Evaluation of a Technique to Trap Lemmings Under the Snow

We attempted to live trap lemmings under the snow in their preferred winter habitat at two sites in the Canadian Arctic using chimney-like boxes. Lemmings used the boxes during winter, but we had very low trapping success in April and May. During spring trapping, in contrast to most of the winter, subnivean temperatures became colder than ambient air temperatures. We hypothesize that our low success in spring resulted from lemmings’ leaving the deeper snow areas where our boxes were located and moving to shallower snow or exposed tundra. We suggest that the trapping boxes could be successful if trapping occurred earlier during winter.Nous avons tenté de capturer des lemmings sous la neige dans leur habitat hivernal préféré en utilisant des boîtes en forme de cheminée à deux sites situés dans l’Arctique canadien. Les boîtes ont été utilisées par les lemmings durant l’hiver mais nous avons eu un très faible succès de capture en avril et mai. Contrairement à la majorité de l’hiver, les températures sous-nivales étaient plus froides que les températures de l’air pendant que nous avons trappé au printemps. Nous émettons l’hypothèse que notre faible succès au printemps est dû au déplacement des lemmings des sites de fort enneigement, où nos boîtes étaient installées, vers ceux de faible enneigement ou vers la toundra exposée. Nous suggérons que les boîtes de trappage pourraient être plus utiles si le trappage se faisait plus tôt au courant de l’hiver

Spin- and angle-resolved spectroscopy of S2p photoionization in the hydrogen sulfide molecule.

Angle- and spin-resolved photoelectron spectroscopy with circularly and linearly polarized synchrotron radiation were used to study the electronic structure of the hydrogen sulfide molecule. A strong effect of the molecular environment appears in the spin-resolved measurements and, although less clearly, in the angular distribution of the sulfur 2p photoelectrons. The anisotropy and spin parameters of the three main spectral components have been obtained. The validity of simple atomic models in explaining the results is discussed

Probing the molecular environment using spin-resolved photoelectron spectroscopy.

Angle- and spin-resolved photoelectron spectroscopy with linearly and circularly polarized synchrotron radiation were used to study the electronic structure of model triatomic molecules, hydrogen sulfide, and carbonyl sulfide. The spin-polarization measurements of the molecular field split components of the S 2p photolines revealed a strong effect of the different molecular environments. The validity of simple atomic models to explain the results is discussed

Unbalanced dissimilar-fibre Mach-Zehnder interferometer: application as filter

An unbalanced Mach-Zehnder interferometer made using dissimilar-fibre fused taper couplers is proposed for filtering applications. The all-fibre device is compact, rugged, simple to make and provides extended control and flexibility for the design of various types of filters

Laparoscopic management of fallopian tube prolapse masquerading as adenocarcinoma of the vagina in a hysterectomized woman

BACKGROUND: Fallopian tube prolapse as a complication of abdominal hysterectomy is a rare occurrence. A case with fallopian tube prolapse was managed by a combined vaginal and laparoscopic approach and description of the operative technique is presented. CASE PRESENTATION: A 39-year-old woman with vaginal prolapse of the fallopian tube after total abdominal hysterectomy presented with an incorrect diagnosis of adenocarcinoma of the vaginal apex. The prolapsed tube and cystic ovary were removed by vaginal and laparoscopic approach. The postoperative course went well. CONCLUSIONS: Early or late fallopian tube prolapse can occur after total abdominal hysterectomy and vaginal hysterectomy. Symptoms consist of persistent blood loss or leukorrhea, dyspareunia and chronic pelvic pain. Vaginal removal of prolapsed tube with laparoscopic surgery may be a suitable treatment. The abdominal or vaginal approach used in surgical correction of prolapsed tubes must be decided in each case according to the patient's individual characteristics

A Two-dimensional Splashing Model for Investigating Impingement Characteristics of Supercooled Large Droplets

This document is the Accepted Manuscript of the following article: C. Wang, S. Chang, M. Leng, H. Wu, and B. Yang, 'A two-dimensional splashing model for investigating impingement characteristics of supercooled large droplets', International Journal of Multiphase Flow, Vol. 80, April 2016, pp. 131-149. This manuscript version is made available under the terms of the Creative Commons CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/. The Version of Record is available online at doi: https://doi.org/10.1016/j.ijmultiphaseflow.2015.12.005. © 2015 Elsevier Ltd. All rights reserved.In this article, a two-dimensional (2D) splashing model is proposed to investigate the dynamics when supercooled large droplets (SLD) impinging on a wall surface in the aircraft-icing field. Energy conservation for droplet motion and impingement is used to capture the properties of the splashed droplets. A new statistical treatment of the droplet impinging energy and angle during the droplet-wall interaction is introduced in order to calculate the average dynamics of the SLD within a micro-control volume on wall surface. Based on the LEWICE predictions of droplet collection efficiencies and the available experimental ones, a new criterion for droplet splashing/deposition as well as a new formulation for the splashed mass is suggested. Lagrangian approach is adopted to describe the movement and impingement of SLD. The proposed model together with the previously developed droplet tracking method (DTM) for calculating droplet collection efficiency with the effect of droplet reimpingement constitute a relatively complete predicting approach of SLD impingement characteristics. Comparisons between the current predictions and the experimental observations, including SLD impingement over clean and contaminated airfoil surfaces as well as shapes of ice accretion in typical icing conditions, are carried out. Further, results obtained with the LEWICE splashing model are also plotted on the same graphs in order to assess the accuracy of the current splashing model in predicting SLD impingement. Results show that good agreement is achieved between the current predictions, including SLD impingement and ice accretion shapes, and the experimental ones. The predictions of the impingement distribution over contaminated surfaces obtained with the current splashing model show a much closer agreement with the experimental results than the ones obtained with LEWICE splashing model. For further investigation of SLD impingement, the properties of the droplet splashing and reimpingement during the ice accretion process are also addressed.Peer reviewe

Ultraviolet light photosensitivity in Ge-doped silica fibers: wavelength dependence of the light-induced index change.

A novel technique is reported for detecting permanent and transient light-induced refractive-index changes (photosensitivity) in optical fibers. The index change is detected by irradiating one arm of an unbalanced Mach–Zehnder fiber interferometer with UV light, thereby changing its optical path length. From a measurement of the change in the spectral response of the Mach–Zehnder interferometer, the change in the fiber core index as a function of wavelength can be determined. The equilibrium change in the core index is found to have an almost constant value of approximately 2.3 × 10−5 over the measured wavelength range of 700 to 1400 nm

Bragg gratings fabricated in monomode photosensitive optical fiber by UV exposure through a phase mask

A photolithographic method is described for fabricating refractive index Bragg gratings in photosensitive optical fiber by using a special phase mask grating made of silica glass. A KrF excimer laser beam (249 nm) at normal incidence is modulated spatially by the phase mask grating. The diffracted light, which forms a periodic, high-contrast intensity pattern with half the phase mask grating pitch, photoimprints a refractive index modulation into the core of photosensitive fiber placed behind, in proximity, and parallel, to the mask; the phase mask grating striations are oriented normal to the fiber axis. This method of fabricating in-fiber Bragg gratings is flexible, simple to use, results in reduced mechanical sensitivity of the grating writing apparatus and is functional even with low spatial and temporal coherence laser sources