A CLOSED-CIRCUIT APPARATUS WITH AN INFRARED CO2 ANALYZER AND A GEIGER TUBE FOR CONTINUOUS MEASUREMENT OF CO2 EXCHANGE IN PHOTOSYNTHESIS AND RESPIRATION

Increasing levels of atmospheric greenhouse gases due to fossil fuel use, deforestation and other anthropogenic sources have changed the global climate. Global warming is the most widespread problem of the new millennium. Carbon dioxide (CO2) is the most important greenhouse gas released as a result of human activities. “Stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system” is the main objective of the UNFCCC. To help achieve this, the Protocol allows developed nations to credit removals of greenhouse gas emissions by natural sinks that store carbon. Forest based land use systems such as natural forests, forest plantations and agroforestry systems sequester CO2, through the C stored in their biomass. Management of forests and agroforestry systems is identified as the most promising option to mitigate atmospheric Carbon dioxide (CO2). The objective of the present study was to investigate the carbon sequestration potential of Kandyan Homegarden in Sri Lanka located in Kandy and Matale District. Two representative gardens were selected from each District in Kandy and Matale. After conducting a comprehensive vegetation survey done in 16, 10 x 10m plots in each garden in a 1 ha area located to capture the maximum variability in terms of tree density, topographic and edaphic differences. All the trees were measured for dbh and height and from the results dominant tree species which contribute to the long term carbon sequestration were selected using Important Value Index. Trees were then categorized into diameter classes and a tree each from each diameter class was selected for detailed measurements including stem and canopy volume. Representative number of trees per diameter class was destructively sampled to get the weight measurements and these were used to extrapolate the weight of the rest of the trees according to the volumes estimated. In this way the total aboveground biomass and carbon lodged in these gardens were arrived at. The potential to sequester carbon dioxide without being emitted to the atmosphere was also calculated for the individual gardens and extrapolated to all the Homegardens in the particular district. According to the results, average total aboveground carbon content that could be lodged in the Homegardens and total carbon dioxide that can be stored as carbon without being emitted to the atmosphere in Kandy District (Agro ecological zone WM3a) are 89.98 t C/ha and 330.23 t C/ha and are 103.89 t C/ha and 381.27 t C/ha in Matale District (Agro ecological zone IUI) respectively. According to the Forestry Sector Master Plan (1995) the total extent of the Homegardens in Kandy District is 61,029 ha and 20,258 ha in Matale District. Therefore total aboveground carbon content and carbon dioxide stored in the form of carbon in the Homegardens in Kandy District vary between 5,397,404 t C (5 x 106) – 5,585,374 (5 x 10 6) t C and 19,888,182 t C (19.89 x 106 ) – 20,499,030 t C (20.45 x 106 ) respectively. In Matale District the total aboveground carbon content and carbon dioxide stored as carbon in homegardens vary between 2,455,674 t C (2.45 x 10 6 ) – 1,753,532 t C (1.75 x 10 6) and 9,012,176 t C (9.00 x 10 6 ) – 6,435,358 t C (6.44 x 10 6 ) respectively. Annual litterfall rate of selected Homegarden system in Kandy District is 8.16 t/ha and 9.38 t/ha in selected Homegarden in Matale District. Mean annual litterfall rate in Kandyan Homegarden system is equal to 8.77 tons ha-1 year-1.

Carbon dioxide elimination pattern in morbidly obese patients undergoing laparoscopic surgery

Toadfish (Opsanus tau) essentially lacking circulating erythrocytes were pre pared by repeated exchange transfusion with serum. The rate of nitrogen secretion is not changed by removal of the erythrocytes. Oxygen secretion is slowed dras tically. This shows that nitrogen secretion does not require erythrocytes and is not driven by oxygen secretion. In the absence of circulating erythrocytes, oxygen and nitrogen are brought into the swimbladder in proportion to their concentrations in blood plasma. Carbon dioxide partial pressure in the secreted gas mixture is three to fourfold greater than the pressure generated by acidifying arterial blood. This implies counter-current multiplication of the small increment of carbon dioxide pressure brought about by acidification of the blood. In the presence of blood buffers, increased carbon dioxide pressure will increase blood bicarbonate. Three independent estimates indicate that, during gas secretion, gas gland blood is near pH 6.5. Total carbon dioxide (CO2, HCO3, CO3) is increased from the arterial value near 2 mM to about 14 mM, divided nearly equally between carbon dioxide and bicarbonate anion. The increment in total blood carbon dioxide concentration together with the well-known increment in lactate anion may serve to salt out inert gases from solution in blood plasma.

