Influence of vitamin B12 availability on oceanic dimethylsulfide and dimethylsulfoniopropionate

2016 ◽  
Vol 13 (2) ◽  
pp. 293 ◽  
Author(s):  
Peter A. Lee ◽  
Erin M. Bertrand ◽  
Mak A. Saito ◽  
Giacomo R. DiTullio
Keyword(s):  
Vitamin B12 ◽  
Ross Sea ◽  
Molecular Level ◽  
Global Scale ◽  
Cellular Level ◽  
Iron Availability ◽  
Equatorial Pacific Ocean ◽  
Incubation Experiments ◽  
Production Capacities ◽  
And Control

Environmental context Cobalamin, or vitamin B12, is receiving increased attention as a critical trace nutrient in the growth and metabolic processes of oceanic phytoplankton and bacterial communities. We present evidence that indicates B12 has a more significant role in the biogeochemical cycling of the climatically important compounds dimethylsulfide and dimethylsulfoniopropionate than previously understood. Several possible mechanisms are examined that link cellular-level processes involving B12 to global-scale biogeochemical processes involving the oceanic cycling of dimethylsulfoniopropionate and dimethylsulfide. Abstract Evidence is presented showing that dissolved dimethylsulfoniopropionate (DMSPd) and dimethylsulfide (DMS) concentrations are influenced by the availability of vitamin B12 in two oceanographically distinct regions with different DMS production capacities, the central equatorial Pacific Ocean and the Ross Sea, Antarctica. In both locations, addition of B12 to incubation experiments resulted in decreases in DMS and, in some cases, DMSPd concentrations relative to unamended controls. In no case did increasing iron availability significantly (α=0.1) alter DMS concentrations relative to controls. The relative decreases in DMS between B12 addition and control experiments were significant (α=0.1) in five of seven experiments conducted at ambient iron levels. Overall, DMS concentrations were on average 33.4% (±15.1%; 1 standard deviation) lower, relative to unamended controls, by the end of incubation experiments when B12 was added. Declines in DMSPd were observed in three of five experiments. Similar trends were observed when B12 was added to iron-supplemented bottle incubation experiments (30.4±10.4% lower final DMS concentrations in +B12Fe treatments relative to +Fe treatments). Several possible molecular-level explanations exist for this link between B12 and DMS production, including potential B12 dependence of methyltransferase enzymes involved in both DMS and DMSP degradation. Although the enzymology of these reactions remains unclear, the relationships described here provide evidence for plausible mechanisms behind the microbial modulation of oceanic DMS.

Enhancement of iron availability by some organic materials

1979 ◽  
Vol 93 (1) ◽  
pp. 115-120 ◽  
Author(s):  
A. A. Parsa ◽  
A. Wallace ◽  
J. P. Martin
Keyword(s):  
Calcareous Soil ◽  
Dry Matter ◽  
Organic Materials ◽  
Iron Availability ◽  
Lawsonia Inermis ◽  
Plant Materials ◽  
Phenolic Substances ◽  
And Control ◽  
Layer Chromatography ◽  
Positive Effect

SUMMARYIn a preliminary laboratory experiment in Iran, not reported here, 5 out of 30 plant materials incorporated into a highly calcareous soil had a positive effect on increasing the DTPA- (diethylenetriaminepentaacetic acid)-extractable Fe and all except one significantly increased the vegetative growth of sorghum. The plant materials included Lawsonia inermis L., Malva silvestris L., Zyzyphus nummularia Wak. and Lavandula carnopifolia L. A glasshouse study was repeated with two California soils pretreated with 0·5% Fe2O3 to determine if these organic materials have practical value in making Fe available to plants. A calcareous, Fe-deficient Hacienda (fine-loamy, mixed, thermic aquic natrargid) and a non-calcareous Yolo (fine-silty, mixed, non-acid, thermic typic xerothents). The previously mentioned organic materials and Laminaria saccharina L. (Lamour) were incorporated into the soils at two rates, 15000 and 20000μg/g, as air dry and in ash form. An adequate supply of major and micronutrients other than Fe was ensured. Other treatments included 5 μg Fe/g as FeSO4, Fe-138 chelate and control. All of the plant materials with the exception of L. carnopifolia significantly increased dry-matter yield and Fe, Zn, Cu and Mn uptake by sorghum in the Hacienda soil. In the Yolo soil the above were not significant. Thin-layer chromatography of the extracts of the plant materials revealed the presence of significant quantities of phenolic substances.

