A new prenylated xanthone from the stem bark of Calophyllum lowii

Our detailed study on the chemical constituents of the stem bark of Calophyllum lowii has resulted in the isolation and characterization of one new xanthone calowiium (1) along with three other xanthone derivatives – caloxanthone L (2), β-mangostin (3), and macluraxanthone (4). Several triterpenoids and steroids, viz. friedelin (5), stigmasterol (6) and sitosterol (7) were also successfully isolated from this plant. The structures of these components were established by means of spectroscopic analysis –nuclear magnetic resonance (NMR 1D, 2D), UV, FTIR, and mass spectrometry

Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats

In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security

The application of mathematical modelling to aspects of adjuvant chemotherapy scheduling.

In this paper simple models for tumour growth incorporating age-structured cell cycle dynamics are considered in the presence of two non-cross-resistant S-phase specific chemotherapeutic drugs. According to the seminal work of Goldie and Coldman, if one cannot deliver two cell cycle phase non-specific, non-cross-resistant drugs simultaneously, for example due to toxicity, and both drugs are identical apart from resistance, one should alternate their delivery as rapidly as possible. However consider S-phase specific drugs. One might speculate that, for example, alternating the two drugs at intervals of T, where T is the mean cell cycle time, is better than alternating the drugs at intervals of T/2, as the latter strategy allows the possibility of a cell cycle sanctuary. Such speculation implicitly requires a sufficiently low variance of the cell cycle time, and hence it is not clear if such reasoning prevents a generalisation of the results of Goldie and Coldman. This question is addressed in this paper via a detailed modelling investigation, as motivated by suggestions for future colorectal adjuvant chemotherapy trials and developments in hepatic arterial infusion technology. It is shown that the cell cycle distribution of the resistant cell populations is strongly influenced by the chemotherapy schedule. The consequences of this can be dramatic, and can lead to chemotherapy failure at resonant chemotherapy timings, especially for a small standard deviation of the cell cycle time. The novel aspects of this observation are highlighted compared to other models in the literature exhibiting resonant behaviour in the timing of a periodic chemotherapy protocol. The above investigation also results in the principal prediction of this paper that reducing the drug alternation time to approximately a few hours, if possible, can result in substantial improvements in predicted chemotherapy outcomes. Critically, such improvements are not predicted by the Goldie Coldman model or other chemotherapy scheduling models in the literature

Measuring Ankle Angle and Analysis of Walking Gait using Kinovea

Understanding the biomechanics of motion related to human walking gait is important in the area of rehabilitation. Infrared cameras motion capture systems have been widely used. Nevertheless, the system is very expensive and thus alternative solutions are explored. This study is aimed to measure the angle of ankle during walking and then assess the reliability of Kinovea in analysing walking gait. Firstly, a motion capture-analysis system combining HD VideoCam-Kinovea was validated. Then, a motion capture-analysis system combining HD DSLR Camera-Kinovea was used to capture the motion of walking and the relative angles of ankle during walking gait phases are measured. Three volunteered healthy subjects without any gait disorders, age ranged from 20 - 24 years were recruited for this study. Basic statistical analysis was carried out to compute the mean, standard deviation (SD) and variance. In terms of walking gait analysis that is the main part of the current study, the results revealed no statistically significant difference (variance < 5%) in the measured data for the same subject under five trials. This proves that the protocol is repeatable and the current system combining HD DSLR Camera-Kinovea is reliable