The Dilworth Number of Auto-Chordal-Bipartite Graphs

The mirror (or bipartite complement) mir(B) of a bipartite graph B=(X,Y,E) has the same color classes X and Y as B, and two vertices x in X and y in Y are adjacent in mir(B) if and only if xy is not in E. A bipartite graph is chordal bipartite if none of its induced subgraphs is a chordless cycle with at least six vertices. In this paper, we deal with chordal bipartite graphs whose mirror is chordal bipartite as well; we call these graphs auto-chordal bipartite graphs (ACB graphs for short). We describe the relationship to some known graph classes such as interval and strongly chordal graphs and we present several characterizations of ACB graphs. We show that ACB graphs have unbounded Dilworth number, and we characterize ACB graphs with Dilworth number k

Measuring physical inactivity:do current measures provide an accurate view of "sedentary" video game time?

BACKGROUND: Measures of screen time are often used to assess sedentary behaviour. Participation in activity-based video games (exergames) can contribute to estimates of screen time, as current practices of measuring it do not consider the growing evidence that playing exergames can provide light to moderate levels of physical activity. This study aimed to determine what proportion of time spent playing video games was actually spent playing exergames. METHODS: Data were collected via a cross-sectional telephone survey in South Australia. Participants aged 18 years and above (n = 2026) were asked about their video game habits, as well as demographic and socioeconomic factors. In cases where children were in the household, the video game habits of a randomly selected child were also questioned. RESULTS: Overall, 31.3% of adults and 79.9% of children spend at least some time playing video games. Of these, 24.1% of adults and 42.1% of children play exergames, with these types of games accounting for a third of all time that adults spend playing video games and nearly 20% of children's video game time. CONCLUSIONS: A substantial proportion of time that would usually be classified as "sedentary" may actually be spent participating in light to moderate physical activity

An Examination of the Implications of Excess Hospital Bed Capacity

The United States has excess hospital bed capacity. For many years, health care experts have suggested the "over bedding" of the American hospital system has been of the key drivers of high medical costs. Dating back to 1959. when Milton Roemer, MD, proclaimed "A built bed is a filled bed," there is evidence that the availability of hospital beds creates the demand for hospital services. In turn, overuse of hospitalization, the most expensive mode of medical care, propels overall health care costs. For the period 1960 to 1980, the number of hospital beds in the United States rose 55 percent while population increased only 26 percent. Medical care prices were also skyrocketing. For the period 1974 to 1982, the medical care services CPI (consumer price index), a measure of price inflation, was increasing dramatically each year. The average annual rate of increase for the period was 10.59 percent. In 1983, the annual increases in medical CPI began to slow with the average annual rate of increase dropping to 8.66 percent. The trend is continuing with the annual increases for 1994 and 1995 being only 5.2 percent and 5.1 percent respectively. For the twenty-year period 1975 to 1994, this paper will examine a possible relationship between the annual percentage change of medical consumer price index (CPI) and the percentage rate o f reduction of hospital beds per thousand population. Since national HMO information is only available since 1976, it will also explore a possible correlation between HMO penetration and the reduction in the number o f hospital beds from 1976 to 1994. A subsequent analysis will address the relationship between HMO penetration and hospital beds regionally for the period 1983 to 1994.Master'sCollege of Arts and Sciences: Public AdministrationUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/117755/1/Berry.pd

Surface characteristics of brassica leaves and their influence on infection by fungal pathogens

The role epicuticular waxes play in resistance of brassicas to foliar diseases was investigated for two known brassica pathogens, Altemaria brassicicola and Erysiphe crucifer arum, a weak parasite Altemaria altemata and a non-pathogen Erysiphe graminis. Waxes of swede, oilseed rape and Brussels sprout leaves from different leaf positions were found to be composed of eight analogous compounds but in varying proportions. Epicuticular waxes from seven Brussels sprout mutant lines, in comparison to a commercial variety, again had eight similar groups of compounds, however the variations in proportions were more distinct. Correlations could be made between prevalence of certain compound groups and wax crystal configuration. Waxes containing high ketones and hydrocarbons had crystals in the form of rods which projected from the cuticle and these surfaces tended to be waxy. Conditions in which the brassicas were grown could modify crystal morphology. Temperature was seen to transform the crystalline configuration of wax crystals, whereas light intensity altered their dimensions.Waxy surfaces had the lowest wettability and permeability, and also tended to be most resistant to Altemaria infection. Infection by Erysiphe cmciferamm seemed to be related to the genetic background of the host and not surface phenotype. Treatment of the surface with surfactant, which reduced the wettability, and environmental conditions which increased wettability had equivalent effects on Altemaria infection but variations in Erysiphe infections could not be explained by changes in leaf surface wettability.Microscopic examination of leaf surface behaviour and early penetration IV events revealed that the varying features of the different brassica leaf surfaces, or even a non-host surface in the case of Erysiphe cruciferarum, did not greatly affect extra-matrical development of the Alternaría pathogens or Erysiphe cruciferarum. Variations seen in numbers of sub-cuticular hyphae, originating from successful penetrations of the cuticle by A. brassicicola and A. altemata, correlated with the degree to which the host was infected with blackspot. With Alternaría, the penetration phase seemed to be crucial as the determinant of successful infection. The significant phase for successful infection by Erysiphe cruciferarum seemed to be the fungal-host interface. Resistance was of a quantitative nature and was expressed by the extent of colony development.When the growth oí Erysiphe graminis, was observed on swede leaves, it was found that the infection course of the pathogen was only moderately affected by the leaf surface. Many conidia attempted penetration and several formed rudimentary haustoria within the epidermal cells. It is concluded that the epicuticular waxes confer a degree of resistance to Alternaría pathogens, but play a limited role in resistance to powdery mildew