A significant discrepancy was noted in our laboratory between the total plasma carbon dioxide concentration measured by the Kodak Ektachem 700 and the bicarbonate concentration derived from the Corning 170 pH/Blood Gas analyser in an 8-day-old patient. The concentration of total carbon dioxide was 18 mmol/L while the derived bicarbonate was 13 mmol/L. The patient was eventually diagnosed as maple syrup urine disease. This finding led us to examine the effect of various organic acids on the measurement of carbon dioxide by the Ektachem 700. Several interfered significantly. Clinicians should be aware that when organic acid concentrations are increased, the Ektachem 700 total carbon dioxide result may be falsely raised.

Dark respiration in light as well as in dark was estimated for attached leaves of an evergreen (Heteromeles arbutifolia Ait.) and a deciduous (Lepechinia fragans Greene) shrub species using an open gas-exchange system. Dark respiration in light was estimated by the Laisk method. Respiration rates in the dark were always higher than in the light, indicating that light inhibited respiration in both species. The rates of respiration in the dark were higher in the leaves of the deciduous species than in the evergreen species. However, there were no significant differences in respiration rates in light between the species. Thus, the degree of inhibition of respiration by light was greater in the deciduous species (62%) than in the evergreen species (51%). Respiration in both the light and darkness decreased with increasing leaf age. However, because respiration in the light decreased faster with leaf age than respiration in darkness, the degree of inhibition of respiration by light increased with leaf age (from 36% in the youngest leaves to 81% in the mature leaves). This suggests that the rate of dark respiration in the light is related to the rate of biosynthetic processes. Dark respiration in the light decreased with increasing light intensity. Respiration both in the light and in the dark was dependent on leaf temperature. We concluded that respiration in light and respiration in darkness are tightly coupled, with variation in respiration in darkness accounting for more than 60% of the variation in respiration in light. Care must be taken when the relation between respiration in light and respiration in darkness is studied, because the relation varies with species, leaf age, and light intensity.

British Food Journal Volume 48 Issue 4 1946

Solving the problem of carbon dioxide emissions

The history and results of a clinical examination were recorded for 32 spring-born suckler calves which were hospitalised for intravenous fluid therapy. Blood samples were taken before treatment, during treatment and before discharge and analysed for colostral status, total carbon dioxide as an indication of acid-base status, and haematocrit. All the calves were given intravenously 5 to 10 litres of electrolyte solution containing 144 mmol/litre sodium, 4 mmol/litre potassium, 113 mmol/litre chloride and 35 mmol/litre bicarbonate, supplemented, in 24 calves, with up to 450 ml of 1M sodium bicarbonate. Nearly all the calves were recumbent but less than half were dehydrated on admission. The signs of dehydration were well correlated with each other and with the haematocrit. Neither the history nor the clinical signs were useful predictors of acidosis. There was no relationship between the severity of acidosis and the degree of dehydration. Acidosis was more prevalent in older calves (P < 0.01). For the severely acidotic calves, supplementary intravenous fluid with sodium bicarbonate significantly (P < 0.05) improved the total blood carbon dioxide at discharge. All 32 calves recovered. It is possible to treat acidotic calves with intravenous fluid therapy effectively, economically and according to their individual needs. The Harleco apparatus is a simple, useful, cost-effective adjunct to the diagnosis and treatment of this life-threatening condition.

The amount of total carbon dioxide estimated from pH and alkalinity was plotted against AOU. Results obtained were compared with those of a phosphate vs. AOU plot previously reported by the present authors. As a result, the following pints were confirmed: 1) The relationship between total carbon dioxide and AOU is given by a straight line with a slope of about 100/270 in an atomic ratio of carbon to oxygen for a group of waters with equal chlorinity and temperature. 2) The atomic ratio of carbon to phosphorus of about 100 to 1 obtained from the comparison of the ratios of ΣCO2 to AOU and P to AOU coincides with the C to P ratio given by FLEMING for a composite plankton sample. 3) Total carbon dioxide consists of three components; oxidative total carbon dioxide, reserved total carbon dioxide proportional to chlorosity (major portion of reserved total carbon dioxide) and reserved total carbon dioxide independent of chlorosity (minor portion of reserved total carbon dioxide). 4) Chlorosity-independent portion of reserved total carbon dioxide, as well as reserved phosphate, is remarkably more abundant in the Oyashio waters than in the Kuroshio waters.

