scholarly journals Potassium Flux and Leaf Movement in Samanea saman

1974 ◽  
Vol 64 (4) ◽  
pp. 413-430 ◽  
Author(s):  
R. L. Satter ◽  
G. T. Geballe ◽  
P. B. Applewhite ◽  
A. W. Galston
Keyword(s):  
Circadian Rhythm ◽  
White Light ◽  
Electron Microprobe ◽  
Leaf Movement ◽  
Ion Pumps ◽  
Potassium Flux ◽  
Through Diffusion ◽  
Motor Cells ◽  
Samanea Saman

Samanea leaflets usually open in white light and fold together when darkened, but also open and dose with a circadian rhythm during prolonged darkness. Leaflet movement results from differential changes in the turgor and shape of motor cells on opposite sides of the pulvinus; extensor cells expand during opening and shrink during closure, while flexor cells shrink during opening and expand during closure but change shape more than size. Potassium in both open and closed pulvini is about 0.4 N. Flame photometric and electron microprobe analyses reveal that rhythmic and light-regulated postassium flux is the basis for pulvinar turgor movements. Rhythmic potassium flux during darkness in motor cells in the extensor region involves alternating predominance of inwardly directed ion pumps and leakage outward through diffusion channels, each lasting ca 12 h. White light affects the system by activating outwardly directed K+ pumps in motor cells in the flexor region.

scholarly journals Potassium Flux and Leaf Movement in Samanea saman

1974 ◽  
Vol 64 (4) ◽  
pp. 431-442 ◽  
Author(s):  
R. L. Satter ◽  
G. T. Geballe ◽  
A. W. Galston
Keyword(s):  
Differential Effect ◽  
Red Light ◽  
Leaf Movement ◽  
Phytochrome A ◽  
Level Increase ◽  
Potassium Flux ◽  
Motor Cells ◽  
Samanea Saman ◽  
Increasing Temperature

Phytochrome, a membrane-localized biliprotein whose conformation is shifted reversibly by brief red or far-red light treatments, interacts with the rhythmic oscillator to regulate leaflet movement and potassium flux in pulvinal motor cells of Samanea. Darkened pinnae exposed briefly to red light (high Pfr level) have less potassium in motor cells in the extensor region, more potassium in motor cells in the flexor region, and smaller angles than those exposed to far-red light (low Pfr level). Increase in temperature from 24° to 37° increases the differential effect of the light treatments during opening (the energetic phase) but not during closure, implying that phytochrome controls an energetic process. It seems likely that phytochrome interacts with rhythmically controlled potassium pumps in flexor and extensor cells. During nyctinastic closure of white-illuminated pinnae, exposure to far-red light before darkening results in larger angles than does exposure to red. As in rhythmic opening, the angles of all pinnae and the differential effect of the light treatments increases with increasing temperature.

scholarly journals Plasma Membrane Aquaporins in the Motor Cells of Samanea saman

2002 ◽  
Vol 14 (3) ◽  
pp. 727-739 ◽  
Author(s):  
Menachem Moshelion ◽  
Dirk Becker ◽  
Alexander Biela ◽  
Norbert Uehlein ◽  
Rainer Hedrich ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Motor Cells ◽  
Samanea Saman

Phase Shifting Effect of Caffeine in the Circadian Rhythm of Phaseolus coccineus L

1975 ◽  
Vol 30 (11-12) ◽  
pp. 855-856 ◽  
Author(s):  
W. Mayer ◽  
I. Scherer
Keyword(s):  
Circadian Rhythm ◽  
Phaseolus Coccineus ◽  
Phase Shifting ◽  
Leaf Movement ◽  
Circadian Leaf Movement

Abstract Caffeine, Circadian Rhythm, Sleep and Wakefulness, Phaseolus coccineus L. 4-hour caffeine pulses (10 mᴍ) offered via the trans­ piration stream advances or delays the phase of the circadian leaf movement rhythm of Phaseolus coccineus as a function of the phase of application. It is hypothesized that the caffeine effect upon sleep and wakefulness in man is partly due to this phase-shifting effect.

Leaf Movement Rhythm In Arabidopsis Thaliana

1992 ◽  
Vol 47 (11-12) ◽  
pp. 925-928 ◽  
Author(s):  
Wolfgang Engelmann ◽  
Karl Simon ◽  
Chen Jyh Phen
Keyword(s):  
Arabidopsis Thaliana ◽  
Circadian Rhythm ◽  
Computer System ◽  
Leaf Movement ◽  
Leaf Movements ◽  
Weak Light

A circadian rhythm of leaf movements of Arabidopsis thaliana and its recording in continuous weak light with a video-computer system is described

Cuatrocapaite-(NH4) and cuatrocapaite-(K), two new minerals from the Torrecillas mine, Iquique Province, Chile, related to lucabindiite and gajardoite

