scholarly journals Carbon Flux in the Temperate Zooxanthellate Sea Anemone Anthopleura aureoradiata

2021 ◽  
Author(s):  
◽  
Christopher Lynton Gibbons
Keyword(s):  
Respiration Rate ◽  
Maximum Rate ◽  
Rocky Shore ◽  
Temperature Tolerance ◽  
Sea Anemone ◽  
Field Conditions ◽  
Algal Density ◽  
Laboratory Conditions ◽  
Compensation Irradiance ◽  
Rate Of Photosynthesis

<p>This study investigated the algal density and growth, photophysiology and contribution of algae to animal respiration requirements (CZAR), in the symbiosis between the sea anemone Anthopleura aureoradiata and its dinoflagellate symbionts (zooxanthellae) under field and laboratory conditions. A. aureoradiata was collected during summer and winter on sunny and cloudy days from a rocky shore and mudflat environment. Algal densities displayed a trend of being 2.6 and 1.7 times greater during summer than winter on the mudflat on a sunny and cloudy day respectively. Algal division was asynchronous under field conditions over a daily period, and was 2.1 and 1.3 times greater on the rocky shore and mudflat respectively, during winter than summer on sunny days. Under field conditions, the efficiency and maximum rate of photosynthesis (per cell and per association) as well as respiration rate, were all greater during summer than winter. Cloud cover resulted in a difference in a higher maximum rate of photosynthesis per cell on a sunny day than a cloudy day within summer at Kau Bay. Additionally, these photosynthetic parameters and respiration rate were all greater on the rocky shore than mudflat while the photosynthetic compensation irradiance was greater on the mudflat. The CZAR was greatest on the rocky shore during summer on a sunny day (151%) and was also > 100% on a cloudy day in summer at this same site (129%); on the mudflat the CZAR was greatest during summer on a sunny day (89%). The CZAR was measured to be zero during winter at both sites during winter on cloudy days. Additionally, under laboratory conditions A. aureoradiata was exposed to gradual (GTC) and rapid (RTC) temperature changes. While under GTC and RTC, the algal density did not vary, though higher temperatures led to an increase in algal division. Under both GTC and RTC, the photosynthetic efficiency, maximum photosynthetic rate (per cell and per association) and respiration rate all increased with temperature, however under GTC these parameters all decreased between 32.5 [degrees]C and 35 [degrees] C. Photosynthetic compensation irradiance increased with temperature under both GTC and RTC until 30 [degrees] C, after which respiration exceeded maximum photosynthesis, meaning that photosynthetic compensation did not occur. Furthermore, photosynthetic saturation irradiance increased with temperature and peaked at 15 [degrees] C before declining with temperature under both GTC and RTC. The CZAR under GTC increased with temperature until it peaked at 15 [degrees] C (128%), before decreasing to zero at 30 [degrees] C - 35 [degrees] C. Under RTC, the CZAR was zero for all temperatures except at 10 [degrees] C where it was 25.1%. A CZAR < 100% may suggest that the symbiosis between A. aureoradiata and its zooxanthellae is parasitic under most conditions and at most times of the year. Alternatively, there may be some benefit to the symbiosis due to a competitive advantage over other macro-invertebrate species as a result of carbon translocation from the symbiont providing extra support for reproduction and growth. This study also showed A. aureoradiata to have a wide temperature tolerance reflecting the fluctuating conditions of a variable temperate environment. The wide temperature tolerance of this species suggests that it will tolerate short term (50 - 100 years) increases in ocean temperatures however, the threat beyond this time frame with other factors such as ocean acidification remains to be determined.</p>

scholarly journals Carbon Flux in the Temperate Zooxanthellate Sea Anemone Anthopleura aureoradiata

