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Influence of Humic Substances on Yield and Fruit Quality of Organic Cantaloupe
No full textThis research spotlighted the use of biostimulants in cantaloupe (Cucumis melo L.) yield production and fruit quality. Biostimulants are additives that have been produced from biological substances and used to enhance crop yield, nutrient uptake, tolerance to abiotic stress, and agricultural practices. This research was conducted summer of 2019–2021. In this study, we tested, under monitored and replicated conditions, the effect of humic acid, fulvic acid, and biochar. Two organic cantaloupe varieties, PMR Delicious 51 and Divergent F1, and one conventional variety, Delicious 51, were used in this experiment over three growing seasons. The organic treatments were biochar (B), humic acid (HA), and a combination of humic acid and fulvic acid (HA+FA). The humic substances substantially positively affected yield production, sensory attributes, and phytochemical profile. In three trials, Divergent F1 cantaloupe significantly increased the number of fruit per plant, mean weight, mean width, and mean height when humic acid and fulvic acid were applied compared to control. PMR Delicious yielded significantly higher values in 2019 and 2021. For the 2020 trial, there was no significant difference in yield parameters. Biochar generated the highest moisture content for both varieties. There was a significant advantage for humic substances in antioxidant activity as HA+FA substantially outperformed all treatments in both varieties. HA+FA had significantly higher firmness for both varieties. Similar volatile compounds were found in all treatments; however, they were distinct concentrations. Humic substances have a beneficial effect on cantaloupe production and phytochemical profile
Low-Salt Diet Reduces Anti-CTLA4 Mediated Systemic Immune-Related Adverse Events while Retaining Therapeutic Efficacy against Breast Cancer
Get PDFImmune checkpoint inhibitor (ICI) therapy has revolutionized the breast cancer treatment landscape. However, ICI-induced systemic inflammatory immune-related adverse events (irAE) remain a major clinical challenge. Previous studies in our laboratory and others have demonstrated that a high-salt (HS) diet induces inflammatory activation of CD4+T cells leading to anti-tumor responses. In our current communication, we analyzed the impact of dietary salt modification on therapeutic and systemic outcomes in breast-tumor-bearing mice following anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4) monoclonal antibody (mAb) based ICI therapy. As HS diet and anti-CTLA4 mAb both exert pro-inflammatory activation of CD4+T cells, we hypothesized that a combination of these would lead to enhanced irAE response, while low-salt (LS) diet through blunting peripheral inflammatory action of CD4+T cells would reduce irAE response. We utilized an orthotopic murine breast tumor model by injecting Py230 murine breast cancer cells into syngeneic C57Bl/6 mice. In an LS diet cohort, anti-CTLA4 mAb treatment significantly reduced tumor progression (day 35, 339 ± 121 mm3), as compared to isotype mAb (639 ± 163 mm3, p \u3c 0.05). In an HS diet cohort, treatment with anti-CTLA4 reduced the survival rate (day 80, 2/15) compared to respective normal/regular salt (NS) diet cohort (8/15, p \u3c 0.05). Further, HS plus anti-CTLA4 mAb caused an increased expression of inflammatory cytokines (IFNγ and IL-1β) in lung infiltrating and peripheral circulating CD4+T cells. This inflammatory activation of CD4+T cells in the HS plus anti-CTLA4 cohort was associated with the upregulation of inflammasome complex activity. However, an LS diet did not induce any significant irAE response in breast-tumor-bearing mice upon treatment with anti-CTLA4 mAb, thus suggesting the role of high-salt diet in irAE response. Importantly, CD4-specific knock out of osmosensitive transcription factor NFAT5 using CD4cre/creNFAT5flox/flox transgenic mice caused a downregulation of high-salt-mediated inflammatory activation of CD4+T cells and irAE response. Taken together, our data suggest that LS diet inhibits the anti-CTLA4 mAb-induced irAE response while retaining its anti-tumor efficacy
Game Theoretic Mitigation of Internal and External Attacks Against Cyber Systems
No full textThe field of cybersecurity plays a crucial role for building safer societies and more resilient communities. Known attacks against cyber systems are of two important kinds, viz. internal attacks and external attacks. Internal attacks are those that are launched by malicious components from within a system while external attacks are those that are launched by malicious entities from outside a system. This dissertation presents novel game theoretic techniques for defending cyber systems against both internal and external attacks. Hardware Trojans can launch attacks from within a system. To defend against such threats, this dissertation first presents the design of a novel auction-based market structure that can act as a reliable platform for trading ICs when sellers (manufacturers) in the market can be malicious in nature. Further, the dissertation analytically characterizes novel game theoretic techniques that can be used to strategically test acquired ICs to check for the presence of Trojans in a cost-effective manner. The designed testing strategies account for the complex hierarchical classification structure exhibited by Trojans which can impact attack-defense strategies. The dissertation also presents game theoretic strategies for performing sequential hardware Trojan testing where a defender can test acquired ICs over time. External attacks, which are attacks launched from outside a system, exploit the system’s communication constructs. To defend a systems communication capabilities against external attacks from jammers, we first presented a novel redundancy-based transmission scheme that can provide reliability and finally presented a novel deception-based technique that misleads jammers using fake communications
Modeling of the Selective Laser Melting (SLM) Process Using the ANSYS Software
No full textA high-power laser is utilized as the energy source in the Selective Laser Melting (SLM) technique, a form of AM Powder Bed Fusion (PBF) technology, to melt and fuse certain areas of a metal powder layer. Complex geometric metallic pieces may be produced using the SLM method. Additionally, SLM products have mechanical characteristics that are typically comparable with those of parts produced conventionally. The quality and mechanical characteristics of AM parts can be greatly impacted by defects including keyholing, lack of fusion, and balling. The amount and nature of defects observed during SLM process depend on the input laser energy. The energy input into the materials may be connected to the key process parameters, such as hatch spacing, scan speed, layer thickness, and laser power. In this study, the SLM process was modeled using the ANSYS Additive Science. The goal was to establish optimal process parameters that would result in defect-free components and to also determine the impact of the scan speed and laser power on the grain size distribution. Ti6Al4V and AlSi10Mg alloys were used in this study. To validate the simulation results, ANSYS input process parameters were matched with published experimental data. The width and depth of the melt pool as well as the grain sizes predicted by the simulation were observed to be qualitatively comparable with referenced experimental data. The quantitative melt pool width and depth, as well as grain sizes obtained from the simulation differed from the referenced experimental data
Comparison of K-12 Teachers’ Perceptions of Their Teacher Preparation Programs
No full textThe primary purpose of this study was to compare K-12 West Tennessee teachers’ perceptions of their teacher preparation programs regarding the factors of planning, engaging, and assessing student learning based on whether they attended HBCUs or PWUs. This quantitative study examined 103 certified West Tennessee elementary, middle, and high school teachers from the Jackson Tennessee Madison County School District and the Trenton Special School District. The data offered a contextualized perspective on how teachers view their teacher preparation programs at HBCUs versus PWUs and how their perceptions of these programs affected their effectiveness as teachers. Although. In the demographics section of the survey, participants self-reported their gender, age, ethnicity, the length of time teaching, the type of teacher preparation program institution attended, and the highest educational level attained. The Development National Survey of a Teachers Education Program Graduates served as the study\u27s main data source. Three research questions guided this study: Are West Tennessee teachers’ perceptions of their ability to: 1) plan, instruct and assess, 2) instruct and engage, and 3) assess student learning different when comparing teachers who completed teacher preparation programs at HBCUs and those who completed teacher preparation programs at PWUs? Among the major findings of the study, the data revealed that while there were no significant differences in the teachers’ perceptions of their teacher education programs, it should be noted that the mean response of a 2 for these survey items indicates that teachers from both HBCUs and PWUs perceived that their institutions moderately prepared them in Core Area 1,2, and 3. This research provides universities, both school districts and local, with feedback on the benefits of teacher perceptions on how best teacher preparation programs at an HBCU or PWU are preparing preservice teachers. Based on recommendations, ensure that the teacher preparation programs provide a level of professional training on planning, engaging, and assessing students based on each grade level, thus allowing the teachers to make more informed decisions about implementation and the resources being used to teach students
HD 166620: Portrait of a Star Entering a Grand Magnetic Minimum
Get PDFHD 166620 was recently identified as a Maunder minimum candidate based on nearly 50 years of Ca II H and K activity data from Mount Wilson and Keck HIRES. These data showed clear cyclic behavior on a 17 yr timescale during the Mount Wilson survey that became flat when picked up later with Keck HIRES planet-search observations. Unfortunately, the transition between these two data sets—and therefore the transition into the candidate Maunder minimum phase—contained little to no data. Here, we present additional Mount Wilson data not present in Baum et al., along with photometry over a nearly 30 yr baseline that definitively traces the transition from cyclic activity to a prolonged phase of flat activity. We present this as conclusive evidence of the star entering a grand magnetic minimum and therefore the first true Maunder minimum analog. We further show that neither the overall brightness nor the chromospheric activity level (as measured by SHK) is significantly lower during the grand magnetic minimum than its activity cycle minimum, implying that an anomalously low mean or instantaneous activity levels are not a good diagnostic or criterion for identifying additional Maunder minimum candidates. Intraseasonal variability in SHK, however, is lower in the star’s grand minimum; this may prove a useful symptom of the phenomenon