My name is Henry Nick, and I am a rising junior at Penn. I am majoring in Neuroscience with minors in Chemistry, Sociology, and Cognitive Science. This summer, I was lucky to be matched with Dr. Sigrid Veasey and her lab in the Center for Sleep and Circadian Neurobiology to examine the effects of sleep fragmentation and orexin loss on inflammation of the brain.

What is your summer research project? 

This summer, my primary project sought to explore the effects of sleep fragmentation and loss of orexinergic neurons on the health and wellbeing of the brain. Under guidance and mentorship from Dr. Veasey and the peers and colleagues in her lab, I have been able to analyze hippocampi from multiple groups of mice – rested wild type, sleep fragmented wild type, rested orexin knockout, and sleep fragmented orexin knockout – to determine if sleep fragmentation causes an enhanced proinflammatory response in brains when orexinergic neurons – neurons that determine whether an animal should be asleep or awake – are not active. 

What are the implications of your research? 

Sleep fragmentation occurs when there are frequent, abnormal awakenings during the sleep-wake cycle, disrupting the natural sleep cycle. Artificial lighting, longer work commuting times, night-shift work, and increasing availability of computers and televisions have all contributed to shortened sleep times, and is especially common in more densely populated inner city environments, where all of these are more common. These interruptions cause negative impacts on cognitive performance; including mood, attention, memory, and executive function.

Lack of sleep causes a loss of orexin neurons which causes systemic inflammation in monocytes. Monocytes are a type of white blood cell produced in the bone marrow. They fight infections and remove dead or damaged cells and fight cancer cells. Orexin is a neuropeptide that regulates various physiological phenomena such as wakefulness, feeding, reward, and thermogenesis. The body energy level influences orexin neuronal activity to coordinate arousal and energy homeostasis. Loss of orexin signaling has been linked to narcolepsy, obesity, and age-related disorders caused by reduced energy expenditure, reduced food intake, and weight loss.

What new skills have you gained through your research? 

It was a nice change of pace to be able to conduct in-person research this summer through the STEER program coming out of a long period of remote work. My research relied on examining mouse brains, so I had to go through a rigorous training protocol in order to ensure I was adequately trained to work with animals. This taught me a lot behind the ethics of research which I know will be a lifelong skill. Within the lab, I focused on immunohistochemistry, which provides researchers with a window into inflammation. This staining technique uses antibodies conjugated to enzymes that catalyze reactions to form detectable compounds to visualize and localize specific antigen markers in a tissue sample. I was unfamiliar with this entire process prior to STEER but had to go through it multiple times this summer since I was looking for a whole array of protein markers. I was grateful to have this opportunity to build my wet lab and animal handling skills which I know I will use a lot in the future.

What is your summer research project?

I was drawn to the topic of wildfires because while they are an extremely common and natural occurrence, they have become far more frequent and threatening to both human and animal life in the recent years, with multitudes of research pointing to anthropogenic climate change as the reason behind this. Moreover, while a lot of data has emphasized the effect of wildfires on physical/respiratory health, there is much less on that of wildfires on mental health. Under the mentorship of Dr. Hwang, I used R to investigate the connection between poor mental health days (dependent variable) and several fire indicators, such as percent risk of fire damage, PM2.5, poor AQI days, etc (independent variables). The figure that is attached shows that there is a positive correlation between bad mental health and increased risk of wildfire damage – a relationship that is more prominent when variation due to poverty level as well as education is removed. 

What are the implications of your research?

My methods and project was fairly straightforward and simple in its design. I think similar or more advanced models could be used to make great strides in health monitoring and improving treatment for populations that are most strongly disadvantaged by climate change, because comprehensive health services (including mental health services) are significantly more inaccessible to subgroups facing climate disasters in regions that are less equipped to treat human health and recover following major environmental events. 

What new skills have you gained through your research?

At the start of this program, I was definitely very unfamiliar with statistical analytics, and essentially all programming languages. While I would consider myself a beginner still, I have gained a lot more experience working with large quantities of data in R, and because I have spent all past research summers in a physical wetlab, I’ve also become more comfortable with the remote, computer-based side of research. Finally, I learned a lot about how to present data and explain statistically significant results to an audience of my peers and mentors. 

My name is Meg Gladieux, I am going into my third year at Penn, and I am a double major in Cognitive Science and French and Francophone studies. My academic and research interests lie in children’s development, particularly in how environmental influences shape cognitive development and implications for social policy. This summer, I worked with Dr. Jianghong Liu, whose research focuses on early childhood exposures and brain and behavioral outcomes in children and adolescents.

What is your summer research project?

