672 research outputs found
2023 Hollister Lecture
No full textMr. Stepien graduated from Elmhurst College in 1965 and began his career as a middle school social studies teacher. In 1978, he became a program developer and senior author for the K-7 social studies series for the Scott, Foresman Company. When IMSA opened in 1985, he was tapped to plan curriculum, hire faculty, and help with facility design. Joining its faculty, he taught at IMSA for ten years. In 1994, Mr. Stepien became IMSA’s director of the Center for Problem-Based Learning, turning his full attention to research and writing about applications of PBL in elementary and secondary schools. He established the Consortium for Problem-Based Learning at Northern Illinois University in 1997 and became a national consultant in PBL for the Association for Supervision and Curriculum Development (ASCD). Mr. Stepien consulted with more than fifty schools every year, presented at numerous national meetings and conventions, and consulted with organizations such NASA, the Museum of Science and Industry (Chicago), Prime Time School Television, and The Wall Street Journal
Go-or-grow models in biology: a monster on a leash
No full textGo-or-grow approaches represent a specific class of mathematical models used to describe populations where individuals either migrate or reproduce, but not both simultaneously. These models have a wide range of applications in biology and medicine, chiefly among those the modeling of brain cancer spread. The analysis of go-or-grow models has inspired new mathematics, and it is the purpose of this review to highlight interesting and challenging mathematical properties of reaction-diffusion models of the go-or-grow type. We provide a detailed review of biological and medical applications before focusing on key results concerning solution existence and uniqueness, pattern formation, critical domain size problems, and traveling waves. We present new results related to the critical domain size and traveling wave problems, and we connect these findings to the existing literature. Moreover, we demonstrate the high level of instability inherent in go-or-grow models. We argue that there is currently no accurate numerical solver for these models, and emphasize that special care must be taken when dealing with the "monster on a leash"
Meal inertia: the impact of eating different sized meals on vigilant attention throughout the night
No full textAbstract #0171Gupta CC, Dorrian J, Centofanti S, Coates A, Kennaway D, Wittert G, Heilbronn L, Catcheside P, Noakes M, Stepien J, Chandrakumar D, Coro D, Banks
Neoplastic transformation is associated with coordinate induction of nuclear and cytoplasmic oxidative phosphorylation genes
No full textNeoplastic transformation was found to have a marked effect on the expression of nuclear DNA (nDNA)- and mitochondrial DNA (mtDNA)-encoded oxidative phosphorylation (OXPHOS) genes. Examining three pairs of human diploid fibroblasts and their SV 40-transformed counterparts revealed that mRNAs for the nuclear-encoded ATP synthase beta and the adenine nucleotide translocator (ANT) isoform 1 and 2 genes were markedly induced, whereas the mRNA for the ANT isoform 3 gene remained unchanged. The mRNA levels for the mtDNA-encoded 12 S rRNA, ND2, ATPase6+8, COIII, ND5+6, and Cytb genes were also increased, whereas the mtDNA number declined. Similar analysis of a cervical carcinoma (HeLa), fibrosarcoma (HT1080), and an Epstein-Barr virus (EBV)-transformed lymphoblastoid line (EBV-L) revealed that all three ANT isoforms were also expressed in these cells. Hence, changes in the expression of OXPHOS genes may be a common feature of transformed cells
One year of COVID-19: infection rates and symptoms in patients with inherited metabolic diseases followed by MetabERN
No full textBackground: Since the beginning of the COVID-19 pandemic, MetabERN has been monitoring the SARS-CoV-2 infection rates within its metabolic community. To gather data on the total number of cases and the severity of symptoms among IMD patients one year into the pandemic, an online survey was distributed among all MetabERN healthcare providers (HCP). Epidemiological analysis was performed by integrating the survey’s data with the MetabERN database. Results: Survey’s respondents reported a total of 452 cases of COVID-19 among their IMD patients (213 paediatric and 239 adults). Considering the total number of patients followed by the respondents (n = 26,347), the registered prevalence of COVID-19 in the IMD population was of 1716 × 100,000. Italy emerged as the most affected country (25.4% of cases), followed by the United Kingdom (14.2% of cases). Most of the paediatric cases of COVID-19 displayed no or mild symptoms during the disease: 34% of HCP reported having asymptomatic patients in 75–100% of cases, while 37.5% reported mild symptoms in about a quarter of their patients. Similarly to paediatric cases, most adult IMD patients with COVID-19 were asymptomatic or had mild symptoms: about one third of respondents reported 75–100% asymptomatic patients and about 65% of HCP had between 0 and 50% of patients with mild symptoms. The majority of the respondents reported no deaths due to COVID-19 in adult and paediatric patients with IMDs. Conclusions: Most of MetabERN’s IMD patients who got COVID-19 during the first year of the pandemic had mild symptoms and a positive outcome of the disease. However, fatal events were recorded in paediatric patients; this, together with the lack of information on the long-term effects of COVID-19 in IMDs, call for caution in the metabolic population
Lord Kelvin and Andrey Andreyevich Markov in a Queue with Single Server
No full textWe use Lord Kelvin's method of images to show that a certain innite system of equations with interesting boundary conditions leads to a Markovian dynamics in an L 1 - type space. This system originates from the queuing theory.Мы используем метод изображений лорда Кельвина, чтобы показать, что некоторая бесконечная система уравнений с интересными граничными условиями приводит к марковской динамике в пространстве L^1-типа. Эта система берет свое начало в теории массового обслуживания
