123 research outputs found

    Computer Assisted Determination of the Ionization Constants of an Unusual Dibasic Acid

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    The ionization constants for an unusual keto ester were determined by examination of the complex visible-UV absorption spectra of the monobasic salt. Interpretation of changes with pH of the spectra at four different wave lengths required an estimate of 12 molar absorbancies and two ionization constants. A computer program permitted progressive selection of best values. The ratio of K1 to K2 for this acid is exceptionally high and exceeds that for any other acid for which we have found data

    Widespread Selection Across Coding and Noncoding DNA in the Pea Aphid Genome

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    Genome-wide patterns of diversity and selection are critical measures for understanding how evolution has shaped the genome. Yet, these population genomic estimates are available for only a limited number of model organisms. Here we focus on the population genomics of the pea aphid (Acyrthosiphon pisum). The pea aphid is an emerging model system that exhibits a range of intriguing biological traits not present in classic model systems. We performed low-coverage genome resequencing of 21 clonal pea aphid lines collected from alfalfa host plants in North America to characterize genome-wide patterns of diversity and selection. We observed an excess of low-frequency polymorphisms throughout coding and noncoding DNA, which we suggest is the result of a founding event and subsequent population expansion in North America. Most gene regions showed lower levels of Tajima’s D than synonymous sites, suggesting that the majority of the genome is not evolving neutrally but rather exhibits significant constraint. Furthermore, we used the pea aphid’s unique manner of X-chromosome inheritance to assign genomic scaffolds to either autosomes or the X chromosome. Comparing autosomal vs. X-linked sequence variation, we discovered that autosomal genes show an excess of low frequency variants indicating that purifying selection acts more efficiently on the X chromosome. Overall, our results provide a critical first step in characterizing the genetic diversity and evolutionary pressures on an aphid genome

    The Probability of Spotted Lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), Escape Differs Among Life Stages and Between Two Trapping Techniques Commonly Used By Landowners, Sticky Bands and Duct Tape.

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    The invasive Lycorma delicatula (White) was first identified in Pennsylvania, U.S.A. in 2014, and has since increased its range to several Eastern states. Lycorma delicatula pose a serious threat to many native species, including hardwoods and grapes, and land owners are continually seeking effective traps to control populations. Both commercially-produced Web-Cote brand sticky bands and less expensive duct tape are often used by land owners to trap L. delicatula. However, the probability of escape from these adhesives has not been formally assessed, and almost certainly differs as a function of life stage and type of adhesive used. The purpose of this work was to determine if the effect of adhesive type (Web-Cote sticky bands vs. duct tape) on the probability of escape differs based on life stage. Additionally, we wanted to know how escape probability differs among life stages when individuals were exposed to each adhesive type, separately. In all life stages, the probability of escape from duct tape was greater than from Web-Cote sticky bands, indicating that sticky bands are a more effective tool in L. delicatula population control. In trials using only Web-Cote sticky bands, the probability of escape was low in second (21.1%), third (32.6%), and fourth (38.5%) instars relative to adults (84.1%). In trials using only duct tape, the probability of escape remained high among all life stages, with approximately 72% of second instars and 100% of adults escaping. Recent studies indicate that alternate trapping techniques, including circle trunk traps, are even more effective at capturing L. delicatula than sticky bands, though they are costlier. We propose a hybrid approach to L. delicatula trapping which utilizes relatively inexpensive sticky bands early in the season, and fewer, more effective circle trunk traps later in the season

    Correction to The Probability of Spotted Lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), Escape Differs Among Life Stages and Between Two Trapping Techniques Commonly Used by Landowners, Sticky Bands and Duct Tape. The Great Lakes Entomologist 53(3-4): 170-177.

