scholarly journals Observations on the mobilization of peat nitrogen in incubation experiments

1959 ◽  
Vol 31 (1) ◽  
pp. 268-281
Author(s):  
Jaakko Kivekäs ◽  
Erkki Kivinen
Keyword(s):  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
The Other ◽  
Incubation Experiments ◽  
Different Types ◽  
Working Out ◽  
Original Amount

60 peat samples from northern Finland representing different types of peat were incubated in a laboratory at a temperature of 17—18° C. The ammonium nitrogen, the nitrate nitrogen and the pH in the samples were determined after one month of incubation as well as after three months of incubation. The results were compared to results from determinations made before incubation. An attempt was made to elucidate the factors that influence the mobilization of nitrogen. On the basis of the above results it is evident that the differences between the various peat types as mobilizers of nitrogen are under these circumstances not very distinct, nor do these differences seem to be dependent on the types of peat. The following facts can, however, be established: In the amounts of ammonium nitrogen an increase takes place in most groups of samples during the first month. This increase is fairly big in the Sphagnum-dominated peats. The increase in ammonium nitrogen continues in the unlimed samples in most peat groups during all three months of incubation. After three months of incubation the amount of ammonium nitrogen in the limed samples is smaller than in the unlimed samples, although it is usually bigger than in the original samples. After the first month of incubation the amounts of nitrate nitrogen in all types of peat have decreased compared to the amounts in the original samples. In the limed samples the decrease is not as great as in the unlimed ones. After three months of incubation the amount of nitrate nitrogen has considerably increased as compared to the amount after one month of incubation. In the limed samples it might to some extent exceed the original amount of nitrate nitrogen, however, this is seldom the case in the unlimed samples. If the results are calculated on the basis of weight unit, it can be stated that the ability to mobilize nitrogen is greater in the Sphagnum peats than in the other peat groups. Working out the results in kg per ha it will be noted that somewhat more nitrogen is mobilized in the Carex-dominated than in the Sphagnum-dominated peats. The results obtained by experiments in the laboratory are not directly applicable to conditions in the field.

scholarly journals Influence of lime on the accumulation of mineral nitrogen in incubation experiments of peat soils

1957 ◽  
Vol 29 (1) ◽  
pp. 229-237
Author(s):  
Armi Kaila ◽  
Sylvi Soini
Keyword(s):  
Nitrate Nitrogen ◽  
Nitrogen Nutrition ◽  
Ammonium Nitrogen ◽  
Mineral Nitrogen ◽  
Peat Soils ◽  
Prolonged Incubation ◽  
The Third ◽  
Nitrite Nitrogen ◽  
Incubation Experiments ◽  
Three Samples

In the present paper the effect of lime on the mobilization of peat nitrogen was studied using incubation experiments under laboratory conditions. In the first experiment in which 13 samples of virgin peat soils were incubated for four months at 7°C, lime caused a marked nitrification of ammonium nitrogen in three samples, and a fairly low increase in the ammonium nitrogen content of five samples. The accumulation of total mineral nitrogen was benefited by lime in five samples and only in one of them could a marked increase be detected. In the second experiment the amounts of lime applied to five peat samples corresponded to 4000, 8000 or 12 000 kg/ha of CaCO3. At the end of an incubation period of four months at 9—15°C the total amounts of mineral nitrogen accumulated did not depend on the fate of liming, as did the nitrification in SCp-and BCp-samples, and also, in part, in the Sp- and CSp-samples. After the prolonged incubation up to 12 months the amount of lime applied had little or no effect upon the accumulation of nitrate-nitrogen or total mineral nitrogen except in the SCp-sample in which a positive correlation between these figures existed. Traces of nitrite-nitrogen were detected in some of the samples incubated for four months with the heaviest applications of lime. In the third experiment carried out at 7°C the treatment with lime was equal to that in the second series, but half of the pots were treated with ammonium nitrate corresponding to 100 kg/ha of nitrogen. The effect of lime on the treated samples appeared to be similar to that in the untreated one. Owing to the large variation, the fate of applied mineral nitrogen could not be distinctly detected. The loss of ammonium nitrogen through volatilization from the most heavily limed pots may be a possible explanation for the lower amounts of total mineral nitrogen in the incubated BCp-samples. Some reasons for these variable results are discussed and attention is also paid to the importance of nitrification on the nitrogen nutrition of plants.

