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71.
Genome sequence of the mercury-methylating and pleomorphic Desulfovibrio africanus Strain Walvis Bay
Brown SD Wall JD Kucken AM Gilmour CC Podar M Brandt CC Teshima H Detter JC Han CS Land ML Lucas S Han J Pennacchio L Nolan M Pitluck S Woyke T Goodwin L Palumbo AV Elias DA 《Journal of bacteriology》2011,193(15):4037-4038
Desulfovibrio africanus strain Walvis Bay is an anaerobic sulfate-reducing bacterium capable of producing methylmercury (MeHg), a potent human neurotoxin. The mechanism of methylation by this and other organisms is unknown. We present the 4.2-Mb genome sequence to provide further insight into microbial mercury methylation and sulfate-reducing bacteria. 相似文献
72.
Brown SD Gilmour CC Kucken AM Wall JD Elias DA Brandt CC Podar M Chertkov O Held B Bruce DC Detter JC Tapia R Han CS Goodwin LA Cheng JF Pitluck S Woyke T Mikhailova N Ivanova NN Han J Lucas S Lapidus AL Land ML Hauser LJ Palumbo AV 《Journal of bacteriology》2011,193(8):2078-2079
Desulfovibrio desulfuricans strain ND132 is an anaerobic sulfate-reducing bacterium (SRB) capable of producing methylmercury (MeHg), a potent human neurotoxin. The mechanism of methylation by this and other organisms is unknown. We present the 3.8-Mb genome sequence to provide further insight into microbial mercury methylation. 相似文献
73.
Marlen Almasbegy Mircea Pfleiderer 《Der Zoologische Garten (in deutscher Sprache / in German)》2011,80(6):309-348
The Blackfooted Cat (Felis nigripes), also called Small Spotted Cat, is a species endemic to the drier areas of Southern Africa. Ethological observations can give insight into their specialised adaptations to their environment. The investigations were carried out at the base of Karoo Cat Research. The large nature-type enclosures allow the cats to show a wide range of their natural behaviour. This study was done in the hope that it will lead to improved zoo-keeping and husbandry of the Blackfooted Cat in zoological gardens.It is alarming to note that worldwide the zoo populations of these cats, having always been quite low, have dramatically decreased recently, especially in Europe, where at present only 5 males and 2 females are kept at 3 different sites. Worldwide, most cats die at a rather young age from either Amyloidosis, a kidney disease, or from respiratory tract infections. The possibility is discussed that both diseases are, at least partly, due to inadequate keeping conditions.It is imperative, though not always easily accomplished, that these cats are kept in enclosures that, at least in part, provide desert conditions: a dry climate (relative air humidity of 30 to 40%), and a preponderantly sandy substrate with fitting vegetation. As Blackfooted Cats habitually cover large distances during their nightly prowls, they would require larger enclosures than other cats of the Genus Felis. The enclosures should also give the cats adequate shelter to allow them to hide from disturbances caused by the public. Failing to provide this may be the cause of numerous, possibly lethal, stress-related diseases. Due to the Blackfooted Cat's extremely shy nature and solitary way of living, especially in respect of keeping their progeny healthy, the choice of the right curator is of utmost importance.The experiment of having young Blackfooted Cats reared simultaneously by their own mother and by humans aimed to avoid an imprinting-like bond but at the same time to create the basis for a lasting relationship of trust towards the human carers. The Karoo Cat Research Station proved to be a suitable observation area, offering the possibility of caring for three young Blackfooted Cats from the age of 6 to 16 weeks together with their mother. The behaviour patterns defining the opposites “tame” and “shy” were evaluated numerically and presented in diagram form. The result of this experiment was a stress-free and relaxed relationship between the animals and their carers that was not only observed in the kittens but was also maintained with the adult cats.The activity rhythm of seven Blackfooted Cats in human care in South Africa was studied throughout two seasons with considerable temperature variations.In graphic representations, data are presented, such as the weather or sexual differences, which could not be influenced by humans but have a clearly recognisable effect on the activity rhythm.Altered keeping conditions had an important influence on the divergence of the rest periods of the three young Blackfooted Cats from the usual diaphasic activity pattern of most felid species.The behaviour of wild-caught animals was studied and compared with that of well integrated or zoo-born individuals. Here too an important reduction in activity was noted. The effect of behavioural enrichment measures, such as play, feeding methods, olfactory stimuli, as well as the rearing of young, on a positive increase in diurnal activity is discussed. 相似文献
74.