A simple algorithm to generate the minimal separators and the maximal cliques of a chordal graph

We present a simple unified algorithmic process which uses either LexBFS or MCS on a chordal graph to generate the minimal separators and the maximal cliques in linear time in a single pass

The DIM system: Turn-Taking in Dyadic Telephone Dialogues

The analysis of human conversations has revealed that the design of interfaces using spoken dialogue must differ radically from those using written communication. Such characteristics as prosody, confirmations, echoes, and other speech phenomena must be considered. This work is a step in that direction. Prosodic, syntactic and semantic information from actual human dialogues has been used to build a turn-taking model empirically for dydadic telephone dialogues. The ability to predict completion of turns has been the biggest motivating factor in the development of this model. The design and evaluation of the model are presented in this report

Use of CATME Peer Review Measurement Tool to Assess Team Work Skills

Short Abstract: Initiating an initiative focused on identifying best practices for developing and improving teamwork skills, researchers at Purdue Polytechnic Institute, School of Engineering Technology have begun to define research in this area. This project is intended to be multi‐institutional, investigating skills within the Capstone experiences of engineering, technology, and computing programs. Full Abstract: Initiating an initiative focused on identifying best practices for developing and improving teamwork skills, researchers at Purdue Polytechnic Institute, School of Engineering Technology have begun to define research in this area. This project is intended to be multi‐institutional, investigating skills within the Capstone experiences of engineering, technology, and computing programs. Teamwork as defined and measured by the existing team are those dimensions measured by the CATME Peer Review (Ohland, et al, 2006), which is currently used by thousands of technology and engineering instructors and institutions worldwide. The CATME Peer Review measurement tool is used to collect self and peer evaluations of team members’ contributions on five different teamwork dimensions. These teamwork dimensions are 1) pose the knowledge, skills, and abilities to help the team; 2) expect quality work from the team; 3) keep the team on schedule; 4) positive interactions between teammates to help the team; and 5) all team members contribute to the team\u27s work and success. This research team has evaluated a semester of data to provide an example of how to evaluate teamwork skills and subsequently begin the task of improving skills and the capstone environment (Lucietto, et al, 2017)

Interleukin 6 plays a role in the migration of magnetically levitated mesenchymal stem cells spheroids

Mesenchymal stem cells (MSCs) reside quiescently within a specialised ‘niche’ environment in the bone marrow. However, following appropriate signalling cues, MSCs mobilise and migrate out from the niche, typically toward either sites of injury (a regenerative response) or toward primary tumours (an intrinsic homing response, which promotes MSCs as cellular vectors for therapeutic delivery). To date, very little is known about MSC mobilisation. By adopting a 3D MSC niche model, whereby MSC spheroids are cultured within a type I collagen gel, recent studies have highlighted interleukin-6 (IL-6) as a key cytokine involved in MSC migration. Herein, the ability of IL-6 to induce MSC migration was further investigated, and the key matrix metalloproteinases used to effect cell mobilisation were identified. Briefly, the impact of IL-6 on the MSC migration in a two-dimensional model systems was characterised—both visually using an Ibidi chemotaxis plate array (assessing for directional migration) and then via a standard 2D monolayer experiment, where cultured cells were challenged with IL-6 and extracted media tested using an Abcam Human MMP membrane antibody array. The 2D assay displayed a strong migratory response toward IL-6 and analysis of the membrane arrays data showed significant increases of several key MMPs. Both data sets indicated that IL-6 is important in MSC mobilisation and migration. We also investigated the impact of IL-6 induction on MSCs in 3D spheroid culture, serving as a simplistic model of the bone marrow niche, characterised by fluorescently tagged magnetic nanoparticles and identical membrane antibody arrays. An increase in MMP levels secreted by cells treated with 1 ng/mL IL-6 versus control conditions was noted in addition to migration of cells away from the central spheroid mass

The impact of CMOS scaling projected on a 6b full-Nyquist non-calibrated flash ADC

A 6-bit 1.2 Gs/s non-calibrated flash ADC in a standard 45nm CMOS process, that achieves 0.45pJ/conv-step at full Nyquist bandwidth, is presented. Power efficient operation is achieved by a full optimization of amplifier blocks, and by innovations in the comparator and encoding stage. The performance of a non-calibrated flash ADC is directly related to device properties; a scaling analysis of our ADC in and across CMOS technologies gives insight into the excellent usability of 45nm technology for AD converter design