16812 research outputs found
Sort by
Uncovering a Role for PAM-1 in Spindle Dynamics in the One-Cell C. elegans Embryo
No full textTransparent nematodes like Caenorhabditis elegans (C. elegans) are useful for studying early embryonic processes like mitosis and meiosis. For cells to divide, they must go through the process of mitosis properly. The separation of chromosomes is achieved by the spindles in mitosis, and the spindles are organized by the centrosomes. When mitosis goes wrong, problems like cancer may arise. In C. elegans, the pam-1 gene encodes for a puromycin sensitive aminopeptidase (PAM-1) that belongs to the M1 aminopeptidase family. When pam-1 is mutant in C. elegans, there is a higher occurrence of symmetrical division during mitosis, and the centrosomes move prematurely. PAM-1 is required to prevent premature centrosome movements and to properly attach the chromosomes to the mitotic spindle. Additionally, the absence of PAM-1 triggers the spindle assembly checkpoint. The wee-1.3(lz5) suppressor has been known to rescue some of the defects observed in pam-1 mutant C. elegans, such as improper cell division and low hatch rate. Proteins like β-tubulin, SPD-2, and SPD-5 are important for the spindle structures in C. elegans. Based on previous findings specific to the centrosomes of mutant embryos, a cell cycle regulator, CDK-1, is suspected to be important for centrosome regulation. Through the marking of these proteins with GFP and RFP, antibody staining, and the creation of a new strain, the effect of pam-1, CDK-1, and wee-1.3(lz5) on the embryos of C. elegans during the first mitosis was studied primarily using confocal microscopy. So far, it has been seen that pam-1 mutant embryos took longer than wildtype embryos to orient the spindle and to begin cytokinesis, and the mutant embryos were more likely to experience defects with the tubulin structures. It has also been seen that pam-1 mutant embryos had larger centrosomes than wildtype early in the cell cycle, and SPD-2::GFP and SPD-5::RFP intensity levels sometimes differed depending on the timepoint in the cell cycle. Overall, this research aims to improve the understanding of the mitotic spindles and centrosomes in pam-1 mutant embryos of C. elegans
Protein Interactions Between PAM-1 and Cell Cycle Proteins in C. elegans
No full textCaenorhabditis elegans are transparent nematodes used as model organisms for genetics research as their simple organ systems allow us to make and observe the effect of genetic mutations within the reproductive system to better understand fertility. The puromycin sensitive aminopeptidase PAM-1 is needed to regulate oocyte maturation and oocyte to embryo transition in C. elegans. In wildtype C. elegans a maturation promoting factor (MPF) regulates oocyte maturation. The MPF is made up of a cyclin B subunit and a protein kinase catalytic CDK-1 subunit. MPF is activated by CDC-25.1, a phosphatase, and is made inactive by WEE-1.3, a kinase. When MPF is active the oocyte matures to be fertilized, and when MPF is inactive oocytes are unable to mature. When wee-1.3 expression is knocked down in wildtype C. elegans, MPF is overactive, and oocyte maturation proceeds too quickly. However, when wee-1.3 expression is knocked down in pam-1 mutants, oocyte maturation is promoted normally, indicating that pam-1 mutations partially protect C. elegans from defects in oocyte maturation. WEE-1.3 is one of many proteins involved in maturation and oocyte to embryo transition. My research looks to address if other cell cycle proteins involved with the MPF interact with pam-1 mutants similarly to WEE-1.3, protecting C. elegans from defects in maturation and oocyte to embryo transition. To do so, I will use DIC and confocal microscopy to observe oocyte maturation rates of wildtype and pam-1 mutant C. elegans when the expression of these proteins is knocked down. If interactions are present this would give us a better understanding of the specific role each protein plays in the maturation and development of C. elegans
The Nascent Polypeptide-Associated Complex Modulates Response to Endoplasmic Reticulum Stress in Saccharomyces cerevisiae
No full textThe process of protein synthesis is easily influenced by fluctuations in an organism’s internal and external environments. When proteostasis is disrupted, proteins may achieve unintended 3-dimensional conformations, presenting an avenue for inappropriate interactions and aggregation. Protein aggregation is commonly associated with various mammalian neurodegenerative diseases, including Creutzfeldt-Jakob, Parkinson’s, and Huntington’s diseases. Prions and prion-like proteins, including PrPsc, ⍺-synuclein, and huntingtin — respectively associated with the aforementioned diseases — are unique in their ability to transmit their misfolded conformation onto other correctly folded proteins. To prevent this transmission and the subsequent consequences, organisms have evolved quality control systems to oversee proteostasis. Among these mechanisms are molecular chaperones, a group of proteins that survey and facilitate protein folding and/or localization. Some chaperones are known to associate with the protein synthesis machinery to guide the folding and localization of nascent polypeptides prior to the termination of their synthesis. Two chaperone complexes, the Ribosome-Associated Complex (RAC) and Nascent Polypeptide-Associated Complex (NAC) are conserved across eukaryotes. Our lab has previously shown that the human RAC can rescue deficiencies associated with loss of endogenous RAC in Saccharomyces cerevisiae, but the capabilities of the human NAC to replace the yeast NAC have gone largely uncharacterized. Thus, we have generated a comprehensive set of yeast strains to characterize the functions of the human NAC subunits alone and in concert with one another, specifically in the contexts of endoplasmic reticulum stress response and prion formation
Optimization of the Heat Treatment Protocol and Metrology of Ge-As-Pb-Se Glass
