Search Results - (Author, Cooperation:L. Fernando)

2014-08-30

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Amino Acid Sequence ; Animals ; Antibodies, Monoclonal/immunology/*therapeutic use ; Antibodies, Neutralizing/immunology/therapeutic use ; Antibodies, Viral/immunology/*therapeutic use ; Cross Reactions/immunology ; Ebolavirus/immunology ; Enzyme-Linked Immunosorbent Assay ; Female ; Guinea ; Guinea Pigs ; Hemorrhagic Fever, Ebola/blood/*drug therapy/immunology/virology ; *Immunization, Passive ; Macaca mulatta/immunology/virology ; Male ; Molecular Sequence Data ; Sequence Alignment ; Viral Envelope Proteins/chemistry/immunology ; Viremia/drug therapy/immunology/virology

1749-6632

Blackwell Publishing Journal Backfiles 1879-2005

Natural Sciences in General

Electronic Resource

1365-3091

Blackwell Publishing Journal Backfiles 1879-2005

Geosciences

Electronic Resource

1573-8590

hypersaline coastal lagoon ; physico-chemical seasonal variations ; winds ; Artemia ; cysts ; Baja California ; Mexico

Springer Online Journal Archives 1860-2000

Biology

Geography

Abstract San Jose lagoon is a hypersaline body of water located in Mexico in the Baja California Peninsula. The lagoon belongs to a system that lies between the fault ridge known as San Jose Creek. Because of its marine origin, it can be considered as thalassohaline, but its isolation from the ocean has brought about changes in its salt composition. It has an area of 13,500 m2, a mean depth of 80 cm and a total volume of 10,000 m3. It does not desiccate and can be considered as a permanent lagoon. Seasonal variations are small. TheArtemia population in San Jose produces cysts all year. To determine the physico-chemical conditions inducing permanent production of cysts, temperature, salinity, dissolved oxygen, and pH of the lagoon were monitored, as well as relative humidity and wind conditions in the region in different seasons of the year. From spring to summer, differences of 1 mg L−1 of O2, 1°C in water temperature, and 8 g L−1 in salinity were observed, and from summer to winter differences of 3.3 mg L−1, 6.5°C, and 14 g L−1, respectively. Despite small seasonal variations, the lagoon exhibits strong spatial and daily changes that are important for cyst production.

Electronic Resource

0930-7516

Chemistry ; Industrial Chemistry and Chemical Engineering

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Process Engineering, Biotechnology, Nutrition Technology

The development and optimization of the synthesis of an analogue of sperm whale oil have been carried out. The product is an ester with characteristics similar to those of natural sperm whale oil. A central composite design was applied in the synthesis of this fine chemical. The variables selected for the present study are reaction temperature, initial concentration of catalyst and working pressure. Temperature is the most significant factor in the esterification process, and its influence is positive. Pressure influence can be neglected, and the catalyst concentration has a positive influence on the process. Depending on the temperature value, the influence of the interactions can be more important than that of the other two main effects, pressure and catalyst concentration. Response surface models have been found adequate to represent the yield of ester. The commercial quality of the synthesized product is very similar to that of natural spermaceti. Because of its low cost, this synthesis process is considered, from an economical point of view, very attractive.

3 Ill.

Electronic Resource

article

2006

Magnet ; Elektrodynamik ; Elektromagnetische Induktion ; Fall (Phys) ; Lenzsche Regel ; Physik ; Bremsvorgang

American journal of physics, Bd. 74 (2006) H. 9, S. 815-817, 0002-9505

1943-2909

English

2018-04-28

Nature Publishing Group (NPG)

2045-2322

Natural Sciences in General

2018-03-06

BioMed Central

1476-072X

Medicine

2018-03-06

SpringerOpen

2251-7316

Economics

2018-03-20

American Physical Society (APS)

1539-3755

1550-2376

Physics

Statistical Physics

2018-06-27

National Academy of Sciences

0027-8424

1091-6490

Biology

Medicine

Natural Sciences in General

2018-02-03

American Physical Society (APS)

1098-0121

1095-3795

Physics

Electronic structure and strongly correlated systems

2018-05-18

MDPI Publishing

2073-4433

Geosciences

2018-08-09

American Physical Society (APS)

