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The Speculative Artifact 2022, Students Of Risd, Risd Archives Dec 2022

The Speculative Artifact 2022, Students Of Risd, Risd Archives

All Student Newspapers

The Speculative Artifact was a student publication created for the Graphic Design seminar/studio Critical Issues Studio, taught by Anther Kiley in Fall 2022. The publication features designs and concepts for artifacts of the future created by students. Artifacts include language aids, a sex worker kit, food packaging, a garden pack, style-transferred furniture, a post-taste apartment, a maze sculpture, a personality magazine, animal-human cohabitation, signage, a friend-dating system, coding tech, a transhuman sticker book, and television programming with animal languages


Household Size And Household Wealth In Indonesia With The Influence Of Spatial Aspects, Thomas Soseco Dec 2022

Household Size And Household Wealth In Indonesia With The Influence Of Spatial Aspects, Thomas Soseco

Economics and Finance in Indonesia

Investigating household wealth should also include spatial analysis to capture the influence of location on the households’ net wealth and to avoid underestimation of the effect of the change of variables due to estimation that ignores spatial aspects. This paper examines factors influencing household net wealth in Indonesia with the influence of spatial lag using data from the Indonesian Family Life Survey (IFLS) for 1993–2014. The article relies on the Spatial Durbin Model (SDM) to analyze the data. Results show that household net wealth in Indonesia is spatially related to each other, and the spillover effect makes the change of …


Full Issue Dec 2022

Full Issue

Criterion: A Journal of Literary Criticism

No abstract provided.


Smart Classroom User Manual, Claire Nickerson Mlis Dec 2022

Smart Classroom User Manual, Claire Nickerson Mlis

Library Faculty Publications

In 2018, Fort Hays State University began building a prototype for a low-cost, portable smart classroom. This project was a collaboration between the library and the Institute for New Media Studies and was funded by the Institute of Museum and Library Services. This manual assumes that you are working with a smart classroom kit with components that have already been collected and set up, either by you or by an organization or consortium. If you are trying to create a smart classroom kit or set up the smart classroom screens, please consult the Smart Classroom Designs document. If you are …


Species Data And Vector Modeling: Evaluating Datasets For Improved Models Of Ixodes Ricinus Tick Distribution In Europe Under A Changing Climate, Steven Jones Dec 2022

Species Data And Vector Modeling: Evaluating Datasets For Improved Models Of Ixodes Ricinus Tick Distribution In Europe Under A Changing Climate, Steven Jones

Electronic Theses and Dissertations

To increase capacity for monitoring and surveillance of tick-borne diseases, publicly available tick distribution and climate change datasets are required to create accurate predictive distribution models. It is difficult, however, to assess model accuracy and utility when using incomplete datasets.  The more recent development of comprehensive tick databases for Europe and availability of climate change scenarios from multiple IPCC Assessment Reports allows for improved modeling efforts. Multiple tick datasets were combined and three climate change projections were compared by predicting current and future distributions of Ixodes ricinus ticks in Europe using the MaxEnt species distribution model. Overall, much of Europe …


A Comparison Of The Mental Health Of Police Officers And Correctional Officers In Rural Appalachia, Sierra Thomas Dec 2022

A Comparison Of The Mental Health Of Police Officers And Correctional Officers In Rural Appalachia, Sierra Thomas

Electronic Theses and Dissertations

The purpose of this study was to explore perceptions of mental health among police officers and correctional officers within rural Appalachia. The main goal of this research was to better understand how the occupational demands of working in the criminal justice field can impact one’s mental health over time. Several research questions were explored, including the prevalence of various mental health problems, associated stressors, the structure of support among officers, and the perceptions of mental health treatment services. Data were gathered through semi-structured interviews with 21 police and correctional officers located in rural Appalachia. Results provided a better understanding of …


Examining The Politicization And Framing Of Hea 117 In The Us Between 2019 And 2021, Elise S. Ahn Dec 2022

