TAMU-CC Repository
The Texas A&M University‐Corpus Christi (TAMU‐CC) repository is an open online site for storing and sharing digital content created or owned by the TAMU‐CC community. Content includes published and unpublished research and scholarship as well as archival materials. The service is managed by the Mary and Jeff Bell Library in cooperation with the Texas Digital Library. Learn more
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Recent Submissions
Cellular response of keratinocytes to the entry and accumulation of nanoplastic particles
(2024-04-29) Martin, Leisha; Simpson, Kayla; Brzezinski, Molly; Watt, John; Xu, Wei
Plastic accumulation in the environment is rapidly increasing, and nanoplastics (NP), byproducts of environmental weathering of bulk plastic waste, pose a significant public health risk. Particles may enter the human body through many possible routes such as ingestion, inhalation, and skin absorption. However, studies on NP penetration and accumulation in human skin are limited. Loss or reduction of the keratinized skin barrier may enhance the skin penetration of NPs. The present study investigated the entry of NPs into a human skin system modeling skin with compromised barrier functions and cellular responses to the intracellular accumulations of NPs. Two in vitro models were employed to simulate human skin lacking keratinized barriers. The first model was an ex vivo human skin culture with the keratinized dermal layer (stratum corneum) removed. The second model was a 3D keratinocyte/ dermal fibroblast cell co-culture model with stratified keratinocytes on the top and a monolayer of skin fibroblast cells co-cultured at the bottom. The penetration and accumulation of the NPs in different cell types were observed
using fluorescent microscopy, confocal microscopy, and cryogenic electron microscopy (cryo-EM). The cellular responses of keratinocytes and dermal fibroblast cells to stress induced by NPs stress were measured. The genetic regulatory pathway of keratinocytes to the intracellular NPs was identified using transcript analyses and KEGG pathway analysis. The cellular uptake of NPs by skin cells was confirmed by imaging analyses. Transepidermal transport and penetration of NPs through the skin epidermis were observed. According to the gene expression and pathway analyses, an IL-17 signaling pathway was identified as the trigger for cellular responses to internal NP accumulation in the keratinocytes. The transepidermal NPs were also found in co-cultured dermal fibroblast cells and resulted in a large-scale transition from fibroblast cells to myofibroblast cells with enhanced production of α-smooth muscle actin and pro-Collagen Ia. The upregulation of inflammatory factors and cell activation may result in skin inflammation and ultimately trigger immune responses.
Dynamics of methane emissions from northwestern Gulf of Mexico subtropical seagrass meadows
(2024-03-21) Yu, Hao; Coffin, Richard; Organ, Hannah
While seagrass meadows are perceived to be pertinent blue carbon reservoirs, they also potentially release methane (CH4) into the atmosphere. Seasonal and diurnal variations in CH4 emissions from a subtropical hypersaline lagoon dominated by Halodule wrightii in southern Texas, USA, on the northwest coast of the Gulf of Mexico were investigated. Dissolved CH4 concentrations decreased in the daytime and increased overnight during the diel observation period, which could be explained by photosynthesis and respiration of seagrasses. Photosynthetic oxygen was found to significantly reduce CH4 emissions from seagrass sediment. Diffusive transport contributed slightly to the release of CH4 from the sediment to the water column, while plant mediation might be the primary mechanism. The diffusive CH4 flux at the sea-air interface was 12.3–816.2 µmol/m2 d, over the range of the sea-air fluxes previously reported from other seagrass meadows. This was related to relatively higher dissolved CH4 concentrations (11.6–258.2 nmol/L) in a mostly closed lagoon with restricted water exchange. This study emphasizes seagrass meadows in the subtropical hypersaline lagoon as a source of atmospheric CH4, providing insights into the interactions between seagrass ecosystems and methane dynamics, with potential implications for seagrass meadow management and conservation efforts.
