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81.
Jilt Sebastian Mriganka Sur Hema A. Murthy Mathew Magimai-Doss 《PLoS computational biology》2021,17(3)
Spiking information of individual neurons is essential for functional and behavioral analysis in neuroscience research. Calcium imaging techniques are generally employed to obtain activities of neuronal populations. However, these techniques result in slowly-varying fluorescence signals with low temporal resolution. Estimating the temporal positions of the neuronal action potentials from these signals is a challenging problem. In the literature, several generative model-based and data-driven algorithms have been studied with varied levels of success. This article proposes a neural network-based signal-to-signal conversion approach, where it takes as input raw-fluorescence signal and learns to estimate the spike information in an end-to-end fashion. Theoretically, the proposed approach formulates the spike estimation as a single channel source separation problem with unknown mixing conditions. The source corresponding to the action potentials at a lower resolution is estimated at the output. Experimental studies on the spikefinder challenge dataset show that the proposed signal-to-signal conversion approach significantly outperforms state-of-the-art-methods in terms of Pearson’s correlation coefficient, Spearman’s rank correlation coefficient and yields comparable performance for the area under the receiver operating characteristics measure. We also show that the resulting system: (a) has low complexity with respect to existing supervised approaches and is reproducible; (b) is layer-wise interpretable, and (c) has the capability to generalize across different calcium indicators. 相似文献
82.
Ferencz Sandor Toth Denes Kaszas Balint Bardosi Sebastian Vicena Viktoria Karadi Oszkar Reglodi Dora Kelemen Dezso 《International journal of peptide research and therapeutics》2021,27(3):1719-1728
International Journal of Peptide Research and Therapeutics - Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide with widespread occurrence and diverse functions. PACAP... 相似文献
83.
Alshareef Ahmed Wu Taotao Giudice J. Sebastian Panzer Matthew B. 《Biomechanics and modeling in mechanobiology》2021,20(6):2301-2317
Biomechanics and Modeling in Mechanobiology - Computational models of the brain have become the gold standard in biomechanics to understand, predict, and mitigate traumatic brain injuries. Many... 相似文献
84.
Karl Sebastian Moritz Fester Georgina Hockings Rudie Jansen van Vuuren Marlice van Vuuren 《Ecology and evolution》2021,11(9):3672
We have investigated the relationship between spotted hyaenas in the south Namib Desert and large herbivorous prey and have summarized an updated overview of predator‐prey relationships in this resource‐limited arid environment. Over the 52‐month study, we recorded the densities (#/km−2, ±SE) of the four local large herbivorous prey species: gemsbok (1.229, ±0.50), springbok (1.352, ±0.48), ostrich (0.648, ±0.23), and greater kudu (0.343, ±0.00). A fecal analysis was performed on 146 collected spotted hyaena scats, and prey items were identified and hairs cross‐follicle analyzed to the species level. Spotted hyaena diet at the study area remained opportunistic with 240 identified prey items representing eight differing prey species being recorded, ranging from ostrich eggs to large ungulates. The Ivlev''s Electivity Index was used to determine which large herbivorous prey was most selected for. Although gemsbok had a higher representation of prey items in the sampled scats, all sampled large herbivorous prey species scored below 0 and are thus generally avoided in relation to their availability in the environment. If any prey preferences are expressed by spotted hyaena in the Namib, it can be presumed to be a nonsampled prey species. We therefore promote further detailed investigations into all other prey species present, and seasonal variations of prey densities and scat sampling, within the study environment. 相似文献
85.
Colleen M. McMichael Gregory D. Reynolds Lisa M. Koch Chao Wang Nan Jiang Jeanette Nadeau Fred D. Sack Max B. Gelderman Jianwei Pan Sebastian Y. Bednarek 《The Plant cell》2013,25(10):3910-3925
STOMATAL CYTOKINESIS DEFECTIVE1 (SCD1) encodes a putative Rab guanine nucleotide exchange factor that functions in membrane trafficking and is required for cytokinesis and cell expansion in Arabidopsis thaliana. Here, we show that the loss of SCD2 function disrupts cytokinesis and cell expansion and impairs fertility, phenotypes similar to those observed for scd1 mutants. Genetic and biochemical analyses showed that SCD1 function is dependent upon SCD2 and that together these proteins are required for plasma membrane internalization. Further specifying the role of these proteins in membrane trafficking, SCD1 and SCD2 proteins were found to be associated with isolated clathrin-coated vesicles and to colocalize with clathrin light chain at putative sites of endocytosis at the plasma membrane. Together, these data suggest that SCD1 and SCD2 function in clathrin-mediated membrane transport, including plasma membrane endocytosis, required for cytokinesis and cell expansion. 相似文献
86.
