scholarly journals Carbon dioxide-induced bioluminescence increase in Arachnocampa larvae

2020 ◽  
Vol 223 (15) ◽  
pp. jeb225151 ◽  
Author(s):  
Hamish Richard Charlton ◽  
David John Merritt
Keyword(s):  
Carbon Dioxide ◽  
Light Output ◽  
Malpighian Tubule ◽  
Light Response ◽  
Light Organ ◽  
Nitrogen Gas ◽  
Physiological Basis ◽  
Light Organs ◽  
Tubule Cells ◽  
Releasing Effect

ABSTRACTArachnocampa larvae utilise bioluminescence to lure small arthropod prey into their web-like silk snares. The luciferin–luciferase light-producing reaction occurs in a specialised light organ composed of Malpighian tubule cells in association with a tracheal mass. The accepted model for bioluminescence regulation is that light is actively repressed during the non-glowing period and released when glowing through the night. The model is based upon foregoing observations that carbon dioxide (CO2) – a commonly used insect anaesthetic – produces elevated light output in whole, live larvae as well as isolated light organs. Alternative anaesthetics were reported to have a similar light-releasing effect. We set out to test this model in Arachnocampa flava larvae by exposing them to a range of anaesthetics and gas mixtures. The anaesthetics isoflurane, ethyl acetate and diethyl ether did not produce high bioluminescence responses in the same way as CO2. Ligation and dissection experiments localised the CO2 response to the light organ rather than it being a response to general anaesthesia. Exposure to hypoxia through the introduction of nitrogen gas combined with CO2 exposures highlighted that continuity between the longitudinal tracheal trunks and the light organ tracheal mass is necessary for recovery of the CO2-induced light response. The physiological basis of the CO2-induced bioluminescence increase remains unresolved, but is most likely related to access of oxygen to the photocytes. The results suggest that the repression model for bioluminescence control can be rejected. An alternative is proposed based on neural upregulation modulating bioluminescence intensity.

scholarly journals The Carbon Dioxide-induced Bioluminescence Increase in Arachnocampa Larvae

2020 ◽  
Author(s):  
Hamish Richard Charlton ◽  
David John Merritt
Keyword(s):  
Carbon Dioxide ◽  
Light Output ◽  
Malpighian Tubule ◽  
Light Response ◽  
Light Organ ◽  
Nitrogen Gas ◽  
Physiological Basis ◽  
Light Organs ◽  
Summary Statement ◽  
Releasing Effect

AbstractArachnocampa larvae utilise bioluminescence to lure small arthropod prey into their web-like silk snares. The luciferin-luciferase light-producing reaction occurs in a specialised light organ composed of Malpighian tubule cells in association with a tracheal mass. The accepted model for bioluminescence regulation is that light is actively repressed during the non-glowing period and released when glowing through the night. The model is based upon foregoing observations that carbon dioxide (CO2) – a commonly-used insect anaesthetic – produces elevated light output in whole, live larvae as well as isolated light organs. Alternative anaesthetics were reported to have a similar light-releasing effect. We set out to test this model in Arachnocampa flava larvae by exposing them to a range of anaesthetics and gas mixtures. The anaesthetics isoflurane, ethyl acetate, and diethyl ether did not produce high bioluminescence responses in the same way as CO2. Ligation and dissection experiments localised the CO2 response to the light organ rather than it being a response to general anaesthesia. Exposure to hypoxia through the introduction of nitrogen gas combined with CO2 exposures highlighted that continuity between the longitudinal tracheal trunks and the light organ tracheal mass is necessary for recovery of the CO2-induced light response. The physiological basis of the CO2-induced bioluminescence increase remains unresolved but is most likely related to access of oxygen to the photocytes. The results suggest that the repression model for bioluminescence control can be rejected. An alternative is proposed based on neural upregulation modulating bioluminescence intensity.Summary StatementCO2 was thought to act as an anaesthetic producing elevated bioluminescence in Arachnocampa. Here we show it acts directly on the light organ and does not act as an anaesthetic.

