Splendid Hybrids: The Effects of a Tiger Beetle Hybrid Zone on Apparent Species Diversity

Nonexpert citizen groups are being used to monitor species to track ecosystem changes; however, challenges remain for proper identification, especially among diverse groups such as beetles. Tiger beetles, Cicindela spp., have been used for biological diversity monitoring because of their diversity and the ease of recognition. The finding of an apparent hybrid zone among Cicindela denverensis Casey, Cicindela limbalis Klug, and Cicindela splendida Hentz in central Nebraska prompted a detailed study of the biogeography of this species group within Nebraska, a test of characteristics that could be used by citizen scientists, and limited breeding experiments. This study suggests that while C. denverensis appears to hybridize with both C. limbalis and C. splendida within the hybrid zone, all three species maintain their integrity across most of their ranges, largely occupy unique geographic regions, and at least C. denverensis and C. splendida cooccur in many areas with no evidence of hybridization. Evidence of hybridization between C. limbalis and C. splendida was found at only two sites. Furthermore, breeding experiments with virgin C. splendida and C. denverensis showed that they are capable of producing hybrid larvae in the laboratory. The presence of morphological intergrades serves as a cautionary note when using biological indicator species

Splendid Hybrids: The Effects of a Tiger Beetle Hybrid Zone on Apparent Species Diversity

Nonexpert citizen groups are being used to monitor species to track ecosystem changes; however, challenges remain for proper identification, especially among diverse groups such as beetles. Tiger beetles, Cicindela spp., have been used for biological diversity monitoring because of their diversity and the ease of recognition. The finding of an apparent hybrid zone among Cicindela denverensis Casey, Cicindela limbalis Klug, and Cicindela splendida Hentz in central Nebraska prompted a detailed study of the biogeography of this species group within Nebraska, a test of characteristics that could be used by citizen scientists, and limited breeding experiments. This study suggests that while C. denverensis appears to hybridize with both C. limbalis and C. splendida within the hybrid zone, all three species maintain their integrity across most of their ranges, largely occupy unique geographic regions, and at least C. denverensis and C. splendida cooccur in many areas with no evidence of hybridization. Evidence of hybridization between C. limbalis and C. splendida was found at only two sites. Furthermore, breeding experiments with virgin C. splendida and C. denverensis showed that they are capable of producing hybrid larvae in the laboratory. The presence of morphological intergrades serves as a cautionary note when using biological indicator species

Array tomography: Characterizing FAC-sorted populations of zebrafish immune cells by their 3D ultrastructure

For 3D reconstructions of whole immune cells from zebrafish, isolated from adult animals by FAC-sorting we employed array tomography on hundreds of serial sections deposited on silicon wafers. Image stacks were either recorded manually or automatically with the newly released ZEISS Atlas 5 Array Tomography platform on a Zeiss FEGSEM. To characterize different populations of immune cells, organelle inventories were created by segmenting individual cells. In addition, arrays were used for quantification of cell populations with respect to the various cell types they contained. The detection of immunological synapses in cocultures of cell populations from thymus or WKM with cancer cells helped to identify the cytotoxic nature of these cells. Our results demonstrate the practicality and benefit of AT for high-throughput ultrastructural imaging of substantial volumes. LAY DESCRIPTION: To look at immune cells from zebrafish we employed array tomography, a technique where arrays of serial sections deposited on solid substrates are used for imaging. Cell populations were isolated from the different organs of zebrafish involved in haematopoiesis, the production of blood cells. They were chemically fixed and centrifuged to concentrate them in a pellet that was then dehydrated and embedded in resin. Using a custom-built handling device it was possible to place hundreds of serial sections on silicon wafers as well ordered arrays. To image a whole cell at a resolution that would allow identifying all the organelles (i.e. compartments surrounded by membranes) inside the cell, stacks of usually 50–100 images were recorded in a scanning electron microscope (SEM). This recording was either done manually or automatically using the newly released Atlas Array Tomography platform on a ZEISS SEM. For the imaging of the sections a pixel size of about 5 nm was chosen, which defines membrane boundaries very well and allows segmentation of the membrane topology. After alignment of the images, cellular components were segmented to locate the individual organelles within the 3D reconstruction of the whole cell and also to create an inventory of organelles. Based on their morphologies we could identify specific cell types in the different hematopoietic organs. We could also quantify the proportion of each cell type in the whole population isolated from a given organ. Some of these specific cells from zebrafish were grown in a culture dish together with human cancer cells. By time-lapse light microscopy we observed that the fish cells attacked the cancer cells and killed them. From this we concluded that these cells must be similar to the cytotoxic cells from humans that play an important role in defence against spontaneously arising cancer cells in our bodies. They form special structures, called immunological synapses that we could also identify on our arrays and reconstruct in 3D. This is the first time the potential of zebrafish immune cells to form immunological synapses has been demonstrated. Our study is a good example for the practicality and benefit of array tomography in high-throughput ultrastructure imaging of substantial volumes, applicable to many areas of cell and developmental biology

Plant growth environments with programmable relative humidity and homogeneous nutrient availability

