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PubMed1984

Effect of the defoliant thidiazuron on ethylene evolution from mung bean hypocotyl segments.

The effect of the defoliant thidiazuron (N-phenyl-N'1,2,3-thiadiazol-5-ylurea) on ethylene evolution from etiolated mung bean hypocotyl segments was examined. Treatment of hypocotyl segments with concentrations of thidiazuron equal to or greater than 30 nanomolar stimulated ethylene evolution. Increased rates of ethylene evolution from thidiazuron-treated tissues could be detected within 90 minutes of treatment and persisted up to 30 hours after treatment. Radioactive methionine was readily taken up by thidiazuron-treated tissues and was converted to ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC) and an acidic conjugate of ACC. Aminoethoxyvinylglycine, aminooxyacetic acid, cobalt chloride, and alpha-aminoisobutyric acid reduced ethylene evolution from treated tissues. An increase in the endogenous content of free ACC coincided with the increase in ethylene evolution following thidiazuron treatment. Uptake and conversion of exogenous ACC to ethylene were not affected by thidiazuron treatment. No increases in the extractable activities of ACC synthase were detected following thidiazuron treatment.

Journal Article↗

PubMed1985

Effect of temperature on h(2) evolution and acetylene reduction in pea nodules and in isolated bacteroids.

Nitrogenase (EC 1.7.99.2) activity in pea (Pisum savitum) nodules formed after infection with Rhizobium leguminosarum (lacking uptake hydrogenase) was measured as acetylene reduction, H(2) evolution in air and H(2) evolution in Ar:O(2). With detached roots the relative efficiency, calculated from acetylene reduction, showed a decrease (from 55 to below 0%) with increasing temperature. With excised nodules and isolated bacteroids similar results were obtained. However, the relative efficiency calculated from H(2) evolution in Ar:O(2) was unaffected by temperature. Measurements on both excised nodules and isolated bacteroids showed a marked difference between acetylene reduction and H(2) evolution in Ar:O(2) with increased temperature, indicating that either acetylene reduction or H(2) evolution in Ar:O(2) are inadequate measures of nitrogenase activity at higher temperature.

Journal Article↗

PubMed2004

Constraining active contour evolution via lie groups of transformation.

We present a novel approach to constraining the evolution of active contours used in image analysis. The proposed approach constrains the final curve obtained at convergence of curve evolution to be related to the initial curve from which evolution begins through an element of a desired Lie group of plane transformations. Constraining curve evolution in such a way is important in numerous tracking applications where the contour being tracked in a certain frame is known to be related to the contour in the previous frame through a geometric transformation such as translation, rotation, or affine transformation, for example. It is also of importance in segmentation applications where the region to be segmented is known up to a geometric transformation. Our approach is based on suitably modifying the Euler-Lagrange descent equations by using the correspondence between Lie groups of plane actions and their Lie algebras of infinitesimal generators, and thereby ensures that curve evolution takes place on an orbit of the chosen transformation group while remaining a descent equation of the original functional. The main advantage of our approach is that it does not necessitate any knowledge of nor any modification to the original curve functional and is extremely straightforward to implement. Our approach therefore stands in sharp contrast to other approaches where the curve functional is modified by the addition of geometric penalty terms. We illustrate our algorithm on numerous real and synthetic examples.

Algorithms↗

PubMed2004

The quantitative genetics of floral trait variation in Lobelia: potential constraints on adaptive evolution.

Although pollinator-mediated natural selection has been measured on many floral traits and in many species, the extent to which selection is constrained from producing optimal floral phenotypes is less frequently studied. In particular, negative correlations between flower size and flower number are hypothesized to be a major constraint on the evolution of floral displays, yet few empirical studies have documented such a trade-off. To determine the potential for genetic constraints on the adaptive evolution of floral displays, I estimated the quantitative genetic basis of floral trait variation in two populations of Lobelia siphilitica. Restricted maximum likelihood (REML) analyses of greenhouse-grown half-sib families were used to estimate genetic variances and covariances for flower number and six measures of flower size. There was significant genetic variation for all seven floral traits in both populations. Flower number was negatively genetically correlated with four measures of flower size in one population and three measures in the other. When the genetic variance-covariance matrices were combined with field estimates of phenotypic selection gradients, the predicted multivariate evolutionary response was less than or opposite in sign to the selection gradient for flower number and five of six measures of flower size, suggesting genetic constraints on the evolution of these traits. More generally, my results indicate that the adaptive evolution of floral displays can be constrained by trade-offs between flower size and number, as has been assumed by many theoretical models of floral evolution.

