949 resultados para unique features
Resumo:
The paper describes egg laying and reproduction in ICHTHYOPHIS MALABARENSIS. 100 eggs, the largest ever in Apoda, are laid in a single string and manipulated by the female into a massive clutch. The reproductive strategies in the species are discussed.
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Recently, several reports showed that about 80 % of mid-log phase Mycobacterium smegmatis, Mycobacterium marinum, and Mycobacterium bovis BCG cells divide symmetrically with 5-10 % deviation in the septum position from the median. However, the mode of cell division of the pathogenic mycobacterial species, Mycobacterium tuberculosis, remained unclear. Therefore, in the present study, using electron microscopy, fluorescence microscopy of septum- and nucleoid-stained live and fixed cells, and live cell time-lapse imaging, we show the occurrence of asymmetric cell division with unusually deviated septum/constriction in 20 % of the 15 % septating M. tuberculosis cells in the mid-log phase population. The remaining 80 % of the 15 % septating cells divided symmetrically but with 2-5 % deviation in the septum/constriction position, as reported for M. smegmatis, M. marinum, and M. bovis BCG cells. Both the long and the short portions of the asymmetrically dividing M. tuberculosis cells with unusually deviated septum contained nucleoids, thereby generating viable short and long cells from each asymmetric division. M. tuberculosis short cells were acid fast positive and, like the long cells, further readily underwent growth and division to generate micro-colony, thereby showing that they were neither mini cells, spores nor dormant forms of mycobacteria. The freshly diagnosed pulmonary tuberculosis patients' sputum samples, which are known for the prevalence of oxidative stress conditions, also contained short cells at the same proportion as that in the mid-log phase population. The probable physiological significance of the generation of the short cells through unusually deviated asymmetric cell division is discussed.
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Acetyl-CoA carboxylase, which has a molecular mass of 265 kDa (ACC-alpha), catalyzes the rate-limiting step in the biosynthesis of long-chain fatty acids. In this study we report the complete amino acid sequence and unique features of an isoform of ACC with a molecular mass of 275 kDa (ACC-beta), which is primarily expressed in heart and skeletal muscles. In these tissues, ACC-beta may be involved in the regulation of fatty acid oxidation, rather than fatty acid biosynthesis. ACC-beta contains an amino acid sequence at the N terminus which is about 200 amino acids long and may be uniquely related to the role of ACC-beta in controlling carnitine palmitoyltransferase I activity and fatty acid oxidation by mitochondria. If we exclude this unique sequence at the N terminus the two forms of ACC show about 75% amino acid identity. All of the known functional domains of ACC are found in the homologous regions. Human ACC-beta cDNA has an open reading frame of 7,343 bases, encoding a protein of 2,458 amino acids, with a calculated molecular mass of 276,638 Da. The mRNA size of human ACC-beta is approximately 10 kb and is primarily expressed in heart and skeletal muscle tissues, whereas ACC-alpha mRNA is detected in all tissues tested. A fragment of ACC-beta cDNA was expressed in Escherichia coli and antibodies against the peptide were generated to establish that the cDNA sequence that we cloned is that for ACC-beta.
