Photorespiration and the postillumination CO2 burst

1971 ◽  
Vol 49 (8) ◽  
pp. 1277-1284 ◽  
Author(s):  
N. R. Bulley ◽  
E. B. Tregunna
Keyword(s):  
Light Intensity ◽  
Action Spectrum ◽  
Visible Spectrum ◽  
Sample Volume ◽  
Gas Analysis ◽  
Short Period ◽  
Rate Of Photosynthesis ◽  
Measurable Rate ◽  
Soybean Leaves ◽  
Sudden Reduction

An open system of gas analysis was used to study the kinetics of the short postillumination CO2 burst (PIB) from soybean leaves. After correcting for the sample volume in the gas analyzer (IRGA), we found that the maximum measurable rate of CO2 evolution occurred within 8 s after the sudden reduction in light intensity, lasted for about 6 s, and then declined rapidly. The corrected rate was 45% higher than the rate indicated by the IRGA output. The maximum rate of the PIB was proportional to the effect of light intensity on the preceding apparent rate of photosynthesis in 21% O2 and 350 ppm CO2. A similar proportionality was found between the PIB and the light intensity in each of the five parts of the visible spectrum which were tested. No PIB was found when the O2 concentration was reduced to less than 2% O2. The effect of 21% O2 on the rate of CO2 evolution after 8 s in the dark relative to the rate in 2% O2 was about 20% greater than the effect of 21% O2 on apparent photosynthesis in the preceding light period. This difference may be ascribed to internal refixation during photosynthesis.The results supported the theory that photorespiration continues for a short period longer than photosynthesis after a sudden reduction in light intensity. This period is much shorter than previous papers have indicated. The action spectrum for the PIB provides no support for flavin-activation as the mechanism of the light effect.

RUMEN GAS ANALYSIS BY GAS-SOLID CHROMATOGRAPHY

1961 ◽  
Vol 41 (2) ◽  
pp. 187-196 ◽  
Author(s):  
J. M. McArthur ◽  
J. E. Miltimore
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Hydrogen Sulphide ◽  
Sample Volume ◽  
Gas Analysis ◽  
Complete Analysis ◽  
Thermal Detector ◽  
Thermal Detection ◽  
Methane Carbon

Methods are described for sampling and analysing rumen gases. The analysis requires less than 15 minutes for the determination of hydrogen, oxygen, nitrogen, methane, carbon monoxide, carbon dioxide, and hydrogen sulphide, i.e., for all gases occurring in the rumen. The method is sensitive and requires only a small quantity of sample, and the sample volume need not be known. The presence of water or other vapours in the sample does not influence the results. Relative thermal detector responses have been determined for gases which occur in the rumen. These eliminate the necessity for the calibration of gas chromatographs using thermal detection. The first complete analysis of rumen gas is presented.

scholarly journals Evidences from Action Spectra for a Specific Participation of Chlorophyll b in Photosynthesis

1960 ◽  
Vol 43 (4) ◽  
pp. 723-736 ◽  
Author(s):  
Jack Myers ◽  
C. S. French
Keyword(s):  
Oxygen Evolution ◽  
Platinum Electrode ◽  
Red Light ◽  
Chlorophyll B ◽  
Long Wavelength ◽  
Action Spectra ◽  
Rate Of Photosynthesis ◽  
Measurable Rate ◽  
Low Levels ◽  
Light Beams

Rate of oxygen evolution in photosynthesis was measured as the current from a polarized platinum electrode covered by a thin layer of Chlorella. The arrangement gave a reproducibly measurable rate of photosynthesis proportional to light intensity at the low levels used and gave rapid response to changes in illumination. Two phenomena have been explored. The Emerson effect was observed as an enhancement of photosynthesis in long wavelength red light (700 mµ) when shorter wavelengths were added. Two light beams of wavelengths 653 and 700 mµ when presented together gave a photosynthetic rate about 25 per cent higher than the sum of the rates obtained separately. Large and reproducible transients in rate of oxygen evolution were observed accompanying change in illumination between two wavelengths adjusted in intensity to support equal steady rates of photosynthesis. The transients were found not to be specifically related to long wavelength red light. Both enhancement and the transients have identical action spectra which are interpreted as demonstrating a specific photochemical participation of chlorophyll b.

scholarly journals Photosynthesis and Respiration by the Flag Leaf and Components of the Ear During Grain Development In Wheat

1970 ◽  
Vol 23 (2) ◽  
pp. 245 ◽  
Author(s):  
LT Evans ◽  
HM Rawson
Keyword(s):  
Light Intensity ◽  
Dark Respiration ◽  
Flag Leaf ◽  
Gas Analysis ◽  
Constant Light ◽  
Grain Development ◽  
Flag Leaves ◽  
Photosynthesis And Respiration

Rates of photosynthesis and dark respiration of the ears and flag leaves of three varieties of wheat grown at 21 DC under a constant light intensity of 3200 f.c. were measured by infrared gas analysis twice weekly throughout the period of grain development. Measurements were made on both the intact ears and the separated grains and ear structures, in air and in a mixture of nitrogen plus 320 p.p.m. C02. Dry weights of the grains, ears, and main stems were also determined.

