PRODUCTION OF VITAMIN B12 BY RHIZOBIUM SPECIES

1952 ◽  
Vol 30 (5) ◽  
pp. 521-524 ◽  
Author(s):  
Margaret O. Burton ◽  
A. G. Lochhead

A study was made of the capacity for synthesis of vitamin B12 by 70 strains representing six species of Rhizobium, namely, R. meliloti, R. trifolii, R. leguminosarum, R. japonicum, R. lupini, and R. phaseoli. Rhizobium meliloti was sharply distinguished from the other species by its ability to produce significantly higher quantities of the vitamin, one strain producing, under the experimental conditions, over 1000 mμgm. per ml. of culture liquid. The remaining species did not show significant differences in B12 synthesizing capacity. No correlation was noted between vitamin-producing capacity and effectiveness of the individual strains with respect to nitrogen fixation.

2013 ◽  
Vol 295-298 ◽  
pp. 1209-1214 ◽  
Author(s):  
Si Hang Shan ◽  
Peng Fei Fan ◽  
Yi Xing ◽  
Geng Qiao

Two kinds of vitamin B12 waste water from a pharmaceutical factory were treated separately by methods of combining micro-electrolysis with physiochemical and O3 oxidation. Effects of the reaction conditions on the removal rate of color were investigated. Results showed that the color removal rate of vitamin B12 waste water, which was treated by combined micro-electrolysis and physiochemical treatment reached 71.25%, while the color removal rate of the other waste water which treated by O3 oxidation reached 68.80%. The decolorizing treatment of those different natures of vitamin B12 waste water effectively provides a useful reference for this kind of waste water.


1978 ◽  
Vol 13 (2) ◽  
pp. 95-102 ◽  
Author(s):  
P S Theocaris ◽  
E E Gdoutos

A unified interpretation of interferometric and holographic fringe patterns obtained from birefringent materials is presented by using physical concepts only. The two fundamental fringe systems, corresponding to the individual stress-optical retardations along the principal stress directions, are considered to recombine mechanically for the formation of isochromatic and isopachic fringe patterns. This mechanical interference is shown to be more pronounced only when certain conditions concerning the position and the spatial frequencies of the original systems are satisfied. It is shown that only one of the isochromatic and isopachic fringe patterns, corresponding to the shorter diagonals of the individual quadrangles, formed by the two initial fundamental fringe systems, is obtained under normal experimental conditions, and that it is possible to have in one region of the pattern one system and in another region the other. Both isochromatics and isopachics can be obtained only when special precautions are taken during the application of the particular experimental method. The factors influencing the formation of either the isochromatics or the isopachics, or both, are indicated and analysed. The existing confusion in the literature concerning the interpretation of holo-interferometric patterns is thoroughly discussed and clarified. Two simple examples—that is, the circular disc in diametral compression and the infinite plate with a circular hole in tension—are selected to show the main features in this interpretation.


1986 ◽  
Vol 59 (1) ◽  
pp. 27-39 ◽  
Author(s):  
Rabindra Nath Datta ◽  
Dipak Kumar Basu

Abstract The hplc studies with all their limitations have been employed to obtain information regarding the vulcanization of rubber accelerated by CTOS and MBTS in the early part of the reaction. It is noticed that even in the initial part of the induction period (the scorch safety, t2, of the recipe is 10.5 min), CTOS and MBTS react so rapidly with each other and also with rubber that at the end of 10 min we could detect only MBT, while the concentration of the other components formed in the reaction—namely, CTOS, OBTS, CPTD, BPTD, PMTU, CPTM, BPTM, etc.—decreased to an extremely low level. We noticed that under the experimental conditions, OBTS and CPTU have the same retention time. This naturally obscures the path for understanding the individual effect of these accelerators. The sharp disappearance of OBTS, associated with the abundant formation of MBT and nonavailability of CPTU (from CPTD, Figure 11b), gives testimony to the fact that the unsymmetrical thiourea (PMTU) rather than the symmetrical one (CPTU) is solely formed in the vulcanizates under discussion. The accelerating as well as retarding effect of thiourea has been reported by Dućhac^ek in the vulcanization of NR. Substituted thiourea, namely, bis(oxydiethylene) thiourea, has also been shown to influence the vulcanization of SBR in the presence of a mixture of accelerators formed by the early reaction of OTOS and OBTS. The influence of PMTU, however, remains to be investigated, and studies in this line are being pursued. Also, we could not isolate the effect of MDB from that of CPTD, since both of them have the same retention time. From our experience, we know that in comparison with CPTD, the proportion of MDB formed under the experimental conditions is very low and, hence, it is believed that CPTD plays the major role. It has also been observed that BPTD rapidly transforms into BPTM which, as noticed by us, also influences vulcanization. It is concluded that in the binary system containing CTOS and MBTS, the intermediate accelerators, OBTS, CPTD, and BPTD play a vital role, and their growth and decay, either in the presence or absence of the ZDC, control the fate of the vulcanization reaction.


