Intersection of Longest Cycle and Largest Bond in 3-Connected Graphs

A bond in a graph is a minimal nonempty edge-cut. A connected graph $G$ is dual Hamiltonian if the vertex set can be partitioned into two subsets $X$ and $Y$ such that the subgraphs induced by $X$ and $Y$ are both trees. There is much interest in studying the longest cycles and largest bonds in graphs. H. Wu conjectured that any longest cycle must meet any largest bond in a simple 3-connected graph. In this paper, the author proves that the above conjecture is true for certain classes of 3-connected graphs: Let $G$ be a simple 3-connected graph with $n$ vertices and $m$ edges. Suppose $c(G)$ is the size of a longest cycle, and $c^*(G)$ is the size of a largest bond. Then each longest cycle meets each largest bond if either $c(G) \geq n - 3$ or $c^*(G) \geq m - n - 1$. Sanford determined in her Ph.D. thesis the cycle spectrum of the well-known generalized Petersen graph $P(n, 2)$ ($n$ is odd) and $P(n, 3)$ ($n$ is even). Flynn proved in her honors thesis that any generalized Petersen graph $P(n, k)$ is dual Hamiltonian. The author studies the bond spectrum (called the co-spectrum) of the generalized Petersen graphs and extends Flynn's result by proving that in any generalized Petersen graph $P(n, k)$, $1 \leq k < \frac{n}{2}$, the co-spectrum of $P(n, k)$ is $\{3, 4, 5, ..., n+2\}$.Comment: 16 pages, 19 figures. Paper presented at the 54th Southeastern International Conference on Combinatorics, Graph Theory and Computing (March 6-10, 2023); submitted on May 9, 2023 to the conference proceedings book series publication titled "Springer Proceedings in Mathematics and Statistics" (PROMS). Paper abstract also on https://www.math.fau.edu/combinatorics/abstracts/ren54.pd

Manual-scanning optical coherence tomography probe based on position tracking

A method based on position tracking to reconstruct images for a manual-scanning optical coherence tomography (OCT) probe is proposed and implemented. The method employs several feature points on a hand-held probe and a camera to track the device's pose. The continuous device poses tracking, and the collected OCT depth scans can then be combined to render OCT images. The tracking accuracy of the system was characterized to be about 6 μm along two axes and 19 μm along the third. A phantom target was used to validate the method. In addition, we report OCT images of a 54-stage Xenopus laevis tadpole acquired by manual scanning

Effect modification of the association between meteorological variables and mortality by urban climatic conditions in the tropical city of Kaohsiung, Taiwan

A deeper understanding of extreme hot weather are needed in cities sensitive to heat effects, an investigation was done in the tropical town of Kaohsiung in Taiwan. Its 11 districts were divided into three climatic classes varying from high urban heat, low levels of green space and lack of proximity to water bodies to low urban heat, adequate green space and proximity to water bodies. Daily data on natural mortality, meteorological variables, and pollutants from May-October 1999-2008 were analysed using generalised additive models for the time-series data. Subgroup analyses were conducted, stratifying decedents according to the level of planning activity required in order to mitigate adverse heat effects in their residential areas, classifying districts as “level 1” for those requiring a high level of mitigation action; “level 2” for those requiring some action; and “level 3” for those that need only preserve existing conditions. Stratified analyses showed that mortality increases per 1 °C rise on average, either on the same day or in the previous 4 days (lags 0-4), were associated with 2.8%, 2.3% and -1.3% for level 1, 2 and 3 districts, respectively. The slope describing the association between temperature and mortality was higher above 29.0 °C resulting in corresponding increases of 4.2%, 5.0% and 0.3% per per 1 °C rise in temperature, respectively. Other meteorological variables were not significantly associated with mortality. It is concluded that hot season mortality in Kaohsiung is only sensitive to heat effects in districts classified as having unfavourably climatic conditions and requiring mitigation efforts in city planning. Urban planning measures designed to improve climatic conditions could reduce excess mortality resulting from extreme hot weathe

The Effects of PCSO-524®, a Patented Marine Oil Lipid derived from the New Zealand Green Lipped Mussel (Perna canaliculus), on Pulmonary and Respiratory Muscle Function in Non-asthmatic Elite Runners