Previous studies revealed a close connection between heat shock and manganese-dependent superoxide dismutase (SOD2) in eukaryotes. This paper shows that SOD mimics based on manganese complexes caused an increase in thermotolerance for a mutant fission yeast deficient in mitochondrial superoxide dismutase. Manganese compounds used for tests are SOD mimics, from two different classes: salen manganese (EUK-8) and Mn porphyrin (Mn(III)TE-2-PyP(5+)). The tests were conducted using a Schizosaccharomyces pombe model, comparing the viability of two strains at chronic heat stress (37°C)--a wild type versus a strain with the mitochondrial superoxide dismutase gene deleted [SOD2(-)]. The presence of massive free radical species in S. pombe SOD2(-) was demonstrated using a luminol-enhanced chemiluminescence test derived from a menadione-mediated survival protocol. Conclusions: Survival tests revealed that the SOD2-deleted S. pombe is about 100 times more sensitive to heat stress than the wild-type strain. This survival deficit can be corrected by EUK-8 and Mn(III)TE-2-PyP(5+) to almost the same degree but not by manganese chloride II (MnCl(2)). Using a simple spot assay for viability testing, this new model proved to be an easy alternative for the initial estimation of manganese SOD mimics efficiency. 相似文献
75.
Stavri H Ulea I Radu DL Branaru MG Moldovan O Bogdan MA Tudose C Raileanu M Duiculescu D Ene L Olar V Ionita C Popa GL Popa MI Brennan PJ 《Journal of microbiological methods》2011,86(3):283-290
To demonstrate the usefulness of enzyme-linked immunosorbent assay for serodiagnosis of mycobacterioses due to environmental mycobacteria we utilized a panel of glycolipid antigens selective for Mycobacterium avium-intracellulare, Mycobacterium kansasii, Mycobacterium xenopi, Mycobacterium scrofulaceum and Mycobacterium gordonae. The levels of circulating antibodies were determined against the environmental mycobacteria, and Mycobacterium tuberculosis in human immunodeficiency virus-negative and -positive patient sera. The method used immunomagnetic separation of the antigens, with covalent immobilization of antibodies to superparamagnetic amine and carboxyl terminated particles in solutions of the specific antigens. Enzyme-linked immunosorbent assay was performed on 195 patient sera: 34 with infections due to environmental mycobacteria, 114 with tuberculosis, 47 with other respiratory diseases. There were 46 human immunodeficiency virus-1 infected individuals. Among the 34 infections due to environmental mycobacteria, 9 patients were singularly infected with an environmental mycobacterium, and 25 co-infected with both M. tuberculosis and an environmental mycobacterium. Sensitivity, specificity and false positivity ranges were determined for each of the volunteer groups: tuberculosis positive, human immunodeficiency virus negative; tuberculosis positive, human immunodeficiency virus positive; those with infections due to individual environmental mycobacteria (such as M. scrofulaceum and M. kansasii); and those with other respiratory diseases. We demonstrate that such multiple assays, can be useful for the early diagnosis of diverse environmental mycobacterial infections to allow the start of treatment earlier than henceforth. 相似文献
76.
77.
We discuss the potential of molecular magnets as the building blocks of a quantum computer. The simplification in the control procedure for the quantum gates in many-spin systems coming from the high symmetry is shown to lead to a relatively simple way to address the spin degrees of freedom in molecular magnets. The advantage of an anisotropic effective spin interaction in memory applications is demonstrated on the example of the Grover quantum search algorithm in a generic easy-axis molecular magnet. Electric control of the coupling between the spins is shown to enable two-qubit quantum gates in polyoxometalates. 相似文献
78.