We describe the design, characterization, and use of “programmable”, sterile growth environments for individual (or small sets of) plants. The specific relative humidities and nutrient availability experienced by the plant is established (RH between 15% and 95%; nutrient concentration as desired) during the setup of the growth environment, which takes about 5 minutes and <1$ in disposable cost. These systems maintain these environmental parameters constant for at least 14 days with minimal intervention (one minute every two days). The design is composed entirely of off-the-shelf components (e.g., LEGO® bricks) and is characterized by (i) a separation of root and shoot environment (which is physiologically relevant and facilitates imposing specific conditions on the root system, e.g., darkness), (ii) the development of the root system on a flat surface, where the root enjoys constant contact with nutrient solution and air, (iii) a compatibility with root phenotyping. We demonstrate phenotyping by characterizing root systems of Brassica rapa plants growing in different relative humidities (55%, 75%, and 95%). While most phenotypes were found to be sensitive to these environmental changes, a phenotype tightly associated with root system topology – the size distribution of the areas encircled by roots – appeared to be remarkably and counterintuitively insensitive to humidity changes. These setups combine many of the advantages of hydroponics conditions (e.g., root phenotyping, complete control over nutrient composition, scalability) and soil conditions (e.g., aeration of roots, shading of roots), while being comparable in cost and setup time to Magenta® boxes

Effects of Language Context on Ratings of Shy and Unsociable Behaviors in English Language Learning Children

Purpose The primary goal of this study was to explore the effect of the language context on the socially withdrawn behaviors of school aged-children who are English Language Learners (ELLs) from middle to high SES backgrounds. This is one of the first studies to address the frequently confused concepts of shyness and unsociability as independent constructs within the ELL population. This study also investigated the feasibility of an experimental parent and child questionnaire that examines shyness and unsociability across native and English speaking contexts. Method Children and parents (34 ELL and 37 native English speaking) were administered an experimental questionnaire examining shy and unsociable behavior in native language and English-speaking contexts. Results Parents and children from the ELL group reported significantly higher ratings of shy behavior in English versus native language contexts, whereas unsociable ratings did not differ across language contexts. Conclusions Shyness and unsociability are distinguishable behaviors in ELL children and these constructs should be considered when examining withdrawal. Additionally, examining ELL children’s behavior across language contexts provides a valuable method for investigating language influenced behavioral problems. This study demonstrates the need for service providers to evaluate behavior across subtype and language context before pathologizing withdrawal in ELL children

New ant associations for Glaucopsyche lygdamus doubleday (Lycaenidae)

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Influence of Temperature on Rate of Uptake and Subsequent Horizontal Transfer of [\u3csup\u3e14\u3c/sup\u3eC]Fipronil by Eastern Subterranean Termites (Isoptera: Rhinotermitidae)

The effect of temperature on [14C]fipronil uptake and transfer from donor (D) to recipient (R) Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) workers was evaluated. Test chambers used in the fipronil uptake study were constructed from petri dishes containing autoclaved soil treated with 1 ppm [14C]fipronil (1.14 μCi of total radioactivity per petri dish), distilled water, and R. flavipes workers. Test chambers were held in environmental growth chambers preset at 12, 17, 22, 27, and 32°C. For the fipronil transfer study, donor termites stained with Nile blue-A were exposed to soil treated with 1 ppm [14C]fipronil for 2 h. Donors were then combined with unexposed recipient termite workers at either 1D:5R, 1D:10R, or 1D:20R ratios. Test chambers consisted of a nest and feeding chamber connected by a piece of polyethylene tube and held in growth chambers at 12, 17, 22, 27, and 32°C. Worker termites were sampled over time and the amount of [14C]fipronil present was measured by scintillation counting. Some degree of uptake and transfer occurred at all temperatures and ratios in this study. The highest level of uptake occurred by termites held at 22-32°C, followed decreasingly by 17 and 12°C. Maximum transfer of [14C]fipronil occurred at the higher ratios (1:5 \u3e 1:10 \u3e 1:20) of donors to recipients. Data presented in this study suggest that temperature is one of the key factors affecting the rate of uptake and subsequent horizontal transfer of [14C]fipronil in subterranean termites

Effect of Temperature, Moisture, and Soil Texture on DCPA Degradation

Turf managers sometimes experience poor or early loss of control of targeted weeds, even when herbicides are applied at recommended rates. This study was conducted to determine the influence of soil temperature and moisture on the rate of DCPA (dimethyl tetrachloroterephthalate) degradation in soil. The effect of six soil temperatures, three soil moistures, and three soil textures on the degradation of DCPA was measured in the laboratory through HPLC analysis. Soil temperature influenced the rate of DCPA degradation in the following order: 10\u3c\u3c15\u3c\u3c20\u3c25=30\u3e35°C. The average half-life ranged from 92 d at 10°C to 18 d at 30°C. Soil moisture content influenced the rate of degradation in the following order: low (0.1 kg H2O kg-1 soil) medium (0.2 kg H20 kg-1 soil) = high (0.4 kg H2O kg-1 soil). The average half-life values of DCPA were 49, 33, and 31 d for the low, medium, and high soil moisture levels, respectively. A mathematical model of DCPA loss was utilized to determine the relative contribution of time, soil moisture, and soil temperature to the rate of degradation. Faster degradation of DCPA was observed from a sand/soil moisture (47.5:52.5, w/w) than from either a sand or a soil (Flanagan silt loam [fine, montmorillonitic, mesic Aquic Argiudoll]). It was concluded that the dissipation rate of DCPA is largely dependent on soil environmental conditions including soil temperature, soil moisture, soil texture, and the time interval since the application to the soil. Thus, it is suggested that soil environmental factors be considered in determining the timing of second or subsequent applications when necessary rather than following a fixed application schedule