My summer research focused largely on an independent literature search that integratively examined the current work in the fields of community and environmental health regarding cumulative outcomes of toxic environmental exposures and social disadvantage on children’s cognition. I examined journal articles across several databases to understand the current state of the field and to identify gaps in understanding of this very important dimension of community health. Through this process, I particularly concentrated on two key environmental exposures: air pollution, including PM2.5, PM10, and PAH, and lead exposure. I also analyzed a few recent publications dealing with secondhand tobacco smoke as well as other common household toxicants affecting children, including pesticides and PBDE. I focused on these exposures because they are the most prevalent exposures in children, with high risk in children’s environments through nearby industrial sites, heavily trafficked areas, homes, particularly homes with older infrastructure, schools, and other buildings and background exposures. 

I cross-searched these key childhood sources of toxic exposure with multidimensional indicators of adversity including material hardship, parental education, family dynamics, socioeconomic status, neighborhood conditions, and exposure to violence and trauma. While independently each toxic physical exposure and social exposures are associated with adverse cognitive outcomes, particularly relating to school performance, recent studies seem to indicate a cumulative effect when children encounter both types of environmental exposure. I developed a framework for thinking about cumulative environmental exposures within different domains of children’s holistic environments. The magnification of negative cognitive outcomes for children experiencing both environmental toxicity and social adversity is through prolonged toxic stress, in which there is a prolonged stress reaction in the brain due to both external biological and psychosocial factors and internal autonomic stress responses to the external world. These prolonged stress responses interfere with healthy cognitive development, increasing the likelihood of cognitive difficulties in childhood and beyond. 

What are the implications of your research?

Thinking about policy and practical implications was a really big part of my work this summer. It’s important to systematically collect evidence that a problem exists, but ultimately, the goal of research is to figure out ways to solve problems. If we know that children facing more adversity and hardship are at higher risk of toxic environmental exposures and that these exposures actually amplify the negative effects of one another, it becomes even more vital to protect these vulnerable children from these risk factors both in their physical environments and social environments. The mechanism for the relationship between physical and psychosocial exposures contributing to toxic stress is multifaceted and still poorly understood. It is associated with neurotransmitter disruptions and inflammatory responses that hinder brain development. In fact, in MRI studies, we can see physical differences between the brains of children who have experienced high levels of toxic stress and those who have not. 

This ultimately demonstrates that not only are vulnerable children more likely to be encountering the toxic environmental exposures, but their adverse social environments actually make the impact of those environmental exposures worse. Environmental pollution and overall climate change are having the biggest effects on disadvantaged communities, particularly the children within them. Mitigation of environmental hazards is thus most vital in the most poverty-stricken communities. Improving building infrastructure, increasing educational initiatives, and preventing further air and lead pollution from industry and construction through policy are possible first steps. Ultimately, protecting children through cultivating safe and loving holistic environments is the best way to ensure healthy development. Several promising recent papers suggest that increasing support within schools for children at high risk for exposure to toxicants in their homes and neighborhoods and increasing access to safe greenspaces may act as protective mechanisms that mitigate the impact of toxic stress (McCrae et al., 2021; Aerts et al., 2018).

What new skills have you gained through your research?

This summer, I didn’t only have the opportunity to work on my own independent project, but also contributed broadly to much of my mentor’s other work and ongoing projects. In addition to developing my own critical thinking skills, independent thought, and creativity in scientific inquiry, I have also been able to take part in several other projects through supporting roles. I have helped edit several manuscripts and prepare them for publication. I have also gone through the process of submitting several papers to journals as well as making edits and addressing the comments of peer reviewers. Additionally, I have been able to support my mentor in preparing peer reviews and providing suggestions on other manuscripts that are in production related to environmental and community health. These experiences gave me invaluable insight into the overall research process beyond data collection, inquiry, and literature review.

Through my research and overall experience in STEER this summer, I feel that I have gained so many skills that I will carry with me throughout my education, into further research, and toward my future career. I have become skilled at literature synthesis as well as citation management. I have learned how to take a collection of papers and draw connections across them to find new insights and identify current gaps within the current field. I have also become extremely proficient in navigating databases and sorting through extensive libraries of research to pick out the articles that are the most relevant to the problem I am researching. Finally, I have learned a lot about community health and participatory action research in community environmental work. Especially in studying people and the real-life effects of their environments on their well-being, research must prioritize inclusivity of community needs.

I am Esha Srinivasan and I am originally from a suburb of Raleigh, North Carolina. I am a rising sophomore at the University of Pennsylvania where I am majoring in biochemistry and minoring in music. My after college plans include veterinary school! My love for animals and my experience with environmental science in high school made me really excited for the opportunity of being a STEER scholar. Lucky enough to spend the summer in Philadelphia, I worked in a translational human immunodeficiency virus (HIV) research lab with Dr. Katharine Bar. I found the summer to be extremely rewarding, considering how apt it is to study infectious pathogens in the midst of a global health crisis.