Examining The Politicization And Framing Of Hea 117 In The Us Between 2019 And 2021, Elise S. Ahn

Journal of Comparative & International Higher Education

In 2019, the U.S. Department of Education (DED) began increasing its enforcement of the Higher Education Act, Section 117 statute, which provides instructions for institutional reporting regarding foreign and contracts. The three questions guiding this article include: What were DED’s stated premises for the investigations? How was international engagement characterized in the notices? And finally, what traits, characteristics, and/or qualities were attributed to different actors? After providing an overview of Section 117, this article examines the notices of investigation issued by DED between 2019 and 2021 to better understand how the Agency discursively characterized malign and/or undue foreign influence utilizing …


A Cross-Sectional Exploratory Study On Voluntary Reporting Of Professional Groups In U.S. Commercial Aviation, James Norman Dec 2022

A Cross-Sectional Exploratory Study On Voluntary Reporting Of Professional Groups In U.S. Commercial Aviation, James Norman

Theses and Dissertations

Aviation safety culture research does not exist regarding the specific factors that either promote or discourage voluntary safety reporting among different frontline groups in U.S. Part 121 operations. Moreover, while safety culture has been shown to vary across workgroups, cross-sectional research across multiple aviation organizations regarding voluntary reporting is lacking. To address this gap in the literature, an exploratory study was conducted utilizing a sequential, confirmatory mixed methods approach. A 28-item survey was distributed to air traffic controllers, dispatchers, maintenance technicians, and pilots. The instrument quantitatively assessed organizational safety values, reporting friction, previous reporting experience, just culture, and voluntary reporting …


Alfred Russel Wallace Notes 23: The Jersey Devil, And Friends, Charles H. Smith Dec 2022

Alfred Russel Wallace Notes 23: The Jersey Devil, And Friends, Charles H. Smith

Faculty/Staff Personal Papers

For nearly three hundred years reports have surfaced of a purported cryptid form known as the ‘Jersey devil.’ In this work an interpretation of the goals of biogeography is given, and how this field can be related to such alleged phenomena, as well as to some of the ideas of Alfred Russel Wallace (1823-1913) that seem to find their origin in the writings of Benedict de Spinoza (1632-1677).


Territoriality In American Criminal Law, Emma Kaufman Dec 2022

Territoriality In American Criminal Law, Emma Kaufman

Michigan Law Review

It is a bedrock principle of American criminal law that the authority to try and punish someone for a crime arises from the crime’s connection to a particular place. Thus, we assume that a person who commits a crime in some location— say, Philadelphia—can be arrested by Philadelphia police for conduct deemed criminal by the Pennsylvania legislature, prosecuted in a Philadelphia court, and punished in a Pennsylvania prison. The idea that criminal law is tied to geography in this way is called the territoriality principle. This idea is so familiar that it usually goes unstated.

This Article foregrounds and questions …


From Mesoamerica To Aleppo And Transylvania: The Global Migration Of The Chile Pepper, Arianne M. Peterson, Arianne Peterson Dec 2022

From Mesoamerica To Aleppo And Transylvania: The Global Migration Of The Chile Pepper, Arianne M. Peterson, Arianne Peterson

Master's Theses

This thesis explores the migration of the chile pepper, or capsicum anuum, from Mesoamerica into the Old World after 1500, focusing on two case studies of the Aleppo pepper in Syria and paprika in what was once Hungarian Nagyvarad, and which is now Romanian Oradea. Using foodways as a historical lens, and considering the movement of food as historical, it can be seen that the chile pepper, despite its low profit value, illustrates a globalization that existed well before modern times, and it came to cement itself within many different cultures as a symbol of identity. Despite its far-away …


Big Data For Comprehensive Analysis Of Real Estate Market, Yonglin Xiao Dec 2022

Big Data For Comprehensive Analysis Of Real Estate Market, Yonglin Xiao

Electronic Theses, Projects, and Dissertations

This Culminating Experience Project explored the application of big data in the real estate industry in order to address the problem of analyzing the accurate property estimates value. The research questions were: (Q1): What are the benefits and advantages of utilizing big data in the real estate market? (Q2): What are the trends in the application of big data in the real estate market? (Q3): What are the challenges in applying big data in the real estate market? (Q4): What are the methods and processes of applying big data in appraisal of assets in the real estate market? To answer …