scholarly journals The bacterial oxidation of ammonia in the sea

1956 ◽  
Vol 35 (3) ◽  
pp. 621-630 ◽  
Author(s):  
C. P. Spencer
Keyword(s):  
Nitrogen Cycle ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
Open Ocean ◽  
The Other ◽  
Bacterial Oxidation ◽  
Land Drainage ◽  
Bottom Deposits ◽  
Other Hand ◽  
Oxidation Of Ammonia

The final regeneration stages of the nitrogen cycle in the sea are believed to consist of the bacterial oxidation of ammonium-nitrogen to nitrite and finally nitrate-nitrogen. There have been many attempts to demonstrate the presence in the sea of marine counterparts to the terrestrial Nitrosomonas and Nttrobacter. (See Zobell, 1946, for bibliography of the earlier work.) Bacteria which can oxidize either ammonia or nitrite are easily demonstrated in samples of bottom material or water contaminated by land drainage or bottom deposits. On the other hand, there has been general failure to demonstrate the presence of such species in the upper layers of the open ocean.

scholarly journals Effect of thinning on the amount of mineral nitrogen

2018 ◽  
Vol 64 (No. 7) ◽  
pp. 289-295
Author(s):  
Holík Ladislav ◽  
Rosíková Jana ◽  
Vranová Valerie
Keyword(s):  
Nitrogen Content ◽  
Soil Nitrogen ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
The Other ◽  
Small Decrease ◽  
The Impact ◽  
The Given ◽  
Soil Nitrogen Cycle ◽  
Insight Into

The soil nitrogen cycle and the dynamics of its transformation are closely related to the functioning of the forest ecosystem. This cycle, and the availability of nitrogen as a necessary nutrient in the soil, can be influenced by the process of thinning. The aim of this study is to describe the impact of silvicultural measures on the content of ammonium and nitrate nitrogen in forest soil. Attention is paid to the organic (spruce treatments) and organomineral horizon (beech treatments) in which the transformation of soil nitrogen is most pronounced. Spruce treatments at the Rájec-Němčice area and beech stands at the Březina area, both in the region of Drahanská vrchovina (Czech Republic), were selected for the experiments. Two variants of thinning thinning from below and thinning from above, were performed in the spruce treatments, and thinning from above was performed in the beech treatments. Control variants with no silvicultural measures were defined in both treatments. The amount of ammonium nitrogen in the spruce treatments with thinning from above was in most cases higher than in the other variants. On the contrary, in variant with thinning from below, the ammonium nitrogen content decreased. In terms of the nitrate nitrogen content, the values were generally higher for variants with silvicultural measures than for the control variants. In the beech treatments, the amount of ammonium nitrogen increased and, on the contrary, there was a small decrease in the amount of nitrate nitrogen due to the effect of thinning from above. The differences between thinning from above and the control variants in the beech treatments were less noticeable than in the spruce treatments. Overall, however, it can be said that the nitrogen content available to the vegetation increased. The results of the given experiment provide insight into the trends of nitrogen mineralization intensity in stands in which silvicultural measures are performed.

scholarly journals Hiketeia

1973 ◽  
Vol 93 ◽  
pp. 74-103 ◽  
Author(s):  
John Gould
Keyword(s):  
Dominant Role ◽  
Ancient Greece ◽  
Social Institutions ◽  
The Other ◽  
Sixth Century ◽  
Dead Body ◽  
Greek Literature ◽  
The World ◽  
The One ◽  
Working Out

