scholarly journals Life after Harvest: Circadian Regulation in Photosynthetic Pigments of Rocket Leaves during Supermarket Storage Affects the Nutritional Quality

Nutrients ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1519
Author(s):  
Lorena Ruiz de Larrinaga ◽  
Victor Resco de Dios ◽  
Dmitri Fabrikov ◽  
José Luis Guil-Guerrero ◽  
José María Becerril ◽  
...  
Keyword(s):  
Nutritional Quality ◽  
Continuous Light ◽  
Continuous Darkness ◽  
Endogenous Rhythms ◽  
Research Perspective ◽  
Nutrition Science ◽  
Light Darkness ◽  
New Research ◽  
Quality Assessments ◽  
First Time

Vegetables, once harvested and stored on supermarket shelves, continue to perform biochemical adjustments due to their modular nature and their ability to retain physiological autonomy. They can live after being harvested. In particular, the content of some essential nutraceuticals, such as carotenoids, can be altered in response to environmental or internal stimuli. Therefore, in the present study, we wondered whether endogenous rhythms continue to operate in commercial vegetables and if so, whether vegetable nutritional quality could be altered by such cycles. Our experimental model consisted of rocket leaves entrained under light/darkness cycles of 12/12 h over 3 days, and then we examined free-run oscillations for 2 days under continuous light or continuous darkness, which led to chlorophyll and carotenoid oscillations in both constant conditions. Given the importance of preserving food quality, the existence of such internal rhythms during continuous conditions may open new research perspective in nutrition science. However, while chromatographic techniques employed to determine pigment composition are accurate, they are also time-consuming and expensive. Here we propose for the first time an alternative method to estimate pigment content and the nutritional quality by the use of non-destructive and in situ optical techniques. These results are promising for nutritional quality assessments.

Light-Induced Enhancement in Proline Levels in Vigna Radiata Exposed to Environmental Stresses.

1995 ◽  
Vol 22 (3) ◽  
pp. 383 ◽  
Author(s):  
S Arora ◽  
PP Saradhi
Keyword(s):  
Heavy Metal ◽  
Salt Stress ◽  
Water Stress ◽  
Vigna Radiata ◽  
Continuous Light ◽  
Heavy Metal Stress ◽  
Metal Stress ◽  
Cadmium Nitrate ◽  
Continuous Darkness ◽  
First Time

Four-day-old Vigna radiata (L.) Wilczek seedlings were exposed to water stress (5% mannitol), salt stress (200 mM sodium chloride) and heavy metal stress (2.5 mM cadmium nitrate), in continuous light and darkness. The seedlings exposed to any of these stresses accumulated higher levels of proline in their shoots compared with control seedlings. Irrespective of the type of stress, accumulation of proline was higher in light than in the dark, which suggests that the photosynthetic activity of the seedlings might be responsible for light-induced enhancement of proline levels. In a second set of experiments, seeds were germinated under water stress, salt stress and heavy metal stress in continuous light and darkness. The plumule did not emerge from seeds germinated under stress, even after day 7. However, a 1.0-1.5 cm long radicle did emerge in light and in darkness. In spite of the lack of photosynthetic organs, seedlings raised under stress in light accumulated more proline than those raised in continuous darkness. In a third set of experiments, roots excised from 7-day-old light-grown seedlings were exposed to salt stress in light and in continuous darkness. The roots exposed to stress accumulated considerably more proline in light than in darkness. The results obtained in the last two sets of experiments suggest, for the first time, that some factoris) or process(es) other than photosynthesis plays an important role in light-induced enhancement of proline accumulation.

scholarly journals Ideal culture conditions for Dicyma pulvinata conidia mass production

2009 ◽  
Vol 44 (10) ◽  
pp. 1232-1238 ◽  
Author(s):  
Débora Ferreira Melo ◽  
Sueli Corrêa Marques de Mello
Keyword(s):  
Mass Production ◽  
Continuous Light ◽  
Culture Conditions ◽  
Block Designs ◽  
Complete Darkness ◽  
Continuous Darkness ◽  
Parboiled Rice ◽  
Light Regimes ◽  
Light Darkness ◽  
Set Up

The objective of this work was to set up ideal conditions for conidia mass production of Dicyma pulvinata. Four isolates were compared in terms of their growth and conidia production on various substrates (grains of parboiled rice, common rice, maize and wheat, besides chipped maize and rice husk), temperatures (19, 22, 25, 28 and 31ºC), growth containers (aluminum trays, polypropylene bags and Erlenmeyers) and light regimes (continuous darkness, 6 and 12 hours of light/darkness, and continuous light). Temperature effects on conidia germination capacity were also evaluated. The experiments were done in randomized complete block designs, in factorial arrangements (isolates x treatments - substrates, containers, temperatures and light regimes), with four replicates. In general, parboiled rice and polypropylene bags provided the best development of the fungus. Complete darkness and 6 hours of light increased mycelial growth, whereas continuous light favored sporulation. All tested temperatures favored the cultures of the fungus, except 31ºC. Temperatures between 19 and 25ºC ensure spore germination of more than 76%.