Susannah And Cold Mountain: Examining The Portrayal Of Appalachian Culture In Opera, Savannah Bennett Dec 2022

Susannah And Cold Mountain: Examining The Portrayal Of Appalachian Culture In Opera, Savannah Bennett

Electronic Theses and Dissertations

This thesis applies qualitative literary analysis and ethnographic methods to examine the portrayal of Appalachia in the operas Susannah and Cold Mountain. The operas were premiered almost 60 years apart, yet they share many themes that epitomize roles, patterns, and stereotypes within the Appalachian region. One theme observed is the role and expectations of Appalachian women and how they have developed over time, as the plots are placed roughly a century apart. The depictions of Appalachian religious traditions and representations of violence are also explored as these themes play a considerable role in Susannah and Cold Mountain. By analyzing …


Green On The Map - The Influence Of Conservation Easements On The Naturalness Of Landscapes In The United States, Nakisha Fouch Dec 2022

Green On The Map - The Influence Of Conservation Easements On The Naturalness Of Landscapes In The United States, Nakisha Fouch

All Dissertations

Large protected areas have long been the cornerstone of conservation biology, however, in an era branded by the human dominance of ecosystems, regional landscape structure and function are often a consequence of accumulated land-use decisions that may or may not include a nod to conservation planning. With underrepresentation of habitats in publicly protected areas, attention has focused on the function of alternative land conservation mechanisms. Private conservation easements (CEs) have proliferated in the United States, yet assessing landscape-level function is confounded by holder and donor intent, national and regional policy, regional landscape contexts, varying extents, resolution, and temporal scale. Over …


Urban/Rural Disparities Of Thyroid Cancer Using The Integrated Cancer Repository For Cancer Research (Icare2), Sunita Regmi Dec 2022

Urban/Rural Disparities Of Thyroid Cancer Using The Integrated Cancer Repository For Cancer Research (Icare2), Sunita Regmi

Capstone Experience: Master of Public Health

Abstract:

Background and objective: Multiple studies have shown that the place of residence and the distance to travel from one's residence to nearby health care providers impact cancer diagnosis and treatment. The stage of cancer at the time of diagnosis is paramount for cancer treatment and affects survival. Disparities in cancer treatment exist which affect the outcome disproportionately to certain segments of the population. To date, much of the focus has been on the racial and socioeconomic disparities in the management of thyroid cancer. The effect of geography and location (urban-rural status) on thyroid cancer stage diagnosis has …


Evaluating How The Impacts Of Climate Change On Arizona's Water Supply Will Influence Public Health, Patricia Wrona Dec 2022

Evaluating How The Impacts Of Climate Change On Arizona's Water Supply Will Influence Public Health, Patricia Wrona

Capstone Experience: Master of Public Health

Over the last century, Arizona’s climate has increased more than 1.1 to 1.4 degrees Celsius or 2 to 2.5 degrees Fahrenheit. The temperature in Arizona is expected to increase an additional 2.2°C to 2.8°C in the next 40 years. Climate change poses various health and environmental hazards for the residents of Arizona. One of the most significant impacts is on water supply. As temperatures continue to rise in the desert, the demand for water will increase while the water supply will reduce. A literature review and program evaluation were conducted to evaluate how the impacts of climate change on Arizona’s …


Program Planning On Social Determinants Of Health For Rural Nebraska, Maria H. Cantu Hines Dec 2022

Program Planning On Social Determinants Of Health For Rural Nebraska, Maria H. Cantu Hines

Capstone Experience: Master of Public Health

Social determinants of health (SDOH) are non-health factors that impact health in both direct and indirect ways. Research into SDOH and their effects has been extensive in recent years and has been further documented by the COVID-19 pandemic. Despite the wealth of the literature on the SDOH, awareness of these important factors is not prevalent among community residents. Rural communities are as subject to the impact of SDOH just as their urban counterparts and experience additional complexities related to geography and topography.

