A call for using natural compounds in the development of new antimalarial treatments – an introduction

Natural compounds, mostly from plants, have been the mainstay of traditional medicine for thousands of years. They have also been the source of lead compounds for modern medicine, but the extent of mining of natural compounds for such leads decreased during the second half of the 20th century. The advantage of natural compounds for the development of drugs derives from their innate affinity for biological receptors. Natural compounds have provided the best anti-malarials known to date. Recent surveys have identified many extracts of various organisms (mostly plants) as having antiplasmodial activity. Huge libraries of fractionated natural compounds have been screened with impressive hit rates. Importantly, many cases are known where the crude biological extract is more efficient pharmacologically than the most active purified compound from this extract. This could be due to synergism with other compounds present in the extract, that as such have no pharmacological activity. Indeed, such compounds are best screened by cell-based assay where all potential targets in the cell are probed and possible synergies identified. Traditional medicine uses crude extracts. These have often been shown to provide many concoctions that deal better with the overall disease condition than with the causative agent itself. Traditional medicines are used by ~80 % of Africans as a first response to ailment. Many of the traditional medicines have demonstrable anti-plasmodial activities. It is suggested that rigorous evaluation of traditional medicines involving controlled clinical trials in parallel with agronomical development for more reproducible levels of active compounds could improve the availability of drugs at an acceptable cost and a source of income in malaria endemic countries

Normal Leptin Expression, Lower Adipogenic Ability, Decreased Leptin Receptor and Hyposensitivity to Leptin in Adolescent Idiopathic Scoliosis

Leptin has been suggested to play a role in the etiology of Adolescent Idiopathic Scoliosis (AIS), however, the leptin levels in AIS girls are still a discrepancy, and no in vitro study of leptin in AIS is reported. We took a series of case-control studies, trying to understand whether Leptin gene polymorphisms are involved in the etiology of the AIS or the change in leptin level is a secondary event, to assess the level of leptin receptor, and to evaluate the differences of response to leptin between AIS cases and controls. We screened all exons of Leptin gene in 45 cases and 45 controls and selected six tag SNPs to cover all the observed variations. Association analysis in 446 AIS patients and 550 healthy controls showed no association between the polymorphisms of Leptin gene and susceptibility/severity to AIS. Moreover, adipogenesis assay of bone mesenchymal stem cells (MSCs) suggested that the adipogenic ability of MSCs from AIS girls was lower than controls. After adjusting the differentiation rate, expressions of leptin and leptin receptor were similar between two groups. Meanwhile, osteogenesis assay of MSC showed the leptin level was similar after adjusting the differentiation rate, but the leptin receptor level was decreased in induced AIS osteoblasts. Immunocytochemistry and western blot analysis showed less leptin receptors expressed in AIS group. Furthermore, factorial designed studies with adipogenesis and osteogenesis revealed that the MSCs from patients have no response to leptin treatment. Our results suggested that Leptin gene variations are not associated with AIS and low serum leptin probably is a secondary outcome which may be related to the low capability of adipogenesis in AIS. The decreased leptin receptor levels may lead to the hyposensitivity to leptin. These findings implied that abnormal peripheral leptin signaling plays an important role in the pathological mechanism of AIS

Students’ decision-making about postgraduate education at G University in China: the main factors and the role of family and of teachers

The paper draws on findings from a case study which explored factors influencing students’ decision-making of postgraduate (PG) education at G University in China. Both questionnaires and follow-up interviews were used for data collection. This paper reports the main reasons for students’ choices of subject and institution for PG education, and the influences of families and teachers, and of guanxi in their decision-making. The findings show that both families and teachers play important roles in shaping students’ decision-making about PG education. It provides insights into students’ decision-making about higher education embedded in the Chinese culture of Confucianism

Supervised manifold learning for image and video classification

This paper presents a supervised manifold learning model for dimensionality reduction in image and video classification tasks. Unlike most manifold learning models that emphasize the distance preserving, we propose a novel algorithm called maximum distance embedding (MDE), which aims to maximize the distances between some particular pairs of data points, with the intention of flattening the local nonlinearity and keeping the discriminant information simultaneously in the embedded feature space. Moreover, MDE measures the dissimilarity between data points using L1-norm distance, which is more robust to outliers than widely used Frobenius norm distance. To adapt the nature tensor structure of image and video data, we further propose the multilinear MDE (M2DE). Experiments on various datasets demonstrate that both MDE and M2DE achieve impressive embedding results of image and video data for classification tasks.Department of ComputingRefereed conference pape

Bidirectional visible neighborhood preserving embedding

In this paper, we propose a series of dimensionality reduction algorithms according to a novel neighborhood graph construction method. This paper begins with the presentation of a new manifold learning algorithm called bidirectional visible neighborhood preserving embedding (BVNPE). Similar with existing manifold techniques, BVNPE first links every data point with its k nearest neighbors (NNs). Then, we construct a reliable neighborhood graph by checking two criteria: bidirectional linkage and visible neighborhood preserving. Third, we assign the weights to each edge in this reliable graph based on the pairwise distance between data points. Finally, we compute the low-dimensional embedding, trying to preserve the manifold structure of input dataset by mapping nearby points on the manifold to nearby points in low-dimensional space. Moreover, this paper also proposes a linear BVNPE called BVNPE/L for straightforward embedding of new data, and a multilinear BVNPE called BVNPE/M, which represents the tensor structure of image and video data better. Experiments on various datasets validate the effectiveness of proposed algorithms.Department of ComputingRefereed conference pape

Multiple video trajectories representation using double-layer isometric feature mapping

This paper proposes a novel non-linear dimensionality reduction algorithm, named double-layer isometric feature mapping (DLIso), which generates the trajectories for the video sequence containing different kinds of video clips. First, a nearest neighbor based clustering algorithm is utilized to partition the video sequence into a set of data blocks. Second, intra-cluster graphs are constructed based on the individual character of each data block to build the basic layer for DLIso. Third, the inter-cluster graph is constructed by analyzing the interrelation among these isolated data blocks to build the hyper-layer. Finally, all data points are mapped onto a unique low-dimensional feature space while preserving the corresponding relations in the double layers. Experiments on synthetic datasets as well as the real video sequences demonstrate that the low-dimensional trajectories generated by the proposed method correctly represent the semantic information of the data.Department of ComputingRefereed conference pape