Influence of intramolecular interactions on carbon dioxide gas adsorption capacity in Mesoporous Imine polymers

2018 ◽  
Author(s):  
Jaya Prakash Madda ◽  
Pilli Govindaiah ◽  
Sushant Kumar Jena ◽  
Sabbhavat Krishna ◽  
Rupak Kishor
Keyword(s):  
Carbon Dioxide ◽  
Adsorption Capacity ◽  
Density Functional ◽  
Gas Adsorption ◽  
Ambient Pressure ◽  
Condensation Reaction ◽  
Intramolecular Interactions ◽  
Carbon Dioxide Adsorption ◽  
Nitrogen Gas ◽  
Adsorption Characteristic

<p>Covalent organic Imine polymers with intrinsic meso-porosity were synthesized by condensation reaction between 4,4-diamino diphenyl methane and (para/meta/ortho)-phthaladehyde. Even though these polymers were synthesized from precursors of bis-bis covalent link mode, the bulk materials were micrometer size particles with intrinsic mesoporous enables nitrogen as well as carbon dioxide adsorption in the void spaces. These polymers were showed stability up to 260<sup>o</sup> centigrade. Nitrogen gas adsorption capacity up to 250 cc/g in the ambient pressure was observed with type III adsorption characteristic nature. Carbon dioxide adsorption experiments reveal the possible terminal amine functional group to carbamate with CO<sub>2</sub> gas molecule to the polymers. One of the imine polymers, COP-3 showed more carbon dioxide sorption capacity and isosteric heat of adsorption (Q<sub>st</sub>) than COP-1 and COP-2 at 273 K even though COP-3 had lower porosity for nitrogen gas than COP-1 and COP-2. We explained the trends in gas adsorption capacities and Qst values as a consequence of the intra molecular interactions confirmed by Density Functional Theory computational experiments on small molecular fragments.</p>

Preservation of freshness of yellowtail fillet packaged using carbon dioxide-nitrogen gas mixture

1989 ◽  
Vol 2 (3) ◽  
pp. 135-139 ◽  
Author(s):  
Matsui Yasuda ◽  
Hajime Nishino ◽  
Tokiko Chiba ◽  
Hisako Nakano ◽  
Michio Yokoyama
Keyword(s):  
Carbon Dioxide ◽  
Gas Mixture ◽  
Nitrogen Gas

Light Organ and Eyestalk Compensation to Body Tilt in the Luminescent Midwater Shrimp, Sergestes Similis

1982 ◽  
Vol 98 (1) ◽  
pp. 83-104
Author(s):  
MICHAEL I. LATZ ◽  
JAMES F. CASE
Keyword(s):  
Angular Distribution ◽  
Light Source ◽  
The Body ◽  
Body Tilt ◽  
Light Organ ◽  
Total Compensation ◽  
Angular Movement ◽  
Counter Rotation ◽  
Light Organs ◽  
Before And After

The posterior light organ and eyestalk of the midwater shrimp, Sergestes similis Hansen, are capable of 140° of angular movement within the body during pitch body tilt, maintaining the organs at near horizontal orientations. Counter-rotations compensate for 74–80% of body inclination. These responses are statocyst mediated. Unilateral statolith ablation reduces compensation by 50%. There is no evidence for either homolateral or contralateral control by the single functioning statocyst. Bilateral lith ablation abolishes counter-rotation. Light organ and eyestalk orientations are unaffected by the direction of imposed body tilt. Bioluminescence is emitted downward from horizontal animals with an angular distribution similar to the distribution of oceanic light. The amount of downward directed luminescence in tilted animals decreases at large angles of body inclination due to less than total compensation by the light organs. Eye turning towards a light source is induced by upward-directed illumination. The resulting change in eyestalk orientations never amounts to more than 25°. The turning is abolished by bilateral statolith ablation. Downward directed illumination, comparable in intensity to oceanic light, generally does not generate significant eye turning. Light organ orientations remain unaffected by directional illumination, both before and after bilateral statolith ablation. The compensatory counter-rotations by the posterior light organ and eyestalk suggest that counter-illumination by S. similis remains effective in inclined animals.

The permeability properties of septate junctions in Malpighian tubules of Rhodnius

1987 ◽  
Vol 88 (2) ◽  
pp. 251-265 ◽  
Author(s):  
H.B. Skaer ◽  
S.H. Maddrell ◽  
J.B. Harrison
Keyword(s):  
Structural Characteristics ◽  
Malpighian Tubule ◽  
Malpighian Tubules ◽  
Septate Junctions ◽  
Blood Sucking ◽  
Effects Of Ph ◽  
Intercellular Clefts ◽  
Luminal Flow ◽  
Tubule Cells ◽  
Positively Charged

This paper describes the structural characteristics and permeability properties of the smooth septate junctions between the upper Malpighian tubule cells of a blood-sucking bug, Rhodnius prolixus. The permeability of the paracellular route was tested only for solutes that could be demonstrated not to cross the epithelium via the cellular route. The intercellular clefts were readily permeated by sucrose, inulin and polyethylene glycol (PEG), showing a higher permeability to molecules of smaller radius (PEG versus sucrose). Negatively charged molecules permeated the clefts more readily than positively charged ones. The effects of pH, urea and luminal flow rate on permeability were studied. The results are discussed in relation to the physiological tightness of the Malpighian tubules to certain solutes and to its function as an excretory epithelium.