2019 ◽  
Vol 83 (5) ◽  
pp. 741-748 ◽  
Author(s):  
Anthony R. Kampf ◽  
Nikita V. Chukanov ◽  
Gerhard Möhn ◽  
Maurizio Dini ◽  
Arturo A. Molina Donoso ◽  
...  
Keyword(s):  
General Formula ◽  
White Light ◽  
Electron Microprobe ◽  
Dominant Species ◽  
Empirical Formulas ◽  
Secondary Alteration ◽  
Cell Parameters ◽  
Layer Sequence ◽  
Mohs Hardness

AbstractThe new minerals cuatrocapaite-(NH4) (IMA2018-083) and cuatrocapaite-(K) (IMA2018-084) are the NH4- and K-dominant members of a series with the general formula (NH4,K)3(NaMg□)(As2O3)6Cl6·16H2O. Both minerals were found at the Torrecillas mine, Iquique Province, Chile, where they occur as secondary alteration phases. Both minerals occur as hexagonal tablets up to ~0.3 mm in diameter. They are transparent, with a vitreous lustre and white streak. For both, the Mohs hardness isca. 2½, the crystals are somewhat flexible, but not elastic, the fracture is irregular and the cleavage is perfect on {001}. The measured densities are 2.65(2) and 2.76(2) g/cm3for the NH4- and K-dominant species, respectively. Optically, cuatrocapaite-(NH4) is uniaxial (–) with ω = 1.779(3) andε= 1.541(3) and cuatrocapaite-(K) is uniaxial (–) with ω = 1.777(3) andε= 1.539(3) (white light). The minerals are insoluble in acids, but decompose in NaOH(aq). The empirical formulas, determined from electron-microprobe analyses, are (NH4)2.48Na1.66Mg0.87K0.09(As12O18.05)Cl5.88·16.02H2O and K2.68Na1.33Mg0.93(NH4)0.31(As12O18.01)Cl6.16·16.04H2O. The minerals are trigonal, space groupR${\bar 3}$m; the cuatrocapaite-(NH4) cell parameters area= 5.25321(19),c= 46.6882(19) Å,V= 1115.80(9) Å3andZ= 1; the cuatrocapaite-(K) cell parameters area= 5.2637(15),c= 46.228(8) Å,V= 1109.2(7) Å3andZ= 1. The structures, refined for cuatrocapaite-(NH4) toR1= 1.78% for 544Io> 2σIreflections, contain four types of layers: (1) a planar neutral As2O3(arsenite) sheet; (2) an (${\rm NH}_{\rm 4}^{\vskip -2pt\rm \scale65% +} $,K+) layer that links adjacent arsenite sheets; (3) a Cl–layer placed on the As side of each arsenite; and (4) a layer containing partially occupied Na, Mg and H2O sites that is flanked on either side by Cl layers. The layer sequence for the type 1, 2 and 3 layers is identical to the Cl–As2O3–K–As2O3–Cl layer sequence in the structures of lucabindiite and gajardoite.

scholarly journals Chronobiological Factors Related to Sleep and Neuropsychiatric Symptoms in Persons Living With Dementia

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 436-437
Author(s):  
Nancy Hodgson ◽  
Fanghong Dong
Keyword(s):  
Circadian Rhythm ◽  
White Light ◽  
Salivary Cortisol ◽  
Light Exposure ◽  
Neuropsychiatric Symptoms ◽  
Clear Understanding ◽  
Diurnal Cortisol ◽  
Endogenous Factors ◽  
Subjective Sleep ◽  
Rhythm Pattern

Abstract Circadian rhythm disturbances (CRD) are commonly seen in people living with dementia. A clear understanding of the role of CRD in dementia etiology will be beneficial by exploring the exogenous factors (externally influence the duration of sleep hours, such as light/dark cycles) and endogenous factors (internal biological rhythm, such as diurnal cortisol pattern). This symposium will apply a chronobiological approach to study exogenous and endogenous factors that influence circadian rhythm and their effects on sleep and neuropsychiatric symptoms in persons living with dementia (PLWD). Four paper presentations will use secondary data analysis of data from the Healthy Patterns Clinical Trial (NCT03682185), a randomized controlled trial of a home-based activity intervention designed to improve circadian rhythm disorders in PLWD. We will first describe the circadian rhythm pattern reflected by endogenous factors (salivary cortisol), then examine salivary cortisol (endogenous) and white light intensity (exogenous) and on subjective sleep and neuropsychiatric symptoms (including depression) in PLWD, respectively. In session 1, we will present cortisol diurnal rhythm pattern in PLWD using a cross-sectional design. In session 2, we will discuss the relationship between salivary cortisol indicators and depressive symptoms. In session 3, we focus on the association between diurnal cortisol slope and neuropsychiatric symptoms using the baseline data. In session 4, we describe the association between evening white light exposure and subjective sleep. The discussant will describe how these findings build on our understanding the nature of circadian rhythm disturbance in dementia and inform future research and treatment approaches.