This capstone project aims to raise awareness, provide education, and assist with tools and resources, to empower rural …


Glacier Segmentation From Remote Sensing Imagery Using Deep Learning, Bibek Aryal Dec 2022

Glacier Segmentation From Remote Sensing Imagery Using Deep Learning, Bibek Aryal

Open Access Theses & Dissertations

Large-scale study of glaciers improves our understanding of global glacier change and is imperative for monitoring the ecological environment, preventing disasters, and studying the effects of global climate change. In recent years, remote sensing imagery has been preferred over riskier and resource-intensive field visits for tracking landscape level changes like glaciers. However, periodic manual labeling of glaciers over a large area is not feasible due to the considerable amount of time it requires while automatic segmentation of glaciers has its own set of challenges. Our work aims to study the challenges associated with segmentation of glaciers from remote sensing imagery …


Using Culturally Responsive Teaching And Funds Of Knowledge To Engage Culturally And Linguistically Diverse Students In Authentic Learning, Marybelle Gonzales Dec 2022

Using Culturally Responsive Teaching And Funds Of Knowledge To Engage Culturally And Linguistically Diverse Students In Authentic Learning, Marybelle Gonzales

Open Access Theses & Dissertations

ABSTRACT

This study employed the theoretical frameworks of Culturally Responsive Teaching and Funds of Knowledge as lens for understanding how English as a Second Language (ESL) teachers in the Texas border region use culturally responsive teaching and funds of knowledge to engage culturally diverse students in authentic learning. The results of this study include the following themes: Curriculum, instruction and assessment of culturally and linguistically diverse students; lessons learned from virtual/online teaching and learning during the COVID-19 pandemic; culturally responsive teaching practices; funds of knowledge; and authentic learning. The results indicated that while English as a Second Language (ESL) in …


Faculty Experiences Teaching In An Mba Program In The Context Of Covid-19 A Sensemaking Approach, Jesus Rolando Nuñez Dec 2022

Faculty Experiences Teaching In An Mba Program In The Context Of Covid-19 A Sensemaking Approach, Jesus Rolando Nuñez

Open Access Theses & Dissertations

The Sensemaking framework is often utilized when disruptive events create ambiguity and force individuals to make sense of things differently, personally and professionally, by "structuring the unknown" (Waterman, 1990, p.41). By way of example, the COVID-19 pandemic was a significant disruptor to the education sector. Institutional decisions driven by the initial crisis kept daily functions and the educational process moving forward in 2020 by faculty members leveraging existing technology to continue teaching their students. The pandemic disrupted the daily routine of brick-and-mortar operations and many institutions' face-to-face delivery of academic content. The implications of the pandemic forced every faculty member …


Deep Submarine Infiltration Of Altered Geothermal Groundwater On The South Chilean Margin, Vincent J. Clementi, Yair Rosenthal, Samantha C. Bova, Elizabeth K. Thomas, James D. Wright, Richard A. Mortlock, Owen C. Cowling, Linda V. Godfrey, Laurel B. Childress, Ivano W. Aiello, Alejandro Avila, William Biggs, Christopher D. Charles, Anson H. Cheung, Kimberly Delong, Isabel A. Dove, Xiaojing Du, Emily R. Estes, Ursula Fuentes, Cristina García-Lasanta, Steven L. Goldstein, Anna Golub, Julia Rieke Hagemann, Robert G. Hatfield, Laura L. Haynes, Anya V. Hess, Nil Irvali, Yael Kiro, Minda M. Monteagudo, Jonathan E. Lambert, Chen Li, William M. Longo, Sarah Mcgrath, Hailey Riechelson, Rebecca S. Robinson, John Sarao Dec 2022

