Keeping an Eye on Wild Brown Trout (Salmo trutta) Populations: Correlation Between Temperature, Environmental Parameters, and Proliferative Kidney Disease.

Proliferative kidney disease (PKD) is an emerging disease of salmonids caused by the myxozoan parasite Tetracapsuloides bryosalmonae, which plays a major role in the decrease of wild brown trout (Salmo trutta) populations in Switzerland. Strong evidence demonstrated that water temperature modulates parasite infection. However, less knowledge exists on how seasonal water temperature fluctuations influence PKD manifestation under field conditions, how further environmental factors such as water quality may modulate the disease, and whether these factors coalesce with temperatures role possibly giving rise to cumulative effects on PKD. The aims of this study were to (1) determine the correlation between seasonal course of water temperature and PKD prevalence and intensity in wild brown trout populations, (2) assess if other factors such as water quality or ecomorphology correlate with the infection, and (3) quantitatively predict the implication of these factors on PKD prevalence with a statistical model. Young-of-the-year brown trout were sampled in 45 sites through the Canton of Vaud (Switzerland). For each site, longitudinal time series of water temperature, water quality (macroinvertebrate community index, presence of wastewater treatment plant effluent) and ecomorphological data were collected and correlated with PKD prevalence and intensity. 251 T. bryosalmonae-infected trout of 1,118 were found (overall prevalence 22.5%) at 19 of 45 study sites (42.2%). Relation between PKD infection and seasonal water temperature underlined that the mean water temperature for June and the number of days with mean temperature ≥15°C were the most significantly correlated parameters with parasite prevalence and intensity. The presence of a wastewater treatment plant effluent was significantly correlated with the prevalence and infection intensity. In contrast, macroinvertebrate diversity and river ecomorphology were shown to have little impact on disease parameters. Linear and logistic regressions highlighted quantitatively the prediction of PKD prevalence depending on environmental parameters at a given site and its possible increase due to rising temperatures. The model developed within this study could serve as a useful tool for identifying and predicting disease hot spots. These results support the importance of temperature for PKD in salmonids and provides evidence for a modulating influence of additional environmental stress factors

Rotation curve bifurcations as indicators of close recent galaxy encounters

Rotation curves of interacting galaxies often show that velocities are either rising or falling in the direction of the companion galaxy. We seek to reproduce and analyse these features in the rotation curves of simulated equal-mass galaxies suffering a one-to-one encounter, as possible indicators of close encounters. Using simulations of major mergers in 3D, we study the time evolution of these asymmetries in a pair of galaxies, during the first passage. Our main results are: (a) the rotation curve asymmetries appear right at pericentre of the first passage, (b) the significant disturbed rotation velocities occur within a small time interval, of ~ 0.5 Gyr h^-1, and therefore the presence of bifurcation in the velocity curve could be used as an indicator of the pericentre occurrence. These results are in qualitative agreement with previous findings for minor mergers and fly-byes.Comment: 4 pages, 7 figure

Mass Density Profiles of LSB Galaxies

We derive the mass density profiles of dark matter halos that are implied by high spatial resolution rotation curves of low surface brightness galaxies. We find that at small radii, the mass density distribution is dominated by a nearly constant density core with a core radius of a few kpc. For rho(r) ~ r^a, the distribution of inner slopes a is strongly peaked around a = -0.2. This is significantly shallower than the cuspy a < -1 halos found in CDM simulations. While the observed distribution of alpha does have a tail towards such extreme values, the derived value of alpha is found to depend on the spatial resolution of the rotation curves: a ~ -1 is found only for the least well resolved galaxies. Even for these galaxies, our data are also consistent with constant density cores (a = 0) of modest (~ 1 kpc) core radius, which can give the illusion of steep cusps when insufficiently resolved. Consequently, there is no clear evidence for a cuspy halo in any of the low surface brightness galaxies observed.Comment: To be published in ApJ Letters. 6 pages. Uses aastex and emulateapj5.sty Typo in Eq 1 fixe