Mauriziodiniite, NH4(As2O3)2I, the ammonium and iodine analogue of lucabindiite from the Torrecillas mine, Iquique Province, Chile

2019 ◽  
Vol 84 (2) ◽  
pp. 267-273
Author(s):  
Anthony R. Kampf ◽  
Barbara P. Nash ◽  
Arturo A. Molina Donoso
Keyword(s):  
White Light ◽  
Electron Microprobe ◽  
Empirical Formula ◽  
New Mineral ◽  
Calculated Density ◽  
Secondary Alteration ◽  
Layer Sequence ◽  
Mohs Hardness ◽  
Elastic Fracture ◽  
White Streak

AbstractThe new mineral mauriziodiniite (IMA2019-036), NH4(As2O3)2I, was found at the Torrecillas mine, Iquique Province, Chile, where it is a secondary alteration phase associated with calcite, cuatrocapaite-(NH4), lavendulan, magnesiokoritnigite and torrecillasite on matrix consisting of native arsenic, arsenolite and pyrite. Mauriziodiniite occurs as hexagonal tablets up to ~300 μm in diameter. Crystals are colourless and transparent, with pearly to adamantine lustre and white streak. The Mohs hardness is ~1. Tablets are sectile and easily flexible, but not elastic. Fracture is curved, irregular and stepped. Cleavage is perfect on {001}. The calculated density is 3.916 g/cm3. Optically, mauriziodiniite is uniaxial (–) with ω = 2.07(calc) and ɛ = 1.770(5) (white light). The empirical formula, determined from electron microprobe analyses, is (NH4)0.94K0.03(As2O3)2I0.92Cl0.03. Mauriziodiniite is hexagonal, P6/mmm, a = 5.289(2), c = 9.317(2) Å, V = 225.68(18) Å3 and Z = 1. The structure, refined to R1 = 4.16% for 135 Io > 2σI reflections, contains three types of layers: (1) a planar neutral As2O3 (arsenite) sheet; (2) an NH4+ layer that links adjacent arsenite sheets via bonds to their O atoms; and (3) an I– layer that links adjacent arsenite sheets via bonds to their As atoms. The layer sequence is I–As2O3–NH4–As2O3–I. Mauriziodiniite is isostructural with lucabindiite and is structurally related to gajardoite, cuatrocapaite-(NH4), cuatrocapaite-(K) and torrecillasite.

Canutite, NaMn3[AsO4][AsO3(OH)]2, a new protonated alluaudite-group mineral from the Torrecillas mine, Iquique Province, Chile

2014 ◽  
Vol 78 (4) ◽  
pp. 787-795 ◽  
Author(s):  
A. R. Kampf ◽  
S. J. Mills ◽  
F. Hatert ◽  
B. P. Nash ◽  
M. Dini ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
White Light ◽  
Electron Microprobe ◽  
New Mineral ◽  
Optical Orientation ◽  
Calculated Density ◽  
Secondary Alteration ◽  
Group Mineral ◽  
X Ray ◽  
Mohs Hardness

AbstractThe new mineral canutite (IMA2013-070), NaMn3[AsO4][AsO3(OH)]2, was found at two different locations at the Torrecillas mine, Salar Grande, Iquique Province, Chile, where it occurs as a secondary alteration phase in association with anhydrite, halite, lavendulan, magnesiokoritnigite, pyrite, quartz and scorodite. Canutite is reddish brown in colour. It forms as prisms elongated on [20] and exhibiting the forms {010}, {100}, {10}, {201} and {102}, or as tablets flattened on {102} and exhibiting the forms {102} and {110}. Crystals are transparent with a vitreous lustre. The mineral has a pale tan streak, Mohs hardness of 2½, brittle tenacity, splintery fracture and two perfect cleavages, on {010} and {101}. The calculated density is 4.112 g cm−3. Optically, canutite is biaxial (+) with α = 1.712(3), β = 1.725(3) and γ = 1.756(3) (measured in white light). The measured 2V is 65.6(4)°, the dispersion is r < v (slight), the optical orientation is Z = b; X ^ a = 18° in obtuse β and pleochroism is imperceptible. The mineral is slowly soluble in cold, dilute HCl. The empirical formula (for tabular crystals from near the mineshaft), determined from electron - microprobe analyses, is (Na1.05Mn2.64Mg0.34Cu0.14Co0.03)∑4.20As3O12H1.62. Canutite is monoclinic, C2/c, a = 12.3282(4), b = 12.6039(5), c = 6.8814(5) Å, β = 113.480(8)°, V = 980.72(10) Å3 and Z = 4. The eight strongest X-ray powder diffraction lines are [dobs Å(I)(hkl)]: 6.33(34)(020), 4.12(26)(21), 3.608(29)(310,31), 3.296(57)(12), 3.150(28)(002,131), 2.819(42)(400,041,330), 2.740(100)(240,02,112) and 1.5364(31)(multiple). The structure, refined to R1 = 2.33% for 1089 Fo > 4σF reflections, shows canutite to be isostructural with protonated members of the alluaudite group.

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