| 1. |
- Adlarson, Patrik, et al.
(author)
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Abashian-Booth-Crowe Effect in Basic Double-Pionic Fusion : A New Resonance?
- 2011
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 106:24, s. 242302-
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Journal article (peer-reviewed)abstract
- We report on an exclusive and kinematically complete high-statistics measurement of the basic double-pionic fusion reaction pn -> d pi(0)pi(0) over the full energy region of the ABC effect, a pronounced low-mass enhancement in the pi pi-invariant mass spectrum. The measurements, which cover also the transition region to the conventional t- channel Delta Delta process, were performed with the upgraded WASA detector setup at COSY. The data reveal the Abashian-Booth-Crowe effect to be uniquely correlated with a Lorentzian energy dependence in the integral cross section. The observables are consistent with a narrow resonance with m = 2.37 GeV, Gamma approximate to 70 MeV and I(J(P)) = 0(3(+)) in both pn and Delta Delta systems. Necessary further tests of the resonance interpretation are discussed.
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| 2. |
- Schonning, K., et al.
(author)
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The pd -> He-3 eta pi(0) reaction at T-p=1450 MeV CELSIUS/WASA Collaboration
- 2010
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In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 685:1, s. 33-37
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Journal article (peer-reviewed)abstract
- The cross section for the pd -> He-3 eta pi(0) reaction has been measured at a beam energy of 1450 MeV using the WASA detector at the CELSIUS storage ring. The He-3 was detected in coincidence with four photons from the decays of the two mesons. The data indicate that the production mechanism involves the formation of the Delta(1232) isobar. Although the beam energy does not allow the full peak of this resonance to be seen, the invariant mass distributions Of all three pairs of final particles are well reproduced by a phase space Monte Carlo simulation weighted with the p-wave factor of the square of the pi(0) momentum in the He-3 pi(0) system.
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| 3. |
- Deprá, Gabriel C., et al.
(author)
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A new colorful species of Geophagus (Teleostei: Cichlidae), endemic to the rio Aripuanã in the Amazon basin of Brazil
- 2014
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In: Neotropical Ichthyology. - : FapUNIFESP (SciELO). - 1679-6225 .- 1982-0224. ; 12:4, s. 737-746
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Journal article (peer-reviewed)abstract
- Geophagus mirabilis, new species, is endemic to the rio Aripuanã drainage upstream from Dardanelos/Andorinhas falls.The new species is distinguished from all other species of the genus by the presence of one to five large black spots arrangedlongitudinally along the middle of the flank, in addition to the black midlateral spot that is characteristic of species in thegenus and by a pattern of iridescent spots and lines on the head in living specimens. It is further distinguished from allcongeneric species, except G. camopiensis and G. crocatus, by the presence of seven (vs. eight or more) scale rows in thecircumpeduncular series below the lateral line (7 in G. crocatus; 7-9 in G. camopiensis). Including the new species, five cichlids and 11 fish species in total are known only from the upper rio Aripuanã, and 15 fish species in total are known only from the rio Aripuanã drainage
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| 4. |
- Hellström, Anders R., et al.
(author)
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Inactivation of Pmel Alters Melanosome Shape But Has Only a Subtle Effect on Visible Pigmentation
- 2011
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In: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 7:9, s. e1002285-
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Journal article (peer-reviewed)abstract
- PMEL is an amyloidogenic protein that appears to be exclusively expressed in pigment cells and forms intralumenal fibrils within early stage melanosomes upon which eumelanins deposit in later stages. PMEL is well conserved among vertebrates, and allelic variants in several species are associated with reduced levels of eumelanin in epidermal tissues. However, in most of these cases it is not clear whether the allelic variants reflect gain-of-function or loss-of-function, and no complete PMEL loss-of-function has been reported in a mammal. Here, we have created a mouse line in which the Pmel gene has been inactivated (Pmel(-/-)). These mice are fully viable, fertile, and display no obvious developmental defects. Melanosomes within Pmel(-/-) melanocytes are spherical in contrast to the oblong shape present in wild-type animals. This feature was documented in primary cultures of skin-derived melanocytes as well as in retinal pigment epithelium cells and in uveal melanocytes. Inactivation of Pmel has only a mild effect on the coat color phenotype in four different genetic backgrounds, with the clearest effect in mice also carrying the brown/Tyrp1 mutation. This phenotype, which is similar to that observed with the spontaneous silver mutation in mice, strongly suggests that other previously described alleles in vertebrates with more striking effects on pigmentation are dominant-negative mutations. Despite a mild effect on visible pigmentation, inactivation of Pmel led to a substantial reduction in eumelanin content in hair, which demonstrates that PMEL has a critical role for maintaining efficient epidermal pigmentation.
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| 5. |
- Kren, F., et al.
