CAN AMPHIPODS BE USED TO MONITOR MINING-IMPACTED LAKES?

Metal pollution in aquatic systems is complicated and expensive to manage; establishing a sentinel species for contaminated habitats, rather than measuring abiotic parameters, can provide a more complete perspective of the impacts of pollutants. I conducted a dual field/laboratory study to determine whether an amphipod (Hyalella azteca) can serve as a sentinel in a mining-impacted area in Northern Idaho, the Coeur d’Alene (CDA) River Basin. My objectives in the field study were to (1) determine seasonal abundance and metal burden of amphipods in nine chain lakes and a reference lake (Benewah L.) and (2) compare aqueous trace metal levels and limnologic parameters from lake water to patterns in amphipod abundance, size, and metal burden. I predicted that aqueous metal concentrations correlate with amphipod abundance and body burden. I found that amphipod abundance differed across the lakes and over time, but patterns in amphipod abundance and size could not be explained by the factors that I measured. The results confirm that the metals are bioavailable and that uptake is influenced by limnological factors. In the laboratory study, I compared the Zn and Pb tolerances of amphipods from three chain lakes to that of amphipods from the reference site (Benewah L.) and from a commercial source. I hypothesized that chain lake amphipods would have higher metal tolerance, indicated by higher survival and swimming activity following a 96-hour exposure. Chain lake amphipods exhibited higher Zn tolerance than did the commercial amphipods but were not consistently more tolerant than were reference lake amphipods. The Zn tolerance of all amphipod populations varied seasonally. Differences in Pb tolerance were difficult to detect, likely reflecting issues with Pb solubility. The activity assay was not sensitive enough to detect among-population differences as swimming was strongly affected by all Zn and Pb doses. Taken together, these results confirm that chain lake amphipods are more tolerant of metals than are the commercially-obtained amphipods that are routinely used for toxicity testing. Hyalella azteca could become a sentinel for this basin, but only if amphipods from a reference lake serve as the (negative) control population and if the amphipods are monitored year-round

Assessing Feeding Damage from Two Leaffooted Bugs, Leptoglossus clypealis Heidemann and Leptoglossus zonatus (Dallas) (Hemiptera: Coreidae), on Four Almond Varieties.

Leaffooted bugs (Leptoglossus spp; Hemiptera: Coreidae) are phytophagous insects native to the Western Hemisphere. In California, Leptoglossus clypealis and Leptoglossus zonatus are occasional pests on almonds. Early season feeding by L. clypealis and L. zonatus leads to almond drop, while late season feeding results in strikes on kernels, kernel necrosis, and shriveled kernels. A field cage study was conducted to assess feeding damage associated with L. clypealis and L. zonatus on four almond varieties, Nonpareil, Fritz, Monterey, and Carmel. The objectives were to determine whether leaffooted bugs caused significant almond drop, to pinpoint when the almond was vulnerable, and to determine the final damage at harvest. Branches with ~20 almonds were caged and used to compare almond drop and final damage in four treatments: (1) control branches, (2) mechanically punctured almonds, (3) adult Leptoglossus clypealis, and (4) adult Leptoglossus zonatus. Replicates were set up for eight weeks during two seasons. Early season feeding resulted in higher almond drop than late season, and L. zonatus resulted in greater drop than L. clypealis. The almond hull width of the four varieties in the study did not influence susceptibility to feeding damage. The final damage assessment at harvest found significant levels of kernel strikes, kernel necrosis, and shriveled almonds in bug feeding cages, with higher levels attributed to L. zonatus than L. clypealis. Further research is warranted to develop an Integrated Pest Management program with reduced risk controls for L. zonatus

Effects of Behavioral Skills Training on Teachers Conducting the Recess-to-Classroom Transition

Elementary school teachers transition their students from recess to the classroom multiple times a day. When students do not line up quickly or are disruptive in line, teachers can spend valuable instructional time trying to manage students’ inappropriate behaviors. The result is a loss of instructional time that could lead to a decrease in student performance. This study examined how teachers could use behavioral skills training with their students as a way to reduce the length of the recess-to-classroom transition with second–fourth graders. After teachers were trained, they provided their students with training, which included instruction, modeling, rehearsal, and feedback. The result in each teacher’s classroom was that students began to line up more quickly and use their hands and feet appropriately for the duration of the transition. Appropriate behavior and reduced transition times maintained at a 2-week follow-up

Reduction of Benzylidene Dibenzo[ a, d ]cycloheptenes: Over-Reduction of Antiaromatic Dianions to Aromatic Tetraanions

The antiaromaticity of a series of dianions of p-substituted benzylidene dibenzo[a,d]cycloheptenes was examined through calculated measures of antiaromaticity. The nucleus-independent chemical shifts (NICS) and magnetic susceptibility exaltation both showed substantial antiaromatic character in the benzannulated tropylium anion. When the antiaromaticity was normalized for the area of the ring, these tropylium anions were shown to be among the most antiaromatic anions in the chemical literature. Attempts to make the dianion through reduction with lithium or potassium gave the tetraanion as the only species observable in the (1)H NMR spectrum. Quench of the reaction mixture with trimethylsilyl chloride or D(2)O confirmed the presence of the tetraanion, but only as a small portion of the reaction mixture, with the major product being unreacted starting material. The failure to observe starting material was attributed to similarities in the structures of the starting material and anion radical (first reduction), allowing rapid electron transfer between them. The inability to see the dianion (second reduction) could be the result of the very small HOMO-LUMO gap anticipated for highly antiaromatic species, which would allow access to diradical species. The magnitude of the HOMO-LUMO gap was determined by the difference between the HOMO and LUMO energies from geometry optimization and the lowest energy transition from TD-DFT calculations. The HOMO-LUMO gap for the benzylidene dibenzocycloheptatriene dianions was shown to be much smaller than the HOMO-LUMO gap of species for which (1)H NMR spectra had been observed

Creating Digital Activity Schedules to Promote Independence and Engagement

Photographic activity schedules have been demonstrated to be effective in helping individuals with autism and other developmental disabilities learn how to complete both simple and complex sequences of activities without prompting from adults. Although the majority of research studies demonstrating the effectiveness of activity schedules have used schedule books composed of static printed pictures attached to physical pages, recently researchers have begun to demonstrate the effectiveness of technology-based activity schedules. In the current article, we provide a task analysis for creating both simple and complex digital activity schedules using Google Slides, a freely available, web-based technology that operates on a variety of digital platforms. We also provide suggestions for how behavior analysts can train parents to use this technology with their children using telehealth procedures