scholarly journals Measuring Bourdieu Capitals of Landscape Architects In Malaysian Landscape Architecture Firms

2019 ◽  
Vol 266 ◽  
pp. 06002
Author(s):  
Ruzaini Zahari ◽  
Mohd Hisham Ariffin ◽  
Noriah Othman
Keyword(s):  
Factor Analysis ◽  
Landscape Architecture ◽  
Economic Status ◽  
Research Perspective ◽  
Intangible Resources ◽  
Trait Theory ◽  
Trait Theory Of Leadership ◽  
Individual Use ◽  
New Research ◽  
Architecture Firms

Pierre Bourdieu (1986) introduced the concept of capitals as forms of intangible resources that individual use to advance their socio-economic status. Past relevant researches have not focused on all Bourdieu capitals. This study conceptualises the Bourdieu capitals to empirically determine the intangible resources of Malaysian leader landscape architects. The aim of this study is to determine the type of capitals of leader landscape architects in Malaysian landscape architecture firms. All landscape architecture firms (73 nos.) in the database of the Institute of Landscape Architects Malaysia were chosen for the survey. The firms were given the letter of invitation and questionnaires through the post. Thirty-nine firms responded to the invitation which resulted in 90 subordinates landscape architects and assistant landscape architects as respondents. The subordinates were asked to rate their leaders’ (landscape architects) capitals. The data were analysed using descriptive statistics and factor analysis. Factor analysis findings generated 5 factors (capitals). The capitals are social, human, emotional, cultural and design authority. The study findings provide evidence of the validity of scales to measure the intangible resources of the leading landscape architects in Malaysian landscape architecture firms. It also suggests a new research perspective for the Trait Theory of Leadership by replacing the traits with Bourdieu’s forms of capitals.

Control of nitrogen assimilation in Stichococcus bacillaris by growth conditions

1987 ◽  
Vol 65 (3) ◽  
pp. 432-437 ◽  
Author(s):  
Iftikhar Ahmad ◽  
Johan A. Hellebust
Keyword(s):  
Glutamine Synthetase ◽  
Nitrogen Assimilation ◽  
Continuous Light ◽  
Synthetase Activity ◽  
Glutamine Synthetase Activity ◽  
Dark Cycle ◽  
Continuous Darkness ◽  
Cell Carbon ◽  
Stichococcus Bacillaris ◽  
Mixotrophic Conditions

Stichococcus bacillaris Naeg. (Chlorophyceae) grown on a 12 h light: 12 h dark cycle divides synchronously under photoautotrophic conditions and essentially nonsynchronously under mixotrophic conditions. Photoassimilation of carbon under photoautotrophic conditions was followed by a decline in cell carbon content during the dark period, whereas under mixotrophic conditions cell carbon increased throughout the light–dark cycle. The rates of nitrogen assimilation by cultures grown on either nitrate or ammonium declined sharply during the dark, and these declines were most pronounced under photoautotrophic conditions. Photoautotrophic cells synthesized glutamine synthetase and NADPH – glutamate dehydrogenase (GDH) exclusively in the light, whereas in mixotrophic cells about 20% of the total synthesis of these enzymes during one light–dark cycle occurred in the dark. NADH–GDH was synthesized almost continuously over the entire light–dark cycle. In the dark, both under photoautotrophic and mixotrophic conditions, the alga contained more than 50% of glutamine synthetase in an inactive form, which was reactivated in vitro in the presence of mercaptoethanol and in vivo after returning the cultures to the light. The thermal stability of glutamine synthetase activity was less in light-harvested cells than in dark-harvested cells. The inactivation of glutamine synthetase did not occur in cultures growing either heterotrophically in continuous darkness or photoautotrophically in continuous light. This enzyme appears to be under thiol control only in cells grown under alternating light–dark conditions, irrespective of whether this light regime results in synchronous cell division or not.

The Daily Rhythm of Activity of the Cockroach, Blatta Orientalis L

1940 ◽  
Vol 17 (3) ◽  
pp. 267-277 ◽  
Author(s):  
D. L. GUNN
Keyword(s):  
Activity Rhythm ◽  
Continuous Light ◽  
Locomotory Activity ◽  
Continuous Darkness ◽  
Daily Cycle ◽  
Blatta Orientalis ◽  
Physical Stimuli ◽  
Inactive Phase ◽  
Set Up ◽  
Main Activity

1. In an aktograph at 25.5°C., at upwards of 75% relative humidity and with food present, the average locomotory activity of the cockroach per day does not depend on whether there is continuous light for weeks, or continuous darkness, or a daily alternation of light and darkness. 2. When temperature and humidity do not vary during the day and other factors are kept as constant as possible, the cockroach's activity can be largely concentrated into any desired half of the day, simply by suitably adjusting the time of onset of the half-day's darkness. A rhythm can thus be set up, so that the main activity occurs at the same hours each day. 3. This activity rhythm persists for some days in continuous light or continuous darkness, but eventually activity becomes much more evenly spread over the whole day, leaving only a slight residual rhythm which is unrelated to the previous conspicuous one. A new conspicuous rhythm can then be started at once by alternation of light and darkness. 4. There are indications that animal responses to physical stimuli may depend to a considerable extent on whether the animal is in the active or the inactive phase of its daily cycle. A method is suggested for making it possible to study the nocturnal phase during the daytime.

