290 research outputs found

    Spatial encoding in primate hippocampus during free navigation.

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    The hippocampus comprises two neural signals-place cells and θ oscillations-that contribute to facets of spatial navigation. Although their complementary relationship has been well established in rodents, their respective contributions in the primate brain during free navigation remains unclear. Here, we recorded neural activity in the hippocampus of freely moving marmosets as they naturally explored a spatial environment to more explicitly investigate this issue. We report place cells in marmoset hippocampus during free navigation that exhibit remarkable parallels to analogous neurons in other mammalian species. Although θ oscillations were prevalent in the marmoset hippocampus, the patterns of activity were notably different than in other taxa. This local field potential oscillation occurred in short bouts (approximately .4 s)-rather than continuously-and was neither significantly modulated by locomotion nor consistently coupled to place-cell activity. These findings suggest that the relationship between place-cell activity and θ oscillations in primate hippocampus during free navigation differs substantially from rodents and paint an intriguing comparative picture regarding the neural basis of spatial navigation across mammals

    Eocene evolution of whale hearing

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    The origin of whales (order Cetacea) is one of the best-documented examples of macroevolutionary change in vertebrates. As the earliest whales became obligately marine, all of their organ systems adapted to the new environment. The fossil record indicates that this evolutionary transition took less than 15 million years, and that different organ systems followed different evolutionary trajectories. Here we document the evolutionary changes that took place in the sound transmission mechanism of the outer and middle ear in early whales. Sound transmission mechanisms change early on in whale evolution and pass through a stage (in pakicetids) in which hearing in both air and water is unsophisticated. This intermediate stage is soon abandoned and is replaced (in remingtonocetids and protocetids) by a sound transmission mechanism similar to that in modern toothed whales. The mechanism of these fossil whales lacks sophistication, and still retains some of the key elements that land mammals use to hear airborne sound

    Novel Data Acquisition System for Silicon Tracking Detectors

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    We have developed a novel data acquisition system for measuring tracking parameters of a silicon detector in a particle beam. The system is based on a commercial Analog-to-Digital VME module and a PC Linux based Data Acquisition System. This DAQ is realized with C++ code using object-oriented techniques. Track parameters for the beam particles were reconstructed using off-line analysis code and automatic detector position alignment algorithm. The new DAQ was used to test novel Czochralski type silicon detectors. The important silicon detector parameters, including signal size distributions and signal to noise distributions, were successfully extracted from the detector under study. The efficiency of the detector was measured to be 95 %, the resolution about 10 micrometers, and the signal to noise ratio about 10.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 6 pages, LaTeX, 5 eps figures. PSN TUGP00

    [Formula Presented] decay of neutron-rich [Formula Presented] and [Formula Presented] isotopes

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    [Formula Presented] decays of on-line mass-separated neutron-rich [Formula Presented] and [Formula Presented] isotopes have been studied by using [Formula Presented] and [Formula Presented] coincidence spectroscopy. Extended decay schemes to the [Formula Presented] daughter nuclei have been constructed. The three-phonon quintuplet in [Formula Presented] is completed by including a new level at 2023.0 keV, which is tentatively assigned the spin and parity of [Formula Presented] The intruder band in [Formula Presented] is proposed up to the [Formula Presented] level at 2322.4 keV. The measured [Formula Presented]-decay half-life for the high-spin isomer of [Formula Presented] is [Formula Presented] Candidates for the three-phonon states, as well as the lowest members of the intruder band in [Formula Presented] are also presented. These data support the coexistence of quadrupole anharmonic vibration and proton particle-hole intruder excitations in [Formula Presented].</p

    Spectroscopy of 34,35Si^{34,35}Si by β\beta decay: sd-fp shell gap and single-particle states

