Fresno City College
  • United States
Recent publications
TNF-related apoptosis-inducing ligand receptor (TRAIL-R) is involved in suppressing inflammatory responses. Bacterial pathogens such as Chlamydia spp. elicit inflammatory responses in humans following genital, ocular, and respiratory infections.
The origin of snake venom involved duplication and recruitment of non-venom genes into venom systems. Several studies have predicted that directional positive selection has governed this process. Venom composition varies substantially across snake species and venom phenotypes are locally adapted to prey, leading to coevolutionary interactions between predator and prey. Venom origins and contemporary snake venom evolution may therefore be driven by fundamentally different selection regimes, yet investigations of population-level patterns of selection have been limited. Here, we use whole-genome data from 68 rattlesnakes to test hypotheses about the factors that drive genomic diversity and differentiation in major venom gene regions. We show that selection has resulted in long-term maintenance of genetic diversity within and between species in multiple venom gene families. Our findings are inconsistent with a dominant role of directional positive selection and instead support a role of long-term balancing selection in shaping venom evolution. We also detect rapid decay of linkage disequilibrium due to high recombination rates in venom regions, suggesting that venom genes have reduced selective interference with nearby loci, including other venom paralogues. Our results provide an example of long-term balancing selection that drives trans-species polymorphism and help to explain how snake venom keeps pace with prey resistance. Analysing whole-genome sequences from 68 rattlesnakes, the authors show a role of long-term balancing selection in maintaining diversity of multiple venom gene families and find reduced selective interference of venom genes with neighbouring loci.
Background: Medical education is known to be stressful. Thus, medical schools have begun amending curricula to incorporate holistic wellness and stress reduction. Assessing medical student stressors is key to curricula development as well as the selection of appropriate reliable measures. This study investigated reliability reporting for studies using the Medical Student Stressor Questionnaire (MSSQ), as no study of this kind currently exists via employing Reliability Generalization (RG). Methods: A meta-analytic method, RG, was used to analyze the reliability reporting practices and reliability coefficients, in the form of Cronbach’s alpha coefficient, for the MSSQ. While a total of 18 studies were initially isolated related to the MSSQ, only those studies reporting reliability based on their sample (n = 8) were included in the final analysis. Blind coding was utilized and percent agreement among raters was excellent (95.18%). Results: Reliability estimates reported for the total scale fell within the excellent range (Range alpha coefficient (?) = 0.800 – 0.970; Mean alpha coefficient (M?) = 0.933, Standard Deviation alpha coefficient (SD?) = 0.050). A larger percent of males was negatively correlated to academic stressors while the number of females in studies was negatively correlated with social, drive, group activities and inter/intrapersonal aspects of medical student stressors. Conclusions: Outcomes provide useful suggestions, implications, and future recommendations regarding the use and application of the MSSQ. Medical student stress is essential to assess via measures which demonstrate robust reliability. Insights into sources of stress can offer important feedback to making specific changes to medical school curricula.
Background: Lead dwell time is the single strongest predictor of failure and complications in transvenous lead extraction. Objectives: To report the success rate and complications of transvenous lead extractions with implant dwell time of at least 15 years. Methods: Procedural and patient data were prospectively collected into a database. The excimer laser was the primary method for lead extraction with use of mechanical rotational sheaths and femoral snares at operator discretion. Results: A total of 443 patients between 2011-2020 underwent lead extraction (707 leads) primarily for infection or device failure at our high-volume center. 40 patients with 69 leads >15 years old were included in this cohort (Table 1). Mean patient age was 53.5 +/- 18.5 years, 67.5% were male. Mean lead dwell time was 19.3 +/- 4.2 years. 35 of 40 (87.5%) patients had successful extraction of all leads (62 of 69 leads - 89.9%). The 5 patients without fully successful extractions resulted in 7 abandoned leads or lead fragments (mean lead age 19.6 +/- 2.3 years). 2 of these patients had abandoned leads (3 total) that were clinically significant. One patient experienced right atrial appendage perforation requiring surgical repair and recovered well. One patient experienced new complete heart block requiring 2 minutes of CPR but did well thereafter. There was no procedure-related mortality. Conclusions: Despite challenges posed by older leads, very old leads can be safely and effectively extracted with low complication rates.
Background Propensity score analysis (PSA) is a popular method to remove selection bias due to covariates in quasi-experimental designs, but it requires handling of missing data on covariates before propensity scores are estimated. Multiple imputation (MI) and single imputation (SI) are approaches to handle missing data in PSA. Objectives The objectives of this study are to review MI-within, MI-across, and SI approaches to handle missing data on covariates prior to PSA, investigate the robustness of MI-across and SI with a Monte Carlo simulation study, and demonstrate the analysis of missing data and PSA with a step-by-step illustrative example. Research design The Monte Carlo simulation study compared strategies to impute missing data in continuous and categorical covariates for estimation of propensity scores. Manipulated conditions included sample size, the number of covariates, the size of the treatment effect, missing data mechanism, and percentage of missing data. Imputation strategies included MI-across and SI by joint modeling or multivariate imputation by chained equations (MICE). Results The results indicated that the MI-across method performed well, and SI also performed adequately with smaller percentages of missing data. The illustrative example demonstrated MI and SI, propensity score estimation, calculation of propensity score weights, covariate balance evaluation, estimation of the average treatment effect on the treated, and sensitivity analysis using data from the National Longitudinal Survey of Youth.
