Masticophis bilineatus

Number of Pages: 4Integrative BiologyGeological Science

Masticophis taeniatus

Number of Pages: 6Integrative BiologyGeological Science

The Status of Three Uncommon Salamanders (Amphibia: Caudata) in Iowa

The smallmouth salamander [Ambystoma texanum (Matthes)], blue-spotted salamander (Ambystoma laterale Hallowell), and central newt [Notophthalmus viridescens louisianensis (Wolterstorff)] were studied in Iowa from fall 1982 through summer 1984. All three species have declined in abundance in Iowa. A. texanum is more abundant and widespread than was previously suspected, but is declining due to habitat destruction. Apparently, only two populations of A. laterale remain in Iowa. N. v. louisianensis has also declined due to habitat destruction, with only three populations known. All three species require ponds in or adjacent to forest. A. ta was found primarily in riparian forest. The other two species inhabited both riparian and upland forest. N. v. louisianensis was associated with permanent ponds containing aquatic vegetation

Comparative Ecology of Two Species of Semiaquatic Snakes in Southeastern North America

The banded water snake (Nerodia fasciata fasciata) and the Eastern cottonmouth (Agkistrodon piscivorus piscivorus) were the focal species in a long-term mark and recapture study in the upper coastal plain of South Carolina, USA. Recapture rates were low for both species. Female N. fasciata were significantly larger than males. Male A. piscivorus were larger than females but not significantly. Age structure and sex ratios were determined for these populations. Recapture latency was greater for A. piscivorus than for N. fasciata. There was little dietary niche overlap between these two species. Nerodia fasciata ingested significantly more fish headfirst and more amphibians tail first. Growth rates were also calculated for both species. Litter size, offspring size, relative clutch mass and parturition dates were determined for N. fasciata

Process simulation and analysis of carbon capture with an aqueous mixture of ionic liquid and monoethanolamine solvent

This study investigated the prospect of using aqueous mixture of 1-butylpyridinium tetrafluoroborate ([Bpy][BF4]) ionic liquid (IL) and monoethanolamine (MEA) as solvent in post-combustion CO2 capture (PCC) process. This is done by analysis of the process through modelling and simulation. In literature, reported PCC models with a mixture of IL and MEA solvent were developed using equilibrium-based mass transfer approach. In contrast, the model in this study is developed using rate-based mass transfer approach in Aspen Plus®. From the results, the mixed aqueous solvent with 5–30 wt% IL and 30 wt% MEA showed 7%–9% and 12%–27% less specific regeneration energy and solvent circulation rate respectively compared to commonly used 30 wt% MEA solvent. It is concluded that the IL concentration (wt%) in the solvent blend have significant impact on specific regeneration energy and solvent circulation rate. This study is a starting point for further research on technical and economic analysis of PCC process with aqueous blend of IL and MEA as solvent

Ecological Parameters of Coluber constrictor etheridgei, with Comparisons to Other Coluber constrictor Subspecies

In 1998, we conducted a radio-telemetry study of Coluber constrictor etheridgei (Tan Racer) in the Angelina National Forest in eastern Texas. Individuals were located once daily from 12 June to 14 August. We determined home-range size, movement distances, movement frequency, and habitat use for this short-term study. We also determined food habits of this population by examination of fecal samples. We compared these parameters to other Racer taxa in Utah (C. c. mormon [Western Yellow-bellied Racer]), Kansas (C. c. fl aviventris [Eastern Yellow-bellied Racer]), and South Carolina (C.c. priapus [Southern Black Racer]). Compared to these populations, Texas Racers exhibited larger home ranges and greater movement frequency and distances during the summer than Utah or Kansas populations, but approximately equal to those of the South Carolina population. Available data on food habits suggests that all populations are consumers of invertebrate and vertebrate prey. We hypothesize that the basic diet of C. constrictor is composed of invertebrates captured by active foraging in areas of abundant herbaceous vegetation, that differences in home-range size and movement distances result from variations in patchiness of suitable foraging habitat across populations, and that the proportion of vertebrate prey in the diet of Coluber populations increases as home-range size and movement distances increase due to increasing patchiness of foraging habitat, resulting in increasing encounters with vertebrate prey

Assessment of cognitive self-statements during marital problem solving: A comparison of two methods