2021 ◽  
Author(s):  
◽  
Christopher Lynton Gibbons
Keyword(s):  
Respiration Rate ◽  
Maximum Rate ◽  
Rocky Shore ◽  
Temperature Tolerance ◽  
Sea Anemone ◽  
Field Conditions ◽  
Algal Density ◽  
Laboratory Conditions ◽  
Compensation Irradiance ◽  
Rate Of Photosynthesis

<p>This study investigated the algal density and growth, photophysiology and contribution of algae to animal respiration requirements (CZAR), in the symbiosis between the sea anemone Anthopleura aureoradiata and its dinoflagellate symbionts (zooxanthellae) under field and laboratory conditions. A. aureoradiata was collected during summer and winter on sunny and cloudy days from a rocky shore and mudflat environment. Algal densities displayed a trend of being 2.6 and 1.7 times greater during summer than winter on the mudflat on a sunny and cloudy day respectively. Algal division was asynchronous under field conditions over a daily period, and was 2.1 and 1.3 times greater on the rocky shore and mudflat respectively, during winter than summer on sunny days. Under field conditions, the efficiency and maximum rate of photosynthesis (per cell and per association) as well as respiration rate, were all greater during summer than winter. Cloud cover resulted in a difference in a higher maximum rate of photosynthesis per cell on a sunny day than a cloudy day within summer at Kau Bay. Additionally, these photosynthetic parameters and respiration rate were all greater on the rocky shore than mudflat while the photosynthetic compensation irradiance was greater on the mudflat. The CZAR was greatest on the rocky shore during summer on a sunny day (151%) and was also > 100% on a cloudy day in summer at this same site (129%); on the mudflat the CZAR was greatest during summer on a sunny day (89%). The CZAR was measured to be zero during winter at both sites during winter on cloudy days. Additionally, under laboratory conditions A. aureoradiata was exposed to gradual (GTC) and rapid (RTC) temperature changes. While under GTC and RTC, the algal density did not vary, though higher temperatures led to an increase in algal division. Under both GTC and RTC, the photosynthetic efficiency, maximum photosynthetic rate (per cell and per association) and respiration rate all increased with temperature, however under GTC these parameters all decreased between 32.5 [degrees]C and 35 [degrees] C. Photosynthetic compensation irradiance increased with temperature under both GTC and RTC until 30 [degrees] C, after which respiration exceeded maximum photosynthesis, meaning that photosynthetic compensation did not occur. Furthermore, photosynthetic saturation irradiance increased with temperature and peaked at 15 [degrees] C before declining with temperature under both GTC and RTC. The CZAR under GTC increased with temperature until it peaked at 15 [degrees] C (128%), before decreasing to zero at 30 [degrees] C - 35 [degrees] C. Under RTC, the CZAR was zero for all temperatures except at 10 [degrees] C where it was 25.1%. A CZAR < 100% may suggest that the symbiosis between A. aureoradiata and its zooxanthellae is parasitic under most conditions and at most times of the year. Alternatively, there may be some benefit to the symbiosis due to a competitive advantage over other macro-invertebrate species as a result of carbon translocation from the symbiont providing extra support for reproduction and growth. This study also showed A. aureoradiata to have a wide temperature tolerance reflecting the fluctuating conditions of a variable temperate environment. The wide temperature tolerance of this species suggests that it will tolerate short term (50 - 100 years) increases in ocean temperatures however, the threat beyond this time frame with other factors such as ocean acidification remains to be determined.</p>

scholarly journals Analysis of Working Qualitative Parameters for No-Till Machines

2011 ◽  
Vol 68 (1) ◽  
Author(s):  
Ovidiu RANTA ◽  
Ioan DROCAS ◽  
Sorin STANILA ◽  
Adrian MOLNAR ◽  
Mircea Valentin MUNTEAN ◽  
...  
Keyword(s):  
Field Experiments ◽  
State Of The Art ◽  
Field Conditions ◽  
Laboratory Conditions ◽  
Experimental Teaching ◽  
No Till ◽  
Soil Bin ◽  
Teaching Facility

