210 research outputs found
Using LEGO robots to support understanding of absolute value in a mathematics classroom
Presentation co-presented by Georgia Southern faculty member Shelli L. Casler-Failing with students Ann Mitchem and Jillian Arnold at Interdisciplinary STEM Teaching and Learning Conference, Savannah, GA.
This presentation will allow participants to become middle school mathematics students as they apply their understanding of absolute value through the use of LEGO robots. A classroom lesson will be conducted (with the participants playing the role of the student) to show how LEGO robots can be an engaging tool to create collaboration among students as well as support the understanding of concepts. Participants will work in groups of 2-3 to operate a robot along a number line and record data on a task sheet as the robot moves forward or backward in random increments. This presentation will culminate with a discussion regarding participantsā reactions to the activity and its implication for classroom use
Mycophagous Beetle Females Do Not Behave Competitively During Intrasexual Interactions In Presence Of A Fungal Resource
Intrasexual interactions can determine which individuals within a population have access to limited resources. Despite their potential importance on fitness generally and mating success especially, femaleāfemale interactions are not often measured in the same species where maleāmale interactions are well-defined. In this study, we characterized femaleāfemale interactions in Bolitotherus cornutus, a mycophagous beetle species native to Northeastern North America. We used dyadic, behavioral assays to determine whether females perform directly aggressive or indirectly exclusionary competitive behaviors. Polypore shelf fungus, an important food and egg-laying resource for B. cornutus females, is patchily distributed and of variable quality, so we tested for competition over fungus as a resource. Behavior of females was assessed in three sets of dyadic trials with randomly paired female partners. Overall, females did not behave aggressively toward their female partner or perform exclusionary behaviors over the fungal resource. None of the behaviors performed by females were individually repeatable. Two scenarios may explain our lack of observed competition: our trial context may not induce competition, or female B. cornutus simply may not behave competitively in the wild. We compare our results to a similar study on maleāmale interactions in the same species and propose future studies on femaleāfemale interactions under different competitive contexts to expand the understanding of female competition
A method for volume stabilization of single, dye-doped water microdroplets with femtoliter resolution
A self-control mechanism that stabilizes the size of Rhodamine B-doped water
microdroplets standing on a superhydrophobic surface is demonstrated. The
mechanism relies on the interplay between the condensation rate that was kept
constant and evaporation rate induced by laser excitation which critically
depends on the size of the microdroplets. The radii of individual water
microdroplets (>5 um) stayed within a few nanometers during long time periods
(up to 455 seconds). By blocking the laser excitation for 500 msec, the stable
volume of individual microdroplets was shown to change stepwise.Comment: to appear in the J. Op. Soc. Am.
Dolphins at the British Museum: Zoomorphic Calusa Sinkers
The subject of everyday or āmundaneā artistic expression in Native American material culture does not always take into account the idea that aesthetic design can have explicit practical as well as decorative function. This article explores this idea through objects from the Floridian archaeological collections at the British Museum
Pharmacological levels of withaferin A (Withania somnifera) trigger clinically relevant anticancer effects specific to triple negative breast cancer cells
Withaferin A (WA) isolated from Withania somnifera (Ashwagandha) has recently become an attractive phytochemical under investigation in various preclinical studies for treatment of different cancer types. In the present study, a comparative pathway-based transcriptome analysis was applied in epithelial-like MCF-7 and triple negative mesenchymal MDA-MB-231 breast cancer cells exposed to different concentrations of WA which can be detected systemically in in vivo experiments. Whereas WA treatment demonstrated attenuation of multiple cancer hallmarks, the withanolide analogue Withanone (WN) did not exert any of the described effects at comparable concentrations. Pathway enrichment analysis revealed that WA targets specific cancer processes related to cell death, cell cycle and proliferation, which could be functionally validated by flow cytometry and real-time cell proliferation assays. WA also strongly decreased MDA-MB-231 invasion as determined by single-cell collagen invasion assay. This was further supported by decreased gene expression of extracellular matrix-degrading proteases (uPA, PLAT, ADAM8), cell adhesion molecules (integrins, laminins), pro-inflammatory mediators of the metastasis-promoting tumor microenvironment (TNFSF12, IL6, ANGPTL2, CSF1R) and concomitant increased expression of the validated breast cancer metastasis suppressor gene (BRMS1). In line with the transcriptional changes, nanomolar concentrations of WA significantly decreased protein levels and corresponding activity of uPA in MDA-MB-231 cell supernatant, further supporting its anti-metastatic properties. Finally, hierarchical clustering analysis of 84 chromatin writer-reader-eraser enzymes revealed that WA treatment of invasive mesenchymal MDA-MB-231 cells reprogrammed their transcription levels more similarly towards the pattern observed in non-invasive MCF-7 cells. In conclusion, taking into account that sub-cytotoxic concentrations of WA target multiple metastatic effectors in therapy-resistant triple negative breast cancer, WA-based therapeutic strategies targeting the uPA pathway hold promise for further (pre)clinical development to defeat aggressive metastatic breast cancer
Tumor-induced STAT3 activation in monocytic myeloid-derived suppressor cells enhances stemness and mesenchymal properties in human pancreatic cancer
Pancreatic cancer (PC) mobilizes myeloid cells from the bone marrow to the tumor where they promote tumor growth and proliferation. Cancer stem cells (CSCs) are a population of tumor cells that are responsible for tumor initiation. Aldehyde dehydrogenase-1 activity in PC identifies CSCs, and its activity has been correlated with poor overall prognosis in human PC. Myeloid cells have been shown to impact tumor stemness, but the impact of immunosuppressive tumor-infiltrating granulocytic and monocytic myeloid-derived suppressor cells (Mo-MDSC) on ALDH1(Bright) CSCs and epithelial to mesenchymal transition is not well understood. In this study, we demonstrate that Mo-MDSC (CD11b(+)/Gr1(+)/Ly6G(ā)/Ly6C(hi)) significantly increase the frequency of ALDH1(Bright) CSCs in a mouse model of PC. Additionally, there was significant upregulation of genes associated with epithelial to mesenchymal transition. We also found that human PC converts CD14(+) peripheral blood monocytes into Mo-MDSC (CD14(+)/HLA-DR(low/ā)) in vitro, and this transformation is dependent on the activation of the STAT3 pathway. In turn, these Mo-MDSC increase the frequency of ALDH1(Bright) CSCs and promote mesenchymal features of tumor cells. Finally, blockade of STAT3 activation reversed the increase in ALDH1(Bright) CSCs. These data suggest that the PC tumor microenvironment transforms monocytes to Mo-MDSC by STAT3 activation, and these cells increase the frequency of ALDH1(Bright) CSCs. Therefore, targeting STAT3 activation may be an effective therapeutic strategy in targeting CSCs in PC. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00262-014-1527-x) contains supplementary material, which is available to authorized users
Oral SARS-CoV-2 host responses predict the early COVID-19 disease course
Oral fluids provide ready detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and host responses. This study sought to evaluate relationships between oral virus, oral and systemic anti-SARS-CoV-2-specific antibodies, and symptoms. Oral fluids (saliva/throat wash (saliva/TW)) and serum were collected from asymptomatic and symptomatic, nasopharyngeal (NP) SARS-CoV-2 RT-qPCR+ human participants (n = 45). SARS-CoV-2 RT-qPCR and N-antigen detection by immunoblot and lateral flow assay (LFA) were performed. RT-qPCR for subgenomic RNA (sgRNA) was sequence confirmed. SARS-CoV-2-anti-S protein RBD LFA and ELISA assessed IgM and IgG responses. Structural analysis identified host salivary molecules analogous to SARS-CoV-2-N-antigen. At time of enrollment (baseline, BL), LFA-detected N-antigen in 86% of TW and was immunoblot-confirmed. However, only 3/17 were saliva/TW qPCR+. Sixty percent of saliva and 83% of TW demonstrated persistent N-antigen at 4 weeks. N-antigen LFA signal in three anti-spike sero-negative participants suggested potential cross-detection of 4 structurally analogous salivary RNA binding proteins (alignment 19ā29aa, RMSD 1ā1.5 Angstroms). At enrollment, symptomatic participants demonstrated replication-associated sgRNA junctions, were IgG+ (94%/100% in saliva/TW), and IgM+ (63%/54%). At 4 weeks, SARS-CoV-2 IgG (100%/83%) and IgM (80%/67%) persisted. Oral and serum IgG correlated 100% with NP+ PCR status. Cough and fatigue severity (p = 0.010 and 0.018 respectively), and presence of weakness, nausea, and composite upper respiratory symptoms (p = 0.037, 0.005, and 0.017, respectively) were negatively associated with saliva IgM but not TW or serum IgM. Throat wash IgM levels were higher in women compared to men, although the association did not reach statistical significance (median: 290 (female) versus 0.697, p = 0.056). Important to transmission and disease course, oral viral replication and persistence showed clear relationships with select symptoms and early oral IgM responses during early infection. N-antigen cross-reactivity may reflect mimicry of structurally analogous host proteins
- ā¦