Anti-HERV-W Env antibodies are correlated with seroreactivity against Mycobacterium avium subsp. paratuberculosis in children and youths at T1D risk
No full textRecent evidence points at the role that human endogenous retroviruses (HERVs) may play through the activation of genes integrated across the human genome. Although a variety of genetic/epigenetic mechanisms maintain most HERVs silenced, independent environmental stimuli including infections may transactivate endogenous elements favoring pathogenic conditions. Several studies associated exposures to Mycobacterium avium subsp. paratuberculosis (MAP) with increased anti-MAP seroreactivity in T1D patients. Here, we assessed humoral responses against HERV envelope antigens (HERV-K Env and HERV-W Env ) and four MAP-derived peptides with human homologs in distinct populations: Sardinian children at T1D risk (rT1D) (n = 14), rT1D from mainland Italy (n = 54) and Polish youths with T1D (n = 74) or obesity unrelated to autoimmunity (OB) (n = 26). Unlike Sardinian rT1D, youths displayed increased anti-HERV-W Env Abs prevalence compared to age-matched OB or healthy controls (24.32 vs. 11.54%, p = 0.02 for Polish T1D/OB and 31.48 vs. 11.90%, p = 0.0025 for Italian rT1D). Anti-HERV-K Env responses showed variable trends across groups. A strong correlation between Abs levels against HERV-W Env and homologous peptides was mirrored by time-related Abs patterns. Elevated values registered for HERV-W Env overlaped with or preceded the detection of T1D diagnostic autoantibodies. These results support the hypothesis of MAP infection leading to HERV-W antigen expression and enhancing the production of autoantibodies in T1D
Unknown God, Known in His Activities: Incomprehensibility of God during the Trinitarian Controversy of the 4th Century
No full textUnknown God, Known in His Activities: Incomprehensibility of God during the Trinitarian Controversy of the 4th Century (European Studies in Theology, Philosophy and History of Religions) Tomasz Stepien (Author), Karolina Kochanczyk-Boninska (Author), 2018. What can man know about God? This question became one of the main problems during the 4th-century Trinitarian controversy, which is the focus of this book. Especially during the second phase of the conflict, the claims of Anomean Eunomius ..
Pilot study examining the effect of cholesterol lowering on platelet nitric oxide responsiveness and arterial stiffness in subjects with isolated mild hypercholesterolaemia
No full textThe definitive version is available at www.blackwell-synergy.com1. Hypercholesterolaemia has been associated with impaired endothelial function. However, there are no available data as to whether hypercholesterolaemia is also associated with platelet dysfunction. 2. In a group of asymptomatic adults with (n = 16) and without (n = 13) mild hypercholesterolaemia, we evaluated inhibition of platelet aggregation in response to the nitric oxide (NO) donor sodium nitroprusside (SNP), as well as the augmentation index (AIx), a parameter of arterial stiffness that is impaired in the presence of endothelial dysfunction. 3. Neither SNP response nor AIx varied significantly between normocholesterolaemic (NC) and hypercholesterolaemic (HC) subjects. 4. Three months treatment with pravastatin (40 mg/day) in HC subjects lowered mean (±SEM) total cholesterol levels from 6.6 ± 0.2 to 5.5 ± 0.2 mmol/L. Platelet response to SNP increased in platelet-rich plasma and tended to increase in whole blood. The AIx did not change significantly. However, falls in low-density lipoprotein (P = 0.03) and total cholesterol (P = 0.08) correlated with reductions in AIx in individual subjects. 5. These data provide evidence that moderate reduction of cholesterol levels may improve platelet responses to NO, whereas improvement in arterial stiffness may be detectable only with more extensive and/or a prolonged reduction in cholesterol levels.Jacqueline M Stepien, Rhonda M Prideaux, Scott R Willoughby, Yuliy Y Chirkov and John D Horowit
Unraveling the nature of sulfur-bearing silicate-phosphate glasses: Insights from multi-spectroscopic (Raman, MIR, 29Si, 31P MAS-NMR, XAS, XANES) investigation
No full textHerein, we investigate silicate-phosphate glasses from the SiO2–P2O5–K2O–MgO–SO3 system enriched with various amounts of sulfur, as a nutrient indispensable for the proper development of plants, in order to gain a profound understanding of the structure of such materials. An inherent capability of glasses from the studied system to incorporate sulfate groups into the vitreous matrix was discussed on the basics of the results from XRF, XRD and internal Al2O3 standard techniques. It has been found, that as much as 3 mol.% of SO3 can be loaded into the glass batches to obtain fully amorphous material, while beyond this limit K2SO4 crystallizes within the matrix. Comprehensive spectroscopic investigation, comprising Raman, Middle Infrared (MIR), 29Si and 31P MAS-NMR, X-ray absorption spectroscopy (XANES and XAS) techniques, has been implemented in order to determine an impact of sulfur on silicate-phosphate glass framework. On this basics, it has been concluded, that sulfur exists in the vitreous matrix in the form of specific domains, in which [SO4]2- anions are surrounded by the shell of charge-compensating K+ cations. Such sulfate groupings maintain their individuality without direct bonding to silico-oxygen or phospho-oxygen subnetwork. Spectroscopic results revealed also, that the presence of sulfur affects silico-oxygen subnetwork to a significantly greater extent than the phospho-oxygen one. It has been demonstrated, that along with SO3 addition, the more polymerized QSi3 units increase in abundance at the expense of less polymerized QSi2 groups. Results of the present study are believed to contribute to a greater understanding of the nature of sulfur-bearing oxide glasses
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