1,717 research outputs found
Principles and components of a strategic EPM process relevant to the peri-urban interface (PUI)
No full textIn the first instance the concern of this paper is with inquiring, as stated in the title of the paper, into principles and components of a strategic environmental planning and management (EPM) process relevant to the PUI. The research focuses attention in particular on the problems and needs of the poor living at the interface
Explicit expressions for the minimum efficiency and most penetrating particle size of Nuclepore filters
No full textNuclepore filters are capillary pore membrane filters with an array of microscopic cylindrical holes of uniform diameters. Their structure is suitable for particle collection and ensuing offline analyses, therefore they are being widely used for exposure assessment of engineered nanoparticles, ambient PM2.5, virus, bacteria, asbestos, etc., as well as in powder manufacturing industries. However, there exists a particle size range in which all the filtration capture mechanisms are not effective. This size is the most penetrating particle size (MPPS), which corresponds to the minimum efficiency (ME) of the filter. Both MPPS and ME are important parameters for a user to select an adequate Nuclepore filter and preferred operating conditions. For rapid estimation of the MPPS and ME, we derived their explicit expressions by simplifying the formulas for the impaction, diffusion and interception deposition and differentiating the combined efficiency with respect to the particle size. The comparison between the experimental data and the prediction from the explicit expressions shows the explicit expressions can provide MPPS for a wide range of filter properties (pore radius, porosity and length) and filtration conditions (particle density, face velocity and temperature). The ME can also be estimated satisfactorily when a simplified term of filter surface diffusion deposition is further considered. By the explicit expressions of MPPS and ME, a quick screening for selecting a Nuclepore filter with the proper properties and suitable filtration conditions can be easily achieved. From the theoretical point of view, the explicit expressions facilitate better understanding of the effects of filter properties and conditions on the filtration characteristic
IN VITRO CYTOTOXICITY OF DOCETAXEL IN CHILDHOOD ACUTE LEUKEMIA
No full textPurpose: In seeking to identify novel effective antileukemic agents, we assessed the in vitro activity Of the taxoid docetaxel (Taxotere; Rhone-Poulenc Rorer, Antony, France) in primary leukemic cells supported in culture by bone marrow-derived stromal layers.
Materials and Methods: Bone marrow samples from children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) were cultured on allogeneic bone marrow-derived stromal layers and exposed to various concentrations of docetaxel. After 7 days of culture, the number of viable leukemic cells were counted by flow cytometry and compared with that in parallel cultures without drugs.
Results: In 20 samples tested (15 B-lineage ALL, one T-lineage ALL, and four AML), the median cytotoxicity was 78% after a 7-day culture in the presence of 100 ng/mL docetaxel (range, 54% to 95%). The effects were dose-dependent and extended to all five ALL samples with the t(9;22)(q34;q11) (Philadelphia chromosome) or 11q23 abnormalities, karyotypes associated with an unfavorable outcome. Studies with continuously growing cell lines demonstrated that docetaxel exerted its cytotoxic effect by inducing apoptosis, and was consistently more effective than paclitaxel (Taxol; Bristol-Myers Squibb, Wallingford, CT) (mean 50% cell kill [LC50], 6.93 v 12.86 ng/mL in six leukemic cell lines). The antileukemic activities of docetaxel and vincristine were synergistic. While the mean (+/- SD) cytotoxicity of vincristine (0.1 ng/mL) was 11.2% +/- 7.3% and that of docetaxel (10 ng/mL) was 19.3% +/- 17.5% in CEM-C7 cells after 24 hours, combining the two agents increased the cytotoxicity to 62.5% +/- 20.7% (P = .003).
