Backscattering of Acoustic Signals from Inhomogenuities in Solids

Examination of the backscattering of ultrasonic waves has been suggested as a possible technique for the non-destructive evaluation of materials because it involves a simple measurement requiring access to a single surface only and because the conversion of normally incident, longitudinal waves to shear waves is minimal at a scattering angle of 180°. While the measurement is simple to carry out, the return signal may be quite complicated, especially for polycrystalline or composite materials. These materials possess local inhomogeneities of differing sizes,orientation and elastic properties from which a plane wave may scatter, often more than once, and then the scattered waves from one or more sources may interfere among themselves. These difficulties are often compounded by coupling among the several modes of propagation associated with inhomogeneity and lead to a dispersion of the incident wave. Thus the backscattered signal represents the complex, three-dimensional, phase sensetive scattering from a material that mat not be well characterized. While there has been substantial effort and much progress in developing techniques for the reconstruction of characteristics of the medium from the scattering of an acoustic wave an accurate prediction of the scattering from inhomogeneous and anisotropic medium, such as a composite material, remains a difficult problem. Generally speaking, our lack of a detailed knowledge of the structure of the medium over distances large enough to support a significant dispersal of the wave makes the development of a reliable model of the medium a formidible task

A randomised trial of an internet weight control resource: The UK Weight Control Trial [ISRCTN58621669]

BACKGROUND: Obesity treatment is notoriously unsuccessful and one of the barriers to successful weight loss reported by patients is a lack of social support. The Internet offers a novel and fast approach to the delivery of health information, enabling 24-hour access to help and advice. However, much of the health information available on the Internet is unregulated or not written by qualified health professionals to provide unbiased information. The proposed study aims to compare a web-based weight loss package with traditional dietary treatment of obesity in participants. The project aims to deliver high quality information to the patient and to evaluate the effectiveness of this information, both in terms of weight loss outcomes and cost-effectiveness. METHODS: This study is a randomised controlled trial of a weight loss package against usual care provided within General Practice (GP) surgeries in Leeds, UK. Participants will be recruited via posters placed in participating practices. A target recruitment figure of 220 will enable 180 people to be recruited (allowing for 22% dropout). Participants agreeing to take part in the study will be randomly allocated using minimisation to either the intervention group, receiving access to the Internet site, or the usual care group. The primary outcome of the study will be the ability of the package to promote change in BMI over 6 and 12 months compared with traditional treatment. Secondary outcomes will be the ability of the Internet package to promote change in reported lifestyle behaviours. Data will be collected on participant preferences, adherence to treatment, health care use and time off work. Difference in cost between groups in provision of the intervention and the cost of the primary outcome will also be estimated. CONCLUSION: A positive result from this study would enhance the repertoire of treatment approaches available for the management of obesity. A negative result would be used to inform the research agenda and contribute to redefining future strategies for tackling obesity

An investigation of home advantage in the Summer Paralympic Games

Purpose: There is a paucity of home advantage research set in the context of para-sport events. It is this gap in the knowledge that this paper addresses by investigating the prevalence and size of home advantage in the Summer Paralympic Games. Methods: Using a standardised measure of success, we compared the performances of nations when competing at home with their own performances away from home in the competition between 1960 and 2016. Both country level and individual sport level analysis was conducted for this time frame. A Wilcoxon signed rank test was used to determine whether there was a genuine difference in nations' performance under host and non-host conditions. Spearman's rank-order correlation was run to assess the relationship between nation quality and home advantage. Results: Strong evidence of a home advantage effect in the Summer Paralympic Games was found at country level (p 0.10). Conclusion: While our results confirm that home advantage is prevalent in the Summer Paralympic Games at an overall country level and within specific sports, they do not explain fully why such an effect does exist. Future studies should investigate the causes of home advantage in the competition and also draw comparisons with the Summer Olympic Games in order to explore any differences between para-sport events and able-bodied events

CCL2 recruits inflammatory monocytes to facilitate breast-tumour metastasis

Macrophages abundantly found in the tumor microenvironment enhance malignancy(1). At metastatic sites a distinct population of metastasis associated macrophages (MAMs) promote tumor cell extravasation, seeding and persistent growth(2). Our study has defined the origin of these macrophages by showing Gr1+ inflammatory monocytes (IMs) are preferentially recruited to pulmonary metastases but not primary mammary tumors, a process also found for human IMs in pulmonary metastases of human breast cancer cells. The recruitment of these CCR2 (receptor for chemokine CCL2) expressing IMs and subsequently MAMs and their interaction with metastasizing tumor cells is dependent on tumor and stromal synthesized CCL2 (FigS1). Inhibition of CCL2/CCR2 signaling using anti-CCL2 antibodies blocks IM recruitment and inhibits metastasis in vivo and prolongs the survival of tumor-bearing mice. Depletion of tumor cell-derived CCL2 also inhibits metastatic seeding. IMs promote tumor cell extravasation in a process that requires monocyte-derived VEGF. CCL2 expression and macrophage infiltration are correlated with poor prognosis and metastatic disease in human breast cancer (Fig S2)(3-6). Our data provides the mechanistic link between these two clinical associations and indicates new therapeutic targets for treating metastatic breast disease