An Enzyme Histochemical and Electron Microscopical Study of the Light Organ of the Glow-worm, Lampyris noctiluca

1965 ◽  
Vol s3-106 (75) ◽  
pp. 247-260
Author(s):  
V. C. BARBER ◽  
C.W. T. PILCHER
Keyword(s):  
Electron Microscopy ◽  
Calcium Ions ◽  
Adenosine Triphosphatase ◽  
Microscopical Study ◽  
The Body ◽  
Light Organ ◽  
Light Organs ◽  
Histochemical Tests ◽  
Electron Microscopical ◽  
Alkaline And Acid Phosphatase

The light organs of female specimens of the glow-worm Lampyris noctiluca were investigated by enzyme histochemical tests, lipid stains, and electron microscopy. Differences, both histochemical and in fine structure, were found between the cells of the photocyte and reflector layers. The photocytes contained a vesiculated reticulum, photocyte granules, amorphous granules, and numerous mitochondria. The reflecter layer did not contain the reticulum or the two types of granules and there were fewer mitochondria. Glycogen granules, and spaces possibly caused by the removal of urate during preparatory procedures, were present in this layer but absent from the photocytes. All the dehydrogenase enzymes, except for glucose-6-phosphate, 6 phosphogluconic, lactic, and β-hydroxybutyric dehydrogenases, which were absent from both layers, showed more activity in the photocyte layer, NADH2 and NADPH2 diaphorase showed no activity in the reflector layer. A transition zone between the two layers was demonstrated both histochemically and morphologically. Alkaline and acid phosphatase could not be demonstrated in the light organ. The adenosine triphosphatase demonstrable in the organ was not activated by magnesium but was activated by calcium ions. Lipid was present in both layers of the organ. The tracheolar supply to the photocytes was good but no tracheolar end organs were observed. The dehydrogenase activity of the body musculature is also reported upon.

Ultrastructure of fat body cells and Malpighian tubule cells in overwintering Scoliopteryx libatrix (Noctuoidea)

PROTOPLASMA ◽  
2017 ◽  
Vol 254 (6) ◽  
pp. 2189-2199 ◽  
Author(s):  
Saška Lipovšek ◽  
Franc Janžekovič ◽  
Tone Novak
Keyword(s):  
Fat Body ◽  
Malpighian Tubule ◽  
Tubule Cells

Removal Machining Performances by Using Inert Gas Filled Micro Bubble Coolant

2020 ◽  
Author(s):  
Manabu Iwai ◽  
Ryouta Yamashita ◽  
Satoshi Anzai ◽  
Shinichi Ninomiya
Keyword(s):  
Carbon Dioxide ◽  
Surface Roughness ◽  
Tool Life ◽  
Flank Wear ◽  
Grinding Force ◽  
Water Soluble ◽  
Inert Gases ◽  
Nitrogen Gas ◽  
Carbon Dioxide Gas ◽  
Micro Bubble

Abstract The authors have proposed a micro bubble coolant in which micro bubbles (20∼50μm in diameter) are included in water soluble coolant. In the previous study, it was confirmed that the tool life was improved by applying the micro bubble coolant to various machining operations such as drilling, turning and grinding. Also, purification effects of the micro bubble coolant were found. In this study, micro bubble coolant in which inert gases (N2 and CO2) were mixed was proposed to be applied to grinding processes for further improvement in grinding performances. When nitrogen gas (2L/min) was mixed with the micro bubble in the water soluble coolant (70L), amount of the dissolved oxygen in coolant decreased to 0.5mg/L. And concentration of the carbon dioxide gas in the coolant increased to 100mg/L when carbon dioxide gas (2L/min) was mixed in. From the result of grinding test on high speed steel, it was found that grinding performances improved when the micro bubble coolant with any of air, N2 and CO2 gases was used. The grinding force decreased by a factor of about 15% and the tool life increased by 20∼30%. When nitrogen gas was mixed in, the surface roughness improved by about 15%. In grinding stainless steels, performances such as grinding force, tool life and surface roughness improved by 10% when nitrogen gas was mixed in. In addition, a tendency of flank wear reduction and improvement in the surface roughness were observed when air micro bubble was mixed into the coolant in the turning of high carbon steel and Inconel 718 as well. When N2 micro bubble was generated in the coolant, a flank wear was reduced by 20% and surface roughness was improved by 30 to 40%. These effects were higher than the coolant with air micro bubble.

