Low temperature ellipsometry of NaV2O5

The dielectric function of alpha'NaV2O5 was measured with electric field along the a and b axes in the photon energy range 0.8-4.5 eV for temperatures down to 4K. We observe a pronounced decrease of the intensity of the 1 eV peak upon increasing temperature with an activation energy of about 25meV, indicating that a finite fraction of the rungs becomes occupied with two electrons while others are emptied as temperature increases. No appreciable shifts of peaks were found s in the valence state of individual V atoms at the phase transition is very small. A remarkable inflection of this temperature dependence at the phase transition at 34 K indicates that charge ordering is associated with the low temperature phase.Comment: Revisions in style and order of presentation. One new figure. In press in Physical Review B. REVTeX, 4 pages with 4 postscript figure

Genomic variation in baboons from central Mozambique unveils complex evolutionary relationships with other Papio species

Background: Gorongosa National Park in Mozambique hosts a large population of baboons, numbering over 200 troops. Gorongosa baboons have been tentatively identified as part of Papio ursinus on the basis of previous limited morphological analysis and a handful of mitochondrial DNA sequences. However, a recent morphological and morphometric analysis of Gorongosa baboons pinpointed the occurrence of several traits intermediate between P. ursinus and P. cynocephalus, leaving open the possibility of past and/or ongoing gene flow in the baboon population of Gorongosa National Park. In order to investigate the evolutionary history of baboons in Gorongosa, we generated high and low coverage whole genome sequence data of Gorongosa baboons and compared it to available Papio genomes. Results: We confirmed that P. ursinus is the species closest to Gorongosa baboons. However, the Gorongosa baboon genomes share more derived alleles with P. cynocephalus than P. ursinus does, but no recent gene flow between P. ursinus and P. cynocephalus was detected when available Papio genomes were analyzed. Our results, based on the analysis of autosomal, mitochondrial and Y chromosome data, suggest complex, possibly male-biased, gene flow between Gorongosa baboons and P. cynocephalus, hinting to direct or indirect contributions from baboons belonging to the “northern” Papio clade, and signal the presence of population structure within P. ursinus. Conclusions: The analysis of genome data generated from baboon samples collected in central Mozambique highlighted a complex set of evolutionary relationships with other baboons. Our results provided new insights in the population dynamics that have shaped baboon diversity

Alteration of Striatal Dopaminergic Neurotransmission in a Mouse Model of DYT11 Myoclonus-Dystonia

Background: DYT11 myoclonus-dystonia (M-D) syndrome is a neurological movement disorder characterized by myoclonic jerks and dystonic postures or movement that can be alleviated by alcohol. It is caused by mutations in SGCE encoding e-sarcoglycan (e-SG); the mouse homolog of this gene is Sgce. Paternally-inherited Sgce heterozygous knockout (Sgce KO) mice exhibit myoclonus, motor impairment and anxiety- and depression-like behaviors, modeling several clinical symptoms observed in DYT11 M-D patients. The behavioral deficits are accompanied by abnormally high levels of dopamine and its metabolites in the striatum of Sgce KO mice. Neuroimaging studies of DYT11 M-D patients show reduced dopamine D2 receptor (D2R) availability, although the possibility of increased endogenous dopamine, and consequently, competitive D2R occupancy cannot be ruled out. Methodology/Principal Findings: The protein levels of striatal D2R, dopamine transporter (DAT), and dopamine D1 receptor (D1R) in Sgce KO mice were analyzed by Western blot. The striatal dopamine release after amphetamine injection in Sgce KO mice were analyzed by microdialysis in vivo. The striatal D2R was significantly decreased in Sgce KO mice without altering DAT and D1R. Sgce KO mice also exhibited a significant increase of dopamine release after amphetamine injection in comparison to wild-type (WT) littermates. Conclusion/Significance: The results suggest e-SG may have a role in the regulation of D2R expression. The loss of e-S

Fertilizer and stocking rates on two King Country soils

Parent materials such as volcanic ash and sedimentary siltstone and sandstone form soils which differ markedly in their physical and chemical properties. In stocking x fertilizer rate trials on two families of soils, Te Kuiti-Tumutumu (volcanic ash) and Mahoenui-Mangatea (siltstonesandstone), the former showed marked response to increasing rates of superphosphate in terms of pasture availability and animal production but the latter showed negligible response above the lowest rate (250 kg/ha). Responses to superphosphate were apparent on Te Kuiti-Tumutumu only at the high stocking rate. Sward composition showed no measurable improvement with the application of superphosphate. Management practices were undoubtedly important in this respect. Differential ‘topdressing should be practised where feasible. When soil test levels for phosphate are medium to low, Te Kuiti-Tumutumu soils should receive at least 500 kg/ha/yr of superphosphate, Mahoenui-Mangatea soils 250 kg/ha/yr. Stocking rates and management practices must be such as to allow full utilization of the additional pasture grown

The CDW structure of the

Low-temperature X-ray diffraction with synchrotron radiation was used to study the CDW structure of the phosphate bronze (PO2)4(WO3)$_{2m}$ with m=4. The CDW state at T = 20\un{K} can be described as a 2-dimensional, incommensurately modulated structure with wave vectors \vect{q}^1 = (0.330 (5), 0.292 (5), 0) and \vect{q}^2 = (-0.330, 0.292, 0). The second type of modulation is found to comprise the mixed second-order satellites \vect{q}^1 - \vect{q}^2 at (0.340 (5), 0, 0). Atomic displacements are mainly found on the wolfram atoms, whereby a tendency is observed for the CDW to concentrate in the middle of the WO3 layers. The consequences are derived for the interpretation of the CDW modulations in this homologous series of compounds