Correlation and reliability of cervical sagittal alignment parameters between lateral cervical radiograph and lateral whole-body EOS stereoradiograph

STUDY DESIGN:  Retrospective analysis. OBJECTIVE:  To evaluate the correlation and reliability of cervical sagittal alignment parameters obtained from lateral cervical radiographs (XRs) compared with lateral whole-body stereoradiographs (SRs). METHODS:  We evaluated adults with cervical deformity using both lateral XRs and lateral SRs obtained within 1 week of each other between 2010 and 2014. XR and SR images were measured by two independent spine surgeons using the following sagittal alignment parameters: C2–C7 sagittal Cobb angle (SCA), C2–C7 sagittal vertical axis (SVA), C1–C7 translational distance (C1–7), T1 slope (T1-S), neck tilt (NT), and thoracic inlet angle (TIA). Pearson correlation and paired t test were used for statistical analysis, with intra- and interrater reliability analyzed using intraclass correlation coefficient (ICC). RESULTS:  A total of 35 patients were included in the study. We found excellent intrarater reliability for all sagittal alignment parameters in both the XR and SR groups with ICC ranging from 0.799 to 0.994 for XR and 0.791 to 0.995 for SR. Interrater reliability was also excellent for all parameters except NT and TIA, which had fair reliability. We also found excellent correlations between XR and SR measurements for most sagittal alignment parameters; SCA, SVA, and C1–C7 had r > 0.90, and only NT had r < 0.70. There was a significant difference between groups, with SR having lower measurements compared with XR for both SVA (0.68 cm lower, p < 0.001) and C1–C7 (1.02 cm lower, p < 0.001). There were no differences between groups for SCA, T1-S, NT, and TIA. CONCLUSION:  Whole-body stereoradiography appears to be a viable alternative for measuring cervical sagittal alignment parameters compared with standard radiography. XR and SR demonstrated excellent correlation for most sagittal alignment parameters except NT. However, SR had significantly lower average SVA and C1–C7 measurements than XR. The lower radiation exposure using single SR has to be weighed against its higher cost compared with XR

High Energy Neutrinos from Cosmic Ray Interactions in Clusters of Galaxies

The spatial clustering of galaxies in galaxy clusters implies that the background of infrared (IR) light in the intracluster medium (ICM) may exceed the universal background. Cosmic rays injected within the ICM propagate diffusively and at low enough energies are trapped there for cosmological times. The photopion production interactions of cosmic rays with the IR photons are responsible for the generation of neutrinos whose detection may shed some light on the origin and propagation of high energy cosmic rays in the universe. Here we discuss our calculations of the flux of neutrinos from single clusters as well as the contribution of photopion production in clusters of galaxies to the diffuse neutrino background.Comment: 10 pages, 10 figures, submitted to PR

Epidemiological and laboratory investigations of outbreaks of diarrhoea in rural South India: implications for control of disease

Two epidemics of acute, watery diarrhoea in villages in North Arcot district, India, were investigated. The attack rates were 10.03 and 15.53 per 100 population, the median duration was 5 days and enteric pathogens were present in 56.8% and 60.3% of specimens from the two villages, but no predominant pathogen was identified. Examination of stools from a 20% age-stratified random sample of the population of one of the villages after the epidemic found 22.9% of asymptomatic subjects excreted bacterial enteric pathogens. Despite the high background of enteric pathogen carriage, the isolation rates for shigellae, enteropathogenic Escherichia coli and Shiga-toxin producing E. coli were significantly higher (P &lt; 0.001, P &lt; 0.02, P &lt; 0.05) during the epidemic. The epidemics may have been caused by faecal contamination of well water following rain. Point-of-use techniques for water disinfection may be most effective for preventing such outbreaks, but further research into the development of appropriate technology is required

The Importance of Satellite Quenching for the Build-Up of the Red Sequence of Present Day Galaxies

