The relationship between membrane proteins and functional cells is not yet fully understood, in large part due to the lack of knowledge about the structure and dynamics of membrane proteins. Because of the recent advancement of biotechnology, the visualization of membrane protein dynamics and energetics has progressed significantly, in large part due to nanodisc technology. Nanodiscs allow for the formation of a native environment for membrane proteins, which is essential to learning more about their structure. Atomic force microscopy (AFM) allows for the precise imaging of membrane proteins as well as the utilization of single-molecule force spectroscopy (SMFS). When completing single-molecule experimentation, it is crucial that the covalent attachment of the probe is completed, because it allows for hundreds of force-extension traces from a single molecule to be completed. Another essential aspect of site-specific attachment is passivation is necessary for unwanted interactions between the AFM cantilever tip and a single probe molecule. The focus of my senior thesis is to work with the optimization of nanodisc technology formation embedded with the membrane protein bacteriorhodopsin (bR). The bR was inserted into nanodiscs in both wild-type and c-terminal cysteine transformed to allow for site-specific labeling. The formation of nanodiscs with c-terminal cysteine bR was then labeled with DBCO-Maleimide tagging to allow for covalent connections when utilizing AFM SMFS. Altogether, this work shows a methodology for the optimization of nanodisc formation containing c-terminal cysteine bR membrane protein and warrants further investigation utilizing AFM imaging and SMFS with varying conditions of site-specific spectroscopy to target the development of protein-membrane dynamics. To see the complete thesis, please visit https://scholar.colorado.edu/concern/undergraduate_honors_theses/xg94hq786.
{"title":"Self-Assembling Nanodiscs Technology Exploration with Single-Molecule Biophysics Experimentation using Site-Specific Attachment Atomic Force Microscopy","authors":"Stephanie Elizabeth Talder","doi":"10.33011/cuhj20231627","DOIUrl":"https://doi.org/10.33011/cuhj20231627","url":null,"abstract":"The relationship between membrane proteins and functional cells is not yet fully understood, in large part due to the lack of knowledge about the structure and dynamics of membrane proteins. Because of the recent advancement of biotechnology, the visualization of membrane protein dynamics and energetics has progressed significantly, in large part due to nanodisc technology. Nanodiscs allow for the formation of a native environment for membrane proteins, which is essential to learning more about their structure. Atomic force microscopy (AFM) allows for the precise imaging of membrane proteins as well as the utilization of single-molecule force spectroscopy (SMFS). When completing single-molecule experimentation, it is crucial that the covalent attachment of the probe is completed, because it allows for hundreds of force-extension traces from a single molecule to be completed. Another essential aspect of site-specific attachment is passivation is necessary for unwanted interactions between the AFM cantilever tip and a single probe molecule. The focus of my senior thesis is to work with the optimization of nanodisc technology formation embedded with the membrane protein bacteriorhodopsin (bR). The bR was inserted into nanodiscs in both wild-type and c-terminal cysteine transformed to allow for site-specific labeling. The formation of nanodiscs with c-terminal cysteine bR was then labeled with DBCO-Maleimide tagging to allow for covalent connections when utilizing AFM SMFS. Altogether, this work shows a methodology for the optimization of nanodisc formation containing c-terminal cysteine bR membrane protein and warrants further investigation utilizing AFM imaging and SMFS with varying conditions of site-specific spectroscopy to target the development of protein-membrane dynamics. \u0000To see the complete thesis, please visit https://scholar.colorado.edu/concern/undergraduate_honors_theses/xg94hq786.","PeriodicalId":126611,"journal":{"name":"University of Colorado Honors Journal","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133603481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Prairie Switch, currently known as El Campo, is located in the coastal plains of Texas. The Prairie Switch was a railroad camp that served as a switching point on the Houston-Victoria Railroad and a shipping point on the New York, Texas, and Mexican Railroad. Ranching and Railroads were the primary industry during the 1880s; the small camp annually shipped an abundance of cattle and crops such as cotton, hay, and corn. My ancestors migrated to the Prairie Switch from Mexico, seeking a better life and opportunities for work. After settlement, ranching, railroads, and church was what daily life consisted of as my family quickly grew to occupy the town. I relive my grandma’s past as she describes her endeavors growing up in the Prairie Switch; her fond memories of picking cotton with her siblings and cousins, and Sunday rituals of god, family, and potlucks. As time continued, my family changed and evolved just as the town did. A greater distance has been created between generations, one that I now experience. I have no ties to the migration of countries or the great Vaqueros of Texas. I live in liminality, unattached and unknowing to my past, but perhaps liminality is my history.