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    The 34,35Alβ^{34,35}Al\beta decays were studied at the CERN on-line mass separator ISOLDE by βγ,βγγ\beta-\gamma, \beta-\gamma-\gamma and βnγ\beta-n-\gamma measurements, in order to corroborate thelow-level description of 34Si^{34}Si and to obtain the first information on the level structure of the N=21 isotope 35Si^{35}Si. Earlier observed γ\gamma lines in 34Al^{34} Al decay were confirmed and new gamma transitions following both beta decay and β\beta-delayed neutron emission were established. The first level scheme in 35Si^{35}Si, including three excited states at 910, 974 and 2168 keV, is consistent with Jπ=3/2J^{\pi} =3/2^{-} and 3/2+3/2^{+} for the first two states respectively. Beta-decay half-life of T1/2=38.6(4)T_{1/2} = 38.6 (4) ms and beta-delayed neutron branching PnP_{n} value (Pn=41(13)(P_{n} =41(13) %) were measured unambiguously. The significance of the single-particle energy determination at N=21, Z=14, for assessing the effective interaction in sd-fp shell-model calculations, is discussed and illustrated by predictions for different n-rich isotopes

    A New Acoustic Portal into the Odontocete Ear and Vibrational Analysis of the Tympanoperiotic Complex

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    Global concern over the possible deleterious effects of noise on marine organisms was catalyzed when toothed whales stranded and died in the presence of high intensity sound. The lack of knowledge about mechanisms of hearing in toothed whales prompted our group to study the anatomy and build a finite element model to simulate sound reception in odontocetes. The primary auditory pathway in toothed whales is an evolutionary novelty, compensating for the impedance mismatch experienced by whale ancestors as they moved from hearing in air to hearing in water. The mechanism by which high-frequency vibrations pass from the low density fats of the lower jaw into the dense bones of the auditory apparatus is a key to understanding odontocete hearing. Here we identify a new acoustic portal into the ear complex, the tympanoperiotic complex (TPC) and a plausible mechanism by which sound is transduced into the bony components. We reveal the intact anatomic geometry using CT scanning, and test functional preconceptions using finite element modeling and vibrational analysis. We show that the mandibular fat bodies bifurcate posteriorly, attaching to the TPC in two distinct locations. The smaller branch is an inconspicuous, previously undescribed channel, a cone-shaped fat body that fits into a thin-walled bony funnel just anterior to the sigmoid process of the TPC. The TPC also contains regions of thin translucent bone that define zones of differential flexibility, enabling the TPC to bend in response to sound pressure, thus providing a mechanism for vibrations to pass through the ossicular chain. The techniques used to discover the new acoustic portal in toothed whales, provide a means to decipher auditory filtering, beam formation, impedance matching, and transduction. These tools can also be used to address concerns about the potential deleterious effects of high-intensity sound in a broad spectrum of marine organisms, from whales to fish

    What we talk about when we talk about "global mindset": managerial cognition in multinational corporations

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    Recent developments in the global economy and in multinational corporations have placed significant emphasis on the cognitive orientations of managers, giving rise to a number of concepts such as “global mindset” that are presumed to be associated with the effective management of multinational corporations (MNCs). This paper reviews the literature on global mindset and clarifies some of the conceptual confusion surrounding the construct. We identify common themes across writers, suggesting that the majority of studies fall into one of three research perspectives: cultural, strategic, and multidimensional. We also identify two constructs from the social sciences that underlie the perspectives found in the literature: cosmopolitanism and cognitive complexity and use these two constructs to develop an integrative theoretical framework of global mindset. We then provide a critical assessment of the field of global mindset and suggest directions for future theoretical and empirical research

    Validation of EN ISO method 10273-Detection of pathogenic Yersinia enterocolitica in foods