Hendrik Klein Grzegorz Niedźwiedzki Sebastian Voigt Abdelouahed Lagnaoui Abdelkbir Hminna Hafid Saber 《Ichnos》2013,20(1):24-30
Early Triassic chirotherian footprint assemblages from Poland, Germany, and Morocco are important for understanding archosaur evolution in the aftermath of the Permian-Triassic crisis. However, their ichnotaxonomy is confusing because various authors have interpreted their diversity differently. After an analysis and ichnotaxonomic re-assessment, the presence of the ichnogenera Brachychirotherium, Isochirotherium, and Chirotherium in these assemblages is not supported. Distant similarities with these ichnotaxa are functions of extra morphological variation and substrate-related factors. Instead, Early Triassic chirotherian footprints described under these names are assigned here to the ichnogenus Protochirotherium and to a more slender morphotype identified as Synaptichnium. In particular, Protochirotherium appears to be more widely distributed in central Pangea as a characteristic morphotype reflecting a distinct stage in archosaur evolution. Trackmakers were nonarchosaurian archosauriforms or, alternatively, stem-group crocodylians. Morphologically and temporally these footprints match the hypothetical ancestor of the Chirotherium barthii trackmaker. Chirotherium barthii appears by the beginning of the Middle Triassic. Because of its restricted stratigraphic range, and its wider distribution in central Pangea, Protochirotherium also has biostratigraphic significance for this region and can be considered as an indicator of Early Triassic-aged strata. 相似文献
87.
Pedro M.G. Soares José Maurício S.C. Mota Emmanuel P. Souza Priscilla F.C. Justino Alvaro X. Franco Fernando Q. Cunha Ronaldo A. Ribeiro Marcellus H.L.P. Souza 《Cytokine》2013,61(1):46-49
Background5-Fluorouracil (5-FU) induces intestinal mucositis, which is characterized by epithelial ulcerations in the mucosa and clinical manifestations, such as pain and dyspeptic symptoms. Cytokines participate in the inflammatory and functional events of intestinal mucositis. IL-4 is an important mediator of intestinal inflammation, with either anti-inflammatory or pro-inflammatory functions, depending on the model of intestinal inflammation. This study aimed to evaluate the role of IL-4 in 5-FU-induced intestinal mucositis.MethodsIL-4+/+ or IL-4?/? mice (25–30 g) were intraperitoneally injected with 5-FU (450 mg/Kg) or saline (C). After 3 days, the mice were sacrificed and the duodenum was evaluated for epithelial damage, MPO activity and cytokine concentration.Results5-FU induced significant damage in the intestinal epithelium of IL-4+/+ mice (reduction in the villus/crypt ratio: control = 3.31 ± 0.21 μm, 5-FU = 0.99 ± 0.10 μm). However, the same treatment did not induce significant damage in IL-4?/? mice (5-FU = 2.87 ± 0.19 μm) compared to wild-type mice. 5-FU-induced epithelial damage increased the MPO activity (neutrophil number) and the level of pro-inflammatory cytokines (IL-4, TNF-α, IL-1β and CXCL-8) in the duodenum. These results were not observed in IL-4?/? mice treated with 5-FU.ConclusionOur data suggest that IL-4 participates as a pro-inflammatory cytokine in a 5-FU-induced intestinal damage model and suggests that IL-4 antagonists may be novel therapeutics for this condition. 相似文献
88.
It has been shown that psychological predispositions to benefit others can motivate human cooperation and the evolution of such social preferences can be explained with kin or multi-level selection models. It has also been shown that cooperation can evolve as a costly signal of an unobservable quality that makes a person more attractive with regard to other types of social interactions. Here we show that if a proportion of individuals with social preferences is maintained in the population through kin or multi-level selection, cooperative acts that are truly altruistic can be a costly signal of social preferences and make altruistic individuals more trustworthy interaction partners in social exchange. In a computerized laboratory experiment, we test whether altruistic behavior in the form of charitable giving is indeed correlated with trustworthiness and whether a charitable donation increases the observing agents' trust in the donor. Our results support these hypotheses and show that, apart from trust, responses to altruistic acts can have a rewarding or outcome-equalizing purpose. Our findings corroborate that the signaling benefits of altruistic acts that accrue in social exchange can ease the conditions for the evolution of social preferences. 相似文献
89.
Floral microcharacters of the genus Chrysolaena H. Rob. (Vernonieae, Asteraceae) were analysed in detail for the first time in order to evaluate the taxonomic position of conflictive species in the group. The results were also compared with studies carried out in species of related genera. In addition to distinctive microcharacters previously studied in some species of the genus, other characters such as trichome types of the corolla, style, anthers and cypselae have been analysed for the first time. The presence of glandular apical appendage and cypselae are common characteristics among species Chrysolaena. In addition to these, this study shows that presence of glands on the style and corollas is another consistent characteristic in the genus. However, the absence of basal stylar node would not be a diagnostic character since this varies widely among species. The results indicate that most of the microcharacters of Chrysolaena analysed are quite consistent in the genus, but they are no more consistent than the pollen morphology (type 'C') and chromosome base number (x = 10). Until now, these last two features would be most useful for separating Chrysolaena from the related genera Lessingianthus and Lepidaploa. At species level, the results show that related species can be distinguished by the different combinations of floral microcharacters. The value of microcharacters could be increased if they are combined with other morphological, cytological, and palynological data. 相似文献
90.
Sophie Aschenberg Stephanie Finzel Sarah Schmidt Sebastian Kraus Klaus Engelke Matthias Englbrecht Jürgen Rech Georg Schett 《Arthritis research & therapy》2013,15(3):R62