To Professor E. R. Dodds, through his edition of Euripides'Bacchaeand again inThe Greeks and the Irrational, we owe an awareness of new possibilities in our understanding of Greek literature and of the world that produced it. No small part of that awareness was due to Professor Dodds' masterly and tactful use of comparative ethnographic material to throw light on the relation between literature and social institutions in ancient Greece. It is in the hope that something of my own debt to him may be conveyed that this paper is offered here, equally in gratitude, admiration and affection.The working out of the anger of Achilles in theIliadbegins with a great scene of divine supplication in which Thetis prevails upon Zeus to change the course of things before Troy in order to restore honour to Achilles; it ends with another, human act in which Priam supplicates Achilles to abandon his vengeful treatment of the dead body of Hector and restore it for a ransom. The first half of theOdysseyhinges about another supplication scene of crucial significance, Odysseus' supplication of Arete and Alkinoos on Scherie. Aeschylus and Euripides both wrote plays called simplySuppliants, and two cases of a breach of the rights of suppliants, the cases of the coup of Kylon and that of Pausanias, the one dating from the mid-sixth century, the other from around 470 B.C. or soon after, played a dominant role in the diplomatic propaganda of the Spartans and Athenians on the eve of the Peloponnesian War.

Comparative Surface Imaging Study of Multifocal Diffractive Intraocular Lenses

2021 ◽  
Author(s):  
Hyeck Soo Son ◽  
Jung Min Lee ◽  
Ramin Khoramnia ◽  
Chul Young Choi
Keyword(s):  
Imaging Study ◽  
The Other ◽  
Intraocular Lenses ◽  
Optical Surface ◽  
Diffractive Optic ◽  
Atomic Force ◽  
Acceptable Range ◽  
Different Types ◽  
Concentric Pattern

Abstract Purpose To analyse and compare the surface topography and roughness of three different types of diffractive multifocal IOLs. Methods Using scanning electron microscope (SEM, Inspect F, 5.0 KV, maximum magnification up to 20,000) and atomic force microscope (AFM, Park Systems, XE-100, non-contact, area profile comparison, 10 × 10 µm, 40 × 40 µm), the surface quality of the following diffractive IOLs was studied: the AcrySof IQ PanOptix (Alcon, USA), the AT LARA 829MP (Carl Zeiss Meditec, Germany), and Tecnis Symfony (Johnson&Johnson Vision, USA). The measurements were made over three representative areas (central non-diffractive optic, central diffractive optic, and diffractive step) of each IOL. Roughness profile in terms of mean arithmetic roughness (Ra) and root-mean-squared roughness (Rq) values were obtained and compared statistically. Results In SEM examination, all IOLs showed a smooth optical surface without any irregularities at low magnification. At higher magnification, Tecnis Symfony showed unique highly regular, concentric, and lineate structures in the diffractive optic area which could not be seen in the other studied diffractive IOLs. The differences in the measured Ra and Rq values of the Tecnis Symfony were statistically significant compared to the other models (p < 0.05). Conclusion Various different topographical traits were observed in three diffractive multifocal IOLs. The Ra values of all studied IOLs were within an acceptable range. Tecnis Symfony showed statistically significant higher surface Ra values at both central diffractive optic and diffractive step areas. Furthermore, compared to its counterparts, Tecnis Symfony demonstrated highly ordered, concentric pattern in its diffractive surfaces.

RADIATION EXPOSURE TO THE BACK WITH DIFFERENT TYPES OF APRONS

2021 ◽  
Author(s):  
Seung Wan Hong ◽  
Tae Won Kim ◽  
Jae Hun Kim
Keyword(s):  
Radiation Exposure ◽  
Effective Dose ◽  
Exposure Time ◽  
The Other ◽  
Lead Apron ◽  
Type Group ◽  
Air Kerma ◽  
Different Types ◽  
The Relationship

Abstract Physicians and nurses stand with their back towards the C-arm fluoroscope when using the computer, taking things out of closets and preparing drugs for injection or instruments for intervention. This study was conducted to investigate the relationship between the type of lead apron and radiation exposure to the backs of physicians and nurses while using C-arm fluoroscopy. We compared radiation exposure to the back in the three groups: no lead apron (group C), front coverage type (group F) and wrap-around type (group W). The other wrap-around type apron was put on the bed instead of on a patient. We ran C-arm fluoroscopy 40 times for each measurement. We collected the air kerma (AK), exposure time (ET) and effective dose (ED) of the bedside table, upper part and lower part of apron. We measured these variables 30 times for each location. In group F, ED of the upper part was the highest (p &lt; 0.001). ED of the lower part in group C and F was higher than that in group W (p = 0.012). The radiation exposure with a front coverage type apron is higher than that of the wrap-around type and even no apron at the neck or thyroid. For reducing radiation exposure to the back of physician or nurse, the wrap-around type apron is recommended. This type of apron can reduce radiation to the back when the physician turns away from the patient or C-arm fluoroscopy.