Deep Submarine Infiltration Of Altered Geothermal Groundwater On The South Chilean Margin, Vincent J. Clementi, Yair Rosenthal, Samantha C. Bova, Elizabeth K. Thomas, James D. Wright, Richard A. Mortlock, Owen C. Cowling, Linda V. Godfrey, Laurel B. Childress, Ivano W. Aiello, Alejandro Avila, William Biggs, Christopher D. Charles, Anson H. Cheung, Kimberly Delong, Isabel A. Dove, Xiaojing Du, Emily R. Estes, Ursula Fuentes, Cristina García-Lasanta, Steven L. Goldstein, Anna Golub, Julia Rieke Hagemann, Robert G. Hatfield, Laura L. Haynes, Anya V. Hess, Nil Irvali, Yael Kiro, Minda M. Monteagudo, Jonathan E. Lambert, Chen Li, William M. Longo, Sarah Mcgrath, Hailey Riechelson, Rebecca S. Robinson, John Sarao

Graduate School of Oceanography Faculty Publications

Submarine groundwater discharge is increasingly recognized as an important component of the oceanic geochemical budget, but knowledge of the distribution of this phenomenon is limited. To date, reports of meteoric inputs to marine sediments are typically limited to shallow shelf and coastal environments, whereas contributions of freshwater along deeper sections of tectonically active margins have generally been attributed to silicate diagenesis, mineral dehydration, or methane hydrate dissociation. Here, using geochemical fingerprinting of pore water data from Site J1003 recovered from the Chilean Margin during D/V JOIDES Resolution Expedition 379 T, we show that substantial offshore freshening reflects deep and focused …


Mechanisms Underlying Childhood Exposure To Blue Spaces And Adult Subjective Well-Being: An 18-Country Analysis, Valeria Vitale, Leanne Martin, Mathew P. White, Lewis R. Elliott, Kayleigh J. Wyles, Matthew H.E.M. Browning, Sabine Pahl, Patricia Stehl, Simon Bell, Gregory N. Bratman, Mireia Gascon, James Grellier, Maria L. Lima, Mare Lõhmus, Mark Nieuwenhuijsen, Ann Ojala, Jane Taylor, Matilda Van Den Bosch, Netta Weinstein, Lora E. Fleming Dec 2022

Mechanisms Underlying Childhood Exposure To Blue Spaces And Adult Subjective Well-Being: An 18-Country Analysis, Valeria Vitale, Leanne Martin, Mathew P. White, Lewis R. Elliott, Kayleigh J. Wyles, Matthew H.E.M. Browning, Sabine Pahl, Patricia Stehl, Simon Bell, Gregory N. Bratman, Mireia Gascon, James Grellier, Maria L. Lima, Mare Lõhmus, Mark Nieuwenhuijsen, Ann Ojala, Jane Taylor, Matilda Van Den Bosch, Netta Weinstein, Lora E. Fleming

School of Psychology

Contact with natural environments is associated with good health and well-being. Although childhood nature experiences may be important in the development of an individual's relationship with nature and subsequent well-being, previous studies have tended to focus on ‘nature’ in general, and the mechanisms by which childhood experiences influence well-being in adulthood remain insufficiently studied. Drawing on cross-sectional survey data from an 18-country sample (N = 15,743) the current work extended previous research by examining: a) blue spaces (coasts, rivers, lakes, etc.) in particular; b) associations between adults' recalled childhood exposure to blue spaces, frequency of recent visits to green and …


Metal Transfer To Sediments, Invertebrates And Fish Following Waterborne Exposure To Silver Nitrate Or Silver Sulfide Nanoparticles In An Indoor Stream Mesocosm, Nathaniel Clark, Joanne Vassallo, Pv Silva, Arr Silva, Marta Baccaro, Neja Medvešček, Magdalena Grgić, Abel Ferreira, Martí Busquets-Fité, Kerstin Jurkschat, Anastasios G. Papadiamantis, Victor Puntes, Iseult Lynch, Claus Svendsen, Den Brink Nw Van, Gestel Cam Van, Susana Loureiro, Richard D. Handy Dec 2022