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A first comprehensive investigation on the deflagration of ammonium perchlorate (AP) in the subcritical regime, below the low pressure deflagration limit (LPL, 2.03 MPa) christened as regime I$^{\prime}$, is discussed by using an elegant thermodynamic approach. In this regime, deflagration was effected by augmenting the initial temperature (T$_{0}$) of the AP strand and by adding fuels like aliphatic dicarboxylic acids or polymers like carboxy terminated polybutadiene (CTPB). From this thermodynamic model, considering the dependence of burning rate ($\dot{r}$) on pressure (P) and T$_{0}$, the true condensed (E$_{\text{s,c}}$) and gas phase (E$_{\text{s,g}}$) activation energies, just below and above the surface respectively, have been obtained and the data clearly distinguishes the deflagration mechanisms in regime I$^{\prime}$ and I (2.03-6.08 MPa). Substantial reduction in the E$_{\text{s,c}}$ of regime I$^{\prime}$, compared to that of regime I, is attributed to HClO$_{4}$ catalysed decomposition of AP. HClO$_{4}$ formation, which occurs only in regime I$^{\prime}$, promotes dent formation on the surface as revealed by the reflectance photomicrographs, in contrast to the smooth surface in regime I. The HClO$_{4}$ vapours, in regime I$^{\prime}$, also catalyse the gas phase reactions and thus bring down the E$_{\text{s,g}}$ too. The excess heat transferred on to the surface from the gas phase is used to melt AP and hence E$_{\text{s,c}}$, in regime I, corresponds to the melt AP decomposition. It is consistent with the similar variation observed for both the melt layer thickness and $\dot{r}$ as a function of P. Thermochemical calculations of the surface heat release support the thermodynamic model and reveal that the AP sublimation reduces the required critical exothermicity of 1108.8 kJ kg$^{-1}$ at the surface. It accounts for the AP not sustaining combustion in the subcritical regime I$^{\prime}$. Further support for the model comes from the temperature-time profiles of the combustion train of AP. The gas and condensed phase enthalpies, derived from the profile, give excellent agreement with those computed thermochemically. The $\sigma _{\text{p}}$ expressions derived from this model establish the mechanistic distinction of regime I$^{\prime}$ and I and thus lend support to the thermodynamic model. On comparing the deflagration of strand against powder AP, the proposed thermodynamic model correctly predicts that the total enthalpy of the condensed and gas phases remains unaltered. However, 16% of AP particles undergo buoyant lifting into the gas phase in the `free board region' (FBR) and this renders the demarcation of the true surface difficult. It is found that T$_{\text{s}}$ lies in the FBR and due to this, in regime I$^{\prime}$, the E$_{\text{s,c}}$ of powder AP matches with the E$_{\text{s,g}}$ of the pellet. The model was extended to AP/dicarboxylic acids and AP/CTPB mixture. The condensed ($\Delta $H$_{1}$) and gas phase ($\Delta $H$_{2}$) enthalpies were obtained from the temperature profile analyses which fit well with those computed thermochemically. The $\Delta $H$_{1}$ of the AP/succinic acid mixture was found just at the threshold of sustaining combustion. Indeed the lower homologue malonic acid, as predicted, does not sustain combustion. In vaporizable fuels like sebacic acid the E$_{\text{s,c}}$ in regime I$^{\prime}$, understandably, conforms to the AP decomposition. However, the E$_{\text{s,c}}$ in AP/CTPB system corresponds to the softening of the polymer which covers AP particles to promote extensive condensed phase reactions. The proposed thermodynamic model also satisfactorily explains certain unique features like intermittent, plateau and flameless combustion in AP/ polymeric fuel systems.
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The silver-haired bat variant of rabies virus (SHBRV) has been identified as the etiological agent of a number of recent human rabies cases in the United States that are unusual in not having been associated with any known history of conventional exposure. Comparison of the different biological and biochemical properties of isolates of this virus with those of a coyote street rabies virus (COSRV) revealed that there are unique features associated with SHBRV. In vitro studies showed that, while the susceptibility of neuroblastoma cells to infection by both viruses was similar, the infectivity of SHBRV was much higher than that of COSRV in fibroblasts (BHK-21) and epithelial cells (MA-104), particularly when these cells were kept at 34 degrees C. At this temperature, low pH-dependent fusion and cell-to-cell spread of virus is seen in BHK-21 cells infected with SHBRV but not with COSRV. It appears that SHBRV may possess an unique cellular tropism and the ability to replicate at lower temperature, allowing a more effective local replication in the dermis. This hypothesis is supported by in vivo results which showed that while SHBRV is less neurovirulent than COSRV when administered via the intramuscular or intranasal routes, both viruses are equally neuroinvasive if injected intracranially or intradermally. Consistent with the above findings, the amino acid sequences of the glycoproteins of SHBRV and COSRV were found to have substantial differences, particularly in the region that contains the putative toxic loop, which are reflected in marked differences in their antigenic composition. Nevertheless, an experimental rabies vaccine based on the Pittman Moore vaccine strain protected mice equally well from lethal doses of SHBRV and COSRV, suggesting that currently used vaccines should be effective in the postexposure prophylaxis of rabies due to SHBRV.
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Among the many new opportunities that digital technologies are enabling are an increased capacity for viewers to interact not only with the program content, but with an increasingly wide array of other digital applications. Within this context this project has developed a new interaction device (incorporating gestural platform technology) and user interfaces to facilitate interactive access to digital media in a lounge room setting. This paper provides an overview of an interdisciplinary design process applied by Australasian CRC for Interaction Design (ACID) researchers—in order to develop the device and present in detail its unique features.
