Schedule of Events

The variably expressed extra eye (ee) mutation in Drosophila melanogaster produces head deformities, which in severe expressions result in ectopic, supernumerary compound eyes. It also possesses other exotic features: ee is both incompletely penetrant and conditionally dominant. Marcey (personal communication) has developed an epigenetic model to explain the genetic behavior of ee. The proposed model predicts that new, inducible mutant phenotypes may be revealed in crosses between ee lines and flies from natural populations that harbor P-elements at various genomic locations. Such novel mutants are predicted to be incompletely penetrant and variably expressed, caused by epigenetic silencing. In one such cross, a new mutation, Crybaby (Cby), was recovered. Cby exhibits the properties expected of an epigenetically-triggered mutation, and its primary phenotype, a disruption in ventral eye development, resembles that of known mutations of the Lobe locus on the second chromosome. Complementation tests between Cby and various Lobe alleles were conducted to determine if Cby represents a new Lobe allele. Cby females were mated to males from eight different Lobe lines, and the F1 progeny were screened to determine if they demonstrated a more severe phenotype than either Lobe or Crybaby. In most cases, the F1 progeny exhibited a more severe phenotype than either Cby or Lobe, suggesting that Cby is an allele of Lobe. Cby females were also bred with male Canton-S (wild-type) flies as a control. The appearance of Cby phenotypes in the F1 of this control cross establishes Cby as a dominant mutation, as are known Lobe alleles.

Most commonly identified in bacteria, RNA thermometers (or thermoswitches), a means of translational regulation, are sequences of nucleotides embedded in mRNA within the Shine-Dalgarno (SD) region or RBS (Ribosome Binding Site). Generally, thermoswitches exhibit imperfect self-complementarity at lower temperatures, creating a secondary structure within the mRNA transcript which prohibits ribosome binding. At higher temperatures, thermoswitches selectively promote translation by linearizing, thus permitting ribosome binding. There exist a few known types of RNATs, the most common being repression of heat shock gene expression (ROSE) thermometers. In 2007, a novel type of thermoswitch (4U) was proposed upon the discovery of a thermoswitch in Salmonella containing four sequential uracils. Putative 4U thermoswitches from Klebsiella pneumoniae and E. coli were identified using a program called RNArobo, which searches genomes according to predicted secondary structure. Each of these oligos was cloned into reporter plasmids, containing GFP and RFP, in chemically competent E. coli. Putative thermometers were placed within the SD region of RFP in the plasmids, and the E. coli were tested for fluorescence after growing under variable temperature conditions, to elucidate the thermoregulatory properties of the oligos. The fluroescence of RFP was compared with the fluroescence of the GFP control.

Freshwater coastal river corridors affect global biochemical processes, most notably carbon and nitrogen cycling. Sea level rise is expected to move tidal ends of coastal river corridors into freshwater regions, exposing freshwater habitats to high salinity levels. Therefore, establishing a baseline categorization of composition and function is essential. This study evaluated the composition, structure, and function of microbial communities in river sediments at the freshwater end of coastal river corridors. Field sediments were collected from six sites spanning coastal United States, followed by microbial DNA extraction and metagenome sequencing prior to the start of this research project. Sequence analysis was conducted using an open access software and data science platform hosted by the US Department of Energy’s Systems Biology Knowledgebase (KBase). Sequences were quality filtered, assigned taxonomic classification, binned and assembled, assigned functional classifications, and evaluated for metagenome-assembled genomes. The taxonomic classification of all samples resulted in the identification of novel bacteria, with the Eel River sample resulting in the highest percentage of reads classified at the genus level (56%) and the Mad River sample resulting in 0% of reads classified at the genus level. The microbes demonstrated functional characteristics including antibiotic resistance, methane metabolism, metal reduction and the expected metabolic abilities for their environment. The microbes also demonstrated possible adaptations to salt stress. Ordinations revealed latitude and distance of the sites from the ocean to be significantly driving sample differences, with a broad group of reductases identified as the most divergent functional group among samples. 

The variably expressed extra eye (ee) mutation in Drosophila melanogaster produces head deformities, which in severe expressions result in ectopic, supernumerary compound eyes. In addition to variable expression, the mutation possesses several other exotic features: ee is both incompletely penetrant and conditionally dominant. Marcey (personal-communication) has developed an epigenetic-model to explain the exotic genetic behavior of ee. The model posits RNAi-mediated transcriptional suppression via epigenetic heterochromatization of a gene that encodes a repressor of activated STAT, a signaling molecule implicated in embryonic eye field establishment. This project is testing the hypothesis that selection for increased penetrance of ee will yield a line, enriched for enhancers of the mutation, that displays high penetrance values and that can be used to study the mutation more effectively. This selection is being accomplished by a series of positive selections over a number of generations. Beginning at generation 1 with a line of flies displaying approximately 45% penetrance, flies have been scored for the presence or absence of ee mutant phenotypes, the penetrances recorded, and virgins that bear the mutant phenotype mated to begin the next generation. Thus far, penetrances have increased from 45% in generation 1 to 63% in generation 3. Penetrance data from subsequent generations will be presented. Obtaining an ee line with very high penetrance of the mutation will aid a variety of experiments aimed at elucidating the genetic basis of extra eye. Incomplete penetrance characterizes many human disease genes and the study of this phenomenon in a model organism may therefore bear importance for biomedical studies.

