POPULATION ECOLOGY OF THE NORTHERN SLIMY SALAMANDER (PLETHODON GLUTINOSUS) IN EAST-CENTRAL ILLINOIS

The importance of plethodontid salamanders in forested habitats has been recognized for decades and more recently plethodontids have been touted as a model taxon for monitoring ecosystem integrity and recovery. However, basic demographic data that are crucial to conservation and management plans are currently lacking for many species and regions. The objectives of our study were to characterize the population density, biomass, and capture success of a peripheral population of Plethodon glutinosus to provide a comparison for eastern populations and set a baseline for future monitoring of Midwestern populations. We estimated the population density of P. glutinosus at our site to be 0.41 salamanders/m2, with an estimated biomass of 0.70 g/m2. We did not find any evidence for temperature or precipitation affecting capture success. Our results showed that our density estimate falls within the range of other population ecology studies of Plethodon and sets a baseline for other peripheral Midwestern populations

Enhanced Formation of Nanometric Titanium Cones by Incorporation of Titanium, Tungsten and/or Iron in a Helium Ion Beam

Surface patterning of bio-compatible titanium (Ti) shows a growing interest in the medical field. The engineering of material surfaces can achieve bactericidal properties and osteointegration improvements in order to develop medical implants. Spikes-like surface morphologies have already demonstrated the development of promising bactericidal properties. A barely new method to produce nanometric-sized cones on titanium consists of helium (He) ion irradiation using low energies ( 100 eV) and temperatures comprised between 0.25 T/T 0.5 (with T being the melting temperature of the material). Ti, iron (Fe) and/or tungsten (W) were incorporated in a He beam, and their amounts were quantified using X-ray Photoelectron Spectroscopy (XPS). The He ion energy was varied from 70 and 120 eV, the surface temperatures from 571 to 651 K for fluences approximately equal to 1024 m−2. After irradiation, the surface morphology was characterized using Scanning Electron Microscopy (SEM) and Focused Ion Beam (FIB). This study demonstrated the capability for irradiated Ti surfaces to form cones with tunable density, aspect ratio, and heights with the incorporation of Ti, Fe and/or W in a He ion. Additionally, the growth rate of the cones was enhanced by about 30 times in comparison to pure He irradiation as a function of the chosen materials introduced in the He beam

Surface Modification of ITER-like Mirrors after One Hundred Cleaning Cycles Using Radio-Frequency Plasma

In ITER, the metallic first mirrors (FMs) will undergo erosion due to their proximity to the fusion plasma and deposition of materials originated from the first walls (mainly beryllium). In-situ plasma cleaning is a promising technique to conserve the FMs optical properties by means of ion sputtering. In this work, the evolution of the optical properties of single-crystal (Sc) and nanocrystalline (Nc) molybdenum (Mo) and rhodium (Rh) mirrors were investigated up to 100 cycles of consecutive contamination and cleaning. Aluminum oxide (AlO) was used as contaminant to replace the toxic beryllium. The plasma cleaning was carried out using a capacitively coupled argon (Ar) plasma excited by a 60 MHz radio-frequency generator resulting in the formation of a self-bias applied on the mirrors of -280 V. The plasma potential being around 30 V, the Ar ion energy was about 310 eV. The optical properties of the mirrors were assessed using ex-situ reflectivity measurements. Moreover, the surface topography was characterized by means of scanning electron microscopy (SEM), focused ion beam (FIB) and roughness measurements using atomic force microscopy (AFM). ScMo and ScRh mirrors formerly exposed to 80 successful cleaning cycles using aluminum/tungsten (Al/W) deposits and air storage exhibit drastic changes in their optical properties after being subject to cleaning cycles using AlO as contaminant. Additionally, freshly polished ScRh were exposed to identical cleaning cycles. All Sc mirrors exhibited pits induced by the polishing procedure using diamond paste in addition of mounds/wavy patterns. The carbon incorporated during the polishing process was demonstrated to be responsible for the pitting of the surface. The Nc mirrors preserved their initial reflectivities after up to 100 cycles. The surface topography was systematically characterized and an average erosion rate for NcRh mirrors of about 59 nm per cycle has been estimated from FIB cross-sections. The optical properties of the Nc mirrors showed a superiority in the present study in comparison to the Sc materials due to the influence of their polishin