{"title":"Prairie Switch","authors":"Gabrielle G. Gonzales","doi":"10.33011/cuhj20232011","DOIUrl":"https://doi.org/10.33011/cuhj20232011","url":null,"abstract":"The Prairie Switch, currently known as El Campo, is located in the coastal plains of Texas. The Prairie Switch was a railroad camp that served as a switching point on the Houston-Victoria Railroad and a shipping point on the New York, Texas, and Mexican Railroad. Ranching and Railroads were the primary industry during the 1880s; the small camp annually shipped an abundance of cattle and crops such as cotton, hay, and corn. \u0000My ancestors migrated to the Prairie Switch from Mexico, seeking a better life and opportunities for work. After settlement, ranching, railroads, and church was what daily life consisted of as my family quickly grew to occupy the town. I relive my grandma’s past as she describes her endeavors growing up in the Prairie Switch; her fond memories of picking cotton with her siblings and cousins, and Sunday rituals of god, family, and potlucks. As time continued, my family changed and evolved just as the town did. A greater distance has been created between generations, one that I now experience. I have no ties to the migration of countries or the great Vaqueros of Texas. I live in liminality, unattached and unknowing to my past, but perhaps liminality is my history. ","PeriodicalId":126611,"journal":{"name":"University of Colorado Honors Journal","volume":"233 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115565757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Preschool expulsions are increasingly studied in terms of their potential negative outcomes on students. This study examined the relationship between preschool teachers’ workplace experiences and their use of disciplinary actions, including expulsions. It sought to understand the sociological mechanisms and supports of the teacher workplace, and the psychological influences on teacher decision making and perceptions that contribute to disciplinary actions. Whereas prior research has illustrated the harmful consequences of expulsions and how teacher experiences may be related to expulsions, this study aimed to increase knowledge about the influence of workplace factors on discipline, primarily in private preschools, which are relatively under-studied. Preschool teachers from the Denver area participated in semi-structured interviews to gain understanding about their stress, perceptions of challenging behaviors, perceived institutional support, and institutional norms regarding discipline. Using open-coding methods, the qualitative data was analyzed and several key themes were established. The findings indicate that preschool teachers generally lack adequate support, especially in regard to challenging behavior management, and that this creates a great deal of stress. Additionally, although preschool expulsions may be declining, they are being replaced by other exclusionary disciplines, including “soft” expulsions to mitigate teacher stress in the absence of knowledge on how to actively improve challenging behaviors. These findings have important implications as they show there needs to be easily accessible training opportunities concentrated on how to handle challenging behaviors and more opportunities for workplace collaboration to better support teachers in dealing with these behaviors, and thus mitigating the negative consequences of exclusionary discipline. To see the complete thesis, please visit https://scholar.colorado.edu/concern/undergraduate_honors_theses/q811kk96s.