A screen for novel sources of cryptic epigenetic variation (CEGV) in Drosophila melanogaster is being conducted in the Marcey lab. CEGV may be a component in the spectrum of natural variation upon which natural selection can act. The screen is based on a model for the production of head defects by the extra eye mutation (ee), which is incompletely penetrant, variably expressed, and conditionally dominant. The model (Marcey, personal communication) posits P transposable element-induced, RNAi-mediated heterochromatization of a gene that encodes a repressor of STAT, a molecule implicated in embryonic eye field establishment. We have predicted that new mutant phenotypes may be uncovered in crosses between ee lines and flies derived from wild, natural populations known to contain P-elements. Such novel mutants might represent RNAi-induced heterochromatization of genes near P-elements. Indeed, several new variants that display characteristics of inducible, epigenetic mutations have been recovered and are being subjected to analysis. Here I report a rescreen of the lines that yielded such variants in order to determine the repeatability of previous work and to determine if the variants represent genuine epigenetic inductions of mutations by components of the ee line or represent new insertions of P-elements into target genes. The following variants have reappeared in crosses of ee to particular wild strains: crybaby, beady, and Scythe. These results indicate that these heritable variations are inducible by genetic components in the ee strain and may be concrete examples of cryptic epigenetic variation in nature. These results hold significance for the fields of both molecular and evolutionary biology. 

Starting new ventures is always a challenge. Based on extant research, frequently identified barriers to entrepreneurship are a lack of access to education, absence of funds, limited understanding of entrepreneurial finance, cultural factors, and gender disparities, among others. Within the literature, it is commonly acknowledged that these lack of resources and support are more likely to hinder traditionally underrepresented cohorts when seeking entrepreneurial opportunities. Thus, the consequence becomes an increased likelihood of failure for minority entrepreneurs. My research focuses on a specific subset of minorities, the Latinx population, and examines the setbacks they face as entrepreneurs in the state of California. The purpose of my research has been to investigate, among others, differences in access to resources and support between Latinx entrepreneurs and non-Latinx entrepreneurs. An additional objective has been to identify key differences and similarities between male and female Latinx entrepreneurs concerning their pathway to entrepreneurship. My investigation analyzes existing literature followed by a qualitative inquiry into key factors that influence entrepreneurship for Latinx founders. Individuals involved in my research have diverse backgrounds in entrepreneurship, ranging from investors to accelerators to community leaders. The panel includes both Latinx and non-Latinx entrepreneurs. The qualitative data collected from the participants via a multi-wave Delphi study confirm existing results and provide new perspectives that have not been identified in previous research, and they offer insights for future research hypotheses.

Over the past decade, the interest in marine microfiber research has grown substantially, along with the scientific understanding of its impact on various ecosystems. Microfibers are less than 5 mm in length and are a type of microplastic that is shed from synthetic fabrics made from materials (i.e., nylon, polyester, acrylic) that frequently pollute various waterways and their inhabitants. This study examines microfibers in the guts and on the gills of the Pacific Squid, Loligo opalescens; this animal is a tertiary consumer and a keystone species for many marine species found along the coast of Southern California. The number of microfibers was quantified under a light microscope for each subject after the dissection and vacuum filtration of the gut and/or gill tissue. On average, the results indicate that the gut tissue contained three times the number of microfibers found on the gills. These findings show that the Pacific Squid, like many other marine animals, are acquiring microfibers from their ecosystem, especially when compared to another cephalopod like Nouryi’s argonaut (Argonauta nouryi). As in other marine organisms, an animal can become contaminated with microfibers in two ways: either from the ambient environment or through their trophic systems. The squid’s role as a keystone species and the theory of microfiber trophic transfer may also indicate that other members of its ecosystem may be enduring a similar impact from microfiber pollution.