Global diversity and distribution of rhizosphere and root‑associated fungi in coastal wetlands: A systematic review
(2024-03-22) Lumibao, Candice Y.; Harris, Georgia; Birnbaum, Christina
Coastal wetlands have been long recognized for their importance to biodiversity and many biogeochemical processes including carbon sequestration; however, our understanding of plant-microbe interactions that govern many processes in these ecosystems remains elusive. Fungal communities are known to play critical roles in coastal wetlands, particularly due to their close relationships with plants, yet, systematic understanding of their distributional patterns and the factors shaping these patterns in natural coastal wetland environments has been rarely assessed. We synthesized existing published literature from fifty-one studies spanning 60 years to examine global fungal distributional patterns in coastal wetlands, draw linkages between fungi, the plant communities, and their environment, and identify gaps in fungal research and suggest future research directions. We focused on studies that reported root-associated fungi and fungi from the plant rhizosphere (i.e., soil surrounding roots) in coastal dunes, intertidal flats, salt marshes, and tidal wetlands. Our synthesis has revealed that (1) 203 fungal species were reported from salt marshes, 59 fungal species from coastal dunes, 32 from tidal wetlands, and ten from intertidal flats; (2) rhizosphere fungal communities were more species-rich and reported more often for all ecosystems except in salt marshes; and (3) nineteen different fungal guilds, which are predominantly arbuscular mycorrhizal fungi. We conclude that more research is needed to better understand root-associated fungal diversity in less studied ecosystems reviewed here. We have identified knowledge gaps in reported data and outlined suggestions to facilitate future plant-fungal research in these declining, but important, coastal ecosystems.
Detection of astrophysical neutrinos at prospective locations of dark matter detectors
(2024-02-29) Zhuang, Yi; Strigari, Louis E.; Jin, Lei; Sinha, Samiran
We study the prospects for detection of solar, atmospheric neutrino, and diffuse supernova neutrino background (DSNB) fluxes at future large-scale dark matter detectors through both electron and nuclear recoils. We specifically examine how the detection prospects change for several prospective detector locations [Sanford Underground Research Facility (SURF), SNOlab, Gran Sasso, China Jinping Underground Laboratory (CJPL), and Kamioka] and improve upon the statistical methodologies used in previous studies. Because of its ability to measure lower neutrino energies than other locations, we find that the best prospects for the atmospheric neutrino flux are at the SURF location, while the prospects are weakest at CJPL because it is restricted to higher neutrino energies. On the contrary, the prospects for the DSNB are best at CJPL, due largely to the reduced atmospheric neutrino background at this location. Including full detector resolution and efficiency models, the CNO component of the solar flux is detectable via the electron recoil channel with exposures of ∼103 ton-yr for all locations. These results highlight the benefits for employing two detector locations, one at high and one at low latitude.
The impact of digitalized community-based squarestepping exercise program on cognitive and balance functions among older adults living in senior facilities: A pilot study
(2024-02-16) Lee, Kyoung Eun; Boham, Mikaela; Zhang, Meng; Ro, YoungHee; Cong, Xiaomei; Huang, Yuxia
Objectives: Older adults exhibit a high desire for active and healthy aging without physical or mental dysfunction, particularly those living independently in senior facilities. Preserving or improving cognitive function and minimizing fall risks are essential for older adults to live a happy and active lifestyle. The purpose of this pilot study was to examine the feasibility, safety, and preliminary effectiveness of the innovative digitalized community-based square-stepping exercise program (DC-SSEP) in improving cognitive and physical function among older adults residing in senior facilities.
Methods: Guided by the Health Promotion Model and Social Cognitive Theory, this pilot study used a quasi-experiment design with one intervention group. A total of 17 older adults recruited from a senior facility in Southern Texas participated in 40 sessions of DC-SSEP over 20 weeks. Cognitive function was measured using the latest version (8.1) of Montreal Cognitive Assessment and the balance function focusing on balance and functional mobility was measured using Berg Balance Scale and Time to Up and Go.
Results: Most participants were non-Hispanic white women. The DC-SSEP was a feasible and safe exercise program for older adults living in senior facilities; and the results showed the preliminary effectiveness of the DC-SSEP in improving cognitive and balance function (P < 0.01) among older adults.
Conclusion: This pilot study is distinctive as it is among the first to evaluate the multi-layered impacts of DC-SSEP using Internet of Things (IoT) technology and integrated operating software in the United States. Despite the small sample size and homogeneity of participants, this pilot study suggests multiple valuable directions for future research using DC-SSEP.