1539-3755

1550-2376

Physics

Statistical Physics

1550-7408

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Stimulation of phagocytosis by serotonin and catecholamincs in Tetrahymena grown in proteose-peptone medium proved to be concentration dependent, the optimal concentrations being ∼0.1 to 1.0 μM. The serotonergic antagonists, spiperone, and metergoline, also stimulated the process, whereas the β- and α-adrenergic antagonists, propranolol, alprenolol, and ergocryptine, had no effect or inhibited phagocytosis. A wide variety of derivatives of the biogenic amines had no effect on phagocytosis, demonstrating the specificity of recognition mechanism for neurohormones in Tetrahymena. Such hormones act by at least two independent mechanisms, one for adrenergic agonists, another for dopamine. Presumably, recognition mechanisms for hormones in protozoa resemble in some respects those in multicellular organisms, therefore bespeaking a common origin.

Electronic Resource

1550-7408

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Serotonin and catecholamines affect the regeneration of cilia in Tetrahymena thermophila in a dose-dependent manner: micromolar concentrations are stimulatory, whereas millimolar concentrations have little or no effect. This conclusion is based on motility measurements in regenerating cells and on ciliary counts in scanning electron micrographs. In addition, the recognition mechanism for each hormone appears to be specific and independent. Our results suggest an evolutionary link with hormonal mechanisms in multicellular eukaryotes.

Electronic Resource

1550-7408

Blackwell Publishing Journal Backfiles 1879-2005

Biology

A pharmacological characterization has been performed of the opioid receptor involved in modulation of phagocytosis in the protozoan ciliate Tetrahymena. Studies on inhibition of phagocytosis by mammalian prototypic opioid agonists revealed that morphine and β-endorphin have the highest intrinsic activity, whereas all the other opioids tested can only be considered partial agonists. However, morphine (a mu-receptor agonist) is twice as potent as β-endorphin (a delta-receptor agonist). Furthermore, the sensitivity for the opioid antagonist naloxone, determined in the presence of morphine and β-endorphin, is very similar to the sensitivity exhibited by mammalian tissues rich in mu-opioid receptors. We suggest that the opioid receptor coupled to phagocytosis in Tetrahymena is mulike in some of its pharmacological characteristics and may serve as a model system for studies on opioid receptor function and evolution.

Electronic Resource

1550-7408

Blackwell Publishing Journal Backfiles 1879-2005

Biology

. We have previously reported that a β-endorphin-like substance inhibits phagocytosis in Tetrahymena perhaps by a mu-like opioid receptor. We now report a further characterization of the elements involved in the signal transduction mechanism of this opioid. Affinity chromatography followed by immunoblots of both intracellular extracts and extracellular medium reveal the presence of two main proteins of 64 and 75 kDa. These molecular weights are much higher than that of any known opioid peptide or precursor protein and suggest that we may be dealing with either a novel opioid or with proteins that by chance cross-react with anti-β-endorphin antibody. Nevertheless, when the biological activity of these proteins was tested it was found that they had an effect similar to that of mammalian β-endorphin, namely inhibition of phagocytosis by a naloxone-reversible mechanism. We have probed a size-selected Tetrahymena library with a pro-opiomelanocortin probe and have obtained several positive clones; the sequencing of their inserts should establish whether we are dealing with a bona fide member of the opioid family. Another aspect we have been studying is the G-proteins which appear to be involved in the modulation of phagocytosis. We have found, by means of Western blotting (using an antibody against the conserved GTP-binding region of the α-subunit), two bands of 51 and 59 kDa; no α-subunit of 59 kDa had been reported previously and may represent a novel G-protein. In spite of these differences, the opioid signal transduction mechanism appears to remarkably resemble that present in more complex organisms.

Electronic Resource

1550-7408

Blackwell Publishing Journal Backfiles 1879-2005

Biology

A study of calcium metabolism in Tetrahymena during the regeneration of cilia evidenced that the process is inhibited by nifedipine and trifluoperazine. This suggests that calcium ions play an important regulatory role in this process. This was confirmed by studies on calcium uptake and efflux which showed that there was a net increase in calcium uptake prior to the reinitiation of motility. The increase coincided with a period of sensitivity to the calcium antagonist TMB-8 and with an increase in the intracellular level of cGMP. The process was also inhibited by neomycin and stimulated by phorbol esters, which suggests that hydrolysis of phosphatidylinositol phosphates may take place as part of the calcium regulatory network during the regeneration of cilia.

Electronic Resource

1749-6632

Blackwell Publishing Journal Backfiles 1879-2005

Natural Sciences in General

Electronic Resource