Arqueología y ríos de las Tierras Bajas de América del Sur

Los ríos de las Tierras Bajas han sido espacios claves para entender problemas suprarregionales de la antropología de América del Sur, tales como: el poblamiento americano, la cronología y dispersión de innovaciones tecnológico-culturales como la arquitectura en tierra, la alfarería o la agricultura de la mandioca y el maíz, las migraciones y expansiones de poblaciones indígenas y familias lingüísticas, la interacción de grupos cazadores-recolectores entre sí y con horticultores, el surgimiento de la complejidad social y las desigualdades hereditarias, entre otros. Teniendo en cuenta estos problemas generales, en el último World Archaeological Congress (WAC-8, Kyoto) surgió la idea de organizar este dossier entre el Instituto Goiano de Pré-História e Antropologia da Pontifícia Universidade Católica de Goiás y la División Arqueología del Museo de La Plata, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata. Se sugirió a las autoras y los autores invitados abordar el estado del arte de las investigaciones arqueológicas en cada uno de los ríos o cuencas en las que trabajan, según algunos de los siguientes ejes: a) los procesos de formación de sitio y la transformación humana del paisaje fluvial; b) la existencia o no de adaptaciones fluviales; c) la caza, la pesca y la recolección: tecnologías originarias y estrategias de obtención de los recursos acuáticos. Los ríos en la producción agrícola; d) los ríos como marcadores de fronteras culturales y a la vez generadores de interacción social. Los ríos como vías naturales que guiaron la movilidad pedestre y la navegación y e) significados simbólicos y actividades rituales efectuadas en los ríos como, por ejemplo: áreas preferenciales para entierros humanos, los recursos acuáticos y la identidad de género, iconografía, entre otros temas.Dossier: Arqueología y ríos de las Tierras Bajas de América del Sur.Facultad de Ciencias Naturales y Muse

Arqueología y ríos de las Tierras Bajas de América del Sur

Los ríos de las Tierras Bajas han sido espacios claves para entender problemas suprarregionales de la antropología de América del Sur, tales como: el poblamiento americano, la cronología y dispersión de innovaciones tecnológico-culturales como la arquitectura en tierra, la alfarería o la agricultura de la mandioca y el maíz, las migraciones y expansiones de poblaciones indígenas y familias lingüísticas, la interacción de grupos cazadores-recolectores entre sí y con horticultores, el surgimiento de la complejidad social y las desigualdades hereditarias, entre otros. Teniendo en cuenta estos problemas generales, en el último World Archaeological Congress (WAC-8, Kyoto) surgió la idea de organizar este dossier entre el Instituto Goiano de Pré-História e Antropologia da Pontifícia Universidade Católica de Goiás y la División Arqueología del Museo de La Plata, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata. Se sugirió a las autoras y los autores invitados abordar el estado del arte de las investigaciones arqueológicas en cada uno de los ríos o cuencas en las que trabajan, según algunos de los siguientes ejes: a) los procesos de formación de sitio y la transformación humana del paisaje fluvial; b) la existencia o no de adaptaciones fluviales; c) la caza, la pesca y la recolección: tecnologías originarias y estrategias de obtención de los recursos acuáticos. Los ríos en la producción agrícola; d) los ríos como marcadores de fronteras culturales y a la vez generadores de interacción social. Los ríos como vías naturales que guiaron la movilidad pedestre y la navegación y e) significados simbólicos y actividades rituales efectuadas en los ríos como, por ejemplo: áreas preferenciales para entierros humanos, los recursos acuáticos y la identidad de género, iconografía, entre otros temas.Dossier: Arqueología y ríos de las Tierras Bajas de América del Sur.Facultad de Ciencias Naturales y Muse

Cloud fragmentation and proplyd-like features in HII regions imaged by HST

We have analyzed HST ACS and WFPC2 new and archival images of eight HII regions to look for new proto-planetary disks (proplyds) similar to those found in the Orion Nebula. We find a wealth of features similar in size (though many are larger) to the bright cusps around the Orion Nebula proplyds. None of them, however, contains a definitive central star. From this, we deduce that the new cusps may not be proplyds, but instead are fragments of molecular cloud material. Out of all the features found in the eight HII regions examined, only one, an apparent edge-on silhouette in M17, may have a central star. This feature might join the small number of bona fide proplyds found outside the Orion Nebula, in M8, M20 and possibly in M16. In line with the results found recently by Smith et al. (2005), the paucity of proplyds outside the Orion Nebula, may be explained by their transient nature as well as by the specific environmental conditions under whichthey can be observed.Comment: 51 pages; 19 figures; 5 tables. Accepted by A

Discovery of molecular subtypes in leiomyosarcoma through integrative molecular profiling.