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Family businesses dominate in a majority of economies (Astrachan and Shanker, 2003; Chrisman, Chua, and Sharma, 2005; Morck and Yeung, 2004). As entrepreneurial activities have been shown to be central to economic growth it is essential that family businesses, irrespective of ownership patterns, not only survive but also grow thus growing the economy overall. While a great deal is known about entrepreneurial activities and a body of knowledge is being developed in relation to entrepreneurial processes in family firms, more needs to be understood in relation to the dynamics of entrepreneurial activities at the individual family firm level. One area of particular interest is the dynamics within the business and the family and how these dynamics impact upon entrepreneurial activities. Specifically how relationships between and among family members engaged in the business can interact with professional non-family member senior executives. The senior executives can actively use their positions in such ways that initiatives suggested by family members are less successful than they might be. This paper addresses how ‘family’ aspects of a business can assist or impede the entrepreneurial activities of individuals. It takes into account some of the unique features of family businesses – such as the importance of ‘familiness’ as a competitive advantage; the direct links between ownership and control of a business and the recognition (often implicit) that individuals in families do make a difference to how the business functions (Habbershon and Williams, 1999, Sharma, 2004; and Tokarczyk, Hansen Green, and Down, 2007). This emphasis on individuals in families fits well with the idea of entrepreneur as individual, as expressed by Schumpeter (1934), Baumol et al (2007). The theoretical approach that adopted to explore the dynamics of processes occurring within family firms is structuration theory combined with a theory of embeddeness (Dacin, Ventresca and Beal, 1999; Giddens, 1979, 1984, Jack and Anderson, 2002; and Sarason, Dean and Dillard, 2006).
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Over many centuries of settlement, Vietnamese inhabitants have developed a vernacular architecture that is well adapted to the region’s climatic and topographical conditions. Vernacular Vietnamese housing uses natural systems to create a built environment that integrates well with nature. The vernacular combines site-sensitive, passive solar design, natural materials and appropriate structure to achieve harmony among nature, humans and the built environment. Unfortunately, these unique features have not been applied in contemporary Vietnamese architecture, which displays energy-intensive materials and built forms. This research is analysing how environmentally-responsive elements of vernacular architecture could be applied to modern sustainable housing in Vietnam. Elements of many types of vernacular architecture throughout the country are reviewed as precedents for future building planning and design. The paper also looks at culturally and ecologically appropriate legislative and voluntary options for encouraging more sustainable housing.
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Reliable infrastructure assets impact significantly on quality of life and provide a stable foundation for economic growth and competitiveness. Decisions about the way assets are managed are of utmost importance in achieving this. Timely renewal of infrastructure assets supports reliability and maximum utilisation of infrastructure and enables business and community to grow and prosper. This research initially examined a framework for asset management decisions and then focused on asset renewal optimisation and renewal engineering optimisation in depth. This study had four primary objectives. The first was to develop a new Asset Management Decision Framework (AMDF) for identifying and classifying asset management decisions. The AMDF was developed by applying multi-criteria decision theory, classical management theory and life cycle management. The AMDF is an original and innovative contribution to asset management in that: · it is the first framework to provide guidance for developing asset management decision criteria based on fundamental business objectives; · it is the first framework to provide a decision context identification and analysis process for asset management decisions; and · it is the only comprehensive listing of asset management decision types developed from first principles. The second objective of this research was to develop a novel multi-attribute Asset Renewal Decision Model (ARDM) that takes account of financial, customer service, health and safety, environmental and socio-economic objectives. The unique feature of this ARDM is that it is the only model to optimise timing of asset renewal with respect to fundamental business objectives. The third objective of this research was to develop a novel Renewal Engineering Decision Model (REDM) that uses multiple criteria to determine the optimal timing for renewal engineering. The unique features of this model are that: · it is a novel extension to existing real options valuation models in that it uses overall utility rather than present value of cash flows to model engineering value; and · it is the only REDM that optimises timing of renewal engineering with respect to fundamental business objectives; The final objective was to develop and validate an Asset Renewal Engineering Philosophy (AREP) consisting of three principles of asset renewal engineering. The principles were validated using a novel application of real options theory. The AREP is the only renewal engineering philosophy in existence. The original contributions of this research are expected to enrich the body of knowledge in asset management through effectively addressing the need for an asset management decision framework, asset renewal and renewal engineering optimisation based on fundamental business objectives and a novel renewal engineering philosophy.