Conclusion: Docetaxel, at concentrations achievable in vivo, is cytotoxic to ALL and AML cells. These results provide a rationale for clinical trials of docetaxel in patients with acute leukemia
FIGURE 1 in Protura (Hexapoda) from Doi Suthep-Pui National Park, Chiang Mai, Thailand
No full textFIGURE 1. Baculentulus chiangmaiensis sp. nov. A, Dorsal view of head; B, maxillary palpus; C, labial palpus; D, pseudoculus; E, canal of maxillary gland; F, interior view of foretarsus; G, exterior view of foretarsus; H, abdominal appendage II; I, striate band on abdominal tergite VIII; J, comb on abdominal tergite VIII; K, female squama genitalis. Arrows indicate pores. A, C–J, Holotype, male; B, paratype, female. Scale bar: 20 μm for A, F, G; 10 μm for B–E, H–J.Published as part of Nakamura, Osami & Likhitrakarn, Natdainai, 2009, Protura (Hexapoda) from Doi Suthep-Pui National Park, Chiang Mai, Thailand, pp. 1-16 in Zootaxa 2121 on page 2, DOI: 10.5281/zenodo.18810
The antifungal antibiotic clotrimazole alters calcium homeostasis of leukemic lymphoblasts and induces apoptosis
No full textSupport for an integrated approach to program understanding: an application of software visualisation
No full textProgram Comprehension is a key factor in providing effective software maintenance and enabling successful evolution of software systems. The objective of this research is to provide a framework and mechanism to facilitate the understanding of large software systems. There exist a number of theories and models of Program Comprehension where each favours a different approach to comprehension. It is evident that there is no real consensus on how maintainers understand software systems. The disparities in the comprehension strategies are largely dependent on the personal and circumstantial factors. Factors such as the level of technical competence of the maintainers, the size and complexity of the piece of software, and the types and goals of the maintenance activities can influence the process of comprehension. This research proposes an alternative approach to Program Comprehension. It acknowledges that the process of comprehension is opportunistic, and that the current comprehension theories are inadequate in addressing this. There is a need for a more flexible approach towards comprehension, and the Integrated Approach proposed in this thesis provides a way for the utilisation of the various comprehension theories under a single environment. It recognises that any one of the comprehension theories may become active during comprehension. Under the Integrated Approach, maintainers have the option of selecting and executing the various comprehension strategies as they see fit. The Integrated Approach to comprehension is based on a matrix of Program Relationships between Program Elements of a programming language. In this thesis, these Program Relationships are derived for the C programming language constructs. This work also involves the investigation of the roles of both textual and graphical representations during the comprehension process. Both representations are commonly used to alleviate the problem of information overloading when maintainers trying to understand and maintain a software system. The Integrated Approach is realised in a tool named PUI (program [understanding implements) which provides an environment enabling the utilisation of various comprehension theories
The chemistry of [h]-cycloheptatrienyl derivatives of molybdenum and tungsten
