245 research outputs found

    Size constancy in bat biosonar?

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    Perception and encoding of object size is an important feature of sensory systems. In the visual system object size is encoded by the visual angle (visual aperture) on the retina, but the aperture depends on the distance of the object. As object distance is not unambiguously encoded in the visual system, higher computational mechanisms are needed. This phenomenon is termed "size constancy". It is assumed to reflect an automatic re-scaling of visual aperture with perceived object distance. Recently, it was found that in echolocating bats, the 'sonar aperture', i.e., the range of angles from which sound is reflected from an object back to the bat, is unambiguously perceived and neurally encoded. Moreover, it is well known that object distance is accurately perceived and explicitly encoded in bat sonar. Here, we addressed size constancy in bat biosonar, recruiting virtual-object techniques. Bats of the species Phyllostomus discolor learned to discriminate two simple virtual objects that only differed in sonar aperture. Upon successful discrimination, test trials were randomly interspersed using virtual objects that differed in both aperture and distance. It was tested whether the bats spontaneously assigned absolute width information to these objects by combining distance and aperture. The results showed that while the isolated perceptual cues encoding object width, aperture, and distance were all perceptually well resolved by the bats, the animals did not assign absolute width information to the test objects. This lack of sonar size constancy may result from the bats relying on different modalities to extract size information at different distances. Alternatively, it is conceivable that familiarity with a behaviorally relevant, conspicuous object is required for sonar size constancy, as it has been argued for visual size constancy. Based on the current data, it appears that size constancy is not necessarily an essential feature of sonar perception in bats

    Emergence of novel cephalopod gene regulation and expression through large-scale genome reorganization

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    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Schmidbaur, H., Kawaguchi, A., Clarence, T., Fu, X., Hoang, O. P., Zimmermann, B., Ritschard, E. A., Weissenbacher, A., Foster, J. S., Nyholm, S., Bates, P. A., Albertin, C. B., Tanaka, E., & Simakov, O. Emergence of novel cephalopod gene regulation and expression through large-scale genome reorganization. Nature Communications, 13(1), (2022): 2172, https://doi.org/10.1038/s41467-022-29694-7.Coleoid cephalopods (squid, cuttlefish, octopus) have the largest nervous system among invertebrates that together with many lineage-specific morphological traits enables complex behaviors. The genomic basis underlying these innovations remains unknown. Using comparative and functional genomics in the model squid Euprymna scolopes, we reveal the unique genomic, topological, and regulatory organization of cephalopod genomes. We show that coleoid cephalopod genomes have been extensively restructured compared to other animals, leading to the emergence of hundreds of tightly linked and evolutionary unique gene clusters (microsyntenies). Such novel microsyntenies correspond to topological compartments with a distinct regulatory structure and contribute to complex expression patterns. In particular, we identify a set of microsyntenies associated with cephalopod innovations (MACIs) broadly enriched in cephalopod nervous system expression. We posit that the emergence of MACIs was instrumental to cephalopod nervous system evolution and propose that microsyntenic profiling will be central to understanding cephalopod innovations.H.S., O.P.H., E.R., and O.S. were supported by the Austrian Science Fund (FWF) grant P30686-B29. O.S. was supported by Whitman Center Early Career Fellowship (Frank R. Lillie Quasi-Endowment Fund, L. & A. Colwin Summer Research Fellowship, Bell Research Award in Tissue Engineering). H.S. was supported by the short-term grant abroad (KWA) of the University of Vienna. H.S. and O.S. were supported by the University of Chicago/Vienna Strategic Partnership Programme Mobility Grant. A.K. was supported by the JSPS Postdoctoral Fellowship for Overseas Researchers program from Japan. C.B.A. was supported by the Hibbitt Early Career Fellowship. Eggs and paralarvae of E. scolopes were generated in part by support by the NASA Space Biology 80NSSC18K1465 awarded to J.S.F. S.V.N. was supported by the National Science Foundation IOS-1557914. This work was supported by the Francis Crick Institute, which receives its core funding from Cancer Research UK (FC0001003), the UK Medical Research Council (FC001003), and the Wellcome Trust (FC001003)

