No description available.

No description available.

No description available.

Monoamine oxidase (MAO) is a mitochondrial membrane-bound enzyme that catalyzes the oxidative deamination of monoamines in a wide array of organisms. While the enzyme monoamine oxidase has been studied extensively in its role in moderating behavior in mammals, there is a paucity of research investigating this role in invertebrates, where the latter utilizes this enzyme in a major pathway to degrade monoamines. There is especially a dismal lack of information on how MAO influences activity in invertebrates, particularly in account of the circadian cycle. Previous studies revealed MAO degrades serotonin and norepinephrine in arachnids, but did not investigate other critically important compounds like octopamine. Larinioides cornutus is a species of orb-weaving spider that exhibits diel fluctuations in behavior, specifically levels of aggression. The monoamines octopamine and serotonin have been shown to influence aggressive behaviors in L. cornutus, thus this species was used to investigate if MAO is a potential site of regulation throughout the day. Not only did gene expression of MAO orthologs and MAO activity fluctuate at different times of day, but the enzymatic activity was substrate-specific producing a higher level of degradation of octopamine as compared to serotonin in vitro. This study further supports evidence that MAO has an active role in monoamine inactivation in invertebrates and provides a first look at how MAO ultimately may be regulating behavior in an invertebrate.

Circadian clocks are vital to the proper functioning of organisms’ internal processes and behavioral outputs and typically have endogenous periods that approximate (within 1-2 hours) the 24-hour solar day. Clocks that deviate significantly from about 24 hours are often associated with metabolic syndromes or other disease states. For instance, organisms with near-24-hour clocks have higher survivorship under 24-h light:dark (LD) cycles than with 22- or 26-hour cycles. Likewise, mutant organisms with 22-hour clocks survive better under 22-h cycles but fare poorly under 24- and 26-h cycles. In other words, organisms suffer if their circadian clocks do not “resonate” with environmental cycles. Organisms fail to synchronize (entrain) their activity with non-resonant LD cycles and this failure typically leads to a number of physiological disruptions. Interestingly, several spider species have endogenous circadian periods that deviate by several hours from the period of the Earth’s solar day. The object of the present study is to investigate whether the phenomenon of circadian resonance also pertains to these atypical spider circadian rhythms. We investigated three spider species, two of which have internal periods (τ) significantly different from 24 hours. Approximately 50 individuals of each species of spider (Frontinella communis: τ=29.05±0.62 hours; Metazygia wittfeldae: τ=22.74±0.24h; and Cyclosa turbinata: τ=18.54±0.28h) were placed into chambers with periods of 19 (9.5:9.5h L:D), 24 (12:12h L:D), or 29 hours (14.5:14.5h L:D). If resonance is pertinent for spiders, we would expect survivorship to decrease in non-resonant LD cycles. Instead, no spider species exhibited decreased longevity in non-resonant L:D cycles. These findings contradict all previous research into circadian resonance and suggest that spiders do not suffer the costs of extreme desynchronization. In a second experiment, 10-11 spiders from each species were placed into infrared activity monitors to determine if their locomotor activity could entrain to (synchronize with) the three different LD cycles. Individuals from all three spider species entrained to all LD period lengths, again in contrast with prior research in other species. These results indicate that spider circadian clocks have highly unusual limits of entrainment and suggest a remarkable level of plasticity in their release from the selective pressure to maintain an internal period of approximately 24 hours.

Spider silk is known for its extraordinary material properties, being both very strong and extensible. Even though the fibers outperform many synthetic and natural materials, it is impractical to collect industrial amounts of silk from spiders due to their cannibalistic and venomous nature; they cannot be farmed like the commercial silk worm Bombyx mori. Thus, scientists have turned to molecular and engineering techniques to replicate the spider's silk and spinning apparatus. In the current literature there is no detailed protocol on the production of consistent synthetic fibers. To accomplish this, the fibroins and natural spinning apparatus were taken apart and analyzed in order to develop a protocol that biomimics the spider's system. The laboratory procedure, using the natural process as an example, was simplified to: protein production, purification, concentration, fiber spinning, and lastly post spin draw. Large quantities of truncated MaSp I spidroin (spider fibroin) was purified from E. coli and successfully spun into fibers using customized spinning, spooling, and stretching apparatuses. The final fiber products displayed mechanical properties that were comparable to other reported synthetic fibers, but more importantly also displayed low experimental variability between samples. The protocol developed in this study can be further used to characterize other spidroins and silk proteins, and can be further advanced to produce even better fibers with enhanced properties.