No full textThis thesis describes the synthetic, structural and reactivity studies of η- cycloheptatrienyl-molybdenum and -tungsten chemistry. Chapter 1 presents an overview of the chemistry of η-cycloheptatrienyl derivatives of transition metals, in particular group 6 metals. The functional group properties of the η-cycloheptatrienyl ligand are also discussed. Chapter 2 describes the synthesis of [Mo(η-C7H7)(η5-C7H9)] from Mocl5 or [MoCl4(thf)2], which provides a convenient route to η-cycloheptatrienyl-molybdenum compounds, such as [Mo(η-C7H7)LX2] and [Mo(η-C7H7)L2X], where L = tertiary phosphines or acetonitrile and X = halogen, [NBu4] [Mo(η-C7H7)I3], [Mo(η-C7H7)(η- C5H4R)] (R = H or Me) and [Mo(η-C7H7)(η5-C9H7)]. The X-ray crystal structures of [Mo(η-C7H7)(MeCN)I2], [NBu4][Mo(η-C7H7))I3] and [Mo(η-C7H7)(η-C5H4Me)] are presented. The compound [Mo(η-C7H7))(MeCN)I2], mixed with Me3SiCH2MgCl, is a catalyst for ring-opening polymerisation of norbornene giving trans polymer exclusively. The electron-transfer complexes [Mo(η-C7H7)(η-C5H4Me)][tcne] and {[Mo(η-C7H7))(η- C5H5}2[tcnq]} and the intercalation compound {ZrS2[Mo(η-C7H7)(η-C5H4Me)]o.22} are also described. An extension of these synthetic pathways to tungsten is described in chapter 3. Reduction of WCl6 with sodium amalgam in the presence of cycloheptatriene gives [W(η- C7H7)(η5-C7H9)], which is a precursor to the compounds [W(η-C7H7)(MeCN)I2], [W(η- C7H7)(PMe3)X2] (X = Br or I), [W(η-C7H7)(dmpe)I], [W(η-C7H7)(η-C5H4R)] (R = H or Me) and [Mo(η-C7H7)(η5-C9H7)]. The [W(η-C7H7)(MeCN)I2] / Me3SiCH2MgCI system is an active catalyst for ring opening polymerisation of norbomene. The electronic structures of [W(η-C7H7)(η-C5H4R)] (R= H or Me) are discussed on the basis of their He I and He II photoelectron spectra. The intercalation of [W(η-C7H7)(η-C5H4Me)] into ZrS2 is also described. The magnetic properties of the 17-electron compounds [Mo(η-C7H7)(MeCN)I2], [Mo(η-C7H7)(PMe3)I2], [W(η-C7H7)(MeCN)I2], [W(η-C7H7)(PMe3)I2] and [W(η-C7H7) (PMe3)I2] are discussed in chapter 4. They behave as one-dimensional antiferromagnets which was suggested by magnetic model fittings and the crystal structure of [Mo(η-C7H7)(MeCN)I2]. Chapter 5 comprises of two parts. The first part describes a new series of binuclear thiolato-bridged molybdenum complexes [(η-C7H3R¹4)Mo(μ-SR²)3 Mo- (η-C7H3R¹4)][BF4] (R¹ = H or Me; R² = Et, Pr, Bu, Ph or CH2Ph). Dynamic NMR studies reveal that all of these complexes (except for R² = Ph) are fluxional due to inversion at the pyramidal sulfur centre. Cyclic voltammetric studies show that they undergo two reversible one-electron reductions. Second part of this chapter describes the new bridging-imido compound [(η-C7H7)Mo(μ-NAr)2Mo(η-C7H7)] (Ar = 2,6- diisopropylphenyl). Chapter 6 discusses the η-l,2,4,6-tetramethylcycloheptatrienyl-molybdenum system. The new η-tetramethylcycloheptatriene molybdenum compounds [M'(η-C7H4Me4- 1,3,5,7)],[M'(η-C7H4Me4-l,2,4,6)] and [M'(η-C7H4Me4-l,3,4,6)], M' = Mo(CO)3, and new η-tetramethylcycloheptatrienyl-molybdenum compounds [M"(CO)3]+, [M"(CO)2C1], [M"(dmpe)Cl], [M"(η-C6H5Me)]+ and [M"(acac)(PPh3)], M" = Mo(η- CC7H3Me4-1,2,4,6), and [Mo(η3-C7H3Me4-l,2,4,6)(dmpe)(CO)2Cl] are described. Chapter 7 gives the experimental details for the work described in preceeding chapters. Appendix A presents characterising data for all the new compounds and previously unreported data for known compounds. Crystallographic details for the X-ray structure determinations and X-ray powder diffraction data are listed in Appendix B and C respectively
Exchange interaction function for spin-lattice coupling in bcc iron
No full textAuthor name used in this publication: C. H. Woo2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishedVoR allowe
COD removal and nitrification of low-strength domestic wastewater in aerobic granular sludge sequencing batch reactors
No full textAcetate-fed granules were used to start-up reactors for the treatment of low-strength domestic wastewater at 25 °C (R1) and 35 °C (R2). Two hundred milligrams per liter COD in domestic wastewater was easily removed. Granular seeds acclimated to NH4+-N removal after domestic wastewater was used and the specific NH4+-N removal rate increased linely after 7-day operation. Effluent NH4+-N was below 5 mg l?1 and NH4+-N removal efficiency increased to above 90% after 22-day operation with cycle time of 2 h in both reactors with 0.3 kg m?3 day?1 NH4+-N loading rate. In addition, granular seeds cultivated at 25 °C showed good adaptation to higher temperature and the granules in R2 at 35 °C showed good stability in 4-month operation
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