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91.
Differences in oscillatory whistles produced by spinner (Stenella longirostris) and pantropical spotted (Stenella attenuata) dolphins 下载免费PDF全文
Pina Gruden Paul R. White Julie N. Oswald Yvonne Barkley Salvatore Cerchio Marc Lammers Simone Baumann‐Pickering 《Marine Mammal Science》2016,32(2):520-534
Acoustic recordings of two closely related species, spinner dolphin (Stenella longirostris) and pantropical spotted dolphin (Stenella attenuata), were investigated from four different geographic locations: two in the Central Tropical Pacific, one in the Eastern Tropical Pacific and one in the Indian Ocean. The two delphinid species occur in tropical and warm temperate waters, with overlapping ranges. They produce very similar vocalizations, but at the same time their calls exhibit a certain degree of intraspecific variation among different geographic locations as has been observed in other delphinid species. Oscillatory whistles (whistles with at least two oscillations in their frequency contours) were identified and manually extracted from the recordings. Whistles with four or more maxima (oscillations) occurred only in spinner dolphins and they were present in all geographic regions investigated. In addition, the oscillatory whistles with two and three maxima were significantly more frequent in spinner than in spotted dolphins. The differences in oscillatory whistles for these two species seem to be consistent across study areas and therefore, could be used in addition to other whistle features to help distinguish between them. 相似文献
92.
Odontocete occurrence in relation to changes in oceanography at a remote equatorial Pacific seamount 下载免费PDF全文
Simone Baumann‐Pickering Jennifer S. Trickey Sean M. Wiggins Erin M. Oleson 《Marine Mammal Science》2016,32(3):805-825
Seamounts are considered hot spots of biodiversity and can aggregate pelagic predators and their prey. Passive acoustic monitoring was conducted over 3 mo in 2012 to document the occurrence of odontocetes near a seamount chain in the central equatorial Pacific in relation to oceanographic changes over time. Beaked whale echolocation signals were most frequently encountered. The main beaked whale signal was an unknown type, BW38, which resembled signals produced by Blainville's beaked whales. It had high occurrence during high sea surface temperature and low sea surface salinity. Cuvier's beaked whales were the second most detected. They had an opposite pattern and were encountered more often when sea surface temperature was low and net primary productivity was high. Risso's dolphins and short‐finned pilot whales had high acoustic densities, and echolocated predominantly at night. Risso's dolphins occurred more often during low sea surface height deviation. False killer whales were less frequently detected and mostly occurred during the day. Sperm whale detections were fewer than expected and associated with high chlorophyll a. Short duration Kogiidae encounters occurred on average every third day. These types of long‐term site studies are an informative tool to comparatively assess species composition, relative abundance, and relationship to oceanographic changes. 相似文献
93.
Andrew P. Baumann Xiutao Shi Ryan K. Roeder 《Computer methods in biomechanics and biomedical engineering》2016,19(5):465-473
Microarchitectural finite element models have become a key tool in the analysis of trabecular bone. Robust, accurate, and validated constitutive models would enhance confidence in predictive applications of these models and in their usefulness as accurate assays of tissue properties. Human trabecular bone specimens from the femoral neck (n = 3), greater trochanter (n = 6), and lumbar vertebra (n = 1) of eight different donors were scanned by μ-CT and converted to voxel-based finite element models. Unconfined uniaxial compression and shear loading were simulated for each of three different constitutive models: a principal strain-based model, Drucker–Lode, and Drucker–Prager. The latter was applied with both infinitesimal and finite kinematics. Apparent yield strains exhibited minimal dependence on the constitutive model, differing by at most 16.1%, with the kinematic formulation being influential in compression loading. At the tissue level, the quantities and locations of yielded tissue were insensitive to the constitutive model, with the exception of the Drucker–Lode model, suggesting that correlation of microdamage with computational models does not improve the ability to discriminate between constitutive laws. Taken together, it is unlikely that a tissue constitutive model can be fully validated from apparent-level experiments alone, as the calculations are too insensitive to identify differences in the outcomes. Rather, any asymmetric criterion with a valid yield surface will likely be suitable for most trabecular bone models. 相似文献
94.