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    This is a manuscript correction in reference to: Desko M, Schiebel C, Silverman S, Bickel J, Felton K, and Chandler JL. (2020) The Probability of spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), escape differs among life stages and between two trapping techniques commonly used by landowners, sticky bands and duct tape. The Great Lakes Entomologist 53(3-4): 170-177

    Automated astronaut traverses with minimum metabolic workload : Accessing permanently shadowed regions near the lunar south pole

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    Altres ajuts: acords transformatius de la UABThe Artemis exploration zone is a topographically complex impact-cratered terrain. Steep undulating slopes pose a challenge for walking extravehicular activities (EVAs) anticipated for the Artemis III and subsequent missions. Using 5 m/pixel Lunar Orbiter Laser Altimeter (LOLA) measurements of the surface, an automated Python pipeline was developed to calculate traverse paths that minimize metabolic workload. The tool combines a Monte Carlo method with a minimum-cost path algorithm that assesses cumulative slope over distances between a lander and stations, as well as between stations. To illustrate the functionality of the tool, optimized paths to permanently shadowed regions (PSRs) are calculated around potential landing sites 001, nearby location 001(6), and 004, all within the Artemis III 'Connecting Ridge' candidate landing region. We identified 521 PSRs and computed (1) traverse paths to accessible PSRs within 2 km of the landing sites, and (2) optimized descents from host crater rims into each PSR. Slopes are limited to 15° and previously identified boulders are avoided. Surface temperature, astronaut body illumination, regolith bearing capacity, and astronaut-to-lander direct view are simultaneously evaluated. Travel times are estimated using Apollo 12 and 14 walking EVA data. A total of 20 and 19 PSRs are accessible from sites 001 and 001(6), respectively, four of which maintain slopes <10°. Site 004 provides access to 11 PSRs, albeit with higher EVA workloads. From the crater rims, 94 % of PSRs can be accessed. All round-trip traverses from potential landing sites can be performed in under 2 h with a constant walk. Traverses and descents to PSRs are compiled in an atlas to support Artemis mission planning

    Abiotic and Biotic Stressors Causing Equivalent Mortality Induce Highly Variable Transcriptional Responses in the Soybean Aphid

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    Environmental stress affects basic organismal functioning and can cause physiological, developmental, and reproductive impairment. However, in many nonmodel organisms, the core molecular stress response remains poorly characterized and the extent to which stress-induced transcriptional changes differ across qualitatively different stress types is largely unexplored. The current study examines the molecular stress response of the soybean aphid (Aphis glycines) using RNA sequencing and compares transcriptional responses to multiple stressors (heat, starvation, and plant defenses) at a standardized stress level (27% adult mortality). Stress-induced transcriptional changes showed remarkable variation, with starvation, heat, and plant defensive stress altering the expression of 3985, 510, and 12 genes, respectively. Molecular responses showed little overlap across all three stressors. However, a common transcriptional stress response was identified under heat and starvation, involved with up-regulation of glycogen biosynthesis and molecular chaperones and down-regulation of bacterial endosymbiont cellular and insect cuticular components. Stressor-specific responses indicated heat affected expression of heat shock proteins and cuticular components, whereas starvation altered a diverse set of genes involved in primary metabolism, oxidative reductive processes, nucleosome and histone assembly, and the regulation of DNA repair and replication. Exposure to host plant defenses elicited the weakest response, of which half of the genes were of unknown function. This study highlights the need for standardizing stress levels when comparing across stress types and provides a basis for understanding the role of general vs. stressor specific molecular responses in aphids

    Abiotic and Biotic Stressors Causing Equivalent Mortality Induce Highly Variable Transcriptional Responses in the Soybean Aphid

    Get PDF
    Environmental stress affects basic organismal functioning and can cause physiological, developmental, and reproductive impairment. However, in many nonmodel organisms, the core molecular stress response remains poorly characterized and the extent to which stress-induced transcriptional changes differ across qualitatively different stress types is largely unexplored. The current study examines the molecular stress response of the soybean aphid (Aphis glycines) using RNA sequencing and compares transcriptional responses to multiple stressors (heat, starvation, and plant defenses) at a standardized stress level (27% adult mortality). Stress-induced transcriptional changes showed remarkable variation, with starvation, heat, and plant defensive stress altering the expression of 3985, 510, and 12 genes, respectively. Molecular responses showed little overlap across all three stressors. However, a common transcriptional stress response was identified under heat and starvation, involved with up-regulation of glycogen biosynthesis and molecular chaperones and down-regulation of bacterial endosymbiont cellular and insect cuticular components. Stressor-specific responses indicated heat affected expression of heat shock proteins and cuticular components, whereas starvation altered a diverse set of genes involved in primary metabolism, oxidative reductive processes, nucleosome and histone assembly, and the regulation of DNA repair and replication. Exposure to host plant defenses elicited the weakest response, of which half of the genes were of unknown function. This study highlights the need for standardizing stress levels when comparing across stress types and provides a basis for understanding the role of general vs. stressor specific molecular responses in aphids