scholarly journals Derivatised liquid chroamtographic method for statistical estimation of saliva samples by non-invasive technique

2020 ◽  
Vol 11 (SPL4) ◽  
pp. 1240-1243
Author(s):  
Vasundhara S ◽  
Madhusudan Rao Bandlamudi
Keyword(s):  
Diabetes Mellitus ◽  
Blood Glucose ◽  
Glucose Level ◽  
Sample Volume ◽  
Invasive Technique ◽  
Array Detector ◽  
P Value ◽  
Glucose Levels ◽  
Non Invasive ◽  
Short Period

A method was developed and validated for low-level detection of glucose. The method involves quantitation of glucose though derivitisation with PABA and HPLC-DAD analysis. A selective and novel method has been optimised for evaluation of blood glucose levels in blood Serum and saliva biological matrices by R.P-H.P.L.C. The principle analyte was eluted with the conditions of mobile phase having the 50m.M Sodium acetate: Acetonitrile (60:40%, v./v.) using the Phenomax-C.18  (250 x 4.6 mm, 3.5m.) analytical column with the 1.0 ml/min flow rate and 10µl sample volume at 254 nm in a photodiode array detector. The retention times of was 3.4 min within the total run time of 05 min. The curve indicates the correlation coefficient (r2) was superior by having the value 0.998 with a linear range of 40 µg/ml- 600.0 µg/ml. Based on the results obtained in the validation, the developed method was susceptible, accurate, linear and economical. Due to the short time of the chromatographic program, more samples can be analysed within a short period.  Data obtained were subjected to statistical analysis using t-test. Highly significant P-value (P<0.05) was obtained between the serum blood glucose and salivary glucose level. A distinct difference was observed in the salivary glucose between the control and diabetic group. The method was met all the predefined acceptance criteria.  Diabetes mellitus is a globally widespread disease. As the salivary collection is painless and non-invasive, in this study, an attempt has been made to diagnose diabetes mellitus by estimating the salivary glucose level in comparison with serum blood glucose level. Hence the developed method can be used as an index of diabetes mellitus.

scholarly journals Acrocyanosis - An uncommon event at post anaesthesia recovery room- A case report

2014 ◽  
Vol 26 (1) ◽  
pp. 58-60
Author(s):  
Md Azmal Hossain ◽  
Mosammat Maksuhuda Begum
Keyword(s):  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Cold Environment ◽  
Blood Gas ◽  
Operation Theatre ◽  
Left Ureter ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Arterial Blood Gas Analysis ◽  
Short Period

A healthy patient of aged 26 years underwent left ureter-lithotomy and cystostomy under general anesthesia. In post-operative ward, both extremities were cold & nailed were cyanosed. This cyanosis persisted for as long as 8-10 hours. No abnormality was detected in arterial blood gas analysis. This is not a simple peripheral cyanosis induced by cold environment of operation theatre, as warming usually reverses the phenomenon within a short period. But in this case, peripheral cyanosis persisted for as long as 8-10 hours. Therefore, this is a case of acrocyanosis. DOI: http://dx.doi.org/10.3329/jbsa.v26i1.19819 Journal of Bangladesh Society of Anaesthesiologists 2013; 26(1): 58-60

scholarly journals The effects of different syringe volume, needle size and sample volume on blood gas analysis in syringes washed with heparin

2012 ◽  
pp. 189-201 ◽  
Author(s):  
Tuncay Küme ◽  
Ali Riza Şişman ◽  
Ahmet Solak ◽  
Birsen Tuglu ◽  
Burcu Çinkooglu ◽  
...  
Keyword(s):  
Blood Gas Analysis ◽  
Sample Volume ◽  
Gas Analysis ◽  
Blood Gas ◽  
Needle Size

Directional Differences in the Colour Sensitivity of Daphnia Magna

1974 ◽  
Vol 61 (1) ◽  
pp. 261-267
Author(s):  
STEPHEN YOUNG
Keyword(s):  
Eye Movements ◽  
Light Intensity ◽  
Light Beam ◽  
Compound Eye ◽  
Action Spectrum ◽  
Stimulus Light ◽  
Free Swimming ◽  
Action Spectra ◽  
Light Receptor ◽  
Flashing Light

1. The Daphnia compound eye movements can be driven by a flashing light. 2. The action spectrum for the threshold light intensity required to evoke this response depends on the orientation of the stimulus light beam with respect to the animal. 3. If the light falls on the eye through the top of the animal's head the action spectrum peaks at the low wavelength end of the spectrum, while if it falls on the eye through the side of the head the peak is in the yellow-green. 4. Eye movements cannot be evoked by illuminating any part of the animal except the compound eye so neither of these action spectra is due to a light receptor other than the compound eye. 5. Some anomalous action spectra in the literature on the behaviour of free-swimming Daphnia are accounted for.

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