Nature journaling in school gardens is a unique way to engage students in the natural world, providing time to notice, wonder, and observe through writing and drawing while engaging in environmental and sustainability learning. With the number of school gardens increasing in the United States, educators can benefit from understanding what students experience while participating in garden-based learning activities so they can adapt their teaching to fit the educational needs of their participants. School garden studies typically focus on measuring academic and health outcomes and nature journaling studies typically focus on educator experiences with one classroom. We facilitated a nature journaling study with four elementary classrooms in a public, Title I school in the desert southwest to explore student experiences while nature journaling in their school garden. Our findings show that nature journaling provides opportunities for students to engage in sustainability literacy by helping them to develop a sense of place in their school garden, inspire environmental stewardship, and practice systems thinking right outside their classrooms.

The widespread environmental degradation characterizing the Anthropocene is a call to address a deteriorating human-nature relationship. For much of history, humans have been deeply connected with and in respect of nature both physically and psychologically, and this bond can be renewed. Doing so is especially important for future generations, as modern youth have less opportunities to experience the natural world and more opportunities to experience the virtual world. A lack of nature connectedness in our youth has clear implications for sustainability and underscores the need for interventions aimed at reconnecting youth with nature. Primary and secondary education is a particularly valuable leverage point for such interventions, and nature-based school landscapes may be a valuable tool in strengthening the human-nature relationship and reconnecting youth with nature. While studies have indirectly linked garden-based learning and connection with nature in youth, research has not yet directly explored the relationship between the two.

My research explores 12th grade students attending Desert Marigold School in South Phoenix. Desert Marigold practices Waldorf educational philosophy with the school’s garden as a primary teaching tool and recreational space. I used arts-based methods to give students an opportunity to visually communicate their perspectives of the school’s landscape through photography and artistic renderings. Students then verbally described and discussed their media in a series of group interviews. Data were then coded and analyzed for themes of connection with nature expressed in the literature. The results illustrate that students connect with nature in a variety ways through the school’s landscape, demonstrating potential for enhanced sustainability outcomes in education.

Traumatic brain injury (TBI) is a widespread health issue that affects approximately 1.7 million lives per year. The effects of TBI go past the incident of primary injury, as chronic damage can follow for years and cause irreversible neurodegeneration. A potential strategy for repair that has been studied is cell transplantation, as neural stem cells improve neurological function. While promising, neural stem cell transplantation presents challenges due to a relatively low survival rate post-implantation and issues with determining the optimal method of transplantation. Shear-thinning hydrogels are a type of hydrogel whose linkages break when under shear stress, exhibiting viscous flow, but reform and recover upon relaxation. Such properties allow them to be easily injected for minimally invasive delivery, while also shielding encapsulated cells from high shear forces, which would normally degrade the function and viability of such cells. As such, it is salient to research whether shear-thinning hydrogels are feasible candidates in neural cell transplantation applications for neuroregenerative medicine. In this honors thesis, shear-thinning hydrogels were formed through guest-host interactions of adamantane modified HA (guest ad-HA) and beta-cyclodextrin modified HA (host CD-HA). The purpose of the study was to characterize the injection force profile of different weight percentages of the HA shear-thinning hydrogel. The break force and average glide force were also compared between the differing weight percentages. By understanding the force exerted on the hydrogel when being injected, we could characterize how neural cells may respond to encapsulation and injection within HA shear-thinning hydrogels. We identified that 5% weight HA hydrogel required greater injection force than 4% weight HA hydrogel to be fully delivered. Such contexts are valuable, as this implies that higher weight percentage gels impart higher shear forces on encapsulated cells than lower weight gels. Further study is required to optimize our injection force system’s sensitivity and to investigate if cell encapsulation increases the force required for injection.