The effect of antibiotic dietary supplements on the carcass measurements and dressing percentage of bacon pigs

1955 ◽  
Vol 46 (2) ◽  
pp. 173-179 ◽  
Author(s):  
G. Harrington ◽  
J. H. Taylor
Keyword(s):  
Growth Rate ◽  
Vitamin B12 ◽  
Dietary Supplements ◽  
Vegetable Protein ◽  
Animal Protein ◽  
Feeding Trials ◽  
The Mean ◽  
Dressing Percentage ◽  
And Control

1. Certain carcass measurements (length, shoulder and mid-back fats, belly thickness and dressing percentage) made on a total of 402 bacon pigs from four antibiotic feeding trials have been analysed.2. The length of the carcasses showed more variation between pens treated with various doses of penicillin than between control pens or pens treated with aureomycin. This greater variation in length was related to the greater variation in growth rate between the penicillin treatments. No differences in the mean lengths of control, penicillin and aureomycin treatments were found.3. Back fat measurements and belly thickness showed no differences between aureomycin, penicillin and control treatments in overall tests.4. Aureomycin consistently gave higher dressing percentages than penicillin. Animal protein also gave higher dressing percentages than vegetable protein, but no effect of vitamin B12 on this quantity was found.

scholarly journals Differential effects of propofol and ketamine on critical brain dynamics

2020 ◽  
Vol 16 (12) ◽  
pp. e1008418
Author(s):  
Thomas F. Varley ◽  
Olaf Sporns ◽  
Aina Puce ◽  
John Beggs
Keyword(s):  
Cellular Level ◽  
Brain Dynamics ◽  
Neuronal Cultures ◽  
Altered States ◽  
Differential Effects ◽  
States Of Consciousness ◽  
Anaesthetized Rats ◽  
And Control ◽  
The Brain

Whether the brain operates at a critical “tipping” point is a long standing scientific question, with evidence from both cellular and systems-scale studies suggesting that the brain does sit in, or near, a critical regime. Neuroimaging studies of humans in altered states of consciousness have prompted the suggestion that maintenance of critical dynamics is necessary for the emergence of consciousness and complex cognition, and that reduced or disorganized consciousness may be associated with deviations from criticality. Unfortunately, many of the cellular-level studies reporting signs of criticality were performed in non-conscious systems (in vitro neuronal cultures) or unconscious animals (e.g. anaesthetized rats). Here we attempted to address this knowledge gap by exploring critical brain dynamics in invasive ECoG recordings from multiple sessions with a single macaque as the animal transitioned from consciousness to unconsciousness under different anaesthetics (ketamine and propofol). We use a previously-validated test of criticality: avalanche dynamics to assess the differences in brain dynamics between normal consciousness and both drug-states. Propofol and ketamine were selected due to their differential effects on consciousness (ketamine, but not propofol, is known to induce an unusual state known as “dissociative anaesthesia”). Our analyses indicate that propofol dramatically restricted the size and duration of avalanches, while ketamine allowed for more awake-like dynamics to persist. In addition, propofol, but not ketamine, triggered a large reduction in the complexity of brain dynamics. All states, however, showed some signs of persistent criticality when testing for exponent relations and universal shape-collapse. Further, maintenance of critical brain dynamics may be important for regulation and control of conscious awareness.

Vitamin B12 deficiency, hyperhomocysteinemia and thrombosis: a case and control study

2011 ◽  
Vol 93 (4) ◽  
pp. 458-464 ◽  
Author(s):  
Angel F. Remacha ◽  
Joan Carles Souto ◽  
José Luis Piñana ◽  
María Pilar Sardà ◽  
Josep Maria Queraltó ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
B12 Deficiency ◽  
And Control ◽  
Control Study

Well-Being in Practice and Policy

2020 ◽  
pp. 52-73
Keyword(s):  
Control Systems ◽  
Construction Industry ◽  
Well Being ◽  
Global Scale ◽  
Design Guidelines ◽  
The People ◽  
Ex Post ◽  
And Control ◽  
The Relationship

Recent research focuses on the concept of well-being, aiming to systematize it and obtain design guidelines. In latest years, various building certification systems have arisen, which, although used for ex post evaluations, contain, specularly, design guidelines. In a first phase the concept of well-being was intended on a global scale, linked to the pitfalls of pollution and consumption of resources, so design guidelines and control systems developed within the construction industry to ensure the conservation of the environment and therefore the “well-being” and “health” of human communities. Having therefore developed certification systems measuring and evaluating the performance of buildings in relation to their impact on the environment and its resources, we are now faced with a shift of attention on a smaller scale, linked to the performance that buildings offer not so much with respect to the environment as to the people who live in them. This chapter explores the concepts behind such systems and the relationship between building certification systems and people's well-being.