{"title":"Between a Rock and a Hard Place","authors":"A. Brogle","doi":"10.33011/cuhj20231607","DOIUrl":"https://doi.org/10.33011/cuhj20231607","url":null,"abstract":"Preschool expulsions are increasingly studied in terms of their potential negative outcomes on students. This study examined the relationship between preschool teachers’ workplace experiences and their use of disciplinary actions, including expulsions. It sought to understand the sociological mechanisms and supports of the teacher workplace, and the psychological influences on teacher decision making and perceptions that contribute to disciplinary actions. Whereas prior research has illustrated the harmful consequences of expulsions and how teacher experiences may be related to expulsions, this study aimed to increase knowledge about the influence of workplace factors on discipline, primarily in private preschools, which are relatively under-studied. Preschool teachers from the Denver area participated in semi-structured interviews to gain understanding about their stress, perceptions of challenging behaviors, perceived institutional support, and institutional norms regarding discipline. Using open-coding methods, the qualitative data was analyzed and several key themes were established. The findings indicate that preschool teachers generally lack adequate support, especially in regard to challenging behavior management, and that this creates a great deal of stress. Additionally, although preschool expulsions may be declining, they are being replaced by other exclusionary disciplines, including “soft” expulsions to mitigate teacher stress in the absence of knowledge on how to actively improve challenging behaviors. These findings have important implications as they show there needs to be easily accessible training opportunities concentrated on how to handle challenging behaviors and more opportunities for workplace collaboration to better support teachers in dealing with these behaviors, and thus mitigating the negative consequences of exclusionary discipline.\u0000To see the complete thesis, please visit https://scholar.colorado.edu/concern/undergraduate_honors_theses/q811kk96s.","PeriodicalId":126611,"journal":{"name":"University of Colorado Honors Journal","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124130449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Large satellite constellations (LSC) in Low Earth Orbit (LEO) provide the means to deliver internet to previously underserved populations. The LSC’s economic potential combined with a growing demand for internet access has led to multiple companies pledging their own internet LSCs in hopes of capitalizing on this need. This, in addition to growing interest in LEO, risks destabilizing the LEO environment if not regulated properly. The current U.S. Orbital Debris Standard Mitigation Practices (USODSMP) are woefully outdated and only sporadically followed by operators. Furthermore, there are no licensing regulations for other key sustainability requirements, such as propulsion and tracking. Accelerated growth of internet LSCs without proper regulation will lead to an unsafe and unsustainable LEO environment. There needs to be a change in how governments regulate private and public LSCs, in particular those providing internet telecommunications. Internet LSCs are the fastest growing population in LEO, often directly competing for orbits and broadband frequencies. In this thesis I investigate whether the U.S. could apply aspects of terrestrial utility infrastructure to better regulate satellite internet. In particular, I question whether the U.S. government could regulate internet LSCs as monopolies. Such regulatory control would allow the U.S. to better enforce and revise sustainability regulations and ensure fair access to internet services. Viewing internet as a utility, as a necessity of modern life to which all citizens deserve access, this thesis proposes the U.S. license a single internet LSC from within its borders. I explored two potential regulatory approaches: one based on the U.S.’s public utility system and one based on European internet infrastructure. I then presented these approaches to five experts in the field of space sustainability and solicited their feedback. From these results, I determined that both of my regulatory approaches are not feasible in their current forms within the U.S.; however, both approaches produce potential partial applications and variations of their initial design that may find traction. This thesis concludes that adopting an interoperability framework in LEO would allow for precise and targeted sustainability, technology, and capacity standards for each orbital corridor, empower regulatory bodies to enforce these standards, and preserve competition among Commerical Satellite Operators (CSOs). Finally, a government internet LSC competing against commercial internet LSCs, akin to terrestrial municipal internet, would demonstrate technological feasibility, satisfy equity requirements, and provide a baseline LSC for CSOs to compete against. To see the complete thesis, please visit https://scholar.colorado.edu/concern/undergraduate_honors_theses/5138jg42t.