Home advantage in the Winter Paralympic Games 1976–2014

Purpose: There is a limited amount of home advantage research concerned with winter sports. There is also a distinct lack of studies that investigate home advantage in the context of para-sport events. This paper addresses this gap in the knowledge by examining home advantage in the Winter Paralympic Games. Methods: Using a standardised measure of success, we compared the performances of host nations at home with their own performances away from home between 1976 and 2014. Both country level and individual sport level analysis is conducted for this time period. Comparisons are also drawn with the Winter Olympic Games since 1992, the point from which both the Winter Olympic Games and the Winter Paralympic Games have been hosted by the same nations and in the same years. Results: Clear evidence of a home advantage effect in the Winter Paralympic Games was found at country level. When examining individual sports, only alpine skiing and cross country skiing returned a significant home advantage effect. When comparing home advantage in the Winter Paralympic Games with the Winter Olympic Games for the last seven host nations (1992–2014), we found that home advantage was generally more pronounced (although not a statistically significant difference) in the case of the former. Conclusion: The causes of home advantage in the Winter Paralympic Games are unclear and should be investigated further

Inborn and acquired metabolic defects in cancer

The observation that altered metabolism is the fundamental cause of cancer was made by Otto Warburg nearly a century ago. However, the subsequent identification of oncogenes and tumor suppressor genes has displaced Warburg's theory pointing towards genetic aberrations as the underlining cause of cancer. Nevertheless, in the last decade, cancer-associated mutations have been identified in genes coding for tricarboxylic acid cycle (TCA cycle, also known as Krebs cycle) and closely related enzymes that have essential roles in cellular metabolism. These observations have revived interest in Warburg's hypothesis and prompted a flurry of functional studies in the hope of gaining mechanistic insight into the links between mitochondrial dysfunction, metabolic alterations, and cancer. In this review, we discuss the potential pro-oncogenic signaling role of some TCA cycle metabolites and their derivatives (oncometabolites). In particular, we focus on their effects on dioxygenases, a family of oxygen and α-ketoglutarate-dependent enzymes that control, among other things, the levels and activity of the hypoxia-inducible transcription factors and the activity of DNA and histone demethylases

Water safety plans and climate change mitigation

[Excerpt] Definition Quality water at affordable prices for all is a key condition for the promotion of public health, environmental sustainability, and quality and safety of life. In a context of growing external uncertainties arising from changes in the climate and the environment, ensuring these conditions is an upward concern and is of utmost relevance to increase scientific research on the impacts of climate change on water quality modification and in minimization/mitigation strategies

Stable amorphous georgeite as a precursor to a high-activity catalyst .

Copper and zinc form an important group of hydroxycarbonate minerals that include zincian malachite, aurichalcite, rosasite and the exceptionally rare and unstable—and hence little known and largely ignored1—georgeite. The first three of these minerals are widely used as catalyst precursors2, 3, 4 for the industrially important methanol-synthesis and low-temperature water–gas shift (LTS) reactions5, 6, 7, with the choice of precursor phase strongly influencing the activity of the final catalyst. The preferred phase2, 3, 8, 9, 10 is usually zincian malachite. This is prepared by a co-precipitation method that involves the transient formation of georgeite11; with few exceptions12 it uses sodium carbonate as the carbonate source, but this also introduces sodium ions—a potential catalyst poison. Here we show that supercritical antisolvent (SAS) precipitation using carbon dioxide (refs 13, 14), a process that exploits the high diffusion rates and solvation power of supercritical carbon dioxide to rapidly expand and supersaturate solutions, can be used to prepare copper/zinc hydroxycarbonate precursors with low sodium content. These include stable georgeite, which we find to be a precursor to highly active methanol-synthesis and superior LTS catalysts. Our findings highlight the value of advanced synthesis methods in accessing unusual mineral phases, and show that there is room for exploring improvements to established industrial catalysts

The relationship between team ability and home advantage in the English football league system

The existence of home advantage (HA) has been found in a variety of team sports including football. There is a paucity of research on the relationship between team ability and HA in domestic football leagues and the findings of previous studies are inconclusive. Using longitudinal data from the top four football divisions in England, this study investigates the influence of team ability on the HA of teams. The data collected for this study spans 24 seasons from 1995/96 to 2018/19 and includes 48,864 matches from the English Premier League (n=9,120), the Championship (n=13,248), League One (n=13,248) and League Two (n=13,248). Team ability was interpreted in two ways: (1) the division in which teams play; and, (2) their league table position within each division. For both the divisional and positional analysis, HA was calculated as the ratio of home points to total points achieved by teams in each season under review. Evidence of a statistically significant HA was found in all four divisions and for teams of all abilities within each division. Small but statistically significant differences in HA were observed between divisions and between high, moderate and low ability teams within divisions