Traumatic brain injury involves a primary mechanical injury that is followed by a secondary<br/>inflammatory cascade. The inflammatory cascade in the CNS releases cytokines which are<br/>associated with leukocytosis and a systemic immune response. Acute changes to peripheral<br/>immune cell populations post-TBI include a 4.5-fold increase of neutrophils 3 hours post-injury,<br/>and 2.7-fold or higher increase of monocytes 24 hours post-injury. Flow Cytometry is a<br/>technique that integrates fluidics, optics, and electronics to characterize cells based on their light<br/>scatter and antigen expression via monoclonal antibodies conjugated to fluorochromes. Flow<br/>cytometry is a valuable tool in cell characterization however the standard technique for data<br/>analysis, manual gating, is associated with inefficiency, subjectivity, and irreproducibility.<br/>Unsupervised analysis that uses algorithms packaged as plug-ins for flow cytometry analysis<br/>software has been discussed as a solution to the limits of manual gating and as an alternative<br/>method of data visualization and exploration. This investigation evaluated the use of tSNE<br/>(dimensionality reduction algorithm) and FlowSOM (population clustering algorithm)<br/>unsupervised flow cytometry analysis of immune cell population changes in female mice that<br/>have been exposed to a LPS-induced systemic inflammatory challenge, results were compared to<br/>those of manual gating. Flow cytometry data was obtained from blood samples taken prior to and<br/>24 hours after LPS injection. Unsupervised analysis was able to identify populations of<br/>neutrophils and pro-inflammatory/anti-inflammatory monocytes, it also identified several more<br/>populations however further inquiry with a more specific fluorescent panel would be required to<br/>establish the specificity and validity of these populations. Unsupervised analysis with tSNE and<br/>FlowSOM demonstrated the efficient and intuitive nature of the technique, however it also<br/>illustrated the importance of the investigator in preparing data and modulating plug-in settings.

Traumatic brain injury (TBI) is defined as an injury to the head that disrupts normal brain function. TBI has been described as a disease process that can lead to an increased risk for developing chronic neurodegenerative diseases, like frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). A pathological hallmark of FTLD and a hallmark of ALS is the nuclear mislocalization of TAR DNA Binding Protein 43 (TDP-43). This project aims to explore neurodegenerative effects of TBI on cortical lesion area using immunohistochemical markers of TDP-43 proteinopathies. We analyzed the total percent of NEUN positive cells displaying TDP-43 nuclear mislocalization. We found that the percent of NEUN positive cells displaying TDP-43 nuclear mislocalization was significantly higher in cortical tissue following TBI when compared to the age-matched control brains. The cortical lesion area was analyzed for each injured brain sample, with respect to days post-injury (DPI), and it was found that there were no statistically significant differences between cortical lesion areas across time points. The percent of NEUN positive cells displaying TDP-43 nuclear mislocalization was analyzed for each cortical tissue sample, with respect to cortical lesion area, and it was found that there were no statistically significant differences between the percent of NEUN positive cells displaying TDP-43 nuclear mislocalization, with respect to cortical lesion area. In conclusion, we found no correlation between the percent of cortical NEUN positive cells displaying TDP-43 nuclear mislocalization with respect to the size of the cortical lesion area.

Current sideline concussion assessment tools are inaccurate and biased leading to undiagnosed concussions and possibly a second, more severe concussion. This study evaluated the effects of different surface types on postural stability using the Lockhart Monitor iPhone application in order to validate its potential use as a data-driven sideline concussion assessment tool. Participants had three components of their postural sway recorded in 30 and 60-second trials on three different surface types, tile, turf, and natural grass, with eyes open and closed. The statistical analysis found that there was a significant difference between surface types for the sway area (p = 0.0268), but there was no difference for the sway path and velocity. These results call for further research to be conducted on the impact of surface types and the use of the Lockhart Monitor as a sideline concussion assessment tool with larger sample sizes and improved methodologies.

Current sideline concussion assessment tools are inaccurate and biased leading to undiagnosed concussions and possibly a second, more severe concussion. This study evaluated the effects of different surface types on postural stability using the Lockhart Monitor iPhone application in order to validate its potential use as a data-driven sideline concussion assessment tool. Participants had three components of their postural sway recorded in 30 and 60-second trials on three different surface types, tile, turf, and natural grass, with eyes open and closed. The statistical analysis found that there was a significant difference between surface types for the sway area (p = 0.0268), but there was no difference for the sway path and velocity. These results call for further research to be conducted on the impact of surface types and the use of the Lockhart Monitor as a sideline concussion assessment tool with larger sample sizes and improved methodologies.

