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931.
Khalid El Allali Hicham Farsi Mohammed Piro Mohamed Rachid Achaâban Mohammed Ouassat Etienne Challet 《Chronobiology international》2013,30(8):1047-1057
ABSTRACTDaily pattern of locomotor activity (LA), one of the most studied rhythms in humans and rodents, has not been widely investigated in large mammals. This is partly due to the high cost and breakability of used automatic devices. Since last decade, smartphones are becoming ubiquitous. Meanwhile, several applications detecting activity by using internal sensors were made available. In this study, we assumed that this device could be a cheaper and easier way to measure the LA rhythm in humans and large mammals, like camel and goat. A smartphone application (Nokia Mate Health), normally used to quantify physical activities in humans, was chosen for the study. To validate the rhythm data obtained from the smartphone, LA rhythm was simultaneously recorded using an automatic device, the Actiwatch-Mini®. Results showed that the smartphone provided a clear and significant daily rhythm of LA. The visual assessment of the superimposed LA rhythm’s curves in all three species showed that the smartphone application displayed similar rhythms as those recorded by the Actiwatch-Mini. Highly significant positive correlation (p≤ 0.0001) exists between the two recording rhythms. The daily periods were both the same at 24.0 h. Acrophases were also significantly similar and occurring around mid-day: 11:40 ± 0.35 h vs 11:41 ± 0.35 h for the camel, 11:25 ± 0.19 h vs 11:37 ± 0.25 h for the goat and 13:04 ± 0.11 h vs 13:51 ± 0.28 h for humans using smartphone and Actiwatch, respectively. The related mesor and amplitude were also close between the two recording devices. Results indicate clearly that using smartphones constitutes a reliable cheap tool to study LA rhythm for chronobiology studies, especially in laboratories facing lack of funding. 相似文献
932.
Etienne Benson 《Journal of the history of biology》2011,44(1):103-123
In the 1970s, new forms of public scrutiny were applied to the research methods of field biologists in the United States, particularly those studying endangered species and marine mammals. This paper shows how such scrutiny affected researchers’ choice of research methods through an analysis of a key moment in a decade-long controversy over the conservation of bowhead whales. In 1978, researchers at the Naval Arctic Research Laboratory received funding from the Bureau of Land Management to radio-tag bowhead whales. Although this promising but still largely untested technique might have answered one of the central scientific questions in the controversy, it ultimately went unused. Technical considerations played a role in the decision not to use the technique, but the most important factor was scientists’ concerns about potential backlash from Iñupiat whalers and animal protectionists. The same forces that had made marine mammalogists more influential than ever and that had put into their hands the resources necessary to develop more effective research techniques also placed serious constraints on where, when, and how they could do their research. 相似文献
933.
934.
935.
For twenty years, mass spectrometry (MS) has emerged as a particularly powerful tool for analysis and characterization of proteins in research. It is only recently that this technology, especially MALDI-TOF-MS (Matrix Assisted Laser Desorption Ionization Time-Of-Flight) has entered the field of routine microbiology. This method has proven to be reliable and safe for the identification of bacteria, yeasts, filamentous fungi and dermatophytes. MALDI-TOF-MS is a rapid, precise and cost-effective method for identification, compared to conventional phenotypic techniques or molecular biology. Its ability to analyse whole microorganisms with few sample preparation has greatly reduced the time to identification (1-2 min). Furthermore, this technology can be used to identify bacteria directly from clinical samples as blood culture bottles or urines. Future applications will be developed in order to provide direct information concerning virulence or resistance protein markers. 相似文献
936.
Pan E Harinantenaina L Brodie PJ Callmander M Rakotonandrasana S Rakotobe E Rasamison VE Tendyke K Shen Y Suh EM Kingston DG 《Bioorganic & medicinal chemistry》2011,19(1):422-428
Investigation of the endemic Madagascar plant Leptadenia madagascariensis Decne. (Apocynaceae) for antiproliferative activity against the A2780 ovarian cancer cell line led to the isolation of the four new cardenolides 1-4. The structure elucidations of these compounds were based on analyzes of their 1D and 2D NMR spectra and mass spectrometric data. The cardenolides were strongly antiproliferative to the A2780 ovarian cancer cell line, with IC50 values of 0.18, 0.21, 0.17, and 0.29 ??M line, and to the H460 human lung cancer cell line, with IC50 values of 0.16, 0.68, 0.37, and 0.48 ??M, respectively. 相似文献
937.