{"title":"Can Regulating Large Satellite Constellations as Monopolies Improve Sustainability Standards While Providing Effective and Equitable Internet Access?","authors":"Samuel Rodgers","doi":"10.33011/cuhj20231865","DOIUrl":"https://doi.org/10.33011/cuhj20231865","url":null,"abstract":"Large satellite constellations (LSC) in Low Earth Orbit (LEO) provide the means to deliver internet to previously underserved populations. The LSC’s economic potential combined with a growing demand for internet access has led to multiple companies pledging their own internet LSCs in hopes of capitalizing on this need. This, in addition to growing interest in LEO, risks destabilizing the LEO environment if not regulated properly. The current U.S. Orbital Debris Standard Mitigation Practices (USODSMP) are woefully outdated and only sporadically followed by operators. Furthermore, there are no licensing regulations for other key sustainability requirements, such as propulsion and tracking. Accelerated growth of internet LSCs without proper regulation will lead to an unsafe and unsustainable LEO environment. There needs to be a change in how governments regulate private and public LSCs, in particular those providing internet telecommunications. Internet LSCs are the fastest growing population in LEO, often directly competing for orbits and broadband frequencies.\u0000In this thesis I investigate whether the U.S. could apply aspects of terrestrial utility infrastructure to better regulate satellite internet. In particular, I question whether the U.S. government could regulate internet LSCs as monopolies. Such regulatory control would allow the U.S. to better enforce and revise sustainability regulations and ensure fair access to internet services. Viewing internet as a utility, as a necessity of modern life to which all citizens deserve access, this thesis proposes the U.S. license a single internet LSC from within its borders. I explored two potential regulatory approaches: one based on the U.S.’s public utility system and one based on European internet infrastructure. I then presented these approaches to five experts in the field of space sustainability and solicited their feedback. From these results, I determined that both of my regulatory approaches are not feasible in their current forms within the U.S.; however, both approaches produce potential partial applications and variations of their initial design that may find traction. This thesis concludes that adopting an interoperability framework in LEO would allow for precise and targeted sustainability, technology, and capacity standards for each orbital corridor, empower regulatory bodies to enforce these standards, and preserve competition among Commerical Satellite Operators (CSOs). Finally, a government internet LSC competing against commercial internet LSCs, akin to terrestrial municipal internet, would demonstrate technological feasibility, satisfy equity requirements, and provide a baseline LSC for CSOs to compete against.\u0000To see the complete thesis, please visit https://scholar.colorado.edu/concern/undergraduate_honors_theses/5138jg42t.","PeriodicalId":126611,"journal":{"name":"University of Colorado Honors Journal","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114878313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This thesis traces how national allegory is employed, developed, and altered in the early novels of Ngũgĩ wa Thiong’o. Primarily guided by Fredric Jameson’s essay on national allegory and his assertion that the category is “profoundly discontinuous, a matter of breaks and heterogeneities, of the multiple polysemia of the dream rather than the homogenous representation of the symbol,” this study explores how A Grain of Wheat (1967) and Petals of Blood (1977) reconstruct the dislocated memory of the individual through the traumatic history of the collective, and how this reconnection of the private and public allows for a new imagining of the postcolonial nation. The ambivalent motif of shared cultural memory and its many figurations throughout these novels are investigated extensively. In A Grain of Wheat, the motif of betrayal, experienced by nearly every character in the novel, signals an ironic, introspective turn on national unity and an examination of the unfulfilled promises of the Mau Mau’s decolonial struggle. Told through the characters’ individual flashbacks to one another, principally through the arch-traitor Mugo, the memory of betrayal is seen as simultaneously the hollowing of social bonds and the basis for collective regeneration, with the survivors of the Emergency recognizing and negotiating the pitfalls of national consciousness while dedicating themselves to redeeming those who sacrificed their lives for it. Benedict Anderson’s essay on memory and forgetting and Frantz Fanon’s critique of the national leader are vital components to this discussion of how the novel employs the motif of betrayal and memory in order to counter the mandate by Jomo Kenyatta to “forgive and forget” the Mau Mau’s struggle against Kenyan loyalists and colonial occupants. Whereas A Grain of Wheat was primarily concerned with the immediate aftermath of independence on the national psyche, Petals of Blood directs our attention to the epic volume of history and the metamorphoses that the nation undergoes in its constant battle against imperialism and its desire for unity. The ambivalent motif of betrayal in A Grain of Wheat is mirrored by the motifs of ceremony, fire, and education in Petals of Blood, which are employed to construct a Janus-faced history of the nation exploited by the neocolonial government for its self-interest, and intervened upon by the workers and peasantry to cultivate a tradition of renewed resistance. Anderson’s essay on Walter Benjamin’s Angel of History is discussed in reference to how the postcolonial nation inherits the state from its predecessor, and Fanon and Ngũgĩ’s essays on national culture are considered for their dialectical frameworks of history and the cultivation of “combat literature.” In both these novels of his early career, Ngũgĩ sought to imagine how the nation could rejuvenate the energy and idealism of the Mau Mau uprising and empower the Kenyan workers and peasantry into a different, more equitable, socialist mo