Hermosilla T Moreno C Itfinca M Altier C Armisén R Stutzin A Zamponi GW Varela D 《Channels (Austin, Tex.)》2011,5(3):280-286
Angiotensin II regulation of L-type calcium currents in cardiac muscle is controversial and the underlying signaling events are not completely understood. Moreover, the possible role of auxiliary subunit composition of the channels in Angiotensin II modulation of L-type calcium channels has not yet been explored. In this work we study the role of Ca(v)β subunits and the intracellular signaling responsible for L-type calcium current modulation by Angiotensin II. In cardiomyocytes, Angiotensin II exposure induces rapid inhibition of L-type current with a magnitude that is correlated with the rate of current inactivation. Semi-quantitative PCR of cardiomyocytes at different days of culture reveals changes in the Ca(v)β subunits expression pattern that are correlated with the rate of current inactivation and with Angiotensin II effect. Over-expression of individual b subunits in heterologous systems reveals that the magnitude of Angiotensin II inhibition is dependent on the Ca(v)β subunit isoform, with Ca(v)β(1b) containing channels being more strongly regulated. Ca(v)β(2a) containing channels were insensitive to modulation and this effect was partially due to the N-terminal palmitoylation sites of this subunit. Moreover, PLC or diacylglycerol lipase inhibition prevents the Angiotensin II effect on L-type calcium channels, while PKC inhibition with chelerythrine does not, suggesting a role of arachidonic acid in this process. Finally, we show that in intact cardiomyocytes the magnitude of calcium transients on spontaneous beating cells is modulated by Angiotensin II in a Ca(v)β subunit-dependent manner. These data demonstrate that Ca(v)β subunits alter the magnitude of inhibition of L-type current by Angiotensin II. 相似文献
79.
Adrian-Ştefan Andrei Andreea Baricz Manuela Păuşan Vasile Muntean Cosmin Ionel Sicora Mircea Alexe 《Geomicrobiology journal》2017,34(2):130-138
Dating from the Middle Miocene, the massive halite deposits lying beneath the Transylvanian Basin (Central Romania) have been valuable mineral resources quarried for millennia. Among the numerous hypersaline pit lakes that resulted from this mining, Brâncoveanu Lake is unique by its extreme salinity. Assessment of physicochemical variables, water chemistry and trophic status indicated that Brâncoveanu Lake is a permanently stratified, pH-neutral, NaCl-rich and eutrophied system. We investigated the abundance, molecular diversity and vertical distribution of archaeal community by culture-independent approaches. Additionally, the most relevant environmental parameters shaping the archaeal community composition were evaluated by statistical methods. Archaea appeared to largely outnumber Bacteria; altogether the great prevalence of Halobacteriaceae-related sequences could imply a major contribution of this group to the biogeochemical carbon turnover. The fairly distinct composition of archaeal communities reflects the lake's physicochemical stratification. Among the limnological factors, salinity and oxygen showed a significant impact on determining the composition and structure of archaeal assemblages. Furthermore, Brâncoveanu Lake might harbor novel microorganisms such as members of the recently described phylum Nanohaloarchaea. Overall, this study reported the occurrence of halophilic Archaea in a little explored hydrogeochemical system and provided a better insight into geomicrobiology of meromictic hypersaline pit lakes. 相似文献
80.
Mircea Podar Iain Anderson Kira S Makarova James G Elkins Natalia Ivanova Mark A Wall Athanasios Lykidis Kostantinos Mavromatis Hui Sun Matthew E Hudson Wenqiong Chen Cosmin Deciu Don Hutchison Jonathan R Eads Abraham Anderson Fillipe Fernandes Ernest Szeto Alla Lapidus Nikos C Kyrpides Milton H Saier Jr Paul M Richardson Reinhard Rachel Harald Huber Jonathan A Eisen Eugene V Koonin Martin Keller Karl O Stetter 《Genome biology》2008,9(11):R158-18