFR

...29 Labor 9 2009-07-01 2009-07-01 false Interaction With the Family and Medical Leave Act. [Reserved] 2590...Nondiscrimination, and Renewability § 2590.701-8 Interaction With the Family and Medical Leave Act....

2009-07-01

441

75 FR 8424 - Culturally Significant Objects Imported for Exhibition Determinations: “Leaves From an Austrian...  

Federal Register 2010, 2011, 2012, 2013

...Significant Objects Imported for Exhibition Determinations: ``Leaves From an Austrian Mahzor'' SUMMARY: Notice is hereby given...determine that the objects to be included in the exhibition ``Leaves from an Austrian Mahzor,'' imported from abroad for...

2010-02-24

442

Are sucrosyl-oligosaccharides synthesized in mesophyll protoplasts of mature leaves of Cucumis melo ?  

Microsoft Academic Search

Biosynthesis of sucrosyl-oligosaccharides (raffinose, stachyose) was traced in source leaves of Cucumis melo after 14C-photoassimilation. The main carbon compound exported was 14C-labeled stachyose. No oligosaccharide synthesis was detected in young, importing leaves. Mesophyll protoplasts, isolated from mature leaves which had previously photosynthesized 14CO2, did not contain 14C-oligosaccharides but contained [14C]-sucrose and 14C-hexoses. Isolated minor-vein-enriched fractions from the same leaves, however,

K. Schmitz; U. Holthaus

1986-01-01

443

Life after Vouchers: What Happens to Students Who Leave Private Schools for the Traditional Public Sector?  

ERIC Educational Resources Information Center

Few school choice evaluations consider students who leave such programs, and fewer still consider the effects of leaving these programs as policy-relevant outcomes. Using a representative sample of students from the citywide voucher program in Milwaukee, Wisconsin, we analyze more than 1,000 students who leave the program during a 4-year period.…

Carlson, Deven; Cowen, Joshua M.; Fleming, David J.

2013-01-01

444

When Academics Become Parents: An Overview of Family Leave Policies at Canadian Universities.  

ERIC Educational Resources Information Center

Reviews family leave policies in Canadian universities through March 2002. Analysis of pregnancy, adoption, and partner (paternity) leave policies reveal that most Canadian university policies produce income loss and disruption and are characterized by gender regulation and familialism. The paper proposes that improving faculty family leave

Prentice, Susan; Pankratz, Curtis J.

2003-01-01

445

Polyphenols, phytosterols, and reducing sugars in air-cured tobacco leaves injured by ozone air pollution  

Microsoft Academic Search

Air-cured tobacco (Nicotiana tabacum L.) leaves of several production types were analyzed chemically to determine the effects of ozone-induced weather fleck on polyphenols, phytosterols, and reducing sugars. Seven domestic cultivars provided leaf samples for analysis of polyphenols and phytosterols. Quantities of chlorogenic acid, rutin, scopoletin, free quinic acid, and phytosterols were higher in severely flecked leaves than in leaves flecked

H. A. Menser; J. F. Chaplin; A. L. S. Cheng; T. Sorokin

1977-01-01

446

77 FR 3845 - Agency Information Collection (Claim for Credit of Annual Leave) Activities Under OMB Review  

Federal Register 2010, 2011, 2012, 2013

...Collection (Claim for Credit of Annual Leave) Activities Under OMB Review AGENCY...INFORMATION: Title: Claim for Credit of Annual Leave, VA Form 0862. OMB Control Number: 2900-0669...former employee's who were charged annual leave on a non-workday while on active...

2012-01-25

447

77 FR 323 - Agency Information Collection (Trainee Request for Leave): Activity Under OMB Review  

Federal Register 2010, 2011, 2012, 2013

...Information Collection (Trainee Request for Leave): Activity Under OMB Review AGENCY...INFORMATION: Title: Trainee Request for Leave--Chapter 31, Title 38, U. S. C...complete VA Form 28-1905h to request leave from their Vocational Rehabilitation...

2012-01-04

448

76 FR 70830 - Proposed Information Collection (Claim for Credit of Annual Leave) Activity: Comment Request  

Federal Register 2010, 2011, 2012, 2013

...Collection (Claim for Credit of Annual Leave) Activity: Comment Request AGENCY: Human...employee's claims for restored annual leave charged on a nonworkday while on military...technology. Title: Claim for Credit of Annual Leave, VA Form 0862. Type of Review:...