Anaerobic Benzene Biodegradation Linked to Nitrate Reduction

1999 ◽  
Vol 65 (2) ◽  
pp. 529-533 ◽  
Author(s):  
Siobhan M. Burland ◽  
Elizabeth A. Edwards
Keyword(s):  
Carbon Dioxide ◽  
Cell Growth ◽  
Nitrate Reduction ◽  
Dry Weight ◽  
Benzene Oxidation ◽  
Constant Ratio ◽  
Nitrogen Gas ◽  
Benzene Degradation ◽  
Enrichment Cultures

ABSTRACT Benzene oxidation to carbon dioxide linked to nitrate reduction was observed in enrichment cultures developed from soil and groundwater microcosms. Benzene biodegradation occurred concurrently with nitrate reduction at a constant ratio of 10 mol of nitrate consumed per mol of benzene degraded. Benzene biodegradation linked to nitrate reduction was associated with cell growth; however, the yield, 8.8 g (dry weight) of cells per mol of benzene, was less than 15% of the predicted yield for benzene biodegradation linked to nitrate reduction. In experiments performed with [14C]benzene, approximately 92 to 95% of the label was recovered in 14CO2, while the remaining 5 to 8% was incorporated into the nonvolatile fraction (presumably biomass), which is consistent with the low measured yield. In benzene-degrading cultures, nitrite accumulated stoichiometrically as nitrate was reduced and then was slowly reduced to nitrogen gas. When nitrate was depleted and only nitrite remained, the rate of benzene degradation decreased to almost zero. Based on electron balances, benzene biodegradation appears to be coupled more tightly to nitrate reduction to nitrite than to further reduction of nitrite to nitrogen gas.

Corrigendum - Effects of a water stress on the photosynthesis and respiration of wheat ears

1980 ◽  
Vol 31 (5) ◽  
pp. 857
Author(s):  
B Marshall ◽  
RH Sedgley ◽  
PV Biscoe
Keyword(s):  
Carbon Dioxide ◽  
Water Stress ◽  
Maximum Rate ◽  
Dark Respiration ◽  
Light Response ◽  
Grain Filling ◽  
Response Curves ◽  
Rectangular Hyperbola ◽  
Wheat Leaves ◽  
Days After Anthesis

An experiment was conducted on Huntsman winter wheat to investigate the effects of a water stress applied at anthesis on the carbon dioxide exchange of the ears during grain filling. The water stress was created by excluding rain from the soil, not the foliage, of plants growing in the field. Control plants were well watered throughout the period when the treatment was imposed. At intervals for 32 days after anthesis, detailed measurements were made of the photosynthetic rate of ears at different irradiances and rates of ear dark respiration. The measurements were analysed by using the photosynthesis-light response model developed by Marshall and Biscoe (1980) for wheat leaves with a modification for the pathway of respiration from the grains to the glumes. The model is a non-rectangular hyperbola and uses four parameters: Pn,max (maximum rate of net photosynthesis), Rd (rate of dark respiration), � (photochemical efficiency at low light), and F (ratio of physical to total resistance to diffusion of carbon dioxide). Analysis showed that in wheat ears during grain filling, photosynthesis can be treated as occurring predominantly in the glumes and respiration in the grains. The shape of the photosynthesis-light response curves for ears from both treatments were similar, but differed from those for wheat leaves because the maximum rates of photosynthesis were reached more gradually with increasing irradiance. However, the measured response curves were still better fitted by the model than a rectangular hyperbola which has often been used in the past. The water stress at anthesis decreased the maximum rate of ear photosynthesis by 0.8 g carbon dioxide m-2 h-1 throughout the grain-filling period. Initially, the rates of ear respiration were the same, but 32 days after anthesis the treatment had decreased ear respiration rate from 0.04 to 0.01 g carbon dioxide h-1/grain.

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