Metal Transfer To Sediments, Invertebrates And Fish Following Waterborne Exposure To Silver Nitrate Or Silver Sulfide Nanoparticles In An Indoor Stream Mesocosm, Nathaniel Clark, Joanne Vassallo, Pv Silva, Arr Silva, Marta Baccaro, Neja Medvešček, Magdalena Grgić, Abel Ferreira, Martí Busquets-Fité, Kerstin Jurkschat, Anastasios G. Papadiamantis, Victor Puntes, Iseult Lynch, Claus Svendsen, Den Brink Nw Van, Gestel Cam Van, Susana Loureiro, Richard D. Handy

School of Health Professions

No abstract provided.


The Relationship Between Bird Species Richness And Human Appropriation Of Net Primary Productivity, Kaeli Mueller Dec 2022

The Relationship Between Bird Species Richness And Human Appropriation Of Net Primary Productivity, Kaeli Mueller

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As humans harvest increasing amounts of biomass, it is crucial to gain an understanding of how much energy is being appropriated and the impact that this could have on ecosystems and biodiversity. The primary way in which humans impact biodiversity loss is through land use change. One way of quantifying the impact of land use change is through human appropriation of net primary production (HANPP). This measurement represents the total amount of energy derived from photosynthesis that humans remove from ecosystems and appropriate for their own use. My research studies the relationship between HANPP and bird species richness at the …


Normative Evaluations Of Resource Conditions: The Influence Of Visitor Characteristics And Implications For Recreation Management In Urban-Proximate Parks, Jordan E. Nesbitt Dec 2022

Normative Evaluations Of Resource Conditions: The Influence Of Visitor Characteristics And Implications For Recreation Management In Urban-Proximate Parks, Jordan E. Nesbitt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Urban-proximate parks and protected areas provide a unique recreation landscape to individuals living in and near urban centers. They have been shown to provide similar recreation experiences to traditionally studied parks and protected areas such as National Parks, National Forests and Wilderness areas. This study takes place in a set of four urban-proximate parks in Orange County, California, USA. These parks are designated as urban-proximate because they are located within 100 miles of an urban center with 1 million or more people. Using norm theory, a well vetted social science theory, this work sought to identify thresholds of acceptability for …


Examining Geographic Variations In Disaster Preparedness Across The United States And Puerto Rico, Forest Kane Cook Dec 2022

Examining Geographic Variations In Disaster Preparedness Across The United States And Puerto Rico, Forest Kane Cook

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Disaster events, such as floods, wildfires, and earthquakes increasingly cause damage to livelihoods, the economy, and the environment. Preparing for these events to occur is an important part of increasing resilience, however studies have found that households are generally not prepared for these events to happen. When it comes to identifying where these households are, there is typically no related tool or series of maps that can indicate location. In order to fill this gap, we use public survey data from FEMA to create estimates of household preparedness across a number of actions, such as developing an evacuation plan or …


The Latter-Day Saint Home As A Site Of Religious Transition, 1890–1930, Cathy Gilmore Dec 2022

The Latter-Day Saint Home As A Site Of Religious Transition, 1890–1930, Cathy Gilmore

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis examines religion as practiced in the Latter-day Saint home during a period of religious transition between 1890 and 1930. Using the family of June A. Bushman and Hyrum Smith as subjects, we examine how families managed the religious reforms of the Church of Jesus Christ of Latter-day Saints during this period. As individuals who came of age at the turn of the twentieth century, June and Hyrum’s lives intersected with their church’s transition from an isolated religion to a modern, American church.
Administrative modernization, priesthood reforms, reimagined family relationships, and other ecclesiastical changes came into tension with the …


Orbital Mapping Of Seasonal And Yearly Changes In Co2 And Water Ice On The Southern Polar Cap Of Mars, Victoria Michell Ann Karnes Dec 2022