    Bacterial vaginosis

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    Bacterial vaginosis is the most prevalent cause of abnormal vaginal discharge in women of childbearing age. It can have a major impact on quality of life and psychological wellbeing if frequently recurrent and strongly symptomatic. The use of molecular techniques to study the vaginal microbiome is increasing our understanding of the dynamic changes in flora that occur in health and disease. It might soon be possible to separate Gardnerella into different pathogenic and non-pathogenic species. Many groups are studying compounds that can disrupt the biofilm which is dominated by Gardnerella and Atopobium vaginae. Several studies in the last decade support the concept of bacterial vaginosis as a sexually transmitted infection

    Interaction between Dysfunctional Connectivity at Rest and Heroin Cues-Induced Brain Responses in Male Abstinent Heroin-Dependent Individuals

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    BACKGROUND: The majority of previous heroin cue-reactivity functional magnetic resonance imaging (fMRI) studies focused on local function impairments, such as inhibitory control, decision-making and stress regulation. Our previous studies have demonstrated that these brain circuits also presented dysfunctional connectivity during the resting state. Yet few studies considered the relevance of resting state dysfunctional connectivity to task-related neural activity in the same chronic heroin user (CHU). METHODOLOGY/PRINCIPAL FINDINGS: We employed the method of graph theory analysis, which detected the abnormality of brain regions and dysregulation of brain connections at rest between 16 male abstinent chronic heroin users (CHUs) and 16 non-drug users (NDUs). Using a cue-reactivity task, we assessed the relationship between drug-related cue-induced craving activity and the abnormal topological properties of the CHUs' resting networks. Comparing NDUs' brain activity to that of CHUs, the intensity of functional connectivity of the medial frontal gyrus (meFG) in patients' resting state networks was prominently greater and positively correlated with the same region's neural activity in the heroin-related task; decreased functional connectivity intensity of the anterior cingulate cortex (ACC) in CHUs at rest was associated with more drug-related cue-induced craving activities. CONCLUSIONS: These results may indicate that there exist two brain systems interacting simultaneously in the heroin-addicted brain with regards to a cue-reactivity task. The current study may shed further light on the neural architecture that supports craving responses in heroin dependence

    Geospatial data analysis in Russia’s geoweb

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    The chapter examines the role of geospatial data in Russia’s online ecosystem. Facilitated by the rise of geographic information systems and user-generated content, the distribution of geospatial data has blurred the line between physical spaces and their virtual representations. The chapter discusses different sources of these data available for Digital Russian Studies (e.g., social data and crowdsourced databases) together with the novel techniques for extracting geolocation from various data formats (e.g., textual documents and images). It also scrutinizes different ways of using these data, varying from mapping the spatial distribution of social and political phenomena to investigating the use of geotag data for cultural practices’ digitization to exploring the use of geoweb for narrating individual and collective identities online

    Tacaribe Virus but Not Junin Virus Infection Induces Cytokine Release from Primary Human Monocytes and Macrophages

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    The mechanisms underlying the development of disease during arenavirus infection are poorly understood. However, common to all hemorrhagic fever diseases is the involvement of macrophages as primary target cells, suggesting that the immune response in these cells may be of paramount importance during infection. Thus, in order to identify features of the immune response that contribute to arenavirus pathogenesis, we have examined the growth kinetics and cytokine profiles of two closely related New World arenaviruses, the apathogenic Tacaribe virus (TCRV) and the hemorrhagic fever-causing Junin virus (JUNV), in primary human monocytes and macrophages. Both viruses grew robustly in VeroE6 cells; however, TCRV titres were decreased by approximately 10 fold compared to JUNV in both monocytes and macrophages. Infection of both monocytes and macrophages with TCRV also resulted in the release of high levels of IL-6, IL-10 and TNF-α, while levels of IFN-α, IFN-β and IL-12 were not affected. However, we could show that the presence of these cytokines had no direct effect on growth of either TCRV of JUNV in macrophages. Further analysis also showed that while the production of IL-6 and IL-10 are dependent on viral replication, production of TNF-α also occurs after exposure to UV-inactivated TCRV particles and is thus independent of productive virus infection. Surprisingly, JUNV infection did not have an effect on any of the cytokines examined indicating that, in contrast to other viral hemorrhagic fever viruses, macrophage-derived cytokine production is unlikely to play an active role in contributing to the cytokine dysregulation observed in JUNV infected patients. Rather, these results suggest that an early, controlled immune response by infected macrophages may be critical for the successful control of infection of apathogenic viruses and prevention of subsequent disease, including systemic cytokine dysregulation