Adaptation, Biological↗

PubMed1995

Substitution of Azotobacter vinelandii hydrogenase small-subunit cysteines by serines can create insensitivity to inhibition by O2 and preferentially damages H2 oxidation over H2 evolution.

Mutants in which conserved cysteines 294, 297 or 64 and 65 of the Azotobacter vinelandii hydrogenase small subunit were replaced by serines were studied. Cysteines 294 and 297 are homologous to cysteines 246 and 249 of the Desulfovibrio gigas hydrogenase, and these cysteines are ligands to the [3Fe-4S] clusters (A. Volbeda, M.-H. Charon, C. Piras, E. C. Hatchikian, M. Frey, and J. C. Fontecilla-Camps, Nature (London) 373:580-587, 1995). Cysteine 65 is homologous to cysteine 20 of the D. gigas hydrogenase, and this cysteine is a ligand to the proximal [4Fe-4S] cluster. All three mutants retained some hydrogenase activity. All three mutants studied had H2 oxidation-to-H2 evolution activity ratios with whole cells of approximately 1.5, compared with 46 for the wild type. The changes preferentially deplete H2 oxidation activity, while having less effect on evolution. The K64,65C-->S hydrogenase was partially purified and had a specific activity for the evolution reaction that was 22% that of the wild type, while the oxidation-specific activity was 2% that of the wild type. Because cysteine 65 provides a ligand to the proximal [4Fe-4S] cluster, this cluster can be altered without entirely eliminating enzyme activity. Likewise, the detection of H2 evolution and H2 oxidation activities with whole cells and membranes of the K294C-->S and K297C-->S mutants indicates that the [3Fe-4S] cluster can also be altered or possibly eliminated without entirely eliminating enzyme activity. Membranes with K294C-->S or K297C-->S hydrogenase were uninhibited by O2 in H2 oxidation and uninhibited by H2 in H2 evolution. Wild-type membranes and membranes with K64,65C-->S hydrogenase were both sensitive to these inhibitors. These data indicate that the [3Fe-4S] cluster controls the reversible inhibition of hydrogenase activity by O2 or H2.

Azotobacter vinelandii↗

PubMed2006

Evolving digital circuits using hybrid particle swarm optimization and differential evolution.

This paper presents the evolution of combinational logic circuits by a new hybrid algorithm known as the Differential Evolution Particle Swarm Optimization (DEPSO), formulated from the concepts of a modified particle swarm and differential evolution. The particle swarm in the hybrid algorithm is represented by a discrete 3-integer approach. A hybrid multi-objective fitness function is coined to achieve two goals for the evolution of circuits. The first goal is to evolve combinational logic circuits with 100% functionality, called the feasible circuits. The second goal is to minimize the number of logic gates needed to realize the feasible circuits. In addition, the paper presents modifications to enhance performance and robustness of particle swarm and evolutionary techniques for discrete optimization problems. Comparison of the performance of the hybrid algorithm to the conventional Karnaugh map and evolvable hardware techniques such as genetic algorithm, modified particle swarm, and differential evolution are presented on a number of case studies. Results show that feasible circuits are always achieved by the DEPSO algorithm unlike with other algorithms and the percentage of best solutions (minimal logic gates) is higher.

Algorithms↗

PubMed2005

Directed evolution strategies for improved enzymatic performance.

The engineering of enzymes with altered activity, specificity and stability, using directed evolution techniques that mimic evolution on a laboratory timescale, is now well established. However, the general acceptance of these methods as a route to new biocatalysts for organic synthesis requires further improvement of the methods for both ease-of-use and also for obtaining more significant changes in enzyme properties than is currently possible. Recent advances in library design, and methods of random mutagenesis, combined with new screening and selection tools, continue to push forward the potential of directed evolution. For example, protein engineers are now beginning to apply the vast body of knowledge and understanding of protein structure and function, to the design of focussed directed evolution libraries, with striking results compared to the previously favoured random mutagenesis and recombination of entire genes. Significant progress in computational design techniques which mimic the experimental process of library screening is also now enabling searches of much greater regions of sequence-space for those catalytic reactions that are broadly understood and, therefore, possible to model. Biocatalysis for organic synthesis frequently makes use of whole-cells, in addition to isolated enzymes, either for a single reaction or for transformations via entire metabolic pathways. As many new whole-cell biocatalysts are being developed by metabolic engineering, the potential of directed evolution to improve these initial designs is also beginning to be realised.