THE ALTERATION OF INTRACELLULAR ENZYMES: IV. KINETICS OF CATALASE ALTERATION INDUCED BY CHEMICAL AGENTS

1956 ◽  
Vol 34 (1) ◽  
pp. 25-38
Author(s):  
J. Gordin Kaplan ◽  
Woon-Ki Paik
Keyword(s):  
Molecular Level ◽  
Narrow Range ◽  
Intact Cell ◽  
Cellular Level ◽  
Causal Connection ◽  
Rate Limiting Step ◽  
Chemical Agents ◽  
The Difference ◽  
Rate Limiting ◽  
Kinetics Of

The rate with which n-butanol alters the properties of yeast catalase has been studied as a function of temperature and concentration of altering agent. Activation energies for catalase alteration lay within the rather narrow range of 20–23 kcal./mole, thus confirming a prediction made previously on the basis of the difference in energies of activation for heat destruction of altered and unaltered catalases. Alteration by optimal concentration of butanol was a reaction of zero order. Chloroform also altered yeast catalase with an activation energy within this range of μ values. The close agreement in μ values leads us to conclude that the action of these two altering agents, at all concentrations, is characterized by the same rate-limiting step, even though their action differs in other respects. It was concluded that catalase alteration is probably all-or-none on the molecular level, rather than on the cellular level. Alteration was invariably accompanied by a decrease in the size of the treated cells; alteration was sometimes accompanied by changes in the cytochrome spectrum, but there was no causal connection between these two events. These data are consistent with the interfacial hypothesis, which, in its present crude form, pictures alteration as consisting essentially in the desorption of catalase from some intracellular interface at which it is normally bound in the intact cell.

Brief Report: Observations on Conjugated and Unconjugated Blood Folate Levels in Megaloblastic Anemia and the Effects of Vitamin B12

Blood ◽  
1965 ◽  
Vol 26 (3) ◽  
pp. 354-359 ◽  
Author(s):  
K. N. JEEJEEBHOY ◽  
S. M. PATHARE ◽  
J. M. NORONHA
Keyword(s):  
Folic Acid ◽  
Vitamin B12 ◽  
Megaloblastic Anemia ◽  
Vitamin B12 Deficiency ◽  
Cellular Level ◽  
B12 Deficiency

Abstract Vitamin B12 deficiency was associated with a rise in unconjugated folates and marked depletion of intracellular conjugated folates. The changes could be reversed by giving vitamin B12. These results probably indicate a way by which vitamin B12 and folic acid are interrelated at the cellular level.

A wide-spectrum coordination model of schizophrenia

2003 ◽  
Vol 26 (1) ◽  
pp. 84-85
Author(s):  
Hendrik Pieter Barendregt
Keyword(s):  
Molecular Level ◽  
Clinical Symptoms ◽  
Wide Spectrum ◽  
Cellular Level ◽  
Cognitive Level ◽  
Levels Of Abstraction ◽  
Coordination Model ◽  
Target Article ◽  
Four Levels ◽  
Important Notion

AbstractThe target article presents a model for schizophrenia extending four levels of abstraction: molecules, cells, cognition, and syndrome. An important notion in the model is that of coordination, applicable to both the level of cells and of cognition. The molecular level provides an “implementation” of the coordination at the cellular level, which in turn underlies the coordination at the cognitive level, giving rise to the clinical symptoms.

Designing for a green chemistry future

Science ◽  
2020 ◽  
Vol 367 (6476) ◽  
pp. 397-400 ◽  
Author(s):  
Julie B. Zimmerman ◽  
Paul T. Anastas ◽  
Hanno C. Erythropel ◽  
Walter Leitner
Keyword(s):  
Green Chemistry ◽  
Molecular Level ◽  
Positive Impact ◽  
Systems Design ◽  
Global Scale ◽  
Design Stage ◽  
Sustainable Society ◽  
Material Basis ◽  
Chemical Products ◽  
Definition Of

The material basis of a sustainable society will depend on chemical products and processes that are designed following principles that make them conducive to life. Important inherent properties of molecules need to be considered from the earliest stage—the design stage—to address whether compounds and processes are depleting versus renewable, toxic versus benign, and persistent versus readily degradable. Products, feedstocks, and manufacturing processes will need to integrate the principles of green chemistry and green engineering under an expanded definition of performance that includes sustainability considerations. This transformation will require the best of the traditions of science and innovation coupled with new emerging systems thinking and systems design that begins at the molecular level and results in a positive impact on the global scale.

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