Research shows the existence of  large-scale, stable magnetic fields in ~10% of hot, massive (>8x the mass of the Sun) stars.  Magnetospheres have  material trapped and have a stable structure that appears as emission in a star’s spectrum, and allows for calculation of the amount and location of material, as well as the star’s rotation period. The material trapped around the star is easily seen in the infrared (IR), where the star is less bright. Raw spectroscopy of one centrifugal magnetosphere (CM) star, HD 23478, was taken with the IR spectrometer GNIRS on the 8-m Gemini Telescope (Mauna Kea Observatory, HI) over nine separate nights. That data includes flats, arcs, and target and telluric spectra. Using these data products, the target and telluric star data were reduced using an astronomical software system, IRAF, with GNIRS-specific reduction routines to extract clean spectra for each night. Atmospheric effects (due to water vapor) are a significant issue in the IR, and appear as smeared out regions or sharp absorption features, contaminating the data set. A program, XTELLCOR, was used to remove this absorption from the clean spectra, so a full analysis can be performed in the future. Only a few CM stars have been studied with IR spectroscopy, and this is the first study to pair a large data set of both IR and optical spectroscopy, giving researchers a broader image of the effects of the magnetic field on the star and its surroundings.

The objective of this research is to determine the quantity of microfibers (MF) within Engraulis mordax, Sardina pilchardus and Leuresthes tenuis.The species organs (digestive tract and gills) were extracted. The extracted tissues were measured and ground into a paste, which was then suspended in a brine solution. The solutions were then filtered through a vacuum pump, and the results were analyzed using light microscopy. When comparing the digestive tract and gills of E. mordax  there were significantly more microfibers found in the digestive tract than the gills (t=0.0009, df=99, p≤0.05). When comparing the digestive tract and gills of S. pilchardus and L. tenuis there was no significant difference found between the two tissue (t=0.18353347, df=99, p≥0.05) (t=0.13369255, df=99, p≥0.05). E. mordax small and large gills were compared, there was no significant difference found between the two gills sizes (t=0.46, df=99, p≥0.05). L. tenuis small and large digestive tract were compared, no significant differences were found between the two digestive tract sizes (t=0.40, df=99, p≥0.05). The study demonstrated that (1) all three species contained more microfibers in their digestive tract than their gills, (2) more microfibers were found in the gills of the sardines compared to the anchovies (3) and the grunion contained the least amount of microfibers in their digestive tract. 

In 2012, the U.S. government passed the Stop Trading on Congressional Knowledge Act or STOCK Act. This was due to growing concerns that the members of Congress could make stock trading decisions based on information from their respective committees or other laws being passed. Congress has 45 days to publicly disclose trades in their name, their spouse, and dependents or face punishment before a Senate committee. Using this publicly available knowledge, the data can be collected. From the user interface, the user can select various filters to limit the data based on minimum amount, transaction type (sale or purchase), and starting year. The program will then display relevant information, such as the most common stock and total transaction amount. A day trader, i.e. someone who trades stock on a small level, might use this information in addition to other resources to make informed decisions about the future of a stock.

A microfiber is a microscopic strand of plastic measuring under 5 mm long. Clothing made of synthetic fabrics such as polyester, nylon, and spandex are a main source of microfiber pollution. Thousands of plastic strands fall off our clothing during each washing machine cycle. The fibers make their way to the ocean where they can be ingested by living organisms, like fish. The aim of the present study is to investigate and quantify the number of microfibers found in the digestive tract compared to the gills of the Anchovy fish, Engraulis mordax. In comparing the number of microfibers from the digestive tract and gills, it was expected there would be more fibers in the digestive system. To test this hypothesis, the gills and digestive tract were removed and mashed up in a mortar and pestle. Both mashed organs were separately placed into a saltwater solution and allowed to sit for 24 hours. The contents of each beaker were filtered using a vacuum pump and examined under a microscope. The fibers were counted and sorted by color. Results determined that in terms of quantity, more microfibers were found in the digestive tract compared to the gills. After conducting a t-test it was found that the results were statistically significant with a  p-value of 0.00093 (p < 0.05). The quantity of microfibers found in each fish shows the extreme pollution of the ocean these fibers have caused, which may be damaging to the fish as well as their ecosystem.

 
On a daily basis we navigate from one point to another without much difficulty. Even in a virtual setting like a game when provided with certain constraints ( difficult terrains, rivers, walls, etc ), we can navigate very efficiently from point A to B. However, for a computer traversing a given landscape, it requires specific directions to effectively do the same task which a human finds miniscule. In my research, I have worked and implemented the various algorithms that a computer uses to traverse a difficult terrain, or a maze in this case. A maze is an intricate, usually confusing network of interconnecting pathways. We can make a computer traverse the maze by either brute force or by making intelligent decisions. In the research, I used maze generating algorithm ( Depth First search) to first build the mazes and non-optimal path traversal algorithms (Depth First search and Breadth First search) and optimal/ Heuristic path traversal algorithms (Dijktra’s search and A* or Best First Search) to traverse the mazes.