Twenty maritally distressed couples (DC) and 20 nondistressed couples (NDC) were recruited and asked to undertake 10 minutes of problem-solving discussions, which were videotaped. Each individual partner’s cognitive self-statements during the interaction were assessed using two methods: video-assisted recall (VR) and thought listing (TL). Reported cognitions from each method were content- analysed and classified into five categories: partner- referent positive, partner- referent negative, self-referent positive, self- referent negative, and other. Proportions of reported cognitions falling into each category were analysed in two separate two-way MANOVAs (marital distress/ nondistress x sex) for the VR and TL measures. Results of each MANOVA indicated a highly significant effect of marital distress on cognitions, and a significant effect of sex on the VR but not the TL measure. Discriminant analyses showed that the VR and TL methods both discriminated between DC and NDC groups. Post hoc univariate ANOVAs indicated that DC had significantly higher proportions of negative partner- referent cognitions, and lower proportions of positive partner- referent cognitions, than NDC while problem solving. The relative merits of each cognitive assessment method, and their potential use in increasing marital therapy effectiveness, are discussed

Approaching Mechanization of Plant Micropropagation

Investigations of materials and methods for growing plant tissue in a continual-flow, liquid nutrient medium as an alternative to semisolid agar medium have been made. Enhanced growth of plant tissue on microporouspolypropylene membranes floating on a liquid nutrient has been demonstrated. Moreover, in vitro plantlets on the microporous membrane are free from entanglement with the support matrix and readily available to mechanizedhandling. Trained growth of plantlets through polypropylene netting shows potential for mechanization by mass handling (separation, singulation, and transfer) of plant tissue cultures

Mercury Accumulation in Tree Rings: Observed Trends in Quantity and Isotopic Composition in Shenandoah National Park, Virginia

Recent studies have shown that mercury (Hg) concentrations in tree rings have the potential to archive historical Hg exposure from local, regional, and global sources. The southeastern United States has received elevated Hg deposition, yet no studies have evaluated tree ring Hg in this region. Here, we quantify Hg accumulation and isotopic composition in tree rings collected in Shenandoah National Park, Virginia. Cores were collected from three individuals of three tree species—white oak (Quercus alba), northern red oak (Quercus rubra), and pitch pine (Pinus rigida)—within the northern, central, and southern areas of the Park (n = 27 cores). The cores were analyzed for Hg content in 10‐year increments, with some cores dating back to the early 1800s. Overall, tree ring Hg concentrations (ranging from below detection to 4.4 ng/g) were similar to other studies and varied between species, with pitch pine having higher concentrations than the deciduous species. The most notable feature of the tree ring Hg time series was a peak that occurred during the 1930s through 1950s, coinciding with the use of Hg at a local industrial facility. Atmospheric modeling indicates that potential emissions from the plant likely had a stronger impact on the southern region of the Park, consistent with the latitudinal gradient in tree ring Hg concentrations. Mass‐dependent and mass‐independent fractionation of Hg isotopes suggests contributions from both regional anthropogenic and local industrial sources during this period. This study demonstrates the potential usefulness of tree ring dendrochemistry for identifying historical sources of atmospheric Hg exposure.Key PointsTree ring mercury levels in Shenandoah National Park, Virginia, were similar to those measured in other North American forestsTree ring mercury peaked during the 1930s to 1950s, coinciding with mercury use at an industrial facility near the southern end of the ParkMercury isotopes suggest a local source at this time, demonstrating the potential of dendrochemistry to identify historical sourcesPlain Language SummaryFor many years scientists have used tree rings to reconstruct past climate. Increasingly, tree rings are being used to document the historical exposure of trees to pollutants. In this study, we cored trees in Shenandoah National Park, Virginia, dated the tree rings, and then measured the amount of mercury stored within decadal core increments. We were surprised to find that mercury levels peaked in the 1930s to 1950s, even though global mercury emissions continued to rise throughout the past century, mostly as a by‐product of energy production. Our findings suggest that the trees were exposed to a local pollutant source during this earlier time period, perhaps from a nearby industrial plant that used mercury in the production of rayon. By examining the chemistry of wood within tree rings, we can get a clearer picture of when and where human activities have affected air pollution over recent centuries.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153685/1/jgrg21576_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153685/2/jgrg21576.pd