Light-induced suppression of the rat circadian system

1995 ◽  
Vol 268 (5) ◽  
pp. R1111-R1116 ◽  
Author(s):  
P. Depres-Brummer ◽  
F. Levi ◽  
G. Metzger ◽  
Y. Touitou
Keyword(s):  
Locomotor Activity ◽  
Body Temperature ◽  
Circadian Rhythms ◽  
Prolonged Exposure ◽  
Light Exposure ◽  
Continuous Light ◽  
Circadian System ◽  
Short Exposure ◽  
Complete Suppression ◽  
Continuous Darkness

In a constant environment, circadian rhythms persist with slightly altered period lengths. Results of studies with continuous light exposure are less clear, because of short exposure durations and single-variable monitoring. This study sought to characterize properties of the oscillator(s) controlling the rat's circadian system by monitoring both body temperature and locomotor activity. We observed that prolonged exposure of male Sprague-Dawley rats to continuous light (LL) systematically induced complete suppression of body temperature and locomotor activity circadian rhythms and their replacement by ultradian rhythms. This was preceded by a transient loss of coupling between both functions. Continuous darkness (DD) restored circadian synchronization of temperature and activity circadian rhythms within 1 wk. The absence of circadian rhythms in LL coincided with a mean sixfold decrease in plasma melatonin and a marked dampening but no abolition of its circadian rhythmicity. Restoration of temperature and activity circadian rhythms in DD was associated with normalization of melatonin rhythm. These results demonstrated a transient internal desynchronization of two simultaneously monitored functions in the rat and suggested the existence of two or more circadian oscillators. Such a hypothesis was further strengthened by the observation of a circadian rhythm in melatonin, despite complete suppression of body temperature and locomotor activity rhythms. This rat model should be useful for investigating the physiology of the circadian timing system as well as to identify agents and schedules having specific pharmacological actions on this system.

First Results from the VULCAN Diffractometer at the SNS

2010 ◽  
Vol 652 ◽  
pp. 105-110 ◽  
Author(s):  
X.L. Wang ◽  
Thomas Holden ◽  
A.D. Stoica ◽  
K. An ◽  
H.D. Skorpenske ◽  
...  
Keyword(s):  
Neutron Beam ◽  
Research Opportunities ◽  
Instrument Performance ◽  
Measurement Results ◽  
First Results ◽  
Design Calculations ◽  
New Research ◽  
First Time

On Friday June 26, 2009, the neutron beam shutter for the VULCAN diffractometer at the SNS was opened for the first time. Initial measurements to characterize the instrument performance are reported. It is shown that the measurement results are by and large in agreement with design calculations. New research opportunities with VULCAN are discussed.

scholarly journals Interindi: una nueva perspectiva de investigación acerca del indigenismo / Interindi: A New Research Perspective on Indigenismo

2018 ◽  
pp. 84
Author(s):  
Laura Giraudo ◽  
Juan Martín Sánchez
Keyword(s):  
State Of The Art ◽  
The State ◽  
Primary Sources ◽  
Research Project ◽  
Research Perspective ◽  
Scientific Discussion ◽  
Professional Field ◽  
New Research ◽  
Empirical Contribution

This article presents the main objectives and outcomes of the Interindi research project: “El indigenismo interamericano: instituciones, redes y proyectos para un continente, 1940-1960”. Its most ambitious research objective is to provide a methodological, theoretical and empirical contribution to scientific discussion on indigenismo. After discussing the state of the art in this field, advances are offered for a new broader perspective based on two fundamental aspects: 1) the importance of consulting primary sources to explain indigenismo, and 2) the need to remove the discussion of the indigenous question and indigenismo from the auto-referential context in which it has developed.Key WordsIndigenismo, professional field, inter-American networks.ResumenEste artículo presenta los objetivos y resultados principales del proyecto de investigación Interindi: “El indigenismo interamericano: instituciones, redes y proyectos para un continente, 1940-1960”. El objetivo más ambicioso de la investigación es conseguir una contribución metodológica, teórica y empírica a la discusión científica acerca del indigenismo. Tras discutir el estado de la cuestión, se introducen los avances de una nueva perspectiva general que radica en dos aspectos fundamentales: 1) la importancia de acudir al estudio de las fuentes para explicar el indigenismo y 2) la necesidad de sacar la discusión sobre la cuestión indígena y el indigenismo del contexto autorreferencial en que se ha desarrollado.Palabras claveIndigenismo, campo profesional, redes interamericanas.

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