Journal Article↗

PubMed2003

Evolution of energy metabolism and its compartmentation in Kinetoplastida.

Kinetoplastida are protozoan organisms that probably diverged early in evolution from other eukaryotes. They are characterized by a number of unique features with respect to their energy and carbohydrate metabolism. These organisms possess peculiar peroxisomes, called glycosomes, which play a central role in this metabolism; the organelles harbour enzymes of several catabolic and anabolic routes, including major parts of the glycolytic and pentosephosphate pathways. The kinetoplastid mitochondrion is also unusual with regard to both its structural and functional properties.In this review, we describe the unique compartmentation of metabolism in Kinetoplastida and the metabolic properties resulting from this compartmentation. We discuss the evidence for our recently proposed hypothesis that a common ancestor of Kinetoplastida and Euglenida acquired a photosynthetic alga as an endosymbiont, contrary to the earlier notion that this event occurred at a later stage of evolution, in the Euglenida lineage alone. The endosymbiont was subsequently lost from the kinetoplastid lineage but, during that process, some of its pathways of energy and carbohydrate metabolism were sequestered in the kinetoplastid peroxisomes, which consequently became glycosomes. The evolution of the kinetoplastid glycosomes and the possible selective advantages of these organelles for Kinetoplastida are discussed. We propose that the possession of glycosomes provided metabolic flexibility that has been important for the organisms to adapt easily to changing environmental conditions. It is likely that metabolic flexibility has been an important selective advantage for many kinetoplastid species during their evolution into the highly successful parasites today found in many divergent taxonomic groups.Also addressed is the evolution of the kinetoplastid mitochondrion, from a supposedly pluripotent organelle, attributed to a single endosymbiotic event that resulted in all mitochondria and hydrogenosomes of extant eukaryotes. Furthermore, indications are presented that Kinetoplastida may have acquired other enzymes of energy and carbohydrate metabolism by various lateral gene transfer events different from those that involved the algal- and alpha-proteobacterial-like endosymbionts responsible for the respective formation of the glycosomes and mitochondria.

Journal Article↗

PubMed2005

Immunoglobulin M monoclonal gammopathies of undetermined significance and indolent Waldenstrom's macroglobulinemia recognize the same determinants of evolution into symptomatic lymphoid disorders: proposal for a common prognostic scoring system.

PURPOSE: To evaluate the clinicohematologic variables at diagnosis that are prognostically related to neoplastic progression in patients with immunoglobulin M (IgM) monoclonal gammopathies of undetermined significance (MGUS), and indolent Waldenström's macroglobulinemia (IWM), and propose a scoring system to identify subsets of patients at different risk. PATIENTS AND METHODS: We evaluated 217 patients with IgM MGUS and 201 with IWM (male-female ratio, 131:86 and 117:84; mean age, 63.7 and 63.6 years, respectively) diagnosed on the basis of serum monoclonal component (MC) levels and bone marrow lymphoplasmacytic infiltration degree. The variables selected by univariate analyses were multivariately investigated; on the basis of their individual relative hazards, a scoring system was devised to identify subsets of patients at different risk of evolution. RESULTS: After a median follow-up of 56.1 and 60.2 months, 15 of 217 MGUS and 45 of 201 IWM patients, respectively, required chemotherapy for symptomatic WM (13 and 36), non-Hodgkin's lymphoma (2 and 6) and amyloidosis (0 and 3). The median time to evolution (TTE) was not reached for MGUS and was 141.5 months for IWM. The variables adversely related to evolution were qualitatively the same in both groups: MC levels, Hb concentrations and sex. A scoring system based on these parameters identified three risk groups with highly significant differences in TTE in both groups (P < .0001). CONCLUSION: MGUS and IWM identify disease entities with different propensities for symptomatic neoplastic evolution. As both have the same prognostic determinants of progression, we propose a practical scoring system that, identifying different risks of malignant evolution, may allow an individualized clinical approach.

Adult↗

PubMed2002

The localizing value of the abdominal aura and its evolution: a study in focal epilepsies.

