Specialised information processing deficits and distinct metabolomics profiles following TM-domain disruption of Nrg1

While there is considerable genetic and pathologic evidence for an association between neuregulin 1 (NRG1) dysregulation and schizophrenia, the underlying molecular and cellular mechanisms remain unclear. Mutant mice containing disruption of the transmembrane (TM) domain of the NRG1 gene constitute a heuristic model for dysregulation of NRG1-ErbB4 signalling in schizophrenia. The present study focused on specialised behavioural and characterisation of hitherto un-characterised information processing phenotypes in this mutant line. Using a mass spectrometry-based metabolomics approach, we also quantified levels of unique metabolites in brain. Across two different sites and protocols, Nrg1 mutants demonstrated deficits in pre-pulse inhibition, a measure of sensorimotor gating that is disrupted in schizophrenia; these deficits were partially reversed by acute treatment with second-, but not first-, generation antipsychotic drugs. However, Nrg1 mutants did not show a specific deficit in latent inhibition, a measure of selective attention that is also disrupted in schizophrenia. In contrast, in the ‘what-where-when’ cognitive paradigm, Nrg1 mutants displayed sex-specific (males only) disruption of ‘what-when’ performance, indicative of impaired episodic memory. Differential metabolomic profiling revealed that these behavioural phenotypes were accompanied, most prominently, by alterations in lipid metabolism pathways. This study is the first to associate these novel physiological mechanisms, previously independently identified as being abnormal in schizophrenia, with disruption of NRG1 function. These data suggest novel mechanisms by which compromised neuregulin function from birth might lead to schizophrenia-relevant behavioural changes in adulthood

Yrast and near-yrast excitations up to high spin in 10048Cd52

The gamma decay of excited states in the nucleus 100Cd, which is two proton holes and two neutrons away from doubly magic (N=Z=50) 100Sn, has been studied with the Gammasphere array following the 46Ti(58Ni,2p2n) reaction at 215 MeV. Residues were identified by detection of evaporated charged particles in the Microball CsI array, by neutron detection in a set of liquid scintillator detectors, and by a tag on the delayed gamma-ray decay of the known 8+ isomeric state. The level scheme has been extended up to 20ℏ in angular momentum and to nearly 10 MeV in excitation energy. The results are compared with shell-model calculations

High-spin study of rotational structures in 72Br

High-spin states in 3572Br37 were studied using the 40Ca(36Ar, 3pn) reaction. The existing level scheme has been significantly modified and extended. Evidence has been found for a spin reassignment of -1ℏh to the previously observed negative-parity band, which carries implications for the interpretation of a signature inversion in this structure. One signature of the previously assigned positive-parity band is interpreted as negative parity and has been extended to I π=(22-) and its signature partner has been observed up to Iπ = (19-) for the first time. The remaining positive-parity band has been extended to Iπ=(29+). A sequence of states observed to Iπ=(22+) may be the signature partner of this structure. Configurations have been assigned to each of these three structures through comparisons to cranked Nilsson-Strutinsky calculations

High-angular-momentum structures in 64Zn

High-angular-momentum states in 64Zn were populated in the 40Ca( 28Si,4p) reaction at a beam energy of 122 MeV. Evaporated, light, charged particles were identified by the Microball, while γ rays were detected using the Gammasphere array. The main focus of this paper is on two strongly coupled, collective bands. The yrast band, which was previously known, has been linked to lower-lying states establishing the excitation energies and angular momenta of in-band states for the first time. The newly identified excited band decays to the yrast band but firm angular-momentum assignments could not be made. In order to interpret these structures cranked-Nilsson-Strutinsky calculations have been performed. The calculations have been extended to account for the distribution of nucleons within a configuration. The yrast collective band is interpreted as based on the π(f 7/2) -1(p 3/2f 5/2) 2(g 9/2) 1 ν(p 3/2f 5/2) 4(g 9/2) 2 configuration. There are several possible interpretations of the second band but it is difficult to distinguish between the different possibilities

IPv6 Alias Resolution via Induced Fragmentation

Proceedings of the 14th Passive and Active Measurement (PAM 2013) Conference, Hong Kong, CN, March 2013 (Best Paper Finalist).Discovering router-level IPv6 topologies is important to understanding IPv6 growth, structure, and evolution and relation to IPv4. This work presents a fingerprint-based IPv6 alias resolution technique that induces fragmented responses from IPv6 router interfaces. We leverage the way in which IPv6 implements fragmentation to provide reliable inferences. We demonstrate perfect alias resolution accuracy in a controlled environment, and on a small subset of the production IPv6 Internet for which we have ground-truth. Internet-wide testing finds that over 70\% of IPv6 interfaces probed respond to the test. Our promising results suggest a valuable technique to aid IPv6 topology discovery

High-spin states in the A=39A=39 mirror nuclei 39^{39}Ca and 39^{39}K

High-spin states of the mass $A=39$ mirror pair $^{39}$K and $^{39}$Ca were investigated via the fusion-evaporation reaction $^{28}$Si+$^{16}$O at 125 MeV beam energy. The Gammasphere array in conjunction with the $4\pi$ charged-particle detector array Microball and neutron detectors was used to detect $\gamma$ rays in coincidence with evaporated light particles. The results of the first high-spin study of the $T_z=-1/2$ nucleus $^{39}$Ca are discussed in terms of mirror symmetry and compared to spherical shell-model calculations in the $1d_{3/2}$–$1f_{7/2}$ configuration space

Δ\DeltaI = 4 Bifurcation in Identical Superdeformed Bands

What does it mean to find one's place in a book ? Some authors assert that the web actualises the dream of Emmanuel Kant that reason is an independent entity , where each one of us plays a part in its construction. Is this the core of the enlightment ? In his minor works and his correspondence Kant wrote about the book and about reading. We should distinguish between Kant's own concept and the uses to which it is put today. In his work he speaks of the courage necessary to think, of the publisher's responsibility, of the theoretical and practical components of thought. From the perspective of Kant's writings, we can see that our view of hypertext is too preoccupied with the instrument of communication itself to the detriment of understanding what might be communicated