938.
Martin Ko??ák John W. M. Jagt Robert P. Speijer Peter Stassen Etienne Steurbaut 《PloS one》2013,8(11)
New coleoid cephalopods, assignable to the order Sepiida, are recorded from the Selandian/Thanetian boundary interval (Middle to Upper Paleocene transition, c. 59.2 Ma) along the southeastern margin (Toshka Lakes) of the Western Desert in Egypt. The two genera recognised, Aegyptosaepia n. gen. and ?Anomalosaepia Weaver and Ciampaglio, are placed in the families Belosaepiidae and ?Anomalosaepiidae, respectively. They constitute the oldest record to date of sepiids with a ‘rostrum-like’ prong. In addition, a third, generically and specifically indeterminate coleoid is represented by a single rostrum-like find. The taxonomic assignment of the material is based on apical parts (as preserved), i.e., guard, apical prong (or ‘rostrum-like’ structure), phragmocone and (remains of) protoconch, plus shell mineralogy. We here confirm the shell of early sepiids to have been bimineralic, i.e., composed of both calcite and aragonite. Aegyptosaepia lugeri n. gen., n. sp. reveals some similarities to later species of Belosaepia, in particular the possession of a distinct prong. General features of the phragmocone and protoconch of the new form are similar to both Belocurta (Middle Danian [Lower Paleocene]) and Belosaepia (Eocene). However, breviconic coiling and the presence of a longer ventral conotheca indicate closer ties with late Maastrichtian–Middle Danian Ceratisepia. In this respect, Aegyptosaepia n. gen. constitutes a link between Ceratisepia and the Eocene Belosaepia. The occurrence of the new genus near the Selandian/Thanetian boundary suggests an earlier origin of belosaepiids, during the early to Middle Paleocene. These earliest known belosaepiids may have originated in the Tethyan Realm. From northeast Africa, they subsequently spread to western India, the Arabian Plate and, probably via the Mediterranean region, to Europe and North America. 相似文献
939.
Villani G Capitanio N Bizzoca A Palese LL Carlino V Tattoli M Glaser P Danchin A Papa S 《Biochemistry》1999,38(8):2287-2294
Various protolytic residues in subunit I of aa3-600 quinol oxidase of the aerobic Gram-positive Bacillus subtilis were mutagenized to nonpolar residues. Two of the mutations, Y284F and K304L, impaired the bioenergetic function of the microorganism. The Y284F mutation suppressed the electron-transfer activity of quinol oxidase and altered its interaction with CO and H2O2, thus showing destruction of the binuclear domain as observed for the bo3 quinol oxidase of Escherichia coli. The K304L mutation did not alter significantly the redox activity of the oxidase and its interaction with CO and H2O2 but suppressed the proton pumping activity of the enzyme. These results show that the K304 residue, which is invariantly conserved (as K or R) in practically all the sequences of the heme-copper oxidases so far available (around 100), is essential for the proton pumping activity of the oxidase. 相似文献
940.
SigF controls carotenoid pigment production and affects transformation efficiency and hydrogen peroxide sensitivity in Mycobacterium smegmatis 下载免费PDF全文
Provvedi R Kocíncová D Donà V Euphrasie D Daffé M Etienne G Manganelli R Reyrat JM 《Journal of bacteriology》2008,190(23):7859-7863
Carotenoids are complex lipids that are known for acting against photodynamic injury and free radicals. We demonstrate here that sigma(F) is required for carotenoid pigment production in Mycobacterium smegmatis. We further show that a sigF mutant exhibits a transformation efficiency 10(4)-fold higher than that of the parental strain, suggesting that sigma(F) regulates the production of components affecting cell wall permeability. In addition, a sigF mutant showed an increased sensitivity to hydrogen peroxide. An in silico search of the M. smegmatis genome identified a number of SigF consensus sites, including sites upstream of the carotenoid synthesis locus, which explains its SigF regulation. 相似文献