Traumatic brain injury (TBI), a neurological condition that negatively affects neural capabilities, occurs when a blunt trauma impacts the head. Following the initial injury that immediately impacts neural cell function and survival, a series of secondary injury events lead to substantial sustained inflammation for weeks to years post-injury. To develop TBI treatments that may stimulate regenerative processes, a novel drug delivery system that efficiently delivers the appropriate drug/payload to injured tissue is crucial. Hyaluronic acid (HA) hydrogels are attractive when developing a biomaterial for tissue reparation and regeneration. HA is a natural polymer with physicochemical properties that can be tuned to match the properties of the extracellular matrix (ECM) of the many tissues including the central nervous system (CNS). Here, the project objective was to develop a HA hydrogel system for local delivery of a biological payload; this objective was completed by employing a composite system with two parts. The first part is an injectable, shear-thinning bulk hydrogel, and the second is microgels for loading biological payloads. The bulk hydrogel was composed of cyclodextrin modified HA (Cd-HA) and adamantane modified HA (Ad-HA) that give rise to guest-host interactions that facilitate physical crosslinking. The microgel, composed of norbornene-HA (Nor-HA) and sulfated-HA, crosslink via chemical crosslinks upon activation of a UV photoinitiator. The sulfated-HA microgels facilitate loading of biological payloads by mimicking heparin binding sites via the conjugated sulfated group. Neuregulin I, an epidermal growth factor with neuroprotective properties, is one such protein with a heparin binding domain that may be retained in the sulfated-HA microgels. Specifically, the project focused on mechanical testing of this composite microgel/hydrogel system and also developing protein affinity assays.

Polymeric nanoparticles (NP) consisting of Poly Lactic-co-lactic acid - methyl polyethylene glycol (PLLA-mPEG) or Poly Lactic-co-Glycolic Acid (PLGA) are an emerging field of study for therapeutic and diagnostic applications. NPs have a variety of tunable physical characteristics like size, morphology, and surface topography. They can be loaded with therapeutic and/or diagnostic agents, either on the surface or within the core. NP size is an important characteristic as it directly impacts clearance and where the particles can travel and bind in the body. To that end, the typical target size for NPs is 30-200 nm for the majority of applications. Fabricating NPs using the typical techniques such as drop emulsion, microfluidics, or traditional nanoprecipitation can be expensive and may not yield the appropriate particle size. Therefore, a need has emerged for low-cost fabrication methods that allow customization of NP physical characteristics with high reproducibility. In this study we manufactured a low-cost (<$210), open-source syringe pump that can be used in nanoprecipitation. A design of experiments was utilized to find the relationship between the independent variables: polymer concentration (mg/mL), agitation rate of aqueous solution (rpm), and injection rate of the polymer solution (mL/min) and the dependent variables: size (nm), zeta potential, and polydispersity index (PDI). The quarter factorial design consisted of 4 experiments, each of which was manufactured in batches of three. Each sample of each batch was measured three times via dynamic light scattering. The particles were made with PLLA-mPEG dissolved in a 50% dichloromethane and 50% acetone solution. The polymer solution was dispensed into the aqueous solution containing 0.3% polyvinyl alcohol (PVA). Data suggests that none of the factors had a statistically significant effect on NP size. However, all interactions and relationships showed that there was a negative correlation between the above defined input parameters and the NP size. The NP sizes ranged from 276.144 ± 14.710 nm at the largest to 185.611 ± 15.634 nm at the smallest. In conclusion, the low-cost syringe pump nanoprecipitation method can achieve small sizes like the ones reported with drop emulsion or microfluidics. While there are trends suggesting predictable tuning of physical characteristics, significant control over the customization has not yet been achieved.

Chronic wounds affect many people worldwide and significantly impact their quality of life. Hydrogel wound dressings are a promising option for chronic wounds due to their properties, including mild fabrication conditions, high water content, biodegradability, and bioactive molecule delivery capabilities. This thesis will explore the mechanisms that contribute to the wound healing properties of a bovine type I collagen-based hydrogel that incorporates platelet-rich plasma and describe how this hydrogel will be capable of effectively healing chronic wounds.