2018 ◽  
Vol 120 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Eva Greibe ◽  
Linda S. Kornerup ◽  
Christian B. Juul ◽  
Sergey N. Fedosov ◽  
Christian W. Heegaard ◽  
...  

AbstractRecent rat studies show different tissue distributions of vitamin B12 (B12), administered orally as hydroxo-B12 (HO-B12) (predominant in food) and cyano-B12 (CN-B12) (common in supplements). Here we examine male Wistar rats kept on a low-B12 diet for 4 weeks followed by a 2-week period on diets with HO-B12 (n 9) or CN-B12 (n 9), or maintained on a low-B12 diet (n 9). Plasma B12 was analysed before, during and after the study. The content of B12 and its variants (HO-B12, glutathionyl-B12, CN-B12, 5'-deoxyadenosyl-B12 (ADO-B12), and methyl-B12 (CH3-B12)) were assessed in the tissues at the end of the study. A period of 4 weeks on the low-B12 diet reduced plasma B12 by 58 % (from median 1323 (range 602–1791) to 562 (range 267–865) pmol/l, n 27). After 2 weeks on a high-B12 diet (week 6 v. week 4), plasma B12 increased by 68 % (HO-B12) and 131 % (CN-B12). Total B12 in the tissues accumulated differently: HO-B12>CN-B12 (liver, spleen), HO-B12<CN-B12 (kidneys), and HO-B12≈CN-B12 (brain, heart). Notably, more than half of the administered CN-B12 remained in this form in the kidneys, whereas HO-B12 was largely converted to the bioactive ADO-B12. Only <10 % of the other cofactor, CH3-B12, were found in the tissues. In conclusion, dietary CN-B12 caused a higher increase in plasma and total kidney B12 but provided less than half of the active coenzymes in comparison to dietary HO-B12. These data argue that HO-B12 may provide a better tissue supply of B12 than CN-B12, thereby underscoring the lack of a direct relation between plasma B12 and tissue B12.


1934 ◽  
Vol 11 (4) ◽  
pp. 382-396
Author(s):  
L. C. BEADLE

1. The triclad turbellarian Gunda ulvae in its normal habitat is daily subjected both to sea water and to pure stream water. Under experimental conditions it can live permanently in any concentration of sea water down to 5 per cent. It is thus able to maintain a relatively constant internal against a rapidly changing external environment. 2. The manner in which this is done is suggested by the results of the above experiments, from which it is concluded that the following is the course of events when the animal is transferred from pure to dilute sea water (e.g. 10 per cent.): (a) An initial inflow of water through the ectoderm into the parenchyma which causes swelling and a temporary lowering of activity. (b) This water is taken up by the gut cells in the form of intracellular vacuoles, a process which entails expenditure of energy and can be inhibited by cyanide. The parenchyma is thus restored to its original condition and full activity is recovered. (c) After the initial inflow of water the animal begins to set up a resistance, which appears to be effected by a decrease of permeability to water of the ectodermal membrane. (d This resistance is maintained and the gut cells remain vacuolated so long as the animal is kept in dilute sea water. 3. The excretory (water-vascular) system plays no obvious part in this mechanism. 4. Distinction must be drawn between the ultimate impermeability of the ectoderm considered as a membrane and the osmotic resistance of the individual cells of this layer and of the other tissues. The permeability of the ectodermal membrane can be reversibly increased by calcium deficiency, but the osmotic resistance of its individual cells cannot be broken down by these means. This can be brought about by decreasing the osmotic pressure of the water to that of 2 per cent, sea water. Under these conditions the presence of calcium may retard but does not prevent the final swelling and disintegration of the cells, a process which is irreversible. 5. It is suggested that both vacuole formation by the gut cells and the osmotic resistance set up by the individual cells of the other tissues are active processes entailing expenditure of energy, whereas the resistance of the ectodermal membrane to inflow of water into the parenchyma is a passive impermeability.


1976 ◽  
Vol 41 (4) ◽  
pp. 523-529 ◽  
Author(s):  
Daniel R. Boone ◽  
Harold M. Friedman

Reading and writing performance was observed in 30 adult aphasic patients to determine whether there was a significant difference when stimuli and manual responses were varied in the written form: cursive versus manuscript. Patients were asked to read aloud 10 words written cursively and 10 words written in manuscript form. They were then asked to write on dictation 10 word responses using cursive writing and 10 words using manuscript writing. Number of words correctly read, number of words correctly written, and number of letters correctly written in the proper sequence were tallied for both cursive and manuscript writing tasks for each patient. Results indicated no significant difference in correct response between cursive and manuscript writing style for these aphasic patients as a group; however, it was noted that individual patients varied widely in their success using one writing form over the other. It appeared that since neither writing form showed better facilitation of performance, the writing style used should be determined according to the individual patient’s own preference and best performance.


