OH Maser sources in W49N: probing differential anisotropic scattering with Zeeman pairs

Our analysis of a VLBA 12-hour synthesis observations of the OH masers in W49N has provided detailed high angular-resolution images of the maser sources, at 1612, 1665 and 1667 MHz. The images, of several dozens of spots, reveal anisotropic scatter broadening; with typical sizes of a few tens of milli-arc-seconds and axial ratios between 1.5 to 3. The image position angles oriented perpendicular to the galactic plane are interpreted in terms of elongation of electron-density irregularities parallel to the galactic plane, due to a similarly aligned local magnetic field. However, we find the apparent angular sizes on the average a factor of 2.5 less than those reported by Desai et al., indicating significantly less scattering than inferred earlier. The average position angle of the scattered broadened images is also seen to deviate significantly (by about 10 degrees) from that implied by the magnetic field in the Galactic plane. More intriguingly, for a few Zeeman pairs in our set, we find significant differences in the scatter broadened images for the two hands of polarization, even when apparent velocity separation is less than 0.1 km/s. Here we present the details of our observations and analysis, and discuss the interesting implications of our results for the intervening anisotropic magneto-ionic medium, as well as a comparison with the expectations based on earlier work.Comment: 5 pages, 3 figures, submitted to the Proceedings of the IAU Symposium 287: "Cosmic masers - from OH to H0

Global kinematics study of OH masers in W49N

Star formation is underway in the W49N molecular cloud (MC) at a high level of efficiency, with almost twenty ultra-compact (UC) HII regions observed thus far, indicating a recent formation of massive stars. Previous works have suggested that this cloud is undergoing a global contraction. We analyse the data on OH masers in the molecular cloud W49N, observed with the VLBA at the 1612, 1665, and 1667 MHz transitions in LCP and RCP with an aim to study the global kinematics of the masers. We carried out our study based on the locations and observed velocities of the maser spots. The velocities were fitted to the straight line of V$_{obs}$-V$_{sys}$ versus d$_{(\alpha, \delta)m}$, resulting in V$_{ftd}$. The difference between the fitted values and those obtained from observations is $\Delta$V. The V$_{obs}$-V$_{sys}$ velocity shows a gradient as a function of the distance to ($\alpha, \delta$)$_{m}$, where the closer spots have the largest velocities. Spots with similar velocities are located in different sectors, with respect to ($\alpha, \delta$)$_{m}$. Then, we assumed that the spots are moving towards a contraction centre (CC$_{OH}$), which is at the apex of a CONUS. We also assumed that the distance of each spot to CC$_{OH}$ is d$_{cc}$ and that they fall with a velocity V$_{CC}$, with the total velocity being V$_{Tot}$. Using this velocity, we estimated the free-fall velocity. The observed dispersion with respect to the global trend against $d_{cc}$, shows a maximum at 0.12 pc, with a decay from 0.12 to 0.19 pc, which is faster than that taking place between 0.19 and 0.42 pc. Based on $V_{tot}$ an inner mass of M$_{inn}$=2500 $M_{\odot}$ was estimated.The velocities of the OH spots at W49N, together with their positions respect $(\alpha, \delta)_m$, make it possible to trace a global kinematics, which seems to be due to a subcollapse in the W49N molecular cloud.Comment: 21 pages, 10 figure

In Vitro Antioxidant and Antihypertensive Activity of Edible Insects Flours (Mealworm and Grasshopper) Fermented with Lactococcus lactis Strains

The objective of the present study was to evaluate the potential antioxidant and angiotensin converting enzyme inhibition (ACEI) activity of edible insect flours fermented with Lactococcus lactis strains. For the fermentation, mealworm and grasshoppers flours were dissolved (0.5% w/v) in buffer solution (pH 7.0) and individually inoculated (3%) with Lactococcus lactis strains (NRRL B-50571, NRRL B-50572). The samples were incubated for 72 h at 30 ◦C, and the pH was recorded. The degree of hydrolysis (DH) and protein content were determined. The total polyphenol compounds, antioxidant activity (ABTS, DPPH, ORAC, and FRAP), and ACEI of the \u3c3 kDa fractions were ana- lyzed. The pH of the fermented samples decreased to 3.5–3.9 (p \u3c 0.05). The fermented grasshopper flour showed an increased DH (0.42%) and overall higher total polyphenol content (8.23 mg Gallic Acid Equivalent/mL). In general, the highest antioxidant activity was for the grasshopper fractions fermented for 24 h by Lactococcus lactis NRRL B-50572, which also showed 23.47% ACEI inhibition with an IC50 of 0.97 mg/mL. The peptide profile obtained increased after fermentation, being higher for the mealworm flour fermented sample. This study presents, for the first time, the use of specific strains of Lactococus lactis for fermenting edible insect-derived products in the production of bioactive compounds with potential antioxidant and antihypertensive activity

Study of metals in leached soils of a municipal dumpsite in Tampico, Tamaulipas, Mexico: preliminary results