scholarly journals MITOTIC CROSSING OVER AND NONDISJUNCTION IN TRANSLOCATION HETEROZYGOTES OF ASPERGILLUS

Genetics ◽  
1976 ◽  
Vol 82 (4) ◽  
pp. 605-627
Author(s):  
Etta Käfer
Keyword(s):  
Selective Advantage ◽  
The Other ◽  
Translocation Chromosome ◽  
Crossing Over ◽  
Selective Marker ◽  
Reciprocal Translocations ◽  
Poor Growth ◽  
Different Types ◽  
Diploid Genotype ◽  
One Step

ABSTRACT To analyze mitotic recombination in translocation heterozygotes of A. nidulans two sets of well-marked diploids were constructed, homo- or heterozygous for the reciprocal translocations T1(IL;VIIR) or T2(IL;VIIIR) and heterozygous for selective markers on IL. It was found that from all translocation heterozygotes some of the expected mitotic crossover types could be selected. Such crossovers are monosomic for one translocated segment and trisomic for the other and recovery depends on the relative viabilities of these unbalanced types. The obtained segregants show characteristically reduced growth rates and conidiation dependent on sizes and types of mono- and trisomic segments, and all spontaneously produce normal diploid sectors. Such secondary diploid types either arose in one step of compensating crossing over in the other involved arm, or—more conspicuously—in two steps of nondisjunction via a trisomic intermediate.—In both of the analyzed translocations the segments translocated to IL were extremely long, while those translocated from IL were relatively short. The break in I for T1(I;VII) was located distal to the main selective marker in IL, while that of T2(I;VIII) had been mapped proximal but closely linked to it. Therefore, as expected, the selected primary crossover from the two diploids with T2(I;VIII) in coupling or in repulsion to the selective marker, showed the same chromosomal imbalance and poor growth. These could however be distinguished visually because they spontaneously produced different trisomic intermediates in the next step, in accordance with the different arrangement of the aneuploid segments. On the other hand, from diploids heterozygous for T1(I;VII) mitotic crossovers could only be selected when the selective markers were in coupling with the translocation; these crossovers were relatively well-growing and produced frequent secondary segregants of the expected trisomic, 2n+VII, type. For both translocations it was impossible to recover the reciprocal crossover types (which would be trisomic for the distal segments of I and monosomic for most of groups VII or VIII) presumably because these were too inviable to form conidia.—In addition to the selected segregants of expected types a variety of unexpected ones were isolated. The conditions of selection used favour visual detection of aneuploid types, even if these produce only a few conidial heads and are not at a selective advantage. For T2(I;VIII) these "non-selected" unbalanced segregants were mainly "reciprocal" crossovers of the same phenotype and imbalance as the selected ones. For T1(I;VII) two quite different types were obtained, both possibly originating with loss of the small VII-Itranslocation chromosome. One was isolated when the selective marker in repulsion to T1(I;VII) was used and, without being homo- or hemizygous for the selective marker, it produced stable sectors homozygous for this marker. The other was obtained from both coupling and repulsion diploids and showed a near-diploid genotype; it produced practically only haploid stable sectors of the type expected from monosomics, 2n-1 for the short translocation chromosome.

scholarly journals Development of Speech Recognition Systems in Emergency Call Centers

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 634
Author(s):  
Alakbar Valizada ◽  
Natavan Akhundova ◽  
Samir Rustamov
Keyword(s):  
Speech Recognition ◽  
Markov Model ◽  
Hidden Markov ◽  
Call Centers ◽  
The Other ◽  
Language Models ◽  
Emergency Call ◽  
Acoustic Model ◽  
Different Types ◽  
Recognition Systems