2008 ◽  
Vol 1 (2) ◽  
pp. 187-199
Author(s):  
KATHRYN WALLS

According to the ‘Individual Psychology’ of Alfred Adler (1870–1937), Freud's contemporary and rival, everyone seeks superiority. But only those who can adapt their aspirations to meet the needs of others find fulfilment. Children who are rejected or pampered are so desperate for superiority that they fail to develop social feeling, and endanger themselves and society. This article argues that Mahy's realistic novels invite Adlerian interpretation. It examines the character of Hero, the elective mute who is the narrator-protagonist of The Other Side of Silence (1995) , in terms of her experience of rejection. The novel as a whole, it is suggested, stresses the destructiveness of the neurotically driven quest for superiority. Turning to Mahy's supernatural romances, the article considers novels that might seem to resist the Adlerian template. Focusing, in particular, on the young female protagonists of The Haunting (1982) and The Changeover (1984), it points to the ways in which their magical power is utilised for the sake of others. It concludes with the suggestion that the triumph of Mahy's protagonists lies not so much in their generally celebrated ‘empowerment’, as in their transcendence of the goal of superiority for its own sake.


2011 ◽  
Vol 2011 (1) ◽  
pp. 5-28
Author(s):  
Jens Bonnemann

In ethics, when discussing problems of justice and a just social existence one question arises obviously: What is the normal case of the relation between I and you we start from? In moral philosophy, each position includes basic socio-anthropological convictions in that we understand the other, for example, primarily as competitor in the fight for essential resources or as a partner in communication. Thus, it is not the human being as isolated individual, or as specimen of the human species or socialised member of a historical society what needs to be understood. Instead, the individual in its relation to the other or others has been studied in phenomenology and the philosophy of dialogue of the twentieth century. In the following essay I focus on Martin Buber’s and Jean-Paul Sartre’s theories of intersubjectivity which I use in order to explore the meaning of recognition and disrespect for an individual. They offer a valuable contribution to questions of practical philosophy and the socio-philosophical diagnosis of our time.


2020 ◽  
Vol 10 (3) ◽  
pp. 43-57
Author(s):  
See Seng Tan

Abstract: The longstanding effort to develop a people-based regionalism in Southeast Asia has been shaped by an inherent tension between the liberal inclination to privilege the individual and the community under formation, on the one hand, and the realist insistence on the primacy of the state, on the other. This article explores the conditions and constraints affecting ASEAN’s progress in remaking Southeast Asia into a people-focused and caring community in three areas: disaster management, development, and democratization (understood here as human rights). Arguably, the persistent gap in Southeast Asia between aspiration and expectation is determined less by political ideology than by the pragmatic responses of ASEAN member states to the forces of nationalism and protectionism, as well as their respective sense of local and regional responsibility.Resumen: El esfuerzo histórico para desarrollar un regionalismo basado en las personas del sudeste de Asia ha estado marcado por una tensión fundamental entre la inclinación liberal de privilegiar el individuo y la comunidad y la insistencia realista sobre la primacía del estado. Este artículo explora las condiciones y limitaciones que afectan el progreso de la ASEAN en la reestructuración de Asia sudoriental en una comunidad centrada en el cuidado de las personas en: gestión de desastres, desarrollo y democratización (i.e., derechos humanos). La brecha persistente en el sudeste asiático entre la aspiración y la expectativa está determinada por las respuestas pragmáticas de los miembros de la ASEAN sometidos a las fuerzas del nacionalismo y proteccionismo, así como su respectivo sentido de responsabilidad local y regional.Résumé: L’effort historique pour développer un régionalisme fondé sur les peuples en Asie du Sud-Est a été marqué par une tension fondamentale entre l’inclination libérale qui privilégie, d’une part, l’individu et la communauté et, d’autre part, l’insistance réaliste sur la primauté de l’État. Cet article explore les conditions et les contraintes qui nuisent aux progrès de l’ANASE dans le cadre d’une refonte de l’Asie du Sud-Est en une communauté centrée et attentive aux peuples dans trois domaines : la gestion des désastres, le développement et la démocratisation (en référence aux droits humains). Le fossé persistant en Asie du Sud-Est entre les aspirations et les attentes est vraisemblablement moins déterminé par l’idéologie politique que par les réponses pragmatiques des États membres de l’ANASE soumis aux forces du nationalisme et du protectionnisme ainsi que par leur sens respectif de la responsabilité locale et régionale.


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