OBJECTIVE: To evaluate the localizing value of abdominal aura and its evolution into other seizure types. METHODS: The seizures of 491 consecutive patients with focal epilepsies were prospectively classified according to a recently introduced semiologic seizure classification. All patients underwent prolonged EEG video monitoring and MRI scan. Two hundred twenty-three patients (45%) had temporal lobe epilepsies (TLE); 113 patients (23%) had extratemporal epilepsies; and for 155 (32%) patients, the epilepsy could not be localized to one lobe. RESULTS: Abdominal auras were more frequent with TLE (117 of 223 patients, 52%) than in extratemporal epilepsy (13 of 113 patients, 12%, p < 0.0001) and more frequent in mesial TLE (70 of 110 patients, 64%) than in neocortical TLE (16 of 41 patients, 39%, p = 0.007). No preponderance to one side existed. Abdominal auras were followed by ictal oral and manual automatisms (automotor seizure) in at least one seizure evolution in all patients with TLE (117 patients, 100%). In contrast, only two patients with extratemporal epilepsy (2 of 13 patients, 15%, p < 0.0001) had abdominal auras evolving into automotor seizures. An abdominal aura is associated with TLE with a probability of 73.6%. The evolution of an abdominal aura into an automotor seizure, however, increases the probability of TLE to 98.3%. CONCLUSIONS: These results demonstrate that evolution of abdominal aura into automotor seizure permits differentiation between temporal lobe epilepsy and extratemporal epilepsy, showing that analysis of seizure evolution provides more localizing information than does the frequency of particular seizure types.

Abdomen↗

PubMed1978

Carbon dioxide evolution during the cell cycle of the fission yeast Schizosaccharomyces pombe.

The rate of CO2 evolution was measured in synchronous cultures of the fission yeast Schizosaccharomyces pombe growing in a minimal medium. The rate of CO2 evolution was found to double sharply at about the time of nuclear division (0.75 of the way through the cell cycle). For the remainder of the cell cycle the rate remained constant. Addition of inhibitors of DNA synthesis or nuclear division did not affect the pattern of CO2 evolution in synchronous cultures. Similarly, in an induced synchronous culture, in which DNA synthesis, nuclear division and cell division--but not growth, were synchronized, CO2 evolution showed a continuous pattern and not the step-wise increase associated with the normal synchronous cultures. When S. pombe was grown in a complete medium, the evolution of CO2 in a synchronous cultures was shown to increase in a continuous manner but at a rate faster than the growth of the culture.

Ascomycota↗

PubMedDate not supplied

Effect of alpha-, beta- and gamma-cyclodextrins on oxygen evolution by the thylakoid membrane. influence of pH and temperature.

The present work investigates the effect of alpha-, beta- and gamma-cyclodextrins (CD), i.e., alpha-CD, beta-CD and gamma-CD, on the oxygen evolution activity, the protein content and the uv-vis spectroscopic characteristics of thylakoid membranes. To study the pH-dependence, the thylakoids were incubated with the cyclodextrins at 273 K for a period of 10 min in the pH range from 5.5 to 9.0. To study the temperature-dependence the membranes were incubated at 273 and 293 K at pH 6.5, that is, the pH which induces a maximal oxygen evolution in the thylakoid preparations. The major observations are: (i) a stimulation of oxygen evolution in thylakoids incubated with alpha- and beta-CD either in acidic or alkaline conditions, (ii) a low inhibitory effect induced by gamma-CD on oxygen evolution, (iii) a significant decrease of the stimulatory effect of alpha- and beta-CD on oxygen evolution as the incubation temperature is raised from 273 to 293 K, (iv) the apparent inability of the cyclodextrins to change the protein contents of the thylakoids, and (v) a significant CD-induced red-shift from 681 to 683 nm observed in the absorption and second derivative spectra of the thylakoid membranes treated with beta-CD. First, it was found that the temperature effect described here is in accord with the general trend of the chemical effect of various cyclodextrins, i.e., the increase of the CD efficiency with decreasing temperature. Secondly, the CD effect is related to the size of the inner cavity diameter of the cyclodextrin molecules. An important conclusion in this work is that the molecular targets of the cyclodextrins are not limited to the thylakoid lipids as was described previously [Rawyler A. and Siegenthaler PA. (1996) Biochim. Biophys. Acta 1278, 89-97], but are located as well in other molecular species exposed at the stromal side of the thylakoid membrane. In particular, the CD-induced red-shift from 681 to 683 nm in the absorption and second derivative spectra of the thylakoid membranes indicates that the cyclodextrins targets might be either the exposed heme macrocycle in cytochrome b559, or the chlorophylls and pheophytins in the pigment-proteins of the photosystems I and II.