The Zapote dumpsite measures 420000 m 2 and is 28 years old; an estimated 2.5 millions tons of waste have accumulated on the site (household waste, clinical waste, commercial waste). The thickness of the waste is 3 to 9 meters. Since operations began, no control regulations have existed on the residues received. The Zapote dumpsite is located within a salt-marsh between a system of channels and river lagoons of brackish water, located in a tropical sedimentary environment in the urban zone of Tampico, Tamaulipas, Mexico. Recently, the Zapote has been closed and work is presently underway in its rehabilitation since a geo-environmental perspective. The present investigation integrates information of preliminary results of metals (Pb, Ni, Cd, Cu, Mg, Fe and Al) contained in sediments that underlie the Zapote dumpsite. In laboratory research the metals of the sediment were correlated with the metals contained in samples of leachate from the Zapote dumpsite. The concentration of metals Pb, Ni, Cd, Cu, Mg, Fe and Al were analyzed in samples of sediments that underlie the body of the dumpsite in layers of 10 cm, reaching a depth of 1.5 m under the interface waste-soil. The results denote high concentrations of metals in layers that are in contact with waste that decreased until reaching 60 to 80 cm of depth. The proportions of the concentrations of metals studied in the soil are comparable with that leached, until layers of 60 to 80 cm of depth are reached, and are then lost in the deepest layers. The high plastic characteristics of clay layers have stood in the way of metallic contaminants in sub layers of the Zapote dumpsite. The results were correlated with metal concentrations of natural and anthropogenic sediments of the region

Updating the distribution of Dicrodon guttulatum Duméril & Bibron, 1839 (Reptilia, Teiidae) with a disjunct population in the eastern slope of the Peruvian Andes

We report a disjunct population of Dicrodon guttulatum Duméril & Bibron, 1839 on the eastern slope of the Cordillera Occidental in the inter-Andean Seasonally Dry Forests of the Marañón River, in the Departments of Cajamarca and Piura in northwestern Peru. We include an updated range distribution map using records from museum specimens, the Global Biodiversity Information Facility, and available photographic records on iNaturalist. In addition, we identify widespread cultivation of rice crops as the main threat to D. guttulatum in the inter-Andean Seasonally Dry Forests of the Marañón

Evolved star water maser cloud size determined by star size

Cool, evolved stars undergo copious mass loss but the details of how the matter is returned to the ISM are still under debate. We investigated the structure and evolution of the wind at 5 to 50 stellar radii from Asymptotic Giant Branch and Red Supergiant stars. 22-GHz water masers around seven evolved stars were imaged using MERLIN, at sub-AU resolution. Each source was observed at between 2 and 7 epochs (several stellar periods). We compared our results with long-term Pushchino single dish monitoring. The 22-GHz emission is located in ~spherical, thick, unevenly filled shells. The outflow velocity doubles between the inner and outer shell limits. Water maser clumps could be matched at successive epochs separated by <2 years for AGB stars, or at least 5 years for RSG. This is much shorter than the decades taken for the wind to cross the maser shell, and comparison with spectral monitoring shows that some features fade and reappear. In 5 sources, most of the matched features brighten or dim in concert from one epoch to the next. One cloud in W Hya was caught in the act of passing in front of a background cloud leading to 50-fold, transient amplification. The masing clouds are 1-2 orders of magnitude denser than the wind average and contain a substantial fraction of the mass loss in this region, with a filling factor <1%. The RSG clouds are ~10x bigger than those round the AGB stars. Proper motions are dominated by expansion, with no systematic rotation. The maser clouds survive for decades (the shell crossing time) but the masers are not always beamed in our direction. Radiative effects cause changes in flux density throughout the maser shells on short timescales. Cloud size is proportional to parent star size; clouds have a similar radius to the star in the 22-GHz maser shell. Stellar properties such as convection cells must determine the clumping scale.Comment: Accepted by A&A 2012 July 10 Main text 29 pages, 62 figures Appendix 44 pages, 23 figure

Run-up parameterization and beach vulnerability assessment on a barrier island: a downscaling approach

We present a downscaling approach for the study of wave-induced extreme water levels at a location on a barrier island in Yucatán (Mexico). Wave information from a 30-year wave hindcast is validated with in situ measurements at 8 m water depth. The maximum dissimilarity algorithm is employed for the selection of 600 representative cases, encompassing different combinations of wave characteristics and tidal level. The selected cases are propagated from 8 m water depth to the shore using the coupling of a third-generation wave model and a phase-resolving non-hydrostatic nonlinear shallow-water equation model. Extreme wave run-up, R2%, is estimated for the simulated cases and can be further employed to reconstruct the 30-year time series using an interpolation algorithm. Downscaling results show run-up saturation during more energetic wave conditions and modulation owing to tides. The latter suggests that the R2% can be parameterized using a hyperbolic-like formulation with dependency on both wave height and tidal level. The new parametric formulation is in agreement with the downscaling results (r2  =  0.78), allowing a fast calculation of wave-induced extreme water levels at this location. Finally, an assessment of beach vulnerability to wave-induced extreme water levels is conducted at the study area by employing the two approaches (reconstruction/parameterization) and a storm impact scale. The 30-year extreme water level hindcast allows the calculation of beach vulnerability as a function of return periods. It is shown that the downscaling-derived parameterization provides reasonable results as compared with the numerical approach. This methodology can be extended to other locations and can be further improved by incorporating the storm surge contributions to the extreme water level

Management of a ruptured epidural catheter, an anesthesiologist's dilemma: a case report

Epidural anesthesia is a widely used anesthetic technique in lower extremity surgeries although it is a relatively safe procedure, it can have complications, such as rupture of the epidural catheter. This is a 69-year-old male patient with a diagnosis of Wagner IV diabetic foot is presented, which was scheduled for left supracondylar amputation in which after epidural block, retention of the catheter tip in the epidural space at level L2-L3 was seen, so hemi laminectomy was performed in a second surgical stage in L2 and removal of the epidural catheter. Ideally a broken needle should be removed as soon as possible