{"title":"Remembering the Nation","authors":"Jaxon Parker","doi":"10.33011/cuhj20231755","DOIUrl":"https://doi.org/10.33011/cuhj20231755","url":null,"abstract":"This thesis traces how national allegory is employed, developed, and altered in the early novels of Ngũgĩ wa Thiong’o. Primarily guided by Fredric Jameson’s essay on national allegory and his assertion that the category is “profoundly discontinuous, a matter of breaks and heterogeneities, of the multiple polysemia of the dream rather than the homogenous representation of the symbol,” this study explores how A Grain of Wheat (1967) and Petals of Blood (1977) reconstruct the dislocated memory of the individual through the traumatic history of the collective, and how this reconnection of the private and public allows for a new imagining of the postcolonial nation.\u0000The ambivalent motif of shared cultural memory and its many figurations throughout these novels are investigated extensively. In A Grain of Wheat, the motif of betrayal, experienced by nearly every character in the novel, signals an ironic, introspective turn on national unity and an examination of the unfulfilled promises of the Mau Mau’s decolonial struggle. Told through the characters’ individual flashbacks to one another, principally through the arch-traitor Mugo, the memory of betrayal is seen as simultaneously the hollowing of social bonds and the basis for collective regeneration, with the survivors of the Emergency recognizing and negotiating the pitfalls of national consciousness while dedicating themselves to redeeming those who sacrificed their lives for it. Benedict Anderson’s essay on memory and forgetting and Frantz Fanon’s critique of the national leader are vital components to this discussion of how the novel employs the motif of betrayal and memory in order to counter the mandate by Jomo Kenyatta to “forgive and forget” the Mau Mau’s struggle against Kenyan loyalists and colonial occupants.\u0000Whereas A Grain of Wheat was primarily concerned with the immediate aftermath of independence on the national psyche, Petals of Blood directs our attention to the epic volume of history and the metamorphoses that the nation undergoes in its constant battle against imperialism and its desire for unity. The ambivalent motif of betrayal in A Grain of Wheat is mirrored by the motifs of ceremony, fire, and education in Petals of Blood, which are employed to construct a Janus-faced history of the nation exploited by the neocolonial government for its self-interest, and intervened upon by the workers and peasantry to cultivate a tradition of renewed resistance. Anderson’s essay on Walter Benjamin’s Angel of History is discussed in reference to how the postcolonial nation inherits the state from its predecessor, and Fanon and Ngũgĩ’s essays on national culture are considered for their dialectical frameworks of history and the cultivation of “combat literature.” In both these novels of his early career, Ngũgĩ sought to imagine how the nation could rejuvenate the energy and idealism of the Mau Mau uprising and empower the Kenyan workers and peasantry into a different, more equitable, socialist mo","PeriodicalId":126611,"journal":{"name":"University of Colorado Honors Journal","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124114317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dimensions: 9x12" Media: Sharpie, Watercolor I like to think our most fragile, beautiful inclinations make for the prettiest portraits. A face never lies, a hand always holds, and a bird may symbolize something bigger than we think.
{"title":"Airplane","authors":"Sage Jordan","doi":"10.33011/cuhj20231995","DOIUrl":"https://doi.org/10.33011/cuhj20231995","url":null,"abstract":"Dimensions: 9x12\" \u0000Media: Sharpie, Watercolor \u0000I like to think our most fragile, beautiful inclinations make for the prettiest portraits. A face never lies, a hand always holds, and a bird may symbolize something bigger than we think.","PeriodicalId":126611,"journal":{"name":"University of Colorado Honors Journal","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124649149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reduced reactive nitrogen species, which primarily consist of ammonia and low-mass amines, occur in the gas-phase and the particle-phase of the atmosphere. Despite being present at trace concentrations, these species can have severe effects on eutrophication, biodiversity, human pulmonary and cardiac health, and deposition. Long-term sampling of these species is infrequent, and such sampling that has taken place is focused around agricultural sources rather than urban environments. A greater understanding of the gas-particle partitioning of these species elucidates our understanding of the roles they play in the aforementioned environmental effects. I adapted the EPA’s procedure for the sampling of ambient air using annular denuders and performed troubleshooting techniques on an ion chromatograph to develop a method to collect and analyze reduced nitrogen species; with this method, phases can be examined separately, thus allowing for a greater understanding of the