SUMMARY: Cultures of the fungus Zygorrhynchus moelleri were grown in a glucose- acetate + ammonia + salts medium in the presence of either radioactive carbon dioxide, or acetate labelled in either the methyl- or the carboxyl-positions. After growth the protein was hydrolysed and the pattern of incorporation of radiocarbon into the amino acids was determined by chromatography and radioautography; activity from carbon dioxide appeared in glutamic and aspartic acids, methionine, threonine, isoleucine, proline and arginine. With labelled acetate lysine and leucine were also radioactive. A pool of free amino acids was present in this fungus. Several amino acids were isolated from the three samples of hydrolysed protein and their specific activities were determined. Assuming that the tricarboxylic acid cycle operated in this organism, a number of predictions concerning the distribution of radiocarbon in certain amino acids which could be made were largely confirmed by the experimental findings. By partial degradation of glutamic and aspartic acids, followed by assay of the radioactivity in the products, it was possible to calculate that about 60% of the oxalacetate used for citrate synthesis was recycled C4-di- carboxylic acid; 40 % was synthesized from pyruvate and carbon dioxide. Approximately 25 % of the total respiratory carbon dioxide evolved could be accounted for in terms of decarboxylations occurring within the citric acid cycle.

Pseudohypobicarbonatemia Caused by an Endogenous Assay Interferent: A New Entity

We have measured total carbon dioxide in plasma with a new carbon dioxide analyzer, and compared the results with total carbon dioxide data derived from measurements of carbon dioxide tension and pH. The results agree sufficiently well to demonstrate that the new instrument provides a simple, efficient procedure for monitoring the precision and accuracy of pH, carbon dioxide tension, or total carbon dioxide in plasma.

&#x0D; &#x0D; &#x0D; &#x0D; For the first time the hydrochemical examination of the spring waters of the village of Aketi of Lanchkhuti municipality was conducted. The content of magnesium and calcium ions, hydrocarbonate ions, chloride ions, sulfate ions, dry balance, permanganate oxidation, total iron ions, dissolved oxygen and carbon dioxide is determined. The content of total iron ions, dissolved oxygen and carbon dioxide. Relatively simple and fast chemical and physico-chemical methods with good reproducibility were selected for determination. Biogenic substances were determined by the photometric method.&#x0D; Objective: We aimed to study the chemical composition of the spring waters of Aketi village of Lanchkhuti municipality. We determined the following: the content of magnesium and calcium ions, hydrocarbonate ions, chloride ions, sulfate ions, dry balance, permanganate oxidation, total iron ions, dissolved oxygen and carbon dioxide in the spring waters of Aketi village of Lanchkhuti municipalityThe relevance of the issue lies in the fact that the content of the above-mentioned ions was determined for the first time in the given waters, for which highly sensitive methods were selected.&#x0D; &#x0D; &#x0D; &#x0D;

Measurements of total carbon dioxide and alkalinity by potentiometric titration in the GEOSECS program

Satellite instruments specifically designed to monitor atmospheric carbon dioxide concentrations have not been flown to date but, high‐resolution infrared sounders, being launched in the next few years, may offer the possibility of at least a basic carbon dioxide monitoring capability. This paper explores the sensitivity of this new generation of advanced infrared sounders to changing carbon dioxide concentrations and also compares this with uncertainties due to the atmospheric temperature, water vapor, and minor constituent concentrations using the current background errors in numerical weather prediction models as a baseline. The sensitivity results shown are computed for the Infrared Atmospheric Sounding Interferometer (IASI), which is due to fly on the European METOP platform from 2005. We show that although the carbon dioxide signal is below or at the instrument noise for IASI and that uncertainties in temperature and water vapor errors can dominate, a careful averaging of the retrieved carbon dioxide fields over areas of 500 × 500 km2 and 2 weeks should be able to extract changes at the level of 1% or less in the total column carbon dioxide amount. We also show results of an information content study for the Atmospheric InfraRed Sounder, AIRS, data, which suggests 50 channels are adequate for inferring the tropospheric carbon dioxide amounts but that they are not sensitive to CO2 changes in the boundary layer.