What is your summer research project?

This summer, I aided in the effort of understanding how HIV evolves in response to treatments and the body’s immune system. I sequenced SIVmac239, a close relative to HIV, in the plasma samples of 13 animals inoculated with the virus. The 13 animals were given antiretroviral therapy (ART) to suppress their viral load. Some animals were given monoclonal antibodies to prolong the suppression of the virus without having to continue ART.  After sequencing, I was able to look at the ambiguities between the original reference sequence and the viruses found within the sample. 

What are the implications of your research?

HIV is a health crisis ubiquitous throughout the world. Several millions of individuals are currently living with HIV globally. Though current medicines are certainly effective at suppressing the virus and prolonging the lives of patients, access to treatments unfortunately differ throughout the world. Not only is healthcare access unequal, but also clades of HIV endemic to Europe and the United States are more well studied than other clades of the virus. Studying all types of HIV assures that any treatments found benefit all that are infected with HIV and not just those infected with a clade native to an affluent country.

Since this research reveals the places in which HIV has changed its sequence, these loci on the HIV genome can help researchers understand how HIV is able to evade the body’s immune response. While ART is able to remove the virus lingering throughout the body, it is not able to remove the reservoir of virus that remains in the cells of the host. Understanding why HIV makes these changes brings us one step closer to finding a cure or preventative for the virus.

What new skills have you gained through your research?

Through this research, I was able to develop a deep appreciation for both the social science and actual science of HIV. Knowing about the debilitating effects this virus has on patients’ lives really motivates its research. I was also in awe of how clever HIV is at avoiding capture. I find it fascinating that a virus’ lack of skill in maintaining its own integrity actually supports its ability to persist in a host.

Gene sequencing was something that I had never done before this summer. At first it was daunting how the entire process seemed to consist of machines and tiny volumes of clear liquids, but it was motivating being able to make parallels between HIV’s replication and the lab methods. Working with SIV instead of HIV taught me how relevant non-human primate models are to research, and about how we are always working towards improving the accuracy of these models. I also enjoyed learning about SIV’s role in the environment and how HIV was once zoonotic. I learned how to turn RNA into DNA and it was fascinating to me that we were able to replicate a process that HIV already knows how to do. I learned how to use the polymerase chain reaction to make copies of DNA. I also learned how to perform gel electrophoresis and how it can be used to confirm the size of sequence fragments. Using software to read and analyze sequences was new to me as well. I always thought it was so cool that we are able to detect these sequences down to single nucleotides. I am excited to be able to use these skills in my science courses in undergrad and beyond.

My name is Hasibe Caballero-Gomez. I’m originally from Los Angeles, California, and currently study at Haverford College. I am a Chemistry major and environmental science minor. This summer I worked for Professor Pepino to investigate policy solutions that could decrease childhood lead poisoning for at risk communities in Philadelphia, PA

This summer I explored various city’s lead policies, regulations, and budgets in order to identify policies that could be translated to Philadelphia and improve health outcomes for children. I interviewed various stakeholders and analyzed published policy recommendations to determine the policy solutions that were the most likely to be successful. In the end, my research explores community engagement policy and the ways pre-exisiting resources in target communities can be adjusted to decrease childhood lead poisoning for at risk populations. 

Lead poisoning has been linked to decreases in academic achievement and IQ at levels as low as 5 ug/dL. Despite efforts from the Philadelphia Health Department to curtail systemic childhood lead poisoning, children continue to be identified with elevated blood lead levels (EBLLs) above the CDC reference level for diagnosis. This problem disproportionately affects low-income Black communities. At the moment remediation is costly, and with the current policies in place comprehensive remediation seems unrealistic.The solutions identified via my research create an interdependent model that offers increased community awareness and engagement with the issue that could potentially improve health and social outcomes for at-risk children.

I learned a lot about how to create questions and navigate interviews with various stakeholders in the field and community. Prior to this experience I have never had to engage as deeply with policy before, so I learned a lot about reading and analyzing policy. I also gained technical skills like learning to map data through R.

At risk communities highlighted with an X.

Interdependent model identified 

My name is Cece Chen and I am a rising senior at the University of Pennsylvania. I am majoring in biochemistry and minoring in healthcare management & neuroscience. During my junior year, I had the opportunity to begin work in the Wells lab, but it was really through the STEER program this summer that I was able to really get involved in my research project. 

What is your summer research project?