magnitude of each risk associated with the gas and particle-phases rather than conflating the total concentration together. Method development is a crucial step in initiating long-term sampling, because consistency is the foundation of accuracy. I began preliminary ambient sampling with a focus on ensuring the procedure works and exploring potential trends. While further sampling over the course of years will be necessary to confirm trends, some trends are beginning to emerge: gas-phase ammonia is present in higher concentrations when the average temperature is greater. The total concentration and the ratio of gas-to-particle concentrations are still being considered, as are these apparent trends. For the future, focus should be directed towards identifying the dominant source of analyte in the second annular denuder, observing effects of different filters, refining the gradient method, and considering the maximum collectable concentration on the denuders and filter. Lay Summary All living things from plants to animals to humans require nitrogen to perform a variety of essential chemical processes. While ~78% of the atmosphere is made up of nitrogen, the vast majority of this exists in an unreactive, and therefore unusable, form. This is due to a strong triple bond between two nitrogen atoms in the nitrogen gas molecule (N2). Reactive nitrogen, on the other hand, is also present in the atmosphere but its lack of a triple bond makes it usable for living things. In small concentrations, reactive nitrogen can deposit onto ecosystems, providing plants and animals with a vital, and often limited, nutrient. In larger concentrations, atmospheric reactive nitrogen forms particulate matter; particulate matter is tiny solids or liquids suspended in the air. Of most interest is particulate matter with a diameter of less than 2.5 micrometers (PM2.5); for reference the width of a human hair is around 70 micrometers. Particulate matter of this size penetrates deeply into the lungs and causes pulmo
{"title":"Long-Term Trends in Gas-Particle Partitioning of Reduced Reactive Nitrogen Species, as Analyzed by Annular Denuders and Ion Chromatography","authors":"J. Schlenker","doi":"10.33011/cuhj20231981","DOIUrl":"https://doi.org/10.33011/cuhj20231981","url":null,"abstract":"Reduced reactive nitrogen species, which primarily consist of ammonia and low-mass amines, occur in the gas-phase and the particle-phase of the atmosphere. Despite being present at trace concentrations, these species can have severe effects on eutrophication, biodiversity, human pulmonary and cardiac health, and deposition. Long-term sampling of these species is infrequent, and such sampling that has taken place is focused around agricultural sources rather than urban environments. A greater understanding of the gas-particle partitioning of these species elucidates our understanding of the roles they play in the aforementioned environmental effects. \u0000I adapted the EPA’s procedure for the sampling of ambient air using annular denuders and performed troubleshooting techniques on an ion chromatograph to develop a method to collect and analyze reduced nitrogen species; with this method, phases can be examined separately, thus allowing for a greater understanding of the magnitude of each risk associated with the gas and particle-phases rather than conflating the total concentration together. Method development is a crucial step in initiating long-term sampling, because consistency is the foundation of accuracy. I began preliminary ambient sampling with a focus on ensuring the procedure works and exploring potential trends. \u0000While further sampling over the course of years will be necessary to confirm trends, some trends are beginning to emerge: gas-phase ammonia is present in higher concentrations when the average temperature is greater. The total concentration and the ratio of gas-to-particle concentrations are still being considered, as are these apparent trends. For the future, focus should be directed towards identifying the dominant source of analyte in the second annular denuder, observing effects of different filters, refining the gradient method, and considering the maximum collectable concentration on the denuders and filter. \u0000Lay Summary\u0000All living things from plants to animals to humans require nitrogen to perform a variety of essential chemical processes. While ~78% of the atmosphere is made up of nitrogen, the vast majority of this exists in an unreactive, and therefore unusable, form. This is due to a strong triple bond between two nitrogen atoms in the nitrogen gas molecule (N2). Reactive nitrogen, on the other hand, is also present in the atmosphere but its lack of a triple bond makes it usable for living things. In small concentrations, reactive nitrogen can deposit onto ecosystems, providing plants and animals with a vital, and often limited, nutrient. In larger concentrations, atmospheric reactive nitrogen forms particulate matter; particulate matter is tiny solids or liquids suspended in the air. Of most interest is particulate matter with a diameter of less than 2.5 micrometers (PM2.5); for reference the width of a human hair is around 70 micrometers. Particulate matter of this size penetrates deeply into the lungs and causes pulmo","PeriodicalId":126611,"journal":{"name":"University of Colorado Honors Journal","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128939161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Previous research has shown that a 5-day course of morphine enhances