The advent of high-throughput methods for the analysis of global gene expression, together with the Malaria Genome Project open up new opportunities for furthering our understanding of the ...fundamental biology and virulence of the malaria parasite. Serial analysis of gene expression (SAGE) is particularly well suited for malarial systems, as the genomes of Plasmodium species remain to be fully annotated. By simultaneously and quantitatively analyzing mRNA transcript profiles from a given cell population, SAGE allows for the discovery of new genes. In this study, one reports the successful application of SAGE in
Plasmodium falciparum, 3D7 strain parasites, from which a preliminary library of 6880 tags corresponding to 4146 different genes was generated. It was demonstrated that
P. falciparum is amenable to this technique, despite the remarkably high A–T content of its genome. SAGE tags as short as 10 nucleotides were sufficient to uniquely identify parasite transcripts from both nuclear and mitochondrial genomes. Moreover, the skewed A–T content of parasite sequence did not preclude the use of enzymes that are crucial for generating representative SAGE libraries. Finally, a few modifications to DNA extraction and cloning steps of the SAGE protocol proved useful for circumventing specific problems presented by A–T rich genomes.
The Pgs28 protein is a major surface antigen of the sexual stages of
Plasmodium gallinaceum — the zygotes and the ookinetes. The protein contains conserved motifs, namely an N-terminal signal ...sequence, four epidermal growth factor-like repeats and a C-terminal hydrophobic domain that serves as a signal for glycosylphosphatidylinositol (GPI) — anchor modification. In this study, we define the protein motifs required for the surface localization of Pgs28 in ookinetes, using transient transfection combined with immunofluorescence and confocal microscopy. Pgs28 fused to the green fluorescent protein (Pgs28-GFP) is expressed in zygotes, intermediate retort forms and ookinetes. Mutational analyses of Pgs28 coding regions reveal that deletions of the signal sequence and the C-terminal domain result in intracellular retention of the fusion protein. Therefore, the signal sequence and C-terminal domain are required for cell surface localization. Additionally, the Pgs28-GFP fusion proteins are shed from the surface of live ookinetes, suggesting that Pgs28 may be involved in interactions with the cells of the mosquito midgut or during motility.
Transcription of the rat tyrosine hydroxylase (TH) gene is controlled by enhancer sequences in its 5' flanking region; these enhancers include the AP1, dyad, and cAMP response element (CRE) motifs. ...We show that a novel basal promoter element (-17 GCCTGCCTGGCGA -5) positioned between the TATA box and +1 works in conjunction with the upstream AP1-dyad and CRE enhancers but cannot support transcription by itself. A mutation of this element, termed partial dyad, reduces basal expression of a reporter gene in TH-positive cell lines and TH-negative lines but has no effect on cAMP- or KCl-induced expression. A double mutant at positions -17 and -11 of the partial dyad reduces transcriptional activation by 80%. Conversely, insertion of this element into a heterologous promoter restores basal expression to levels mediated by the native TH promoter. The partial dyad is a novel activational element that is required for full expression of the TH gene and may assist in the function of the AP1, dyad, and CRE motifs and also other enhancers further upstream. Hence, the rat TH gene is unusual in that its enhancers will not function with a heterologous promoter but require a specific TH promoter sequence for full activation.
Purpose
To highlight the gravity and universality of risky online behaviour of children, adolescents and young adults (AYAs). To understand how such behaviour increases the probability of sexual ...exploitation.
Recent findings
Use of digital media is increasing exponentially, but adults are ill equipped to understand, adapt and cope. Unless parents, children and AYAs are empowered about cybersafety, this online sexual exploitation is very difficult to prevent.
Summary
Some protective legislations are in place, both worldwide and in India, but more work is needed. There is an urgent need to do advocacy, awareness and capacity building about online sexual exploitation of children, adolescents and young adults. (AYAs).
Future research needs to focus on
Understanding the risks that result from lack of awareness of consequences of their online behavior among young people. Building agency in children, adolescents and young adults to protect themselves from risk. Impact analysis and documentation of efforts to intervene.
Effective Personalized Mobile Search Using KNN, implements an architecture to improve user's personalization effectiveness over large set of data maintaining security of the data. User preferences ...are gathered through clickthrough data. Clickthrough data obtained is sent to the server in encrypted form. Clickthrough data obtained is classified into content concepts and location concepts. To improve classification and minimize processing time, KNN(K Nearest Neighborhood) algorithm is used. Preferences identified(location and content) are merged to provide effective preferences to the user. System make use of four entropies to balance weight between content concepts and location concepts. System implements client server architecture. Role of client is to collect user queries and to maintain them in files for future reference. User preference privacy is ensured through privacy parameters and also through encryption techniques. Server is responsible to carry out the tasks like training, reranking of the search results obtained and the concept extraction. Experiments are carried out on Android based mobile. Results obtained through experiments show that system significantly gives improved results over previous algorithm for the large set of data maintaining security.
PDF