Autors was designed a system to modify the SPC romanian seeding machine for in order that it can be used for no-till technology. This machine was manufactured with the help of S.C. MECANICA M.A.R.I..U.S. S.A. in Cluj- Napoca and it was used in laboratory conditions in a state of the art soil bin of Hohenheim University, Stuttgart and in laboratory-field conditions. The field experiments were located on a plot of Experimental Teaching Facility of USAMV Cluj-Napoca, on aluviosol molic soil after SRTS – 200, in location Lunca Someşului Mic (Podişul Someşan) .

scholarly journals Capacity of earwig Marava arachidis (Yersin) to access fennel plants Foeniculum vulgare Mill in laboratory and field

2007 ◽  
Vol 37 (6) ◽  
pp. 1524-1528 ◽  
Author(s):  
Charles Ira Abramson ◽  
Paulo Alves Wanderley ◽  
Alexandre José Soares Miná ◽  
Maria José Araújo Wanderley
Keyword(s):  
Essential Oil ◽  
Field Experiment ◽  
Field Conditions ◽  
Foeniculum Vulgare ◽  
Independent Variables ◽  
Laboratory Conditions ◽  
Potential Capacity ◽  
Males And Females

This research was aimed at obtaining data about earwig behavior (Marava arachidis Y.) on fennel agro-ecosystems and evaluating its potential capacity to access plants in the absence of aphids under laboratory and field conditions. This study establishes a baseline to evaluate earwigs as biological controls to combat aphids that attack fennel plants. Two experiments were developed. In experiment 1, earwigs were studied under laboratory conditions, in experiment 2 under field conditions. Independent variables were sex, exposure to the essential oil of fennel for 24 or 48 hours, and whether the fennel plant was vegetative or flowering. The results indicated that earwigs will climb a fennel plant in the absence of aphids and that few statistical significant results were obtained among the independent variables examined. A difference between male and females was noted in the field experiment in animals receiving 48 h of exposure to the essential oil of fennel. The terminal height reached by males and females in the 48 h vegetative and flower condition also differed.

Control of Photosynthesis in Amaranthus edulis Mutants with Reduced Amounts of PEP Carboxylase

1997 ◽  
Vol 24 (4) ◽  
pp. 469 ◽  
Author(s):  
Louisa V. Dever ◽  
Karen J. Bailey ◽  
Richard C. Leegood ◽  
Peter J. Lea
Keyword(s):  
Maximum Rate ◽  
Compensatory Mechanism ◽  
Wild Type ◽  
Pep Carboxylase ◽  
Temperature Changes ◽  
Rate Of Photosynthesis ◽  
Lower Maximum ◽  
Fine Adjustment ◽  
Control Coefficients ◽  
Wild Type Control

Mutants of the NAD-ME plant have been created using sodium azide. These contain reduced activities of PEP carboxylase ranging from 5 to 100% of wild-type. Those with greater than 50% of the wild-type PEPC content showed a lower maximum rate of photosynthesis and reduced carboxylation efficiency compared to the wild-type plants. The PEPC from these heterozygotes was less sensitive to malate inhibition than the PEPC of the wild-type plants and also had an increased phosphorylation state. Mutants containing 45 and 49% of wild-type PEPC exhibited a greater Amax than was observed for the 55, 66 and 70% mutants. We postulate that there is a compensatory mechanism that activates PEPC when the PEPC protein is less than 55% of the wild-type. Control coefficients were measured for PEP carboxylase from wild-type and heterozygous (55%) plants. Results suggest that activation of PEPC by phosphorylation and metabolites may be more an ‘on-off’ switch than a means of fine adjustment of PEPC activity in response to varying factors such as PEPC content, CO2 or temperature changes.

scholarly journals Using Deep Learning for Image-Based Different Degrees of Ginkgo Leaf Disease Classification