Chloroplasts↗

PubMed1999

A theoretical model of the evolution of virulence in sexually transmitted HIV/AIDS.

INTRODUCTION: The evolution of virulence in host-parasite relationships has been the subject of several publications. In the case of HIV virulence, some authors suggest that the evolution of HIV virulence correlates with the rate of acquisition of new sexual partners. In contrast some other authors argue that the level of HIV virulence is independent of the sexual activity of the host population. METHODS: Provide a mathematical model for the study of the potential influence of human sexual behaviour on the evolution of virulence of HIV is provided. RESULTS: The results indicated that, when the probability of acquisition of infection is a function both of the sexual activity and of the virulence level of HIV strains, the evolution of HIV virulence correlates positively with the rate of acquisition of new sexual partners. CONCLUSION: It is concluded that in the case of a host population with a low (high) rate of exchange of sexual partners the evolution of HIV virulence is such that the less (more) virulent strain prevails.

Acquired Immunodeficiency Syndrome↗

PubMed2002

Genetic events in the evolution of thyroid cancer.

OBJECTIVE: To delineate the evolution of thyroid cancer using the Volgelstein model of cancer evolution and to demonstrate the genetic "hits" in the development of undifferentiated cancer from normal thyroid cells. METHOD: Immunohistochemical and molecular biologic techniques were used to delineate the prevalence of (1) the ras oncogene, (2) p53, and (3) the ret/PTC oncogene in the development of differentiated thyroid cancer from normal cells and hyperplasia. The evolution of differentiated thyroid cancer to the dedifferentiated or anaplastic type was also investigated. The methodology used was standard immunohistochemical staining techniques as well as polymerase chain reaction technology for the elucidation of these various oncogenes and tumour suppressor genes. RESULTS: We have demonstrated that there is a high preponderance of ras and ret/PTC oncogenes in the evolution of thyroid cancer. Further along the continuum, p53 has been demonstrated to be prevalent in the development of dedifferentiated thyroid cancer (i.e., tall cell and insular variety as well as anaplastic cancer). CONCLUSION: Several genetic hits have been demonstrated to be prevalent in the evolution of thyroid cancer. These are preliminary oncogenic maps, and further work in this area will help to establish a definite biologic pattern in the development of this malignancy.

Carcinoma, Papillary↗

PubMed2002

[Elevation of serum lactate dehydrogenase. Diagnostic, prognostic and evolutive values].

OBJECTIVE: Determination of serum lactate dehydrogenase (LDH) levels is an usual practice. However, its place in the diagnosis process is not clear. We have collected serum LDH levels superior to 2-fold the normal rate and we tried to determine their diagnostics interest and, predictive and progressive values. METHODS: Retrospective study during 3 months in hospitalized adults. LDH levels were measured by spectrophotometry (Normal rate: 313-618 UI/L). RESULTS: 196 cases with LDH level elevations higher than 1236 UI/L were analyzed. The etiology of LDH level elevations were was benign in 60% of cases, malignant in 36% and, undetermined in 5%. There was no difference in between average values of LDH level average values of benign and malignant etiology (2708 vs 2842 UI/l). LDH rates and high LDH level elevations were not helpful for in the diagnosis process (a variety of 43 etiology was able to elevate increased LDH rates). In 45% cases, LDH level was 2 to 3-fold the normal rate; in 47.5% cases, 3 to 10-fold normal rate, and in 7.5% cases, superior to 10-fold normal rate. LDH elevations superior to 10-fold the normal rate were caused by benign etiology in 11 cases and malignant disease in 4 cases. A level superior to 10-fold the normal rate was not helpful in determining to determine the benign or malignant characteristics of the initial disease. However, LDH rate superior to 10 normal rate was a pejorative predictive criteria (hospitalization in intensive careunity in 73% of cases and mortality rate of 53%). During follow up of a neoplasia or malignant hemopathy follow up, several LDH measurements LDH level determinations were determined in for a small number of patients. LDH level normalizations is are attributable to efficientan effective treatment; LDH level elevations are associated with a therapeutic failure echappment. Evolution in LDH levels evolution was influenced by progression in neoplasia and malignant hemopathy evolution and also by various several treatments such as like blood transfusions, growth factors, radiotherapy and chemotherapy. CONCLUSION: LDH level elevation, however whatever its rate, don't seem to do not help in differentiating have interest to differentiate benign from malignant diseases. However, an elevation LDH elevation higher than 10-fold the normal rate is a pejorative predictive criteria, since because the mortality rate is superior toupper than 50%. During follow-up of in the neoplasia and malignant hemopathy follow up, so long as they are measured at distance from treatment, variations in LDH levels are a good marker of evolution, rate variations represent an evolutive marker conditionally the level determination would be realize remote several treatment.