International Journal of Exercise Science 11(3): 669-680, 2018. Habitual endurance training may be associated with mild airway inflammation and subsequent deterioration in lung function. PCSO-524™ (Lyprinol®/Omega-XL®), a supplement extracted from the New Zealand green-lipped mussel (Perna canaliculus), has been shown to moderate airway inflammation in asthmatic subjects. The purpose of this study was to determine whether supplementation with PCSO-524™ improves pulmonary and respiratory muscle function in non-asthmatic elite runners. Sixteen male, non-asthmatic elite runners were randomly assigned to either a treatment (PCSO-524™; 1 capsule contains 50 mg n-3 polyunsaturated fatty acids and 100 mg olive oil, n=8) or placebo (1 capsule contains 150 mg olive oil; n=8) group. During the supplementation period, subjects ingested 8 capsules of either treatment or placebo per day for 12 weeks. Resting pulmonary and respiratory muscle function testing were assessed at baseline and every two weeks throughout the 12 week supplementation period. No significant between- or within-subjects main effects were observed in forced vital capacity, forced expiratory volume in 1-second, forced expiratory flow from 25-75% of lung volume (FEF25-75), peak expiratory flow, maximal voluntary ventilation, maximal inspiratory mouth pressure, and closing volume (p\u3e0.05). A significant within-subjects main effect was observed in maximal expiratory mouth pressure (PEmax) (p=0.024) and lung diffusion capacity (DLCO) (pPEmax and DLCO (p\u3e0.05). A significant treatment by time interaction was observed in FEF25-75 (p=0.026) and DLCO (p=0.024), but no other significant interactions were observed (all p\u3e0.05). Supplementation with PCSO-524™ (Lyprinol®/Omega-XL®) does not improve pulmonary or respiratory muscle function in non-asthmatic elite runners

Cell-specific and region-specific transcriptomics in the multiple sclerosis model: Focus on astrocytes.

Changes in gene expression that occur across the central nervous system (CNS) during neurological diseases do not address the heterogeneity of cell types from one CNS region to another and are complicated by alterations in cellular composition during disease. Multiple sclerosis (MS) is multifocal by definition. Here, a cell-specific and region-specific transcriptomics approach was used to determine gene expression changes in astrocytes in the most widely used MS model, experimental autoimmune encephalomyelitis (EAE). Astrocyte-specific RNAs from various neuroanatomic regions were attained using RiboTag technology. Sequencing and bioinformatics analyses showed that EAE-induced gene expression changes differed between neuroanatomic regions when comparing astrocytes from spinal cord, cerebellum, cerebral cortex, and hippocampus. The top gene pathways that were changed in astrocytes from spinal cord during chronic EAE involved decreases in expression of cholesterol synthesis genes while immune pathway gene expression in astrocytes was increased. Optic nerve from EAE and optic chiasm from MS also showed decreased cholesterol synthesis gene expression. The potential role of cholesterol synthesized by astrocytes during EAE and MS is discussed. Together, this provides proof-of-concept that a cell-specific and region-specific gene expression approach can provide potential treatment targets in distinct neuroanatomic regions during multifocal neurological diseases

Fundamental sensitivity limit imposed by dark 1/f noise in the low optical signal detection regime

The impact of dark 1/f noise on fundamental signal sensitivity in direct low optical signal detection is an understudied issue. In this theoretical manuscript, we study the limitations of an idealized detector with a combination of white noise and 1/f noise, operating in detector dark noise limited mode. In contrast to white noise limited detection schemes, for which there is no fundamental minimum signal sensitivity limit, we find that the 1/f noise characteristics, including the noise exponent factor and the relative amplitudes of white and 1/f noise, set a fundamental limit on the minimum signal that such a detector can detect

Addressing Challenges in Obtaining Emergency Medicine Away Rotations and Standardized Letters of Evaluation Due to COVID-19 Pandemic

The Council of Residency Directors in Emergency Medicine (CORD) Advising Students Committee in Emergency Medicine (ASC-EM) anticipates institutional and regional variability in both the spread and response to COVID-19. Travel restrictions and host institution rotation closures will impact the number of emergency medicine (EM) rotations EM-bound medical students can complete in an unprecedented manner. They may prevent students from completing any away rotations this academic cycle, challenging the students’ ability to obtain EM Standardized Letters of Evaluation (SLOEs). EM’s emphasis on residency group SLOEs over other letter types creates an undue burden on these vulnerable students and makes the application process intrinsically inequitable. This inequity warrants a reevaluation of the current application practice. This article outlines ASC-EM\u27s proposed recommendations for all stakeholders, including EM program leadership, medical schools, and EM-bound medical students, to consider for the upcoming EM application cycle