Previous results showed an inducible radiation sensitivity selectively observable for K-RAS-mutated cell lines as a function of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor blockade of phosphatidylinositol 3-kinase (PI3K)-AKT signaling. Therefore, the role of K-Ras activity for a direct (i.e., through activation of PI3K by K-Ras) or an indirect stimulation of PI3K-AKT signaling (through K-Ras activity-dependent EGFR ligand production) was investigated by means of small interfering RNA and inhibitor approaches as well as ELISA measurements of EGFR ligand production. K-RASmt tumor cells presented a constitutively activated extracellular signal-regulated kinase-1/2 signaling, resulting in enhanced production and secretion of the EGFR ligand amphiregulin (AREG). Medium supernatants conditioned by K-RASmt tumor cells equally efficiently stimulated EGFR signaling into the PI3K-AKT and mitogen-activated protein kinase pathways. Knocking down K-Ras expression by specific small interfering RNA markedly affected autocrine production of AREG, but not PI3K-AKT signaling, after treatment of K-RAS-mutated or wild-type cells with EGFR ligands or exposure to ionizing radiation. These results indicate that PI3K-mediated activation of AKT in K-RASmt human tumor cells as a function of EGFR ligand or radiation stimulus is independent of a direct function of K-Ras enzyme activity but depends on a K-Ras-mediated enhanced production of EGFR ligands (i.e., most likely AREG) through up-regulated extracellular signal-regulated kinase-1/2 signaling. The data provide new differential insight into the importance of K-RAS mutation in the context of PI3K-AKT-mediated radioresistance of EGFR-overexpressing or EGFR-mutated tumors. 相似文献
95.
Pfingstl Tobias Wagner Maximilian Baumann Julia Neethling Jan Andries Bardel-Kahr Iris Hugo-Coetzee Elizabeth A. 《Organisms Diversity & Evolution》2022,22(3):789-801
Organisms Diversity & Evolution - The South African coast is known to harbor four different species of intertidal oribatid mites and their distribution strongly correlates with marine... 相似文献
96.
Patrick Jung Michael Schermer Laura Briegel‐Williams Karen Baumann Peter Leinweber Ulf Karsten Lukas Lehnert Sebastian Achilles Jrg Bendix Burkhard Büdel 《Journal of phycology》2019,55(6):1306-1318
In the Atacama Desert, cyanobacteria grow on various substrates such as soils (edaphic) and quartz or granitoid stones (lithic). Both edaphic and lithic cyanobacterial communities have been described but no comparison between both communities of the same locality has yet been undertaken. In the present study, we compared both cyanobacterial communities along a precipitation gradient ranging from the arid National Park Pan de Azúcar (PA), which resembles a large fog oasis in the Atacama Desert extending to the semiarid Santa Gracia Natural Reserve (SG) further south, as well as along a precipitation gradient within PA. Various microscopic techniques, as well as culturing and partial 16S rRNA sequencing, were applied to identify 21 cyanobacterial species; the diversity was found to decline as precipitation levels decreased. Additionally, under increasing xeric stress, lithic community species composition showed higher divergence from the surrounding edaphic community, resulting in indigenous hypolithic and chasmoendolithic cyanobacterial communities. We conclude that rain and fog water, respectively, cause contrasting trends regarding cyanobacterial species richness in the edaphic and lithic microhabitats. 相似文献
97.
98.
Casartelli Alberto Melino Vanessa J. Baumann Ute Riboni Matteo Suchecki Radoslaw Jayasinghe Nirupama S. Mendis Himasha Watanabe Mutsumi Erban Alexander Zuther Ellen Hoefgen Rainer Roessner Ute Okamoto Mamoru Heuer Sigrid 《Plant molecular biology》2019,99(4-5):477-497
Plant Molecular Biology - Degradation of nitrogen-rich purines is tightly and oppositely regulated under drought and low nitrogen supply in bread wheat. Allantoin is a key target metabolite for... 相似文献
99.
N Baumann Y Maurin A Puech P Chauvel P Simon 《Comptes rendus des séances de la Société de biologie et de ses filiales》1980,174(4):437-445
The abnormal behavior observed in diseases of myelin remains unexplained. Mutations in the mouse in which the main phenotypic expression involves myelination is a useful tool. As tonic seizures are observed, an electrophysiological, pharmacological and biochemical study was performed. The convulsions seem to be linked mainly to an alteration of the alpha-adrenergic system. The GABA-ergic system is also modified. The relations between these observations and the defect of myelination remain to be elucidated. 相似文献
100.