Adolescent↗

PubMed2003

[Spectroscopic study on the time evolution behaviors of the laser-induced air plasma].

The time-resolved spectra of the air-breakdown plasma produced by the 1.06 microns beam of a Nd:YAG laser were investigated by using the time-delayed spectra and the spectral line evolution methods. The time evolutions of the short wavelength band and long wavelength band of the continuous spectra of the air-breakdown plasma have been measured. The result shows that the decay rates of both bands are slowing down 0.5 microsecond after the excitation of the plasma, and the attachment and the detachment of free electrons by O2 in the plasma could be the reason for this behavior. The results of the time-resolved measurements of the line spectra show that most of the line spectra have the evolution time longer than their lifetimes, and the evolutions of some line spectra take a fashion of "decay-grow-decay". We consider these evolution behaviors of the line spectra to be related to various recombination processes and the energy transfer processes of the decaying plasma.

Air↗

PubMed2003

Hypothalamic hamartoma and epilepsy in children: illustrative cases of possible evolutions.

The progresses of neuroimaging have allowed an earlier detection of hypothalamic hamartoma in children presenting with gelastic or dacrystic seizures. Associated symptoms can include other types of seizures, precocious puberty, and behavioral or cognitive deterioration. Combination of all these features is not constant and, when present, their evolution may be variable. When epilepsy proves intractable, surgery may be a solution but is not without risks. Therefore, it can only be justified on the basis of a considerable degree of certainty on the progressive character of the disorder, both in terms of epilepsy and global development. Even though epilepsy is a major and usually the most important problem, it is not always possible to predict its course and to be able to evaluate its potential effects on development. Available data suggests that deterioration is partly related to the epileptogenic activity. We reviewed data from 16 personal cases and discussed the possible evolutions of the epilepsy syndrome on the basis of 6 illustrative cases and a review of the literature. We point out that seizures may start early in life and evolve either towards a catastrophic encephalopathy or may be transiently severe and will progressively settle down. Intermediate situations also exist as well as cases presenting with a mild epilepsy. In almost all cases cognitive difficulties are present and may be associated with behavioral disturbances. They are of variable severity, usually in relation to the severity of the epilepsy and the evolution of the EEG abnormalities. Some of our cases also illustrate that, in young children whose seizures are limited to "a sensation of a pleasant feeling", "a pressure to laugh" or "smiling", early detection of the hamartoma may still be difficult and the epilepsy pattern may be misdiagnosed as an epilepsy temporal or frontal origin. Detailed analysis of the electro-clinical evolution of representative cases highlights the variable expression of the epilepsy syndrome and renders difficult any dogmatic position on early surgery. However, recent data suggests that a surgical solution must be sought early. Prospective studies are needed to evaluate, not only outcome in terms of control the seizures without unacceptable side effects but also on the evolution of the cognitive and behavioral profile of children with HH and epilepsy are needed.

Adolescent↗

PubMed2004

[Affecting factors of CO2 evolution from biodegradation of agricultural organic wastes].

On the basis of a preliminary orthogonal design experiment, from which, the primary parameters suitable for the CO2 evolution from bio-degradation of agricultural organic wastes had been obtained, four single factor experiments were installed in greenhouse to seek the optimal parameters for the CO2 evolution. The results showed that the optimal parameters for the CO2 evolution from the bio-degradation of rice straw-pig manure mixture were 50 degrees C, 70% water content and initial pH 6.0-7.0. For fermentation, the optimal initial C/N ratio of substrate for cumulative CO2 evolution was 40/1, but 30/1 was better for compost. The effect of the four parameters on CO2 evolution was in the order of C/N ratio and water content > temperature > pH.

Agriculture↗