    Prevalencija infekcije Neisseriom gonorrhoeae ili Chlamydiom trachomatis kod akutnoga mukopurulentnog cervicitisa

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    The aim of this study was to determine the incidence of N. gonorrhoae (NG) and/or C. trachomatis (CT) in acute mucopurulent cervicitis (MPC). The study included 617 non-pregnant women with MPC, who had not been receiving any antimicrobial treatment. The average age of patients was 22.2 years. There were no statistically significant differences according to place of residence, education, and marital status. Samples for laboratory analysis were collected using a routine procedure; NG was identified using the cytochrome oxidase test and Gram staining. CT was isolated on McCoy cell culture and stained with Lugol solution. NG was isolated in three women (0.8 %) and CT in 58 women (9.4 %). Fifty-six of the CT-positive patients were nullipara and only two were unipara. All NG-positive patients were also nullipara. The mean number of sexual partners was 2.2 in all study subjects, 2.4 in CT-positive subjects, and 2.9 in NG-positive subjects. Vaginal discharge purity according to Schröder was significantly deteriorated in CT-positive patients (p=0.011). When asked about the use of contraceptives, as many as 32.7 % patients answered that they did not use any protection, 39 % women used the rhythm method and coitus interruptus, 20 % were taking oral contraceptives, 6.1 % used mechanical devices, and 1.9 % used chemical protection. Previous acute and chronic pelvic infl ammatory diseases correlated with MPC (p<0.01). Our statistical analysis suggests that chlamydial infection significantly reduces the purity of vaginal discharge, which is more pronounced in nulliparae. Pap smear was not specific enough to demonstrate chlamydial infection. In view of the MPC findings, the prevalence of CT and NG infection is low.Cilj istraživanja jest utvrditi koincidenciju N. gonorrhoae (NG) i/ili C. trachomatis (CT) u akutnim mukopurulentnim cervicitisima (MPC). Istraživanje je provedeno na populaciji 617 žena izvan trudnoće koje prethodno nisu uzimale antimikrobnu terapiju. NG i CT su izolirane iz obrisaka vrata maternice primjenom standardnih metoda. NG je transportirana na selektivnoj hranjivoj podlozi i identificirana citokrom-oksidaznim testom bojenjem po Gramu. CT je izolirana McCoyevom staničnom kulturom nakon bojenja Lugolovom otopinom. NG je izolirana u tri ispitanice (0,8 %), a CT u 58 ispitanica (9,4 %). Srednja dob bolesnica iznosila je 22,2 godine. Školovanje i bračno stanje nisu statistički značajno utjecali na rezultate istraživanja. Među bolesnicama s izoliranom CT prevladavaju nulipare, a u slučaju NG sve su pozitivne bolesnice također bile nulipare. Srednja vrijednost broja partnera za čitavu populaciju iznosi 2,2. Bolesnice s potvrđenom CT imale su prosječno 2,4, a one s potvrđenom NG 2,9 partnera. Vrijednost određivanja stupnja čistoće rodničkog iscjetka po Schroderu značajno je povišena u CT-pozitivnih bolesnica (p=0.011). Utvrđeno je da 32.7 % ispitanica uopće nije koristilo kontracepciju, dok je većina (39 %) rabila ritmičke metode i prekinuti snošaj. Preostale ispitanice uzimale su oralne kontraceptive (20 %), mehaničku zaštitu (6,1 %) ili lokalne kemijske kontraceptive (1,9 %). Također je dokazano da prethodna akutna i kronična zdjelična upalna bolest korelira s MPC-om (p<0.01). Zaključeno je da klamidijska infekcija statistički značajno korelira sa stupnjem čistoće rodničkog iscjetka, posebice u nulipara. Papanicolaouov razmaz nije specifičan u određivanju klamidijske infekcije. Rezultati istraživanja pokazuju da je učestalost klamidijske i gonokokne infekcije ipak relativno niska u odnosu na nalaz MPC-a
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