1,181 research outputs found

    Intermittency study of charged particles generated in Pb-Pb collisions at sNN= 2.76 TeV\sqrt{s_{\mathrm{NN}}}\text{= 2.76 TeV} using EPOS3

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    Charged particle multiplicity fluctuations in Pb-Pb collisions are studied for the central events generated using EPOS3 (hydro and hydro+cascade) at sNN = 2.76 TeV\sqrt{s_{\mathrm{NN}}}\text{ = 2.76 TeV}. Intermittency analysis is performed in the mid-rapidity region in two-dimensional (η\eta, ϕ\phi) phase space within the narrow transverse momentum (p_\rm{{T}}) bins in the low p_\rm{{T}}~region (p_\rm{{T}}~\leq~1.0~GeV/\textit{c}). Power-law scaling of the normalized factorial moments with the number of bins is not observed to be significant in any of the p_\rm{{T}}-bin. Scaling exponent ν\nu, deduced for a few p_\rm{{T}} bins is greater than that of the value 1.304, predicted for the second order phase-transition by the Ginzburg-Landau theory. The link in the notions of fractality is also studied. Fractal dimensions, DqD_{q} are observed to decrease with the order of the moment qq suggesting the multifractal nature of the particle generation in EPOS3.Comment: 7 pages, 8 figure

    Identification and characterisation of an extrachromosomal element from a multidrug-resistant isolate of Trypanosoma brucei brucei

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    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Drug resistance together with difficulties involved in the development of new trypanocides are a major problem in the present control of African trypanosomiasis. DNA based diagnostics for drug resistance would overcome problems in the identification of drug-resistant populations and contribute to effective control measures. However, this requires a detailed knowledge of the mode of action and the mechanisms by which trypanosomes can overcome the toxic effects of trypanocides. In this study, a search for molecular differences between a multidrug-resistant isolate of Trypanosoma brucei brucei, CP 547, and a reference drug-sensitive population, ILTat 1.4, led to the identification of a 6.6 kbp extrachromosomal element in the multidrug-resistant population. In light of the involvement of extrachromosomal elements in drug resistance in Leishmana spp. and cancer cells, the identification of the 6.6 kbp element warranted its characterisation. Several different approaches sere attempted before a sequence which hybridised to the 6.6 kbp element its eventually isolated. This sequence is represented by a 108 bp repeat sequence which forms long arrays of tandem repeats. Since N/a III is the sole restriction enzyme that cuts within the repeat, it has been referred to as an N/a III repeal The repeat is flanked by a 5 bp spacer sequence. However, a unique 5 bp direct repeat flanking two complete, and one partial copy of the N/a III repeat may signify the transposition of these sequences. Hybridisation with the N/a III repeat revealed the presence of 'higher' hybridising elements which also appear to be predominantly composed of long tandem arrays of the N/a Ill repeal Through exploitation of the p01) merase chain reaction using arbitrary primers (AP-PCR), additional sequences were identified which are associated with some of the 6.6 kbp and 'higher' hybridising elements. The 6.6 kbp element and some of the 'higher' hybridising elements display features of circular DNA molecules. The 6.6 kbp element also displays some level of size and sequence heterogeneity within different populations of the same trypanosome isolate. The copy number of the 6.6 kbp element is also not stable and appears to be directly affected by the application of selective drug pressure, but a direct association between the presence of the element and the expression of multidrug resistance could not be determined. The N/a III repeat family represents a newly identified repetitive family specific to members of the Trypanozoon subgenus. This repeat family, representing about 5% of the parasite genome, is dispersed through all size classes of chromosomes, in addition to its presence on the extrachromosomal elements. Transcriptional studies of the N/a III repeats have revealed that their transcription is developmentally regulated, since heterogeneous transcripts ranging from greater than 10 kb to smaller than 300 bp are present in the actively dividing long slender bloodstream and insect stage procyclic forms of the parasite but not nondividing, stumpy bloodstream forms. Lastly, the N/a III repeat lacks an open reading frame and transcripts do not appear to have a spliced leader sequence at the 5' end. Furthermore, there is almost an equal representation of polyadenylatcd and non-polyadenlyated transcripts

    A simple field based method for rapid wood density estimation for selected tree species in Western Kenya

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    Wood density is an important variable for accurate quantification of woody biomass and carbon stocks. Conventional destructive methods for wood density estimation are resource intensive, prohibiting their use, limiting the application of approaches that would minimize uncertainties in tree biomass estimates. We tested an alternative method involving tree coring with a carpenter's auger to estimate wood density of seven tropical tree species in Western Kenya. We used conventional water immersion method to validate results from the auger core method. The mean densities (and 95% confidence intervals) ranged from 0.36 g cm−3 (0.25–0.47) to 0.67 g cm−3 (0.61–0.73) for the auger core method, and 0.46 g cm−3 (0.42–0.50) to 0.67 g cm−3 (0.61–0.73) for the water immersion method. The auger core and water immersion methods were not significantly different for four out of seven tree species namely; Acacia mearnsii, Mangifera indica, Eucalyptus grandis and Grevillea robusta. However, wood densities estimated from the auger core method were lower (t (61) = 7.992, P = <0.001). The ease of the auger core method application, as a non-destructive method in acquiring wood density data, is a worthy alternative in biomass and carbon stocks quantification. This method could protect trees outside forests found in most parts of Africa

    Women and men in tropical dry forests: a preliminary review

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    From a broad review of 670 publications on gender and forests, ~130 were found to address the world’s dry forests. These were examined with the intent to extract gendered social, cultural, political and economic patterns of relevance in such forests. Seven interrelated themes recurred in this literature: 1) population pressure, 2) migration, 3) intra-familial and inter-group conflict, 4) hierarchy and significant power differences, 5) strict gender differentiation, 6) commercialization of crops and NTFPs, and 7) fuelwood collection. Based upon these themes, the uniqueness of each situation and the importance of finetuning any approach to local realities to generate outcomes that can benefit women, we propose four promising ways to enhance the prospects for gender equity in dry forest areas: 1) a strengthening of groups and collective action, 2) explicit challenges to traditional gender norms, 3) a focus on products and spaces that interest women, and 4) addressing migration and population issues

    Variation in Feed Point within Differed L-Slot Multi-frequency Microstrip Patch

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    A rectangular microstrip patch antenna with differed pair of L-slots is presented. The proposed antenna is designed to evaluate the effect of alteration in probe-feed point. The proposed microstrip antenna is suitable for bluetooth, mobile and wireless communication applications simultaneously. It is designed successfully for mobile communication systems and Wireless Local Area Networks (WLAN) applications. The results obtained had showed better improvement in the return loss and radiation pattern in comparison to the other existing antennas
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