nociceptive sensitivity and allodynia when given 10 days after chronic constriction injury (CCI) as measured by the Von Frey test, a test where the hindpaw is poked with force (measured in grams) calibrated filament. This increased sensitivity to touch suggests that post trauma morphine makes second order sensory dorsal horn neurons more excitable. Therefore, it is hypothesized that during morphine enhanced allodynia, dorsal horn neurons will be more excitable to nociceptive stimulus. It was found that morphine enhanced allodynia causes more excitable neurons across a larger spatial range of the spinal cord, both rostral-caudal and dorsal-ventral along the dorsal horn. Mechanisms for the increased excitability of the dorsal horn are proposed and explored. These findings add to a robust literature which has detailed the paradoxical pain amplifying effects of morphine. Further, this study predicts that hyperexcitability of pain and touch pathways may occur as a clinically unintended side effect of morphine when administered to treat ongoing neuropathic pain. Lay Summary When working on the body, opioids take effect on various cells- including cells of the nervous system known as Glia. These glial cells produce various inflammatory responses that are typically known to decrease inflammation in the body. However, prior literature has revealed that following an activated state, these cells enter a “primed” form. If a second immunological activation occurs during this primed state, glial cells have been shown to release proteins that actually potentiate the state of pain. This study examines this hypothesis through the context of peripheral nerve injury (modeling injury, surgery, or trauma), followed by an administration of morphine. Using advanced imaging techniques, we are able to visualize exactly what modulators are inducing this potentiated pain response, as well as where in the nervous system these cells are found. Morphine has a potent effect on various aspects of the nervous system which may be alleviated by other treatment routes that focus specifically on the cell type and location that release the molecules that initiate the healing process. By unveiling the details of this mechanism, we can better understand how to treat patients following injury or surgery without inducing a higher pain response that can be caused by a short-term administration of morphine. To see the complete thesis, please visit https://scholar.colorado.edu/concern/undergraduate_honors_theses/0k225c53t.
{"title":"Effects of Post Trauma Morphine On Dorsal Horn Neuron Excitability: Studies using cFOS and RNAscope","authors":"B. Woodall","doi":"10.33011/cuhj20231847","DOIUrl":"https://doi.org/10.33011/cuhj20231847","url":null,"abstract":"Previous research has shown that a 5-day course of morphine enhances nociceptive sensitivity and allodynia when given 10 days after chronic constriction injury (CCI) as measured by the Von Frey test, a test where the hindpaw is poked with force (measured in grams) calibrated filament. This increased sensitivity to touch suggests that post trauma morphine makes second order sensory dorsal horn neurons more excitable. Therefore, it is hypothesized that during morphine enhanced allodynia, dorsal horn neurons will be more excitable to nociceptive stimulus. It was found that morphine enhanced allodynia causes more excitable neurons across a larger spatial range of the spinal cord, both rostral-caudal and dorsal-ventral along the dorsal horn. Mechanisms for the increased excitability of the dorsal horn are proposed and explored. These findings add to a robust literature which has detailed the paradoxical pain amplifying effects of morphine. Further, this study predicts that hyperexcitability of pain and touch pathways may occur as a clinically unintended side effect of morphine when administered to treat ongoing neuropathic pain.\u0000Lay Summary\u0000When working on the body, opioids take effect on various cells- including cells of the nervous system known as Glia. These glial cells produce various inflammatory responses that are typically known to decrease inflammation in the body. However, prior literature has revealed that following an activated state, these cells enter a “primed” form. If a second immunological activation occurs during this primed state, glial cells have been shown to release proteins that actually potentiate the state of pain. This study examines this hypothesis through the context of peripheral nerve injury (modeling injury, surgery, or trauma), followed by an administration of morphine. Using advanced imaging techniques, we are able to visualize exactly what modulators are inducing this potentiated pain response, as well as where in the nervous system these cells are found. Morphine has a potent effect on various aspects of the nervous system which may be alleviated by other treatment routes that focus specifically on the cell type and location that release the molecules that initiate the healing process. By unveiling the details of this mechanism, we can better understand how to treat patients following injury or surgery without inducing a higher pain response that can be caused by a short-term administration of morphine. \u0000To see the complete thesis, please visit https://scholar.colorado.edu/concern/undergraduate_honors_theses/0k225c53t.","PeriodicalId":126611,"journal":{"name":"University of Colorado Honors Journal","volume":"5 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132954252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：