This work considers a harvested logistic population for which birth rate, carrying capacity and harvesting rate all vary slowly with time. Asymptotic results from earlier work, obtained using a multiscaling technique, are combined to construct approximate expressions for the evolving population for the situation where the population initially survives to a slowly varying limiting state, but then, due to increasing harvesting, is reduced to extinction in finite time. These results are shown to give very good agreement with those obtained from numerical computation.

One of the most promising new targets for trypanocidal drugs to emerge in recent years is the cyclic AMP (cAMP) phosphodiesterase (PDE) activity encoded by TbrPDEB1 and TbrPDEB2. These genes were genetically confirmed as essential, and a highaffinity inhibitor, CpdA, displays potent antitrypanosomal activity. To identify effectors of the elevated cAMP levels resulting from CpdA action and, consequently, potential sites for adaptations giving resistance to PDE inhibitors, resistance to the drug was induced. Selection of mutagenized trypanosomes resulted in resistance to CpdA as well as cross-resistance to membranepermeable cAMP analogues but not to currently used trypanocidal drugs. Resistance was not due to changes in cAMP levels or in PDEB genes. A second approach, a genome-wide RNA interference (RNAi) library screen, returned four genes giving resistance to CpdA upon knockdown. Validation by independent RNAi strategies confirmed resistance to CpdA and suggested a role for the identified cAMP Response Proteins (CARPs) in cAMP action. CARP1 is unique to kinetoplastid parasites and has predicted cyclic nucleotide binding-like domains, and RNAi repression resulted in >100-fold resistance. CARP2 and CARP4 are hypothetical conserved proteins associated with the eukaryotic flagellar proteome or with flagellar function, with an orthologue of CARP4 implicated in human disease. CARP3 is a hypothetical protein, unique to Trypanosoma. CARP1 to CARP4 likely represent components of a novel cAMP signaling pathway in the parasite. As cAMP metabolism is validated as a drug target in Trypanosoma brucei, cAMP effectors highly divergent from the mammalian host, such as CARP1, lend themselves to further pharmacological development

In the present paper, two new subclasses of analytic functions with respect to k-symmetric points defined by differential operator. Some interesting properties belonging to these classes are provided.

Luotonins and its derivatives (Isoluotonins) are alkaloids from the aerial parts of Peganum nigellastrum Bunge. that display three major skeleton types. Luotonins A, B, and E are pyrroloquinazolinoquinoline alkaloids,. A few methods were known for the sysnthesis of Isoluotonin All luotonins have shown promising cytotoxicities towards selected human cancer cell lines, especially against leukemia P-388 cells. Luotonin A is the most active one, with its activity stemming from topoisomerase I-dependent DNAcleavage. Such intriguing biological activities and unique structures have led not only to the development of synthetic methods for the efficient synthesis of these compounds, but also to interest in structural modifications for improving the biological properties. Recent progress in the study of luotonins is covered. 

A new generalised derivative operator is introduced. This operator generalised many well-known operators studied earlier by many authors. New subclasses of analytic functions in the open unit disc are introduced which are defined using generalized derivative operator. Inclusion theorems are investigated for functions to be in the classes. Furthermore, generalised Bernardi-Libera-Livington integral operator is shown to be preserved for these classes.

Most data-hiding techniques have already been investigated in detail as regards image files in both

the spatial and frequency domains. However, they are currently the subject of several investigations in

the video domain. In recent years, among many proposed steganographic methods in the spatial

domain, pixel-value differencing (PVD) provides both high embedding capacity and viable

imperceptibility for images compared with other techniques, such as least significant bit (LSB) method.

It utilizes the remainder of two consecutive pixels in embedding secret data, and the number of

embedded bits is based on the amount of difference. The large amount of difference indicates that more

secret bits can be embedded. However, based on extensive experiments, using such technique to embed

secret data in the frequency domain creates a massive negative effect on hosted data, even resulting in

low embedding capacity, which will lead to undesired distortion in the host file. In this paper, some

modifications to the PVD method are proposed that make it capable of embedding secret information

in macro-blocks of both I-frames and P-frames for MPEG-2 video during compression. The

modifications applied to PVD reduce the distortion drift caused by reversible data hiding within

selected macro-block coefficients. Furthermore, this research devises an adaptive method that can

achieve a more secure scheme for embedding data based on encrypting the host macro-block

coefficients before the hiding process using a secret encrypted key. Based on the simulation results

obtained in this proposed approach, the proposed scheme successfully improves the perceived quality

and achieves much better security compared with PVD-based method while still retaining the

advantage of hiding a large amount of information.

In this paper, the definition of intuitionistic fuzzy parameterised fuzzy soft set (ifpfs-sets) is introduced with their properties. Two operations on intersection are introduced. Also, some examples for these operations are given. The ifpfs-set, namely union and definition of ifpfs-aggregation operator which forms ifpfs-decision making method is Introduced.

Brominated butyl rubber (BIIR) was crosslinked through an esterification reaction using the sodium salt of dicyclopentadiene dicarboxylic acid (DCPDCA) as crosslinking agent. The crosslinked BIIR could de-crosslink upon heating and re-crosslink upon cooling due to Diels-Alder type reversible de-dimerization/re-dimerization of dicyclopentadiene moieties in the rubber networks. Torque measurement of the crosslinked rubber was conducted at various temperatures using a typical curemeter to investigate the thermo-reversibility. It was revealed that proper temperature for thermal processing of the crosslinked BIIR would be around 174 °C, at which the crosslinked polymer exhibits good flowability and is not too high to induce unexpected side reactions. The torque measurement was also carried out to investigate the efficiency of antioxidant on retarding the loss of the thermo-reversibility of the crosslinked polymer during heating-cooling cycles. It was found that addition of antioxidant 2246 [2,2′-methylenebis(6-tert-butyl-4-methylphenol)] into BIIR could significantly improve the thermo-reversibility of DCPDCA crosslinked BIIR. Torque measurement provides a convenient and sensitive method to understand the thermal behavior of reversible covalent crosslinked polymer.

Background: African trypanosomes are capable of both pyrimidine biosynthesis and salvage of preformed pyrimidines from the host, but it is unknown whether either process is essential to the parasite. Methodology/Principal Findings: Pyrimidine requirements for growth were investigated using strictly pyrimidine-free media, with or without single added pyrimidine sources. Growth rates of wild-type bloodstream form Trypanosoma brucei brucei were unchanged in pyrimidine-free medium. The essentiality of the de novo pyrimidine biosynthesis pathway was studied by knocking out the PYR6-5 locus that produces a fusion product of orotate phosphoribosyltransferase (OPRT) and Orotidine Monophosphate Decarboxylase (OMPDCase). The pyrimidine auxotroph was dependent on a suitable extracellular pyrimidine source. Pyrimidine starvation was rapidly lethal and non-reversible, causing incomplete DNA content in new cells. The phenotype could be rescued by addition of uracil; supplementation with uridine, 29deoxyuridine, and cytidine allowed a diminished growth rate and density. PYR6-52/ 2 trypanosomes were more sensitive to pyrimidine antimetabolites and displayed increased uracil transport rates and uridine phosphorylase activity. Pyrimidine auxotrophs were able to infect mice although the infection developed much more slowly than infection with the parental, prototrophic trypanosome line. Conclusions/Significance: Pyrimidine salvage was not an essential function for bloodstream T. b. brucei. However, trypanosomes lacking de novo pyrimidine biosynthesis are completely dependent on an extracellular pyrimidine source, strongly preferring uracil, and display reduced infectivity. As T. brucei are able to salvage sufficient pyrimidines from the host environment, the py