BMPix and PEAK tools: New methods for automated laminae recognition and counting — Application to glacial varves from Antarctic marine sediment

We present tools for rapid and quantitative detection of sediment lamination. The BMPix tool extracts color and gray-scale curves from images at pixel resolution. The PEAK tool uses the gray-scale curve and performs, for the first time, fully automated counting of laminae based on three methods. The maximum count algorithm counts every bright peak of a couplet of two laminae (annual resolution) in a smoothed curve. The zero-crossing algorithm counts every positive and negative halfway-passage of the curve through a wide moving average, separating the record into bright and dark intervals (seasonal resolution). The same is true for the frequency truncation method, which uses Fourier transformation to decompose the curve into its frequency components before counting positive and negative passages. We applied the new methods successfully to tree rings, to well-dated and already manually counted marine varves from Saanich Inlet, and to marine laminae from the Antarctic continental margin. In combination with AMS14C dating, we found convincing evidence that laminations in Weddell Sea sites represent varves, deposited continuously over several millennia during the last glacial maximum. The new tools offer several advantages over previous methods. The counting procedures are based on a moving average generated from gray-scale curves instead of manual counting. Hence, results are highly objective and rely on reproducible mathematical criteria. Also, the PEAK tool measures the thickness of each year or season. Since all information required is displayed graphically, interactive optimization of the counting algorithms can be achieved quickly and conveniently

Mitochondrial respiratory chain deficiency correlates with the severity of neuropathology in sporadic Creutzfeldt-Jakob disease

Mitochondrial dysfunction has been implicated in multiple neurodegenerative diseases but remains largely unexplored in Creutzfeldt-Jakob disease. Here, we characterize the mitochondrial respiratory chain at the individual neuron level in the MM1 and VV2 common molecular subtypes of sporadic Creutzfeldt-Jakob disease. Moreover, we investigate the associations between the mitochondrial respiratory chain and neuropathological markers of the disease. Brain tissue from individuals with sporadic Creutzfeldt-Jakob disease and age-matched controls were obtained from the brain collection of the Austrian Creutzfeldt-Jakob Surveillance. The mitochondrial respiratory chain was studied through a dichotomous approach of immunoreactivities in the temporal cortex and the hippocampal subregions of CA4 and CA3. We show that profound deficiency of all mitochondrial respiratory complexes (I-V) occurs in neurons of the severely affected temporal cortex of patients with Creutzfeldt-Jakob disease. This deficiency correlates strongly with the severity of neuropathological changes, including vacuolation of the neuropil, gliosis and disease associated prion protein load. Respiratory chain deficiency is less pronounced in hippocampal CA4 and CA3 regions compared to the temporal cortex. In both areas respiratory chain deficiency shows a predilection for the MM1 molecular subtype of Creutzfeldt-Jakob disease. Our findings indicate that aberrant mitochondrial respiration could be involved early in the pathogenesis of sporadic Creutzfeldt-Jakob disease and contributes to neuronal death, most likely via ATP depletion. Based on these results, we propose that the restricted MRI diffusion profile seen in the brain of patients with sporadic Creutzfeldt-Jakob disease might reflect cytotoxic changes due to neuronal respiratory chain failure and ATP loss.publishedVersio

The Inception of Star Cluster Formation Revealed by [CII] Emission Around an Infrared Dark Cloud

We present SOFIA-upGREAT observations of [CII] emission of Infrared Dark Cloud (IRDC) G035.39-00.33, designed to trace its atomic gas envelope and thus test models of the origins of such clouds. Several velocity components of [CII] emission are detected, tracing structures that are at a wide range of distances in the Galactic plane. We find a main component that is likely associated with the IRDC and its immediate surroundings. This strongest emission component has a velocity similar to that of the $^{13}$CO(2-1) emission of the IRDC, but offset by $\sim3\:{\rm km\:s}^{-1}$ and with a larger velocity width of $\sim9\:{\rm km\:s}^{-1}$. The spatial distribution of the [CII] emission of this component is also offset predominantly to one side of the dense filamentary structure of the IRDC. The CII column density is estimated to be of the order of $\sim10^{17}-10^{18}\,{\rm cm}^{-2}$. We compare these results to the [CII] emission from numerical simulations of magnetized, dense gas filaments formed from giant molecular cloud (GMC) collisions, finding similar spatial and kinematic offsets. These observations and modeling of [CII] add further to the evidence that IRDC G035.39-00.33 has been formed by a process of GMC-GMC collision, which may thus be an important mechanism for initiating star cluster formation.Comment: 5 pages, 4 figures, submitted to MNRAS Letter

Splitting of the pi - rho spectrum in a renormalized light-cone QCD-inspired model

We show that the splitting between the light pseudo-scalar and vector meson states is due to the strong short-range attraction in the ^1S_0 sector which makes the pion and the kaon light particles. We use a light-cone QCD-inspired model of the mass squared operator with harmonic confinement and a Dirac-delta interaction. We apply a renormalization method to define the model, in which the pseudo-scalar ground state mass fixes the renormalized strength of the Dirac-delta interaction.Comment: 9 pages, 2 figures, revtex, accepted by Phys. Rev. D; Corrected typo

Quark--antiquark states and their radiative transitions in terms of the spectral integral equation. {\Huge III.} Light mesons