(author)
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Exclusive measurements of pp -> d pi(+)pi(0) : Double-pionic fusion without ABC effect
- 2010
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In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 684:2-3, s. 110-113
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Journal article (peer-reviewed)abstract
- Exclusive measurements of the reaction pp -> d pi(+)pi(0) have been carried out at T-p = 1.1 GeV at the CELSIUS storage ring using the WASA detector. The isovector pi(+)pi(0) channel exhibits no enhancement at low invariant pi pi masses, i.e. no ABC effect. Therefore this most basic isovector double-pionic fusion reaction qualifies as an ideal test case for the conventional t-channel Delta Delta excitation process. Indeed, the obtained differential distributions reveal the conventional t-channel Delta Delta mechanism as the appropriate reaction process, which also accounts for the observed energy dependence of the total cross section.
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| 6. |
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| 7. |
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| 8. |
- Petrén, Henrik, et al.
(author)
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eta-meson production in proton-proton collisions at excess energies of 40 and 72 MeV
- 2010
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 82:5, s. 055206-
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Journal article (peer-reviewed)abstract
- The production of eta mesons in proton-proton collisions has been studied using the WASA detector at the CELSIUS storage ring at excess energies of Q = 40 MeV and Q = 72 MeV. The eta was detected through its 2 gamma decay in a near-4 pi electromagnetic calorimeter, whereas the protons were measured by a combination of straw chambers and plastic scintillator planes in the forward hemisphere. About 6.9 x 10(4) and 9.3 x 10(4) events were found at Q = 40 MeV and Q = 72 MeV, respectively, with background contributions of less than 5%. A simple parametrization of the production cross section in terms of low partial waves was used to evaluate the acceptance corrections. Strong evidence was found for the influence of higher partial waves. The Dalitz plots show the presence of p waves in both the pp and the eta {pp} systems and the angular distributions of the eta in the center-of-mass frame suggest the influence of d-wave eta mesons.
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| 9. |
- Pramod, P.K., et al.
(author)
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Betadevario ramachandrani, a new danionine genus and species from the Western Ghats of India (Teleostei: Cyprinidae: Danioninae)
- 2010
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In: Zootaxa. - 1175-5326 .- 1175-5334. ; 2519, s. 31-47
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Journal article (peer-reviewed)abstract
- Betadevario, new genus, with the single species B. ramachandrani, new species, from Karnataka, southwestern India, is closely related to Devario but differs from it in having two pairs of long barbels (vs. two pairs of short or rudimentary barbels, or barbels absent), wider cleithral spot which extends to cover three scales horizontally (vs. covering only one scale in width), long and low laminar preorbital process (vs. absent or a slender pointed spine-like process) along the anterior margin of the orbit, a unique flank colour pattern with a wide dark band along the lower side, bordered dorsally by a wide light stripe (vs. vertical bars, or stripes narrow and usually in greater number).
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| 10. |
- Reinius, Björn, et al.
(author)
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Female-biased expression of long non-coding RNAs in domains that escape X-inactivation in mouse
- 2010
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In: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 11:1, s. 614-
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Journal article (peer-reviewed)abstract
- Background: Sexual dimorphism in brain gene expression has been recognized in several animal species.However, the relevant regulatory mechanisms remain poorly understood. To investigatewhether sex-biased gene expression in mammalian brain is globally regulated or locallyregulated in diverse brain structures, and to study the genomic organisation of brain-expressedsex-biased genes, we performed a large scale gene expression analysis of distinct brainregions in adult male and female mice. Results: This study revealed spatial specificity in sex-biased transcription in the mouse brain, andidentified 173 sex-biased genes in the striatum; 19 in the neocortex; 12 in the hippocampusand 31 in the eye. Genes located on sex chromosomes were consistently over-represented inall brain regions. Analysis on a subset of genes with sex-bias in more than one tissue revealedY-encoded male-biased transcripts and X-encoded female-biased transcripts known to escapeX-inactivation. In addition, we identified novel coding and non-coding X-linked genes withfemale-biased expression in multiple tissues. Interestingly, the chromosomal positions of allof the female-biased non-coding genes are in close proximity to protein-coding genes thatescape X-inactivation. This defines X-chromosome domains each of which contains a codingand a non-coding female-biased gene. Lack of repressive chromatin marks in non-codingtranscribed loci supports the possibility that they escape X-inactivation. Moreover, RNADNAcombined FISH experiments confirmed the biallelic expression of one such noveldomain. Conclusion: This study demonstrated that the amount of genes with sex-biased expression variesbetween individual brain regions in mouse. The sex-biased genes identified are localized onmany chromosomes. At the same time, sexually dimorphic gene expression that is common toseveral parts of the brain is mostly restricted to the sex chromosomes. Moreover, the studyuncovered multiple female-biased non-coding genes that are non-randomly co-localized onthe X-chromosome with protein-coding genes that escape X-inactivation. This raises thepossibility that expression of long non-coding RNAs may play a role in modulating geneexpression in domains that escape X-inactivation in mouse.
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