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Twenty-first-century globalization has led to an extraordinary rise in international trade and transit. Consequentially, invertebrates, plants, and mammals are displaced more frequently, which has catalyzed a historic rise in biological invasions. The Joro Spider (Araneae: Trichonephila clavata) recently established from Asia in a landlocked region of southern Appalachia. Its range continues to expand; its cold tolerance is expected to favor northward invasion. As a large-bodied orbweaver that forms extensive webs and aggregations, the Joro spider is likely capable of inducing fundamental change to community structure via spatial competition. A valuable first step in estimating any invader’s economic or biological impact is to hypothesize regions susceptible to invasion using species distribution models. Recent work also shows that comparing global and regional distribution models yields insight into different stages of invasion. To examine potential spread and niche utilization differences in the Joro spider, one global and two regional models were developed. Maximum Entropy models were trained using open-source citizen science occurrence data and six bioclimatic variables at 2.5-arcminute resolution. An AUC-weighted ensemble model was used to produce each of the 3 global suitability projections. To compare invasive stage differences, projections were then translated to presence-absence maps using a 50% suitability threshold. The Asia-regional model predicts widespread suitability in eastern North America. However, the US-regional model reflects local adaptation to a climate niche that does not occur in the spider’s historic Asian range. Permutation feature importance shows the US-regional model was driven mainly by precipitation seasonality (64%) and annual oscillations in daily temperature range (29.1%). The Asia-regional model was instead driven by mean temperature of the driest quarter (34.9%), maximum temperature of the warmest month (23.6%), and precipitation of the warmest quarter (20.1%). The introduced Joro spider has invaded a North American niche that it is naïve to, but which co-occurs spatially with a niche akin to its historic Asian niche. If the Asia-regional climatic niche is indeed exploitable in North America, then conservative estimates show the bounds of range suitability should approach the 95th meridian and the 28th and 50th parallels. A total of 1,231,711 km2 within North America was predicted above 50% suitability. Altogether, these findings suggest niche versatility and plentiful suitable habitat favors successful North American invasion by the Joro spider.

Identity, who we are, is at the core of every human being, thus at the core of every character from every play. How the character identifies his self through gender and sexual identity will shape both physical and emotional choices that an actor will make through the rehearsal process. As an actor, it is absolutely imperative to resist the urge to pass judgment on the characters we portray. As more characters in modern drama are openly gay, there is an increasing urge for an actor to fall into campy stereotypes. Through a performance of the role of Molina in Manuel Puig's Kiss of the Spider Woman, this thesis will examine the blurring line of gender identity of the leading man in contemporary drama and explore the challenges of portraying a feminine man in a non-stereotypical way, remaining true to the identification of the character. A thorough historical analysis presents a look at the evolution of the homosexual throughout modern drama, from self-loathing party boys of the seventies to ordinary fathers, husbands, and sons in modern households. A structural analysis of Puig's text will aid in the choices made by the actor. Lastly, a complete character analysis will examine the psychological motivations behind Molina's actions as well as the changes in his gender and sexual identity throughout the piece. This thesis will culminate in a comprehensive development, rehearsal and performance journal, which will document and address challenges, discoveries, failures and victories during the production process.

A needlestick injury is defined by the Center for Disease Control (CDC) as a percutaneous injury due to accidental handling of a sharp. The CDC estimates that approximately 400,000 needlestick incidences occur each year in United States healthcare facilities, and reports from other developed countries, such as the United Kingdom and Spain, share similar frequencies. Further, the World Health Organization (WHO) estimates two million international healthcare workers are exposed annually to infectious disease as a consequence of a needlestick event, resulting in 37.6% and 39% of hepatitis B and hepatitis C cases, respectively. In the United States, federal and state legislation have greatly reduced incidence rates since the late 1980s, providing education, better protocols and effective post-exposure management. Additionally, the introduction of national surveillance databases led to stronger epidemiological support for the causation of needlestick injury and consequently, a stronger national awareness. In an effort to better protect healthcare workers, corporations such as DuPont and BD have further reduced needlestick incidences in the United States by designing products ranging from safety-engineered syringes to adhesive strips surrounded in strong synthetic materials such as Kevlar® and Lycra®. These devices are instrumental in minimizing the needlestick problem in both the clinic and in the operating room. As part of the current United States legislation, healthcare organizations are mandated to implement and utilize these safety-engineered syringes and needles. Despite the rise in protective equipment, national database surveillance and federal/state legislature, the incidence rate remains high as hundreds of thousands of injuries persist each year. We sought to find other solutions for better protecting healthcare workers through the implementation of golden orb weaver spider silk in personal protective equipment. This silk, gathered from the Nephila clavipes, is one of the strongest and toughest biomaterials in known existence. Its characteristically high energy absorption makes it an ideal material for reinforcing gloves and other protective equipment for healthcare workers. We believe that products made from this silk would serve as strong barriers against needlestick injury and bloodborne pathogen exposure. We are in the process of designing and fabricating such a glove and completed preliminary strength testing to ensure the superiority of our material. Tensile testing conducted at Tufts' Department of Biomedical Engineering suggests that our silk possesses the same mechanical profile as N. clavipes silk found in published literature. We plan on utilizing Fourier-transform infrared (DSC-FTIR) microspectroscopy to study the protein structure and possibly conducting enzyme degradation assays to assess the property changes under unique conditions. This information combined with our patented extraction and reinforcing methodology will provide the groundwork for partnering with industry leaders to make this product a reality and help eliminate the incidence of needlestick injury.