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    EN ISO 10273 method for the detection of pathogenic Yersinia enterocolitica in foods was validated in the project Mandate M/381 funded by European Commission. A total of 14 laboratories from five European countries participated in the interlaboratory study (ILS) organized during 2013 and 2014. Before the ITS, the method was revised by an international group of experts and the performance of the revised method was assessed in an ILS study. The results are published as a part of the standard EN ISO 10273 revision. The study included three rounds with different sample types; raw milk, iceberg lettuce and minced meat, inoculated with a low and high level of pathogenic Y. enterocolitica strains representing major pathogenic bioserotypes 4/O:3 and 2/O:9. The homogeneity and stability of the samples were verified before dispatching them to the laboratories. The results demonstrated the method sensitivity of 96% in raw milk, 97% in minced meat, and 98% in lettuce at high inoculation level of pathogenic Y. enterocolitica. The specificity was 100% in raw milk, 96% in minced meat, and 98% in lettuce. The level of detection, LOD50, varied between study rounds, being 9.4 CFU/25 ml in raw milk, 9.9 CFU/25 g in minced meat and 63 CFU/25 g in lettuce samples. During the study, confirmation by using real-time PCR method ISO/TS 18867 together with pyrazinamidase testing was also validated, as alternative to conventional biochemical confirmation. When comparing different isolation steps used in the revised method during the study rounds, PSB enrichment and plating on CIN after alkaline (KOH) treatment showed the highest sensitivity (52-92%) in raw milk and minced meat samples. In lettuce samples, however, ITC with KOH treatment before plating on CIN showed higher sensitivity (64% at low level; 82% at high level) than plating on CIN from PSB with KOH treatment (44% at low level; 74% at high level). Statistical analysis of different isolation steps supported the use of two enrichment media, PSB and ITC, in the revised method. Recovery of pathogenic Y. enterocolitica on ON was most efficient after KOH treatment and, based on the analysis, plating on CIN agar without KOH treatment could be left as optional procedure in the method.Peer reviewe

    Gene fusions and oncogenic mutations in MLH1 deficient and BRAFV600E wild-type colorectal cancers

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    Gene fusions can act as oncogenic drivers and offer targets for cancer therapy. Since fusions are rare in colorectal cancer (CRC), their universal screening seems impractical. Our aim was to investigate gene fusions in 62 CRC cases with deficient MLH1 (dMLH1) and BRAFV600E wild-type (wt) status from a consecutive real-life series of 2079 CRCs. First, gene fusions were analysed using a novel FusionPlex Lung v2 RNA-based next-generation sequencing (NGS) panel, and these results were compared to a novel Idylla GeneFusion assay and pan-TRK immunohistochemistry (IHC). NGS detected seven (7/62, 11%) NTRK1 fusions (TPM3::NTRK1, PLEKHA6::NTRK1 and LMNA::NTRK1, each in two cases, and IRF2BP2::NTRK1 in one case). In addition, two ALK, four RET and seven BRAF fusions were identified. Idylla detected seven NTRK1 expression imbalances, in line with the NGS results (overall agreement 100%). Furthermore, Idylla detected the two NGS-identified ALK rearrangements as one specific ALK fusion and one ALK expression imbalance, whilst only two of the four RET fusions were discovered. However, Idylla detected several expression imbalances of ALK (n = 7) and RET (n = 1) that were found to be fusion negative with the NGS. Pan-TRK IHC showed clearly detectable, fusion partner-dependent staining patterns in the seven NTRK1 fusion cases. Overall agreement for pan-TRK antibody clone EPR17341 was 98% and for A7H6R 100% when compared to the NGS. Of the 62 CRCs, 43 were MLH1 promoter hypermethylated (MLH1ph) and 39 were RASwt. All fusion cases were both MLH1ph and RASwt. Our results show that kinase fusions (20/30, 67%) and most importantly targetable NTRK1 fusions (7/30, 23%) are frequent in CRCs with dMLH1/BRAFV600Ewt/MLH1ph/RASwt. NGS was the most comprehensive method in finding the fusions, of which a subset can be screened by Idylla or IHC, provided that the result is confirmed by NGS

    The Evolution of Bat Vestibular Systems in the Face of Potential Antagonistic Selection Pressures for Flight and Echolocation

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    PMCID: PMC3634842This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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