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Picicola donwebbi Meyer, Price

Picicola donwebbi Meyer, Price, and Johnson, new species (Figs. 1–3) Type host. Smithornis rufolateralis Gray, 1864, Rufous-sided Broadbill. Description. Both sexes similar except for terminalia and dimensions. General aspects of body and chaetotaxy as in Fig. 1 for male and Fig. 3 for female. Head with marginal carina well developed, with outer edge and inner border medially pointed; lateral notch present and interrupting, but not breaking, marginal carina at point of curvature around frons. Preantennal suture distinct. Frontal plate located anterior to preantennal suture, distinct and sculptured, but without thickened posterior edge. Tip of conus usually not reaching distal end of first antennal segment (scape). Abdominal tergites II–VII divided with 2 central setae, tergite VIII entire and with 4 central setae. Abdominal segments with prominent pleural thickening and reentrant heads. Margin of male tergite IX with long seta posteriolateral to shorter one on either side. Female subgenital plate vulval margin with 16 short setae and row of 6 very short setae lateromedial to this marginal row, with 4 additional short setae displaced latero-anteriorly. Male genitalia (Fig. 2) with one sensillum on each endomeral arm. Dimensions (in millimeters): Male (n= 5): TW, 0.32–0.33 (0.33); HL, 0.43–0.48 (0.45); CI, 1.33–1.49 (1.38); PW, 0.21–0.22 (0.21); MW, 0.27–0.28 (0.27); AWV, 0.38–0.46 (0.40); GL, 0.24–0.28 (0.27); PL, 0.03–0.04 (0.04); TL, 1.43–1.55 (1.48). Female (n= 5): TW, 0.34–0.37 (0.35); HL, 0.45–0.48 (0.47); CI, 1.31– 1.33 (1.32); PW, 0.22–0.25 (0.23); MW, 0.29–0.30 (0.30); AWV, 0.40–0.44 (0.42); TL, 1.61–1.78 (1.72). Type material. Holotype male is labeled “ex Smithornis rufolateralis, GHANA: Goaso, K. P. Johnson, 28 Mar 2003, BDM 851 ” and is deposited in INHS. Paratypes: 4 males, 5 females with same data as holotype and deposited as follows: 1 male, 1 female (BMNH); 1 male, 1 female (FMNH); 1 male, 2 females and a female DNA voucher specimen (INHS); 1 male, 1 female (OSEC). Diagnosis. Picicola donwebbi differs from Picicola collected from the Picidae by the anterior shape of the head being medially pointed rather than smoothly rounded (as in P. candidus and P. snodgrassi species groups), or with an apical depression or truncate (as in P. thripias species group); by the marginal carina being well developed and complete rather than well developed but thinner where it curves around the frons; and by the lateral notch being present rather than absent. It differs from the Picicola found on the passeriform families Tyrannidae, Furnariidae, Mimidae, Parulidae, Cracticidae, Dicruridae, and Ptilonorhynchidae by having the preantennal suture distinct rather than indistinct; by the frontal plate lacking a thickened posterior edge; and by the marginal carina thin but not interrupted where it curves around the frons rather than nearly broken where it curves around the frons. Picicola donwebbi is morphologically most similar to the Picicola found on the Pittidae as defined by Somadder and Tandan (1977) and is, therefore, placed in their P. quadripustulosus species group. In this species group, it is most closely allied with P. angolensis Somadder and Tandan, 1977, by the males having only two sensilla associated with the endomeral arms; by the number of setae on abdominal tergites III–VI equaling 2 central ( 1.0........... .......................................................................................................................................... donwebbi, sp. nov. Etymology. This species is named in honor of Dr. Donald Webb on occasion of his retirement after 40 years of service to the Illinois Natural History Survey and generations of entomology graduate students at the University of Illinois, Champaign-Urbana.Published as part of Meyer, Mathys J., Price, Roger D. & Johnson, Kevin P., 2008, A new species of Picicola Clay and Meinertzhagen, 1938 (Phthiraptera: Ischnocera) parasitic on the Rufous-sided Broadbill (Passeriformes: Eurylaimidae) in Ghana, pp. 63-68 in Zootaxa 1762 on pages 64-66, DOI: 10.5281/zenodo.18195