(Background: Biliary atresia is a rare gastrointestinal disease in babies where bile flow from the liver to the gallbladder is obstructed. In babies with BA, the extrahepatic bile ducts get damaged in utero and then are obstructed/fibrosed. This prevents the proper flow of bile, so bile builds up in the liver and damages it. This causes liver fibrosis, which eventually leads to liver cirrhosis and liver failure. There are currently no treatments or cure for BA besides a liver transplant, which makes BA the leading indication for pediatric liver transplant. As such, we are interested in studying this disease to hopefully shed more light on prevention and treatment options. Although the cause of BA is still unknown, research seems to point to environmental insults as the primary cause. The Wells lab has already isolated biliatresone, an isoflavonoid from the Dysphania plant, as a biliary toxin. However, this compound is only found in one plant in the outbacks of Australia, so we are trying to see if more common/human accessible compounds, similar to biliatresone, also cause bile duct damage in vitro and in vivo. This is what my project focuses on.)

My project is to investigate the effects of 12 electrophilic compounds, all structurally or functionally similar to biliatresone, and their impacts on cholangiocytes. We have started dosage studies for 4 compounds (COS, DEL, PTL, IAL) to identify the ideal dosage for each compound such that it causes cell damage, but not necessarily cell death. To do this, we treated 2D cell cultures with a range of dosages for each compound and stained with CK19 and phalloidin to evaluate toxicity. Once the ideal dosages have been identified, the goal is to study these 12 compounds in both in vitro and in vivo models.

The original 12 compounds of interest included a class of compounds called microcystins, which is produced by blue-green algae. Knowing this, we have also been working on designing an epidemiological study to investigate if there is any spatial correlation between proximity to water sources (like lakes, rivers, and oceans) and the prevalence of BA cases. 

What are the implications of your research?

There are a lot of unknowns with the disease biliary atresia. We don’t know the cause and we don’t know the cure. Therapeutic options for babies with BA are also very limited, with the most significant of these options being the Kasai procedure. This helps to drain bile from the liver to the small intestines directly and bypasses the obstructed ducts. But even with this surgery, about 50% of babies with BA have to undergo liver transplant before the age of 2 and the remaining kids will need a liver transplant at some point later in life. As such, we are hoping that by exploring the toxin model for BA we can gain a better understanding of the pathophysiology of this disease, which can help lead to better prevention and treatment options. We are also hoping that the epidemiology studies will reveal significant correlations so that we can better recognize and address BA at a population level.

What new skills have you gained through your research?

It was such an honor to be a part of this program. I learned so much from my PI, other lab members, collaborators, and everyone involved in the STEER program. In order to complete my summer project, I had to first learn about the pathophysiology of biliary atresia. In my investigation of the 12 compounds of interest, I not only learned a lot about each compound but also became familiar with using the SciFinder database. Because the program was remote, I was unable to perform wet lab work, but I did learn how to use ImageJ to analyze images that Gauri shared with me. By being involved in the planning phases for the epidemiology studies, I also learned a lot about study design, such as thinking about different databases and control groups. Finally, this program taught me so much about environmental health research and about engaging with communities– I am looking forward to learning more and doing more in the fight for environmental justice. 

My name is Alina Mizrahi, and I am originally from Mexico City. I am a rising senior at the University of Pennsylvania, majoring in Cognitive Science and Political Science. Through the STEER program, I worked with Dr. Jianghong Liu to determine the effects of the lead-related dietary pattern on cognition (measured as IQ). 

What is your summer research project?

Using data from a cohort in Jintan, China, Dr. Liu uses longitudinal data to understand the effects that lead can have on children’s development. Among other things, Dr. Liu is working to understand how dietary lead can affect cognitive outcomes in school children. This summer, I analyzed the existing literature regarding both the relationship between dietary patterns and cognition and the link between lead and cognitive functioning in children. In our manuscript we describe how we found an association between lead-related dietary pattern and IQ scores. I also drafted a poster that will be presented at the conference of the International Society for Environmental Epidemiology.

What are the implications of your research?

Lead is prevalent in our environment. Sources of lead exposure are often due to human activities. In the United States it comes mainly from materials such as paint, caulking, and pipe solde in older homes. In China, lead exposure is more often related to air pollution. Whatever the source of exposure, lead is a neurotoxin that can affect neurocognitive development in children. It is important to understand the mechanisms by which lead can have a negative impact on IQ in order to assuage the problem. Through my research, we know more about how dietary lead can affect cognition. This offers insight into a preventative measure, diet monitoring,  that could help mitigate the effects of lead exposure. 

What new skills have you gained through your research?

The STEER program this year was entirely remote, but I had the opportunity to gain new research skills. First, I learned how to conduct a literature synthesis to look for gaps in the existing scholarship. I also learned to write a manuscript that has the potential to be published in a journal. By working with Dr. Liu, I was exposed to the process of submitting articles and posters for publication and presentation, which was very exciting.