We continue the investigation of mesons in terms of the spectral integral equation initiated before [hep-ph/0510410, hep-ph/0511005] for the $b\bar b$ and $c\bar c$ systems: in this paper we consider the light-quark ($u, d,s$) mesons with masses $M\le 3$ GeV. The calculations have been performed for the mesons lying on linear trajectories in the $(n,M^2)$-planes, where $n$ is the radial quantum number. Our consideration relates to the $q\bar q$ states with one component in the flavor space, with the quark and antiquark masses equal to each other, such as $\pi(0^{-+})$, $\rho(1^{--})$, $\omega(1^{--})$, $\phi(1^{--})$, $a_0(0^{++})$, $a_1(1^{++})$, $a_2(2^{++})$, $b_1(1^{+-})$, $f_2(2^{++})$, $\pi_2(2^{-+})$, $\rho_3(3^{--})$, $\omega_3(3^{--})$, $\phi_3(3^{--})$, $\pi_4(4^{-+})$ at $n\le 6$. We obtained the wave functions and mass values of mesons lying on these trajectories. The corresponding trajectories are linear, in agreement with data. We have calculated the two-photon decays $\pi\to \gamma\gamma$, $a_0(980)\to \gamma\gamma$, $a_2(1320)\to \gamma\gamma$, $f_2(1285)\to \gamma\gamma$, $f_2(1525)\to \gamma\gamma$ and radiative transitions $\rho\to\gamma\pi$, $\omega\to\gamma\pi$, that agree qualitatively with the experiment. On this basis, we extract the singular part of the interaction amplitude, which corresponds to the so-called "confinement interaction". The description of the data requires the presence of the strong $t$-channel singularities for both scalar and vector exchanges.Comment: 48 pages, 24 figure

The autophagic marker p62 highlights Alzheimer type astrocytes in metabolic/hepatic encephalopathy

Metabolic/hepatic encephalopathy is neuropathologically characterized by the presence of Alzheimer type II astrocytes (AA II) with large and clear nuclear morphology. To date, there is no good immunohistochemical marker to better identify these cells. Here, we assessed cases of hepatic encephalopathy of different etiologies by immunohistochemistry using an anti-p62 antibody. We observed peripheral or diffuse nuclear staining of variable intensity in AA II in all cases but not in normal controls or reactive astrocytes. We conclude that p62 is a useful immunohistochemical marker for the identification of AA II and may be helpful for the neuropathological diagnosis of metabolic/hepatic encephalopathy in difficult or equivocal cases

Highly multimode memory in a crystal

We experimentally demonstrate the storage of 1060 temporal modes onto a thulium-doped crystal using an atomic frequency comb (AFC). The comb covers 0.93 GHz defining the storage bandwidth. As compared to previous AFC preparation methods (pulse sequences i.e. amplitude modulation), we only use frequency modulation to produce the desired optical pumping spectrum. To ensure an accurate spectrally selective optical pumping, the frequency modulated laser is self-locked on the atomic comb. Our approach is general and should be applicable to a wide range of rare-earth doped material in the context of multimode quantum memory

Histotype-Dependent Oligodendroglial PrP Pathology in Sporadic CJD: A Frequent Feature of the M2C “Strain”

In sporadic Creutzfeldt-Jakob disease, molecular subtypes are neuropathologically well identified by the lesioning profile and the immunohistochemical PrPd deposition pattern in the grey matter (histotypes). While astrocytic PrP pathology has been reported in variant CJD and some less frequent histotypes (e.g., MV2K), oligodendroglial pathology has been rarely addressed. We assessed a series of sCJD cases with the aim to identify particular histotypes that could be more prone to harbor oligodendroglial PrPd. Particularly, the MM2C phenotype, in both its more "pure" and its mixed MM1+2C or MV2K+2C forms, showed more frequent oligodendroglial PrP pathology in the underlying white matter than the more common MM1/MV1 and VV2 histotypes, and was more abundant in patients with a longer disease duration. We concluded that the MM2C strain was particularly prone to accumulate PrPd in white matter oligodendrocytes

Discovery of interstellar mercapto radicals (SH) with the GREAT instrument on SOFIA

We report the first detection of interstellar mercapto radicals, obtained along the sight-line to the submillimeter continuum source W49N. We have used the GREAT instrument on SOFIA to observe the 1383 GHz Doublet Pi 3/2 J = 5/2 - 3/2 lambda doublet in the upper sideband of the L1 receiver. The resultant spectrum reveals SH absorption in material local to W49N, as well as in foreground gas, unassociated with W49N, that is located along the sight-line. For the foreground material at velocities in the range 37 - 44 km/s with respect to the local standard of rest, we infer a total SH column density ~ 2.6 E+12 cm-2, corresponding to an abundance of ~ 7 E-9 relative to H2, and yielding an SH/H2S abundance ratio ~ 0.13. The observed SH/H2S abundance ratio is much smaller than that predicted by standard models for the production of SH and H2S in turbulent dissipation regions and shocks, and suggests that the endothermic neutral-neutral reaction SH + H2 -> H2S + H must be enhanced along with the ion-neutral reactions believed to produce CH+ and SH+ in diffuse molecular clouds.Comment: Accepted for publication in Astronomy and Astrophysics (SOFIA/GREAT special issue

Baryon spectra with instanton induced forces

Except the vibrational excitations of $K$ and $K^*$ mesons, the main features of spectra of mesons composed of quarks $u$, $d$, and $s$ can be quite well described by a semirelativistic potential model including instanton induced forces. The spectra of baryons composed of the same quarks is studied using the same model. The results and the limitations of this approach are described. Some possible improvements are suggested.Comment: 5 figure