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Analysis of either footprints or footwear impressions which have been recovered from a crime scene is a well known and well accepted part of forensic investigation. When this evidence is obtained by investigating officers, comparative analysis to a suspect’s evidence may be undertaken. This can be done either by the detectives or in some cases, podiatrists with experience in forensic analysis. Frequently asked questions of a podiatrist include; “What additional information should be collected from a suspect (for the purposes of comparison), and how should it be collected?” This paper explores the answers to these and related questions based on 20 years of practical experience in the field of crime scene analysis as it relates to podiatry and forensics. Elements of normal and abnormal foot function are explored and used to explain the high degree of variability in wear patterns produced by the interaction of the foot and footwear. Based on this understanding the potential for identifying unique features of the user and correlating this to footwear evidence becomes apparent. Standard protocols adopted by podiatrists allow for more precise, reliable, and valid results to be obtained from their analysis. Complex data sets are now being obtained by investigating officers and, in collaboration with the podiatrist; higher quality conclusions are being achieved. This presentation details the results of investigations which have used standard protocols to collect and analyse footwear and suspects of recent major crimes.
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Real-time networked control systems (NCSs) over data networks are being increasingly implemented on a massive scale in industrial applications. Along with this trend, wireless network technologies have been promoted for modern wireless NCSs (WNCSs). However, popular wireless network standards such as IEEE 802.11/15/16 are not designed for real-time communications. Key issues in real-time applications include limited transmission reliability and poor transmission delay performance. Considering the unique features of real-time control systems, this paper develops a conditional retransmission enabled transport protocol (CRETP) to improve the delay performance of the transmission control protocol (TCP) and also the reliability performance of the user datagram protocol (UDP) and its variants. Key features of the CRETP include a connectionless mechanism with acknowledgement (ACK), conditional retransmission and detection of ineffective data packets on the receiver side.
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Fiber Bragg grating (FBG) sensor technology has been attracting substantial industrial interests for the last decade. FBG sensors have seen increasing acceptance and widespread use for structural sensing and health monitoring applications in composites, civil engineering, aerospace, marine, oil & gas, and smart structures. One transportation system that has been benefitted tremendously from this technology is railways, where it is of the utmost importance to understand the structural and operating conditions of rails as well as that of freight and passenger service cars to ensure safe and reliable operation. Fiberoptic sensors, mostly in the form of FBGs, offer various important characteristics, such as EMI/RFI immunity, multiplexing capability, and very long-range interrogation (up to 230 km between FBGs and measurement unit), over the conventional electrical sensors for the distinctive operational conditions in railways. FBG sensors are unique from other types of fiber-optic sensors as the measured information is wavelength-encoded, which provides self-referencing and renders their signals less susceptible to intensity fluctuations. In addition, FBGs are reflective sensors that can be interrogated from either end, providing redundancy to FBG sensing networks. These two unique features are particularly important for the railway industry where safe and reliable operations are the major concerns. Furthermore, FBGs are very versatile and transducers based on FBGs can be designed to measure a wide range of parameters such as acceleration and inclination. Consequently, a single interrogator can deal with a large number of FBG sensors to measure a multitude of parameters at different locations that spans over a large area.
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In this study, we provide an insight into how private equity players choose their targets and the bid arrangements they prefer. We test our expectations of the unique features of private equity targets using a sample of 23 listed private equity target firms during 2001–2007. We find, relative to a benchmark sample of 81 corporate targets matched by year and industry, the private equity target firms to be larger, more profitable, use their assets more efficiently, more highly levered and have greater cash flow. Multivariate testing indicates that private equity targets have relatively greater financial slack, greater financial stability, greater free cash flow and lower measurable growth prospects. All conclusions are found to be robust to a control sample of 502 takeover bids during 2001–2007.
Taxation of multinational banks : using formulary apportionment to reflect economic reality (Part 1)
Resumo:
Formulary apportionment does not attempt to undertake a transactional division of a highly integrated multinational entity. Rather, it allocates income to the jurisdictions