In the current paradigm, red sequence galaxies are believed to have formed as blue disk galaxies that subsequently had their star formation quenched. Since red-sequence galaxies typically have an early-type morphology, the transition from the blue to the red sequence also involves a morphological transformation. In this paper we study the impact of transformation mechanisms that operate only on satellite galaxies, such as strangulation, ram-pressure stripping and galaxy harassment. Using a large galaxy group catalogue constructed from the SDSS, we compare the colors and concentrations of satellites galaxies to those of central galaxies of the same stellar mass, adopting the hypothesis that the latter are the progenitors of the former. On average, satellites are redder and more concentrated than central galaxies of the same stellar mass. Central-satellite pairs that are matched in both stellar mass and color, however, show no average concentration difference, indicating that the transformation mechanisms affect color more than morphology. The color and concentration differences of matched central-satellite pairs are completely independent of the halo mass of the satellite galaxy, indicating that satellite-specific transformation mechanisms are equally efficient in haloes of all masses. This strongly favors strangulation as the main quenching mechanism for satellite galaxies. Finally, we determine the relative importance of satellite quenching for the build-up of the red sequence. We find that roughly 70 percent of red sequence satellite galaxies with a stellar mass of 10^9 Msun had their star formation quenched as satellites. This drops rapidly to zero with increasing stellar mass, indicating that a significant fraction of red satellites were already quenched before they became a satellite.Comment: 14 pages, 10 figures. Submitted for publication in MNRA

Two-Species Annihilation with Drift: A Model with Continuous Concentration-Decay Exponents

We propose a model for diffusion-limited annihilation of two species, $A+B\to A$ or $B$, where the motion of the particles is subject to a drift. For equal initial concentrations of the two species, the density follows a power-law decay for large times. However, the decay exponent varies continuously as a function of the probability of which particle, the hopping one or the target, survives in the reaction. These results suggest that diffusion-limited reactions subject to drift do not fall into a limited number of universality classes.Comment: 10 pages, tex, 3 figures, also available upon reques

Revision of the Species of \u3cem\u3eLytopylus\u3c/em\u3e from Area de Conservación Guanacaste, Northwestern Costa Rica (Hymenoptera, Braconidae, Agathidinae)

Thirty two new species of Lytopylus (Agathidinae) are described with image plates for each species: Lytopylus alejandromasisi sp. n., Lytopylus alfredomainieri sp. n., Lytopylusanamariamongeae sp. n., Lytopylus angelagonzalezae sp. n., Lytopylus cesarmorai sp. n., Lytopylus eddysanchezi sp. n., Lytopylus eliethcantillanoae sp. n., Lytopylus ericchapmani sp. n., Lytopylus gahyunae sp. n., Lytopylus gisukae sp. n., Lytopylus guillermopereirai sp. n., Lytopylusgustavoindunii sp. n., Lytopylus hartmanguidoi sp. n., Lytopylus hernanbravoi sp. n., Lytopylushokwoni sp. n., Lytopylus ivanniasandovalae sp. n., Lytopylus johanvalerioi sp. n., Lytopylusjosecortesi sp. n., Lytopylus luisgaritai sp. n., Lytopylus mariamartachavarriae sp. n., Lytopylusmiguelviquezi sp. n., Lytopylus motohasegawai sp. n., Lytopylus okchunae sp. n., Lytopyluspablocobbi sp. n., Lytopylus robertofernandezi sp. n., Lytopylus rogerblancoi sp. n., Lytopylussalvadorlopezi sp. n., Lytopylus sangyeoni sp. n., Lytopylus sarahmeierottoae sp. n., Lytopylussergiobermudezi sp. n., Lytopylus sigifredomarini sp. n., and Lytopylus youngcheae sp. n. A dichotomous key and a link to an electronic, interactive key are included. All specimens were reared from Lepidoptera larvae collected in Area de Conservación Guanacaste (ACG) and all are associated with ecological information including host caterpillar, collection date, eclosion date, caterpillar food plant, and locality. Neighbor-joining and maximum likelihood analyses of the barcode region of the mitochondrial cytochrome c oxidase subunit I gene (COI DNA barcode) were conducted to aid in species delimitation