In this paper, various methodologies of acoustic and language models, as well as labeling methods for automatic speech recognition for spoken dialogues in emergency call centers were investigated and comparatively analyzed. Because of the fact that dialogue speech in call centers has specific context and noisy, emotional environments, available speech recognition systems show poor performance. Therefore, in order to accurately recognize dialogue speeches, the main modules of speech recognition systems—language models and acoustic training methodologies—as well as symmetric data labeling approaches have been investigated and analyzed. To find an effective acoustic model for dialogue data, different types of Gaussian Mixture Model/Hidden Markov Model (GMM/HMM) and Deep Neural Network/Hidden Markov Model (DNN/HMM) methodologies were trained and compared. Additionally, effective language models for dialogue systems were defined based on extrinsic and intrinsic methods. Lastly, our suggested data labeling approaches with spelling correction are compared with common labeling methods resulting in outperforming the other methods with a notable percentage. Based on the results of the experiments, we determined that DNN/HMM for an acoustic model, trigram with Kneser–Ney discounting for a language model and using spelling correction before training data for a labeling method are effective configurations for dialogue speech recognition in emergency call centers. It should be noted that this research was conducted with two different types of datasets collected from emergency calls: the Dialogue dataset (27 h), which encapsulates call agents’ speech, and the Summary dataset (53 h), which contains voiced summaries of those dialogues describing emergency cases. Even though the speech taken from the emergency call center is in the Azerbaijani language, which belongs to the Turkic group of languages, our approaches are not tightly connected to specific language features. Hence, it is anticipated that suggested approaches can be applied to the other languages of the same group.

Plausibility and Aesthetic Interpretation

1977 ◽  
Vol 7 (2) ◽  
pp. 327-340 ◽  
Author(s):  
Denis Dutton
Keyword(s):  
Scientific Inquiry ◽  
The Other ◽  
Inquiry Science ◽  
Works Of Art ◽  
Different Types ◽  
Logical Structures ◽  
The One

If a catalogue were made of terms commonly used to affirm the adequacy of critical interpretations of works of art, one word certain to be included would be “plausible.” Yet this term is one which has received precious little attention in the literature of aesthetics. This is odd, inasmuch as I find the notion of plausibility central to an understanding of the nature of criticism. “Plausible” is a perplexing term because it can have radically different meanings depending on the circumstances of its employment. ln the following discussion, I will make some observations about the logic of this concept in connection with its uses in two rather different contexts: the context of scientific inquiry on the one hand, and that of aesthetic interpretation on the other. In distinguishing separate senses of “plausible,” I shall provide reason to resist the temptation to imagine that because logical aspects of two different types of inquiry—science and criticism—happen to be designated by the same term, they may to that extent be considered to have similar logical structures.

Comparison of two types of inocula during acclimation and stable operation for nitrophenol biodegradation in an anaerobic-aerobic SBR

2006 ◽  
Vol 54 (10) ◽  
pp. 39-45
Author(s):  
A. Vargas ◽  
D. González ◽  
A. Estival ◽  
G. Buitrón
Keyword(s):  
Wastewater Treatment ◽  
Treatment Plant ◽  
The Other ◽  
Stable Operation ◽  
Reaction Phase ◽  
Toxic Compound ◽  
Anaerobic Wastewater Treatment ◽  
Significant Difference ◽  
Different Types ◽  
Batch Bioreactors

This work presents a comparison of two inocula used for the acclimation of two anaerobic-aerobic sequencing batch bioreactors used for toxic wastewater treatment. The bioreactors were acclimated with different types of sludge: one coming from an anaerobic wastewater treatment plant and the other one from a conventional aerobic activated sludge plant. The model toxic compound was p-nitrophenol, which is reduced to p-aminophenol during the initial anaerobic phase of the reaction, and later mineralized during a posterior aerated reaction phase. Biodegradation of the compounds was monitored using UV/Vis spectrophotometry. After acclimation stabilization of the sludge and of the process was also monitored. Results show that there is no significant difference in acclimation times and stability of the process between the two employed inocula, and thus an originally anaerobic inoculum presents no apparent advantage over a more easily accessible aerobic one.

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