The appearance of Ulva laetevirens (Ulvophyceae,Chlorophyta) in the northeast coast of the United States of America

Introduced species may outcompete or hybridize with native species, resulting in the loss of native biodiversity or even alteration of ecosystem processes. In this study, we reported an alien distromatic Ulva species, which was found in an embayment (Holly Pond) connected with Long Island Sound, USA. The morphological and anatomical observations in combination with molecular data were used for its identification to species. Anatomy of collected specimens showed that the cell shape in rhizoidal and basal regions was round and the marginal teeth along the basal and median region were not found. These characteristics were primarily identical to the diagnostic characteristics of Ulva laetevirens Areschoug (Chlorophyta). The plastid-encoding tufA and nucleusencoding ITS1 were used for its molecular identification. Phylogenetic analysis for the tufA gene placed the specimens from Holly Pond in a well-supported clade along with published sequences of U. laetevirens identified early without any sequence divergence. In ITS tree, the sample also formed well-supported clades with the sequences of U. laetevirens with an estimated sequence divergence among the taxa in these clades as low as 1%. These findings confirmed the morpho-anatomical conclusion. Native to Australia, this species was reported in several countries along the Mediterranean coast after the late of 1990s. This is the first time that U. laetevirens is found in the northeast coast of United States and the second record for Atlantic North America.     

New developments on estimating satellite interfrequency bias for SVN49

In order to estimating satellite interfrequency bias T_gd for the anomalously behaving SVN49, a modified JPL GIM software suite is presented. This research assumed that the single-frequency user will not need to perform any modification in the receiver software and will not need any detailed knowledge of the satellite anomaly using the code observable. We performed a point positioning analysis and investigated the range residuals for SVN49. It was discovered that the new satellite bias estimate resulted in near zero mean residuals with the shape of P2-P1 and L1-L2 observables being consistent with shapes from other satellites. Also, computed is a 10-day average of the estimated satellite interfrequency bias T_gd, which turned out to be −19.13 ns.     

Cyclic spattering,seismic tremor,and surface fluctuation within a perched lava channel,Kīlauea Volcano

In late 2007, a perched lava channel, built up to 45 m above the preexisting surface, developed during the ongoing eruption near Pu‘u ‘Ō‘ō cone on Kīlauea Volcano’s east rift zone. The lava channel was segmented into four pools extending over a total of 1.4 km. From late October to mid-December, a cyclic behavior, consisting of steady lava level rise terminated by vigorous spattering and an abrupt drop in lava level, was commonly observed in pool 1. We use geologic observations, video, time-lapse camera images, and seismicity to characterize and understand this cyclic behavior. Spattering episodes occurred at intervals of 40–100 min during peak activity and involved small (5–10-m-high) fountains limited to the margins of the pool. Most spattering episodes had fountains which migrated downchannel. Each spattering episode was associated with a rapid lava level drop of about 1 m, which was concurrent with a conspicuous cigar-shaped tremor burst with peak frequencies of 4–5 Hz. We interpret this cyclic behavior to be gas pistoning, and this is the first documented instance of gas pistoning in lava well away from the deeper conduit. Our observations and data indicate that the gas pistoning was driven by gas accumulation beneath the visco-elastic component of the surface crust, contrary to other studies which attribute similar behavior to the periodic rise of gas slugs. The gas piston events typically had a gas mass of about 2,500 kg (similar to the explosions at Stromboli), with gas accumulation and release rates of about 1.1 and 5.7 kg s⁻¹, respectively. The time-averaged gas output rate of the gas pistoning events accounted for about 1–2% of the total gas output rate of the east rift zone eruption.     

Place,gender and the appeal of video lottery terminal gambling: unpacking a focus group study of Montreal youth

Youth gambling has become an important public health issue in Canada and elsewhere owing to the known associations between gambling and delinquency, family dysfunction and suicide. Modern electronic and virtual gambling activities like video lottery terminals (VLTs) may have particular appeal to youth who have been raised in social environments that are increasingly dependent on information and communication technologies. The main objective of the study was to explore why youth gamble and what makes gambling activities like VLTs popular to youth in the places where youth live, study and play. The research is framed within a population health perspective that recognizes the role of social and physical environments in influencing health-related behaviours. Group discussions were conducted with youth to explore the popularity and appeal of gambling and VLTs, and how gambling fits into the daily routines of youth and the spaces they occupy. Methodologically, this research was conscious of responding to calls in the literature to analyze focus groups as an interactive group process rather a collection of individual responses, and to exercise analytic rigour by explicitly making the research team’s positionality and the data collection process transparent. Group discussions revealed gender differences in the appeal of particular gambling activities with young males being more likely to discuss poker, dice, sports-betting and online gambling as exciting social activities, while females described lottery and scratch (instant win) tickets as fun solitary activities. Substantive results point to the need for interventions to address social aspects of gambling that appeal, in particular, to young males potentially through increased provision of healthier alternatives to social engagement and greater attention to young people’s use of space.     

Speleothems and pine trees as sensitive indicators of environmental pollution – A case study of the effect of uranium-ore mining in Hungary

Four decades of U ore production in Hungary provides an opportunity to study the possible environmental effects of mining. The study reveals significant changes in chemical composition of a stalagmite (cave deposit). The good fit between U content changes in the studied deposit and the U ore production rate support the assumption of the relationship with mining activity. An independent chemoenviromental archive, living pine (Pinus sylvestis) trees were also investigated. Data on pine tree cores collected from the same region show different levels of pollution (Cu, Zn, Mn, U) after the 1950s and 1960s, linked to the opening of mines and subsequent dust fallout around the site. Elevated concentrations of detritally derived elements (Si, Al, Th) coupled with a rise in U concentration and change in δ²³⁴U values of the stalagmite suggest increasing amounts of mine-derived dust from 1 to 3 km distance that settled and washed into the karst system. The combined usage of different proxies not only provides historic records for the anthropogenic impact in the environment, but also allows the timing of U concentration increases within the stalagmite and the identification of elemental behavior from the pollution. This study shows that complementary geochemical archives such as stalagmites and tree rings used together can enhance understanding of past environmental contamination.     

GSD‐1G and MPI‐DING Reference Glasses for In Situ and Bulk Isotopic Determination

This paper contains the results of an extensive isotopic study of United States Geological Survey GSD‐1G and MPI‐DING reference glasses. Thirteen different laboratories were involved using high‐precision bulk (TIMS, MC‐ICP‐MS) and microanalytical (LA‐MC‐ICP‐MS, LA‐ICP‐MS) techniques. Detailed studies were performed to demonstrate the large‐scale and small‐scale homogeneity of the reference glasses. Together with previously published isotopic data from ten other laboratories, preliminary reference and information values as well as their uncertainties at the 95% confidence level were determined for H, O, Li, B, Si, Ca, Sr, Nd, Hf, Pb, Th and U isotopes using the recommendations of the International Association of Geoanalysts for certification of reference materials. Our results indicate that GSD‐1G and the MPI‐DING glasses are suitable reference materials for microanalytical and bulk analytical purposes.     

A Discrete Random Model Describing Bedrock Profile Abrasion

We use a simple, collision-based, discrete, random abrasion model to compute the profiles for the stoss faces in a bedrock abrasion process. The model is the discrete equivalent of the generalized version of a classical, collision based model of abrasion. Three control parameters (which describe the average size of the colliding objects, the expected direction of the impacts and the average volume removed from the body due to one collision) are sufficient for realistic predictions.