No full textChalcogenide glasses (ChGs) are used for their optical properties in the infrared spectrum. The optimization of crystal phases in Ge-As-Pb-Se (GAP-Se) glass can be done through heat treatments. Using differential scanning calorimetry (DSC) and X-ray diffraction (XRD), particular nucleation and growth temperatures for crystal growth are identified. This is done by analyzing a theoretical 0°C/min heating rate in the thermal analysis to identify the temperatures. By optimizing the high-index PbSe phase, we can spatially control the refractive index, making a gradient refractive index (GRIN) glass using laser writing
Exploring the Regulatory Landscape of Foraging in Southeastern Pennsylvanian Parks: Thinking About Implications for Addressing Food Insecurity
No full textFood insecurity is a growing concern specifically in urban areas, leaving individuals struggling to seek out alternative methods of obtaining food. Previous research has shown that there is an abundance of edible materials with nutritious components under our noses: in parks and green spaces. However, park regulations and manager perspectives of foraging practices present a likely/possible/potential barrier to obtaining edible species materials. This study seeks to provide a more in-depth understanding of the accessibility of edible species materials to food insecure individuals based on analysis of park rules and manager perspectives of foraging, including how accepting managers seem to be of foraging in the park(s) they oversee. After analyzing the accessibility of edible species through proximity, park rules, and manager perspectives by examining a survey sent out to managers and a map created in ArcGIS Pro, the major findings of this study reveal that access to food in parks, as assessed by proximity and legal/sanctioned harvest, is limited based on park ordinances and manager perspectives about foraging. The second, bolstering finding was that managers have concerns about site and plant harm and a lack of understanding for the extent to which foraging can provide an outlet to offset the impacts of food insecurity. The findings of this study highlight the potentially limiting (intentional or not) park rules on connecting people to food which require a shift in managers’ perspectives and a reframing of park regulations in order for foraging to become a more effective way to offset food insecurity
Variation in Bike Infrastructure Across American Cities
Get PDFWhat explains why some cities have developed extensive bike infrastructure while others have not? Bicycling is a low-cost transportation option and is becoming increasingly popular in the 21st century. While there is extensive literature on bike infrastructure in the United States and its relationship with gentrification and advocacy, there is not significant, explicit dedication and focus toward explaining why variation exists across American cities. In my research design, I examine several factors that could point toward an explanation. The results show that policy diffusion is the most significant factor for bike infrastructure adoption, lending credence to prior literature on the subject
Are All Sports Betting Losses Created Equal?
Get PDFThis study investigates how the cash out feature in sports betting influences bettor reaction to loss and short-term bet likelihood. The cash out changes the mechanics of a sports betting loss outcome in several ways. By getting some of the bet’s stake back through a cash out loss, the transaction mimics a larger loss-smaller gain joint outcome as opposed to a single loss at the time of the bet’s placement. The cash out also introduces the opportunity for regret or positive counterfactuals depending on the cash outs “correctness”. Using survey data from college students responding to hypothetical betting scenarios, it was found that bettors react more positively to “correct” cash outs, where the bet would have lost had they not cashed out, compared to simple bet losses of the same net amount. Interestingly, “incorrect” cash outs, where the bet would have won had they not cashed out, significantly increased short-term betting likelihood when compared to simple bet losses of the same net amount. These findings suggest cash outs may provide sportsbooks with additional benefits beyond what was previously thought, by influencing bettor sentiment and behavior in ways that may encourage continued engagement. Implications for consumer protection and potential regulatory interventions are discussed
The Secret Life of NIM: How Regulation Affects Bank Balance Sheets and Consumer Consequences
Get PDFAfter the Great Recession of 2008, the Dodd-Frank Wall Street Reform and Consumer Protection Act was passed by the Obama Administration in 2010 with hopes to protect citizens against economic downturn spurred by poor banking behaviors. This act of federal financial oversight was unprecedented, and its magnitude and level of strictness caused banks to see an increase in costs, such as increases in personnel numbers and non-interest earning reserve requirements. This research analyzes how banks, specifically community banks, paid for these increased costs by focusing on the net interest margin (NIM). The NIM is a prominent profitability ratio for banking institutions, and it measures the difference between a bank’s net interest income and its net interest expenses as a percentage of average assets. The results of this analysis show that as the regulatory environment tightens, banks tend to widen their NIM, likely to fund higher compliance costs while maintaining stable profit levels. This research also analyzes what this increase in NIM means for consumers; specifically, a widening of the NIM means that consumers are likely paying higher prices to borrow money or are receiving lower payments for lending money. Ultimately, it is concluded that regulation does affect banks’ NIMs, and consumers feel the spillover effects of strict federal regulation
The Grizzly, May 1, 2025
Get PDFThe Grizzly Takes On CoSA! • Senior Alumni Award Honorees • A Goodbye • And a Hello! • Repair Cafe • Hillel: A Home for Many • Ursinus College 2024-25 Crossword • Sports Stars Shine at URSPYS • Ursinus Softball Battles Through Ups and Downshttps://digitalcommons.ursinus.edu/grizzlynews/2054/thumbnail.jp
Cape Sounion
No full textI visited the Temple to Poseidon on Cape Sounion when I visited Greece over spring break.
Submitted as part of the Spring 2025 Study Abroad Photo Contest.https://digitalcommons.ursinus.edu/study_abroad_photos/1041/thumbnail.jp