    Headstrong intervention for pediatric migraine headache: a randomized clinical trial

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    Background The purpose of this study was to evaluate the efficacy of a self-guided CD-ROM program (“Headstrong”) containing cognitive-behavioral self-management strategies versus an educational CD-ROM program for treating headaches, headache-related disability, and quality of life. Methods Participants were 35 children ages 7–12 years with migraine recruited from one university medical center and two children’s hospital headache clinics. Participants were randomly assigned to complete the Headstrong or educational control CD-ROM program over a 4-week period. Data on headache frequency, duration, and severity, migraine-related disability, and quality of life (QOL) were obtained at baseline, post-intervention, and 3-months post-intervention. Results At post-intervention, Headstrong resulted in lower severity (on a 10-point scale) than the control group by child report (5.06 ± 1.50 SD vs. 6.25 ± 1.92 SD, p = 0.03, ES = 0.7). At 3-months post-intervention, parents reported less migraine-related disability (on the PedMIDAS) in the Headstrong group compared to the control group (1.36 ± 2.06 SD vs. 5.18 ± 6.40 SD; p = 0.04, ES = 0.8). There were no other group differences at post treatment or at 3-months post-intervention. Conclusions When compared to an educational control, Headstrong resulted in lower pain severity at post-treatment and less migraine-related disability at 3-months post-intervention, by child and parent report respectively. Headache frequency and quality of life did not change more for Headstrong versus control. Additional research is needed on the Headstrong Program to increase its efficacy and to test it with a larger sample recruited from multiple centers simultaneously.The study reported in this paper was funded by a grant from the National Institutes of Health, (National Institute of Neurological Disorders and Stroke), R01-NS046641, Michael Rapoff, Principal Investigator

    The Lantern Vol. 72, No. 1, Fall 2004

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    • Jazz • Bifocal Brainfreeze • A Mug of Tea • Autumn Blend • Montana Skies • Madeleine Parenthesis • Ghosts Come Out at Night • Time • 144 Cromwell Road • Market East • Secret • Stream • What Might Have Been or What Never Was • Buried Mirth • Conversations With a Writer • Churning Through • Chum-Salmon Intentions • Cages • Lola Sang of Green Glass Landscapes • Peg\u27s Antiques • Life at 120 Decibelshttps://digitalcommons.ursinus.edu/lantern/1165/thumbnail.jp

    Capacity Building for a New Multicenter Network Within the ECHO IDeA States Pediatric Clinical Trials Network

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    Introduction: Research capacity building is a critical component of professional development for pediatrician scientists, yet this process has been elusive in the literature. The ECHO IDeA States Pediatric Clinical Trials Network (ISPCTN) seeks to implement pediatric trials across medically underserved and rural populations. A key component of achieving this objective is building pediatric research capacity, including enhancement of infrastructure and faculty development. This article presents findings from a site assessment inventory completed during the initial year of the ISPCTN. Methods: An assessment inventory was developed for surveying ISPCTN sites. The inventory captured site-level activities designed to increase clinical trial research capacity for pediatrician scientists and team members. The inventory findings were utilized by the ISPCTN Data Coordinating and Operations Center to construct training modules covering 3 broad domains: Faculty/coordinator development; Infrastructure; Trials/Research concept development. Results: Key lessons learned reveal substantial participation in the training modules, the importance of an inventory to guide the development of trainings, and recognizing local barriers to clinical trials research. Conclusions: Research networks that seek to implement successfully completed trials need to build capacity across and within the sites engaged. Our findings indicate that building research capacity is a multi-faceted endeavor, but likely necessary for sustainability of a unique network addressing high impact pediatric health problems. The ISPCTN emphasis on building and enhancing site capacity, including pediatrician scientists and team members, is critical to successful trial implementation/completion and the production of findings that enhance the lives of children and families
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