Reimagining Wilmer's Park

Final project for LARC:340 Site Planning and Design Studio (Fall 2022). University of Maryland, College Park.Wilmer’s Park is a “80-acre parcel containing the ruins of a dance hall, motel, ranch house, covered stage, baseball and football fields. As a major stop on the Chitlin Circuit, Wilmer’s Park opened its doors to African-American musicians, entertainers, athletes and fans from the early 1950s through the late 1960s. Arthur Wilmer used his experience and connections developed as the owner of a night club in Washington, D. C. to bring both popular acts and up-and-coming performers to rural Prince George’s County; the bandstand at Wilmer’s Park showcased everyone from Duke Ellington and Otis Redding to the Temptations, Patti La Belle, and a young Stevie Wonder. The former tobacco farm played an important role in exposing emerging musicians to local African Americans during a time of segregation.” The park has been closed for 10+ years and the purpose of this project is to transform Wilmer’s Park for the residents of Brandywine or nearby communities. For this project, students work in teams of three to design a master plan along with an individual detailed site plan. The design program for these plans came from the residents’ comments from community engagement workshops, notes from Councilman Harrison’s interview, important stakeholders, the field trip, and guest lectures. The master plan does not include all 80 acres of the park and often identifies a phasing plan for the entire project.Prince George's County Parks Departmen

Range-wide experiment to investigate nutrient and soil moisture interactions in loblolly pine plantations

The future climate of the southeastern USA is predicted to be warmer, drier and more variable in rainfall, which may increase drought frequency and intensity. Loblolly pine (Pinus taeda) is the most important commercial tree species in the world and is planted on ~11 million ha within its native range in the southeastern USA. A regional study was installed to evaluate effects of decreased rainfall and nutrient additions on loblolly pine plantation productivity and physiology. Four locations were established to capture the range-wide variability of soil and climate. Treatments were initiated in 2012 and consisted of a factorial combination of throughfall reduction (approximate 30% reduction) and fertilization (complete suite of nutrients). Tree and stand growth were measured at each site. Results after two growing seasons indicate a positive but variable response of fertilization on stand volume increment at all four sites and a negative effect of throughfall reduction at two sites. Data will be used to produce robust process model parameterizations useful for simulating loblolly pine growth and function under future, novel climate and management scenarios. The resulting improved models will provide support for developing management strategies to increase pine plantation productivity and carbon sequestration under a changing climate.Peer reviewedNatural Resource Ecology and Managemen

Efficient isolation, biophysical characterisation and molecular composition of extracellular vesicles secreted by primary and immortalised cells of reproductive origin

Effective communication between the maternal reproductive tract, gametes and the pre-implantation embryo is essential for the successful establishment of pregnancy. Recent studies have recognised extracellular vesicles (EVs) as potent vehicles for intercellular communication, potentially via their transport of microRNAs (miRNAs). The aim of the current investigation was to determine the size, concentration and electrical surface properties (zeta potential) of EVs secreted by; (1) primary cultures of porcine oviductal epithelial cells (POECs) from the isthmus and ampullary regions of the female reproductive tract; (2) Ishikawa and RL95-2 human endometrial epithelial cell line cultures; and (3) the non-reproductive epithelial cell line HEK293T. In addition, this study investigated whether EVs secreted by POECs contained miRNAs. All cell types were cultured in EV-depleted medium for 24 or 48 h. EVs were successfully isolated from conditioned culture media using size exclusion chromatography. Nanoparticle tracking analysis (NTA) was performed to evaluate EV size, concentration and zeta potential. QRT-PCR was performed to quantify the expression of candidate miRNAs (miR-103, let-7a, miR-19a, miR-203, miR-126, miR-19b, RNU44, miR-92, miR-196a, miR-326 and miR-23a). NTA confirmed the presence of EVs with diameters of 50–150 nm in all cell types. EV size distribution was significantly different between cell types after 24 and 48 h of cell culture and the concentration of EVs secreted by POECs and Ishikawa cells was also time dependent. The distribution of EVs with specific electrokinetic potential measurements varied between cell types, indicating that EVs of differing cellular origin have varied membrane components. In addition, EVs secreted by POECs exhibited significantly different time dependant changes in zeta potential. QRT-PCR confirmed the presence of miR-103, let-7a, miR-19a, miR-203, miR-126, and miR-19b in EVs secreted by POECs (CT ≥ 29). Bioinformatics analysis suggests that these miRNAs are involved in cell proliferation, innate immune responses, apoptosis and cellular migration. In conclusion, reproductive epithelial cells secrete distinct populations of EVs containing miRNAs, which potentially act in intercellular communication in order to modulate the periconception events leading to successful establishment of pregnancy

Extracellular vesicles and their nucleic acids for biomarker discovery

Extracellular vesicles (EVs) are a heterogenous population of vesicles originate from cells. EVs are found in different biofluids and carry different macromolecules, including proteins, lipids, and nucleic acids, providing a snap shot of the parental cells at the time of release. EVs have the ability to transfer molecular cargoes to other cells and can initiate different physiological and pathological processes. Mounting lines of evidence demonstrated that EVs' cargo and machinery is affected in disease states, positioning EVs as potential sources for the discovery of novel biomarkers. In this review, we demonstrate a conceptual overview of the EV field with particular focus on their nucleic acid cargoes. Current knowledge of EV subtypes, nucleic acid cargo and pathophysiological roles are outlined, with emphasis placed on advantages against competing analytes. We review the utility of EVs and their nucleic acid cargoes as biomarkers and critically assess the newly available advances in the field of EV biomarkers and high throughput technologies. Challenges to achieving the diagnostic potential of EVs, including sample handling, EV isolation, methodological considerations, and bioassay reproducibility are discussed. Future implementation of ‘omics-based technologies and integration of systems biology approaches for the development of EV-based biomarkers and personalized medicine are also considered

Spatial variability in tree-ring carbon isotope discrimination in response to local drought across the entire loblolly pine natural range

International audienceConsidering the temporal responses of carbon isotope discrimination (13 C) to local water availability in the spatial analysis of 13 C is essential for evaluating the contribution of environmental and genetic facets of plant 13 C. Using tree-ring 13 C from years with contrasting water availability at 76 locations across the natural range of loblolly pine, we decomposed site-level 13 C signals to maximum 13 C in well-watered conditions (13 C max) and isotopic drought sensitivity (m) as a change in 13 C per unit change of Palmer's Drought Severity Index (PDSI). Site water status, especially the tree lifetime average PDSI, was the primary factor affecting 13 C max. The strong spatial correlation exhibited by m was related to both genetic and environmental factors. The long-term average water availability during the period relevant to trees as indicated by lifetime average PDSI correlated with 13 C max , suggesting acclimation in tree gas-exchange traits, independent of incident water availability. The positive correlation between lifetime average PDSI and m indicated that loblolly pines were more sensitive to drought at mesic than xeric sites. The m was found to relate to a plant's stomatal control and may be employed as a genetic indicator of efficient water use strategies. Partitioning 13 C to 13 C max and m provided a new angle for understanding sources of variation in plant 13 C, with several fundamental and applied implications