Rediscovery of the White-necked picathartes Picathartes gymnocephalus in Ghana

Volume: 124Start Page: 151End Page: 15

Picosecond and nanosecond laser ablation of mixed tungsten/aluminium films

In order to extend the investigation of laser-assisted cleaning of ITER-relevant first mirror materials to the picosecond regime, a commercial laser system delivering 10-ps pulses at 355 nm at a frequency of up to 1 MHz has been used to investigate the ablation of mixed aluminum (oxide)/tungsten (oxide) layers deposited on polycrystalline and nanocrystalline molybdenum as well as nanocrystalline rhodium mirrors. Characterization before and after cleaning using scanning electron microscopy and spectrophotometry shows heavy dust formation, resulting in a degradation of the reflectivity. Cleaning using 5-ns pulses at 350 and 532 nm, on the other hand, proved very promising. The structure of the film remnants suggests that in this case buckling was the underlying removal mechanism rather than ablation. Repeated coating and cleaning using nanosecond pulses is demonstrated

In situ work function measurements of W, WO₃ nanostructured surfaces

Surface nanostructuring enables the fabrication of materials with highly desirable properties. Nanostructured tungsten surfaces have potential applications in solar water splitting. Exposing a polished tungsten surface to helium plasma induces various surface morphological changes. Depending on the helium ion energy, temperature, and fluence, helium clusters, helium bubbles and foam-like nanostructures develop on the tungsten surface. In this study, tungsten foam-like nanostructures were formed and/or oxidised, and then examined using X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS) without breaking the vacuum. The chemical state of nanostructured W or WO3 was not modified in comparison to the pristine one. However, measuring the line width of the emitted electrons from the onset of the secondary electrons up to the Fermi edge and subtracting value from the incident photon energy, the work function acquired in situ by UPS for a nanostructured W surface increased by 0.9 eV in comparison to the pristine one. Helium ions effectively eliminated field emission sites via sputtering/implantation and thereby increased the work function. No change in work function was measured for WO3-pristine and its fuzz: the oxidation hindered the effect of helium. In contrast to the W-fuzz sample, no helium bubbles were identified in WO3-fuzz, as helium diffused out during oxidation

ITER first mirror mock-ups exposed in Magnum-PSI

The goal of this work was to investigate coated first mirrors under very harsh erosion conditions. Mock-up mirrors were exposed to high-flux hydrogen/argon plasma in the linear plasma facility Magnum-PSI. Rhodium (Rh) and molybdenum (Mo) coated mirrors of different coating thicknesses, with or without water cooling, exhibited different responses to this exposure. Failures of Rh films were demonstrated for 5 micron thick film, 1 micron film revealed 10% decrease in the specular reflectivity only in the exposed area. In comparison, water cooled Mo mock-ups showed a significant diffuse reflectivity on the entire surface leading to more than 50% specular reflectivity losses in the visible range. The losses for non-cooled Mo samples did not exceed 7% in the whole studied wavelength range of 250-2500 nm. Three phenomena were proposed to explain these results. First the mechanical properties of the films as characterized by scratch and hardness measurements as well as residual stress analysis measured by x-ray diffraction. Rh films showed a high compressive stress value of 2.5 +/- 0.4 GPa leading to poor adhesion of the thick films deposited on stainless steel substrate due to the high amount of available energy per area stored in the unbuckled film i. e. G(0)> 30 J m(-2). It was confirmed by ANSYS simulation that the von Mises stress for the Rh coating was twice as high as that for the Mo coating due to different mechanical properties. Moreover, the maximum stress for thick Rh film (261 MPa) was higher than the critical buckling stress calculated with a buckle clamped Euler column model demonstrating the failure mode of the film. The second phenomenon was roughening of the mirror surface which was flux and temperature dependent, i. e. at low temperatures the surface would roughen randomly without any oriented surface morphology and at higher temperatures the surface diffusion constants would dominate the process and smoothen the surface. The last phenomenon was the significant oxidation and carbidization of the Mo surface even on the non-exposed area, as detected by x-ray photoelectron spectroscopy, leading also to a decrease in the reflectivity in the entire measured range, which was not observed for Rh film