Orbital Mapping Of Seasonal And Yearly Changes In Co2 And Water Ice On The Southern Polar Cap Of Mars, Victoria Michell Ann Karnes

Graduate Theses and Dissertations

This research exhibits a new foundation for the rates of change in CO2 and water ice on the southern polar cap of Mars, where the annual precipitation cycles are known to fluctuate seasonally between the north and south pole, based on observations from the Compact Reconnaissance Imaging Spectrometer (CRISM). The conventional belief is that both CO2 ice and water ice on the southern polar cap condenses and evaporates over the course of a Martian year (MY), condensing during the Martian spring and summer and evaporating during the Martian fall and winter. With this theory in mind, CO2 and water ice …


Understanding The Potential Utility Of Tamarktm Grain Sorghum, Jacob Alan Fleming Dec 2022

Understanding The Potential Utility Of Tamarktm Grain Sorghum, Jacob Alan Fleming

Graduate Theses and Dissertations

Herbicide-resistant crops have been commonly used in corn, cotton, and soybean since the 1990s to control numerous different grass and broadleaf weeds. However, this technology has not been available for grain sorghum producers whom have faced challenges controlling grass weeds. Recently a collaboration between the University of Arkansas and Texas A&M University has resulted in a new bred line of grain sorghum, TamArkTM, which is resistant to ACCase inhibitor herbicides which have been previously used to control grass weeds in broadleaf crops. Multiple studies were conducted to determine the sensitivity of TamArkTM and problematic grass weeds to ACCase inhibitor herbicides, …


Thermal Inactivation Kinetics Of Salmonella In Milk Powder As Impacted By Water Activity And Powder Type, Erika Litta Kadas Dec 2022

Thermal Inactivation Kinetics Of Salmonella In Milk Powder As Impacted By Water Activity And Powder Type, Erika Litta Kadas

Graduate Theses and Dissertations

Historically, low-water activity (aw) foods (aw <0.65) were considered to be microbiologically safe for consumption. However, these foods have been implicated in outbreaks of pathogens such as Salmonella enterica, at a frequency that surely challenges this assumption of safety. Although usually implicated in outbreaks involving poultry and egg products, Salmonella spp. have frequently been the culprit in several outbreaks and recalls associated with low-water activity foods (LWAF) due to contamination resulting from the environment, animals, or even the employees during pre-or post-processing. One such LWAF that has been associated with Salmonella spp. outbreaks is milk powder. Milk powders are used in a variety of products ranging from infant formula to confectionary goods. With their widespread use, improving their safety is imperative. A key step in improving their safety is to thoroughly investigate preventive controls related to milk powder processing. The Food Safety Modernization Act (FSMA) established the Preventive Controls for Human Foods Rule, which mandates that processors design and establish a food safety plan outlining any potential hazards and the steps they will take to ensure those hazards do not compromise the safety of the product. Presently, the dairy industry does not have an established kill-step for milk powders post-spray drying. Spray drying may reduce some microbial populations, however, desiccation(e.g., spray drying) is not considered a kill-step. The work outlined in this thesis aims to assist our dairy industry partners in establishing their own thermal process for milk powders post-spray drying. Moisture sorption isotherms of two milk powders (nonfat dry milk: NFDM and a milk protein concentrate with 85% protein content: MPC-85) were determined and showcased that the temperatures at which the isotherms were determined (23, 40, or 60°C) significantly affected both the adsorption and desorption isotherms (p<0.0001) for each powder. Secondly, the thermal inactivation kinetics of Salmonella spp. in both powders were evaluated at two different water activities (0.20 and 0.30) and three temperatures (75, 80, and 85°C) to determine the effect of water activity on the thermal resistance of a cocktail of Salmonella spp. The D-values of Salmonella were heavily influenced by the thermal treatment temperature (p< 0.0001), but not the water activity (p >0.05). The overall findings contained within this thesis provide valuable information about the thermal inactivation kinetics of Salmonella spp. to our partners in the dairy industry so that they may implement an appropriate thermal process for their milk powders.