2011-11-15

449

Evidence from Maternity Leave Expansions of the Impact of Maternal Care on Early Child Development  

ERIC Educational Resources Information Center

We study the impact of maternal care on early child development using an expansion in Canadian maternity leave entitlements. Following the leave expansion, mothers who took leave spent 48-58 percent more time not working in their children's first year of life. This extra maternal care primarily crowded out home-based care by unlicensed…

Baker, Michael; Milligan, Kevin

2010-01-01

450

25 CFR 39.119 - When must a student leave a gifted and talented program?  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false When must a student leave a gifted and talented...Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR... § 39.119 When must a student leave a gifted and talented program? A student must leave the gifted...

2011-04-01

451

Biomonitoring of traffic air pollution in Rome using magnetic properties of tree leaves  

Microsoft Academic Search

We report a biomonitoring study of air pollution in Rome based on the magnetic properties of tree leaves.In a first step, magnetic properties of leaves from different tree species from the same location were compared. It was observed that leaves of evergreen species, like Quercus ilex, present much higher magnetic intensities than those of deciduous species, like Platanus sp., suggesting

Eva Moreno; Leonardo Sagnotti; Jaume Dinarès-Turell; Aldo Winkler; Antonio Cascella

2003-01-01

452

A role for decaying leaves in mitigating the harmful effects of acid rain  

Microsoft Academic Search

Harmful effects of acid rain have been considered a serious problem. In this paper we have studied the ability of several common types of leaves to mitigate the effect of acid rain via the ability of these leaves to act as buffers in water.The pH of leaf suspensions of cypress, pine, oak, cinchona and ficus leaves has been determined and

Radi Salim; Shukri Khalaf

1994-01-01

453

Correlations between resistance of tobacco to Bemisia tabaci (Gennadius) and chemical components of tobacco leaves  

Microsoft Academic Search

With the aim for the resistance mechanism of tobacco to Bemisia tabaci , we determined the chlorophyll content of tobacco leaves, the chemical components and amino acid content in fresh or cured tobacco leaves, and analyzed the correlations between resistance of tobacco to Bemisia tabaci and chemical components of tobacco leaves. Results show that significantly negative correlation occurs between the

Ren Guang-wei; Chen Dan; Wang Ying

2011-01-01

454

Nutrient uptake by leaves and roots of the seagrass Thalassia hemprichii in the Spermonde Archipelago, Indonesia  

Microsoft Academic Search

The kinetics of ammonium and phosphate uptake by leaves and roots of the tropical seagrass Thalassia hemprichii were investigated in laboratory experiments. Uptake in leaves of plants from 3 different locations, covering the range from coastal to oceanic conditions in the region of investigation (Spermonde Archipelago, South Sulawesi, Indonesia), was compared. The leaves from all plant samples showed a clear

J. Stapel; Aarts L. T; Van Duynhoven H. M. B; DeGroot D. J; Van den Hoogen H. W. P; M. A. Hemminga

1996-01-01

455

Effects of simulated acid rain on the surface tension of selected leaves  

Microsoft Academic Search

In this study the effect of simulated acid rain on the surface tension of leaves of selected crop plants is reported. The contact angle measurements of liquids (water and n-propanol mixtures) on various plant leaves (bean, mustard, lettuce, cress) showed that the acid rain effect can be investigated when analyses of the surface tension of leaves are estimated. Acid rain

K. S. Birdi; B. R. Larsen; R. Sanchez

1987-01-01

456

Monocot Leaves are Eaten Less than Dicot Leaves in Tropical Lowland Rain Forests: Correlations with Toughness and Leaf Presentation  

PubMed Central

Background and Aims In tropical lowland rain forest (TLRF) the leaves of most monocots differ from those of most dicots in two ways that may reduce attack by herbivores. Firstly, they are tougher. Secondly, the immature leaves are tightly folded or rolled until 50–100 % of their final length. It was hypothesized that (a) losses of leaf area to herbivorous invertebrates are generally greatest during leaf expansion and smaller for monocots than for dicots, and (b) where losses after expansion are appreciable any difference between monocots and dicots then is smaller than that found during expansion. Methods At six