Leiomyosarcoma (LMS) is a soft tissue tumor with a significant degree of morphologic and molecular heterogeneity. We used integrative molecular profiling to discover and characterize molecular subtypes of LMS. Gene expression profiling was performed on 51 LMS samples. Unsupervised clustering showed three reproducible LMS clusters. Array comparative genomic hybridization (aCGH) was performed on 20 LMS samples and showed that the molecular subtypes defined by gene expression showed distinct genomic changes. Tumors from the muscle-enriched cluster showed significantly increased copy number changes (P=0.04). A majority of the muscle-enriched cases showed loss at 16q24, which contains Fanconi anemia, complementation group A, known to have an important role in DNA repair, and loss at 1p36, which contains PRDM16, of which loss promotes muscle differentiation. Immunohistochemistry (IHC) was performed on LMS tissue microarrays (n=377) for five markers with high levels of messenger RNA in the muscle-enriched cluster (ACTG2, CASQ2, SLMAP, CFL2 and MYLK) and showed significantly correlated expression of the five proteins (all pairwise P&lt;0.005). Expression of the five markers was associated with improved disease-specific survival in a multivariate Cox regression analysis (P&lt;0.04). In this analysis that combined gene expression profiling, aCGH and IHC, we characterized distinct molecular LMS subtypes, provided insight into their pathogenesis, and identified prognostic biomarkers

Organics in comet 67P – a first comparative analysis of mass spectra from ROSINA–DFMS, COSAC and Ptolemy

The ESA Rosetta spacecraft followed comet 67P at a close distance for more than 2 yr. In addition, it deployed the lander Philae on to the surface of the comet. The (surface) composition of the comet is of great interest to understand the origin and evolution of comets. By combining measurements made on the comet itself and in the coma, we probe the nature of this surface material and compare it to remote sensing observations. We compare data from the double focusing mass spectrometer (DFMS) of the ROSINA experiment on ESA's Rosetta mission and previously published data from the two mass spectrometers COSAC (COmetary Sampling And Composition) and Ptolemy on the lander. The mass spectra of all three instruments show very similar patterns of mainly CHO-bearing molecules that sublimate at temperatures of 275 K. The DFMS data also show a great variety of CH-, CHN-, CHS-, CHO2- and CHNO-bearing saturated and unsaturated species. Methyl isocyanate, propanal and glycol aldehyde suggested by the earlier analysis of the measured COSAC spectrum could not be confirmed. The presence of polyoxymethylene in the Ptolemy spectrum was found to be unlikely. However, the signature of the aromatic compound toluene was identified in DFMS and Ptolemy data. Comparison with remote sensing instruments confirms the complex nature of the organics on the surface of 67P, which is much more diverse than anticipated

The LIL for UU-statistics in Hilbert spaces

We give necessary and sufficient conditions for the (bounded) law of the iterated logarithm for $U$-statistics in Hilbert spaces. As a tool we also develop moment and tail estimates for canonical Hilbert-space valued $U$-statistics of arbitrary order, which are of independent interest

RubikAuth: Fast and Secure Authentication in Virtual Reality

There is a growing need for usable and secure authentication in virtual reality (VR). Established concepts (e.g., 2D graphical PINs) are vulnerable to observation attacks, and proposed alternatives are relatively slow. We present RubikAuth, a novel authentication scheme for VR where users authenticate quickly by selecting digits from a virtual 3Dcube that is manipulated with a handheld controller. We report two studies comparing how pointing using gaze, headpose, and controller tapping impacts RubikAuth’s usability and observation resistance under three realistic threat models. Entering a four-symbol RubikAuth password is fast:1.69 s to 3.5 s using controller tapping, 2.35 s to 4.68 s using head pose, and 2.39 s to 4.92 s using gaze and highly resilient to observations; 97.78% to 100% of observation attacks were unsuccessful. Our results suggest that providing attackers with support material contributes to more realistic security evaluations