Information ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 95 ◽  
Author(s):  
Kaizhou Li ◽  
Jianhui Lin ◽  
Jinrong Liu ◽  
Yandong Zhao
Keyword(s):  
Deep Learning ◽  
Ginkgo Biloba ◽  
Plant Disease ◽  
Disease Classification ◽  
Field Conditions ◽  
Laboratory Conditions ◽  
Leaf Disease ◽  
And Training ◽  
Ginkgo Leaf

Diseases from Ginkgo biloba have brought great losses to medicine and the economy. Therefore, if the degree of disease can be automatically identified in Ginkgo biloba leaves, people will take appropriate measures to avoid losses in advance. Deep learning has made great achievements in plant disease identification and classification. For this paper, the convolution neural network model was used to classify the different degrees of ginkgo leaf disease. This study used the VGGNet-16 and Inception V3 models. After preprocessing and training 1322 original images under laboratory conditions and 2408 original images under field conditions, 98.44% accuracy was achieved under laboratory conditions and 92.19% under field conditions with the VGG model. The Inception V3 model achieved 92.3% accuracy under laboratory conditions and 93.2% under field conditions. Thus, the Inception V3 model structure was more suitable for field conditions. To our knowledge, there is very little research on the classification of different degrees of the same plant disease. The success of this study will have a significant impact on the prediction and early prevention of ginkgo leaf blight.

scholarly journals Study of the efficacy of a Wheaton coated bottle with permethrin and deltamethrin in laboratory conditions and a WHO impregnated paper with bendiocarb in field conditions

2014 ◽  
Vol 4 (6) ◽  
pp. 492-497 ◽  
Author(s):  
Nazaire Aïzoun ◽  
Roseric Azondekon ◽  
Rock Aïkpon ◽  
Virgile Gnanguenon ◽  
Razaki Osse ◽  
...  
Keyword(s):  
Field Conditions ◽  
Laboratory Conditions

scholarly journals A Persistent Daily Rhythm in Photosynthesis

1961 ◽  
Vol 45 (1) ◽  
pp. 69-76 ◽  
Author(s):  
J. Woodland Hastings ◽  
Lazarus Astrachan ◽  
Beatrice M. Sweeney
Keyword(s):  
Cell Division ◽  
Diurnal Rhythm ◽  
Maximum Rate ◽  
Photosynthetic Capacity ◽  
Bright Light ◽  
Light Period ◽  
Daily Rhythm ◽  
Single Mechanism ◽  
Rate Of Photosynthesis ◽  
Dim Light

The luminescent marine dinoflagellate, Gonyaulax polyedra, exhibits a diurnal rhythm in the rate of photosynthesis and photosynthetic capacity measured by incorporation of C14O2, at different times of day. With cultures grown on alternating light and dark periods of 12 hours each, the maximum rate is at the 8th hour of the light period. Cultures transferred from day-night conditions to continuous dim light continue to show the rhythm of photosynthetic capacity (activity measured in bright light) but not of photosynthesis (activity measured in existing dim light). Cultures transferred to continuous bright light, however, do not show any rhythm. Several other properties of the photosynthetic rhythm are similar to those of previously reported rhythms of luminescence and cell division. This similarity suggests that a single mechanism regulates the various rhythms.

scholarly journals Light response and photosynthesis in sorghum under field conditions

MAUSAM ◽  
2022 ◽  
Vol 46 (3) ◽  
pp. 303-306
Author(s):  
Y. R. KENJLE ◽  
M. C. VARSHNEYA ◽  
T. R. U. NAIDU
Keyword(s):  
Correlation Coefficients ◽  
Light Response ◽  
Photosynthetic Photon Flux Density ◽  
Field Conditions ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Response Curves ◽  
Light Response Curves ◽  
Air Temperatures ◽  
Rate Of Photosynthesis

