1,720,957 research outputs found
Investigation of the Functions of Insect Arginine Vasopressin-like Peptides
Get PDFCitation: Tokach, R. (2017). Investigation of the Functions of Insect Arginine Vasopressin-like Peptides . 1st Annual Undergraduate Research Experience in Entomology Symposium, November 16, 2016. Manhattam, KS.The neuropeptide arginine vasopressin (AVP) is a multifunctional signaling peptide that is highly conserved across eukaryotic animals. In mammals, it primarily acts as an anti-diuretic and a regulator of blood pressure. These traits among others merit the study of the arginine vasopressin-like (AVPL) hormone found in insects (Aikins et al., 2008). We investigated the bioactivity of AVPL in an assay measuring the recovery time after knockout in water, indicating hormonal activity for alert states in the red flour beetle Tribolium castaneum. We found that injections of an AVPL mimetic peptide (AVP1) prolonged the knockout time, implying that the AVPL causes longer suppression of the recovery from water shock
Adverse Health Impacts on Honey Bee (\u3cem\u3eApis mellifera\u3c/em\u3e L.) Colonies from a Contaminated Environment and Resources
Get PDFHoney bees (Apis mellifera L.) continue to experience high annual declines due to a combination of factors including pesticides. Due to increasing agricultural intensification has led to a reliance on systemic pesticide treated seed which can brought back to the colony in pollen and nectar. Treated seed is not subject to the same guidelines as pesticide applications reducing the regulations on the disposal of treated seed. In 2015, an ethanol plant in Mead, Nebraska began processing expired treated seed for ethanol production. Subsequently, the University of Nebraska-Lincoln Bee Lab started seeing 100% colony failure in apiaries surrounding the plant.
To examine the effects on colony function in this polluted environment compared to other landscapes, queenless colonies were established and allowed to requeen themselves after given resources from “deadout” or contaminated colonies from Mead, Nebraska or from a control site. Colonies given contaminated combs produced fewer overall queen cells and were less likely to successfully requeen themselves compared to those given control resources. These results indicate pesticide laden resources impact queen rearing capacity.
Exposure to pesticides can have sublethal impacts on individual worker aging, queen behavior, and gene expression. Using apiary locations or sites as treatments, small observation hives with age-marked worker bees were set up to monitor bee behavior at the contaminated site and a control site. Results showed significant differences in the onset of critical hive tasks and worker bees at the contaminated site accelerated their aging process resulting in lower brood care and pollen processing by young bees and more precocious foraging which leads to shorter worker longevity. Queen locomotion was largely unaffected, but egg-laying rate was reduced for queens in the contaminated site. These results indicate environments contaminated with widespread systemic pesticide pollution can have differential, subtle, and cascading effects that disrupt critical behaviors and colony functions, reduce overall productivity, and increase risk for colony failure.
Advisors: Autumn Smart and Judy Wu-Smar
Developing sustainable parasitic mite management strategies for beekeepers
No full textThe Western honey bee (Apis mellifera) is an important pollinator worldwide, contributing billions annually to the global economy through pollination services. Honey bees face a variety of different stressors that can cause colony losses. Colony losses have increased in recent decades and one of the leading causes of them in the Northern hemisphere is the parasitic Varroa destructor mite. The mite damages honey bee colonies by feeding on adult and developing honey bees while also vectoring various viruses. In the United States, this parasite is primarily controlled by synthetic acaricides; however, continued reliance on these synthetic acaricides, most recently amitraz, has led to increases in resistant V. destructor mites, thereby limiting potential treatment options. Compounding the issue of invasive parasitic mites for beekeepers is the appearance of a new threat, Tropilaelaps mercedesae. While still primarily limited to its native range in Southeastern Asia and Australasia, T. mercedesae has recently been confirmed in parts of Western Asia and Eastern Europe, regions previously thought to be unsuitable for the mite. Tropilaelaps mercedesae feeds on developing honey bees, like V. destructor, but not adults and can cause colony failures. In this dissertation, I conducted experiments exploring sustainable beekeeping practices while looking to fill knowledge gaps relating to V. destructor and T. mercedesae. I conducted two experiments that evaluated the effectiveness of fall V. destructor treatments in the Southeastern U.S., a critical time to manage V. destructor infestations. From these two experiments, I identified viable alternative treatments to amitraz and demonstrated that continuous treatment with this synthetic chemical increases the amitraz resistance allele frequency for V. destructor, albeit briefly. For T. mercedesae, I contributed to mapping the current global range of the mite and documented a potential dispersal method for the mite on adult honey bees exiting the colony. This suggests that the mite could disperse through honey bee drifting or robbing behaviors. Lastly, I showed that T. mercedesae could be controlled in, although not eradicated from, colonies using a combination of a cultural and chemical control method. Overall, my work provides important information regarding sustainable mite management strategies to help beekeepers understand and control both V. destructor and T. mercedesae. Ultimately, my findings will help to limit future colony losses
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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