Radio numbers for generalized prism graphs

A radio labeling is an assignment $c:V(G) \rightarrow \textbf{N}$ such that every distinct pair of vertices $u,v$ satisfies the inequality d(u,v)+|c(u)-c(v)|\geq \diam(G)+1. The span of a radio labeling is the maximum value. The radio number of $G$, $rn(G)$, is the minimum span over all radio labelings of $G$. Generalized prism graphs, denoted $Z_{n,s}$, $s \geq 1$, $n\geq s$, have vertex set $\{(i,j)\,|\, i=1,2 \text{and} j=1,...,n\}$ and edge set $\{((i,j),(i,j \pm 1))\} \cup \{((1,i),(2,i+\sigma))\,|\,\sigma=-\left\lfloor\frac{s-1}{2}\right\rfloor\,\ldots,0,\ldots,\left\lfloor\frac{s}{2}\right\rfloor\}$. In this paper we determine the radio number of $Z_{n,s}$ for $s=1,2$ and $3$. In the process we develop techniques that are likely to be of use in determining radio numbers of other families of graphs.Comment: To appear in Discussiones Mathematicae Graph Theory. 16 pages, 1 figur

1987 The Analysis

https://jdc.jefferson.edu/analysis/1018/thumbnail.jp

Staphylococcus aureus enterotoxin B regulates prostaglandin E-2 synthesis, growth, and migration in nasal tissue fibroblasts

Background. Superantigens and eicosanoids are important amplifiers and regulators of inflammation in airway diseases. We therefore studied the possible influence of Staphylococcus aureus enterotoxin B ( SEB) on the cyclooxygenase ( COX) pathway and basic functions of airway structural cells. Methods. Fibroblasts were isolated from nasal inferior turbinate tissue and cultured in the presence of different concentrations of SEB. Preincubation with interferon ( IFN)-gamma was performed to induce expression of major histocompatibility complex ( MHC) class II receptors. Prostaglandin E2 ( PGE(2)) production was assayed by enzyme-linked immunosorbent assay, and levels of COX-2 and prostanoid E receptors 1-4 ( EP1-4) were assayed by real-time polymerase chain reaction. Migration and growth tests were performed, and SEB was localized within the cells by confocal microscopy. Results. Stimulation with IFN-gamma and SEB significantly down-regulated PGE2, COX-2, and EP2 expression but not EP1, EP3, or EP4 expression. The enterotoxin blocked cell growth but increased the fibroblast migration rate. SEB was localized within the cell in the presence and absence of MHC-II, suggesting that mechanisms other than conventional binding may allow the enterotoxin to enter the cell. Conclusions. These findings may have major implications for our understanding of the role played by bacterial superantigens in regulating the inflammatory and remodeling mechanisms of upper airway diseases and hence may help elucidate the pathophysiology of these diseases

Survival, biofilm formation, and growth potential of environmental and enteric escherichia coli strains in drinking water microcosms

E. coli is the most commonly used indicator for faecal contamination in a drinking water distribution system (WDS). The assumption is that E. coli are of enteric origin and cannot persist for long outside their host, therefore acting as indicators of recent contamination events. This study investigates the fate of E. coli in drinking water; specifically addressing survival, biofilm formation under shear stress, and regrowth in a series of laboratory-controlled experiments. We show the extended persistence of three E. coli strains (two enteric and one soil isolate) in sterile and non-sterile drinking water microcosms, at 8 and 17°C, with T90 values ranging from 17.4 ± 1.8 to 149 ± 67.7 days, using standard plate counts and a series of (RT)-Q-PCR assays targeting 16S rRNA, tuf, uidA, and rodA genes and transcripts. Furthermore, each strain was capable of attaching to a surface and replicating to form biofilm in the presence of nutrients under a range of shear stress values (0.6, 2.0, and 4.4 dyn cm-2; BioFlux, Fluxion); however, cell numbers did not increase when drinking water was flowed over (t-test; p > 0.05). Finally, E. coli regrowth within drinking water microcosms containing PE-100 pipe-wall material was not observed in the biofilm or water phase using a combination of culturing and Q-PCR methods for E. coli. The results of this work highlight that when E. coli enters drinking water it has the potential to survive and attach to surfaces but that regrowth within drinking water or biofilm is unlikely

Well-structured Cooperative Learning in all classrooms: using the Dual Objective to maximize affective and cognitive gain

The authors contend that the research evidence involving Cooperative Learning as a powerful teaching strategy is unprecedented in educational history and is voluminous in breadth. They say that the research supports its use across diverse nations and cultures, across disciplines, with both genders and with all age groups (including higher education). They lament that more educators don’t use it, but they also fear that a greater concern is teachers using badly designed attempts: usually conceptualized as “groupwork”, which fails to meet the specs of the research studies and holds no special promise of success. However, the design and implementation of well-structured Cooperative Learning, as exemplified in their model called The Dual Objective, results in greater conceptual gain, cognitive skill improvement, social skilldevelopment and better self-management by students. This paper explains both Cooperative Learning (CL) as a general category of instructional design and the specific features of the Dual Objective (DO)

Avoiding the Schism: An Assessment of Attitudes Toward Performance of Literature in Competitive Environments

The number of students involved, variety of events, and general popularity of oral interpretation competition at current forensics tournaments suggests an activity in radiant good health. But this apparent good health may be threatened by controversy between oral interpretation theorists and those involved in competitive interpretation. Concern about the purpose of oral interpretation is responsible for this controversy

Radiology for medical students (1925-2018): an overview

Objective: Radiology has been espoused as an excellent tool for educating medical students since 1925. Advances in technology and PACS mean it has never been easier to demonstrate living anatomy and clinical pathology in exquisite detail to students. The aim of this study was to provide an overview of radiologic publications related to teaching medical students and its evolution through time. Methods: A literature search was performed from inception to November 2018. The search strategies used both text words and relevant indexing related to “radiology”, “medical students” and “curriculum”. Results: 3589 records were identified of which 377 were included. There was a 100 fold increase in rate of publication over time—most were expository or surveys (60%), with few truly experimental articles. Radiology was used in clinical teaching (67%) and anatomy (33%). Almost half of radiologic anatomy teaching was conducted without the input of a Radiologist. Compulsory clinical clerkships/blocks in radiology was offered infrequently (35%). Female first authorship had increased in the last decade (47%). Conclusion: There is a significant increase in articles published on the role of radiology in medical student teaching in the last decade. Research in this area is required in order to investigate the role of radiology in improving the modern medical students’ education

The Role of Coaches, Institutions, and Clinicians in Addressing Athlete Mental Health

Mental health, defined by the World Health Organization as “a state of wellbeing in which every individual realizes his or her own potential, can cope with normal stresses of life, can work productively and fruitfully, and is able to make a contribution to her or his community,” is an important concern for athletes. In 2018, research findings showed that the prevalence of mental health symptoms and disorders among current elite athletes ranged from 19% for alcohol misuse to 34% for anxiety/depression, and from 16% for distress to 26% for anxiety/depression for former elite athletes.2 Research suggests that while athletes have overall better physical health than their non-athlete counterparts, they experience similar rates of mental health symptoms and disorders.https://digitalcommons.library.tru.ca/emergingdiscourses/1001/thumbnail.jp