ABSTRACT. The diurnal variation of rate of photosynthesis (l') with photosynthetic photon flux density (PPFD) model of light response curves and the relationship between PPFD and P were studied for two postmonsoon (rabi) sorghum genotypes, viz.. M35- I and RSV-9R under field conditions at Pune. The half maximal values. i.e., PPFD level at which P=Pmax/2 obtained were 1251 and 937 umolm-2s-1 for M35-l and RSV.9R respectively. The potential rates of photosynthesis were 65,79 and 64.52  umolm-2S-1 whereas the observed maximum rates of photosynthesis were lower. 40.93 and 46.66 umolm-2s-1 in M35-1 and RSV-9R Respectively, due to effect of air temperatures under the field conditions, n1e maximum rate of photosynthesis determined from the model decreased with delay in the sowing of the crop. Correlation coefficients between PPFD and rate of photosynthesis were 0,794 and 0,708 for M35-1 and RSV-9R respectively. The PPFD received and rate of photosynthesis decreased significantly with delay in sorghum sowing.    

scholarly journals Phytopathogens Causing Wilt in Pepper – Distribution, Symptoms and Identification

2013 ◽  
Vol 14 (4) ◽  
pp. 549
Author(s):  
Petar Chavdarov ◽  
Liliya Krasteva ◽  
Nikolaya Velcheva ◽  
Stefan Neykov
Keyword(s):  
Rhizoctonia Solani ◽  
Phytopathogenic Fungi ◽  
Field Conditions ◽  
Laboratory Conditions

In 2012 the evaluation on the development and spread of phytopathogens, causing wilt in pepper was conducted. The observations were carried out under field conditions and natural infectious background in the Plovdiv region. In laboratory conditions were isolated and identified four phytopathogenic fungi of the genus Rhizoctonia, Fusarium, Verticillium and Phytophthora. The results of the analysis showed that the highest percentage of pepper wilt was caused by the fungus - Rhizoctonia solani.

Adsorption, dissipation, and movement of fluometuron in three southeastern United States soils

Weed Science ◽  
1997 ◽  
Vol 45 (1) ◽  
pp. 183-189 ◽  
Author(s):  
William T. Willian ◽  
Thomas C. Mueller ◽  
Robert M. Hayes ◽  
Charles E. Snipes ◽  
David C. Bridges
Keyword(s):  
United States ◽  
Organic Matter ◽  
Soil Profile ◽  
Soil Depth ◽  
Southeastern United States ◽  
Clay Content ◽  
Field Conditions ◽  
Laboratory Conditions ◽  
Controlled Conditions ◽  
Field And Laboratory Conditions

Fluometuron adsorption and dissipation under field and laboratory conditions, and distribution within the soil profile was determined in 3 soils from Tennessee, Mississippi, and Georgia that are representative of the cotton-growing regions of the southeastern United States. Fluometuron adsorption was correlated with organic matter, but not with clay content or soil pH. First-order kinetics explained fluometuron dissipation under field and controlled conditions (r2≥ 0.82). Field dissipation of fluometuron was slower under dry conditions. Fluometuron was not detected below 15 cm in the soil profile in any soil, and concentrations in the 8- to 15-cm soil zone were < 15 ppbw 112 d after treatment. Fluometuron dissipation was more rapid in soil from the 0- to 8-cm depth in Tennessee soil than in Mississippi soil under controlled conditions. Dissipation was more rapid under field conditions than under laboratory conditions at 2 of 3 locations. Fluometuron half-lives in soils from the 0- to 8-cm depth ranged from 9 to 28 d under field conditions and from 11 to 43 d in the laboratory. Fluometuron dissipation in soils from 30- to 45- and 60- to 90-cm depths was not different among soils, with half-lives ranging from 58 to 99 d under laboratory conditions. Fluometuron half-life was positively correlated with soil depth and inversely correlated with organic matter. These data indicate that organic matter, soil depth, and environmental conditions affect fluometuron dissipation.

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