Homogeneous cationic gold(i) catalysis emerged as a preferred avenue for the activation of alkenes and alkynes towards reactions with weak nucleophiles, especially in cyclization reactions. Here we report an intramolecular carboalkoxylation reaction of electron-rich benzyl ethers of 2-ethynylaryl phenols catalysed by a digold(i)-NHC complex. The reaction proceeds efficiently with low catalyst loading and the resulting 2,3-disubstituted benzofurans form in moderate to good yields. Based on the results of a cross-over experiment, spectroscopic data, and DFT calculations, we propose a mechanism that accounts for the observed chemo- and regioselectivity.
We highlight how community colleges implement equity-oriented reform to address inequities facing Latinx students. Through counterstorytelling, we provide lessons learned on the implementation and impact of equity-oriented reform in community college. Key findings revealed that the reform is necessary, but not sufficient to improve racial equity for Latinx students, thus requiring campuses and practitioners to move beyond the margins of superficial efforts and compliance. Implications are shared on how to embed the concept of equity-mindedness to increase Latinx student success into the cultural and structural fabric of the institution.
Chlamydia trachomatis is the most common bacterial sexually-transmitted infection and the major cause of preventable blindness worldwide. The asymptomatic nature of many infections along with uncontrolled inflammation leads to irreversible damage in the upper genital tract and the tarsal conjunctivae, with the major complications of infertility and chronic pelvic pain, and blindness, respectively. Inflammation must, therefore, be tightly regulated to avoid an unrestrained immune response. The genetic factors that regulate inflammation through Toll-like receptor (TLR) signaling pathways during C. trachomatis infection have not been fully characterized. SIGIRR (also known as IL-1R8 or TIR8) can regulate inflammation in response to various pathogens and diseases. However, nothing is known about its role during C. trachomatis infection. Expression of the pro-inflammatory chemokine, IL-8, was measured in epithelial cells infected with C. trachomatis. The effect of SIGIRR was determined by depleting SIGIRR or over-expressing SIGIRR in the epithelial cells before infection. Our results indicate that, in the absence of SIGIRR, epithelial cells induce higher levels of the pro-inflammatory chemokine, IL-8, in response to C. trachomatis infection. In addition, SIGIRR associates with MyD88 in both infected and uninfected infected cells. Collectively, our data demonstrate that SIGIRR functions as a negative regulator of the immune response to C. trachomatis infection. This finding provides insights into the immuno-pathogenesis of C. trachomatis that can be used to treat and identify individuals at risk of uncontrolled inflammation during infection.
Although the use of technology in the K12 classroom has been shown to have a positive impact, research on the use of open education resources (OER) is relatively limited, especially research focusing on low‐achieving students. The present study examines the relationship between usage of Algebra Nation, a self‐guided system that provided instructional videos and practice problems, and the performance of students who had failed the state‐administered Algebra I end‐of‐course (EOC) assessment the previous year. Indicators of usage of Algebra Nation consisted of logins, video views, and practice questions answered. Path analyses and logistic regressions were used to evaluate relationships between usage indicators and algebra scores, controlling for number of absences, free/reduced lunch eligibility, Hispanic/Latino origin, race, and gender. The results indicate that higher levels of logins, video views, and practice questions answered were related to higher scores when the students re‐took the assessment. Logins and practice questions were also related to increases in odds of passing the Algebra I EOC assessment, but not video views. The results suggest that there may be benefits to technology use in the form of an OER adopted by students and teachers on an informal basis and link self‐regulated learning strategies to student achievement.
(−)-Zampanolide is a marine microtubule-stabilizing macrolide that has been shown by in vitro experiments to be a promising anticancer lead compound. Through its unique covalent-binding with β-tubulin, zampanolide exhibits cytotoxic potency towards multi-drug resistant cancer cells that is superior to paclitaxel. However, the limited availability of zampanolide impedes its further in vivo evaluation as a viable drug candidate. Zampanolide is envisioned to become more drug-like if its chemically fragile side chain can be stabilized; hence, this project aims to develop mimics of zampanolide with a stable side chain using straightforward synthetic methods. To this end, twelve novel zampanolide mimics (51-62) with conjugated and planar side chains have been synthesized via a 24-step sequence for each mimic from commercially available 2-butyn-1-ol as starting material. A Horner-Wadsworth-Emmons reaction incorporates the α,β-unsaturated ketone side chain and also closes the core macrocycle. WST-1 cell proliferation assays in three docetaxel-sensitive and two docetaxel-resistant human prostate cancer cell models confirm that a suitably designed side chain can serve as a bioisostere for the N-acyl hemiaminal side chain in zampanolide. Mimic 52 with a 17R chiral center was identified as the optimal candidate with IC 50 values of 0.29-0.46 μM against both docetaxel-sensitive (PC-3 and DU145) and docetaxel-resistant prostate cancer cell lines (PC-3/DTX and DU145/DTX). Zampanolide mimic 52 exhibited equivalent antiproliferative potency towards both docetaxel-sensitive and docetaxel-resistant cell lines, with relative resistance in the range of 0.9-1.6.
The combination of two easily handled, highly acidic liquid HF complex reagents, DMPU-12HF and KHSO4-13HF, generated a highly acidic fluorination system that facilitated exclusive Markovnikov addition of HF to widely...
A solid anhydrous hydrogen fluoride equivalent was prepared by mixing HF gas with an inexpensive anion exchange resin (A26-HF, HF content 30% wt/wt). This reagent is capable of hydrofluorinating alkenes,...
Benzo[b]thiophene heterocycle is an important component of many important small molecule pharmaceuticals and drug candidates as well as and organic semiconducting materials. Several methods allow for construction of benzo[b]thiophene core and although some catalytic methods have been developed, many still rely on stoichiometric activation. Here we report an efficient method for synthesis of 2-substituted benzo[b]thiophenes from 2-alkynyl thioanisoles catalyzed by gold(I)–IPr hydroxide that is applicable to a wide range of substrates with diverse electronic and steric properties. Additionally, we demonstrate experimentally that the carboxylic acid additive and its conjugate base are essential to catalyst turnover.
The City of Fresno, CA with extensive use of galvanized iron pipe (GIP) has historically used groundwater (GW) as its drinking water source. In 2004, Fresno introduced treated surface water (SW) to its distribution system and started receiving increased discolored water reports. A systematic approach was developed to reproduce the nature of GIP corrosion issues in Fresno and to explore potential discoloration mitigation strategies. Laboratory testing showed that the GW was more corrosive to zinc wire (representative of new GIP) and less corrosive to iron wire (representative of aged GIP) compared with SW. For harvested "good" GIP with a relatively high percentage of zinc contacting water, water turbidity (<2.1 Nephelometric Turbidity Unit), iron (<0.01 mg/L), and zinc (<0.66 mg/L) levels were relatively low for both SW and GW conditions. For harvested "bad" GIP with a relatively high percentage of iron surface contacting water, water turbidity, iron, and zinc levels after exposure to typical GW for 13.5 weeks were 47-89% lower than levels after exposure to typical SW, indicating less likelihood of discolored water with GW. A corrosion control strategy with orthophosphate at 1 mg/L as P and water pH 7.5 reduced problems with turbidity, iron, and zinc release by 36-87% for exposure of "bad" GIP to SW only or to the alternating condition between SW and GW.
Content analyses of prime-time television provide a picture of predominant cultural stereotypes and social trends. The present research is a quantitative content analysis of social class in popular broadcast and cable television in the United States. This research advances scholarship by systematically analyzing character class in addition to more commonly examined variables such as race and gender. A model for the operationalization of class for quantitative content analyses of mediated texts is offered. This proof of concept study demonstrates the viability of studying media representations of class quantitatively to systematically document patterns of portrayal.
General chemistry is a foundational course that serves as a gateway to many STEM degrees. A high level of preparedness and motivation to succeed in STEM coursework correlates with success in general chemistry courses, and general chemistry is vital to persistence of students in STEM. Studies have indicated that an increasing number of students, especially underrepresented minority populations, placed into preparatory chemistry courses do not advance to general chemistry. This lack of advancement is an indicator that a one-size-fits-all preparatory chemistry course does not sufficiently target students’ cognitive and non-cognitive needs. In order to better support, prepare, and motivate students in STEM at UC Davis, an online, adaptive-responsive summer preparatory chemistry course (SP-Chem using ALEKS) was piloted as an alternative to placement exams and the fall, classroom-based preparatory chemistry course (WLD-41C) used for placement into general chemistry. Student performance in general chemistry was comparatively evaluated for four placement paths (SP-Chem, WLD-41C, placement exams, and repeating the course). Additionally, indicators of STEM persistence, namely student motivation and STEM identity, were surveyed and comparatively evaluated. Our findings of the effectiveness of an online, adaptive-responsive preparatory chemistry course, using both cognitive and non-cognitive measures, demonstrate the promise that online learning during the summer holds for improving student performance and persistence in general chemistry and STEM coursework.
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368 members
Natalie Brower
  • mental health
Abigail Harrison
  • Department of Anthropology
Amber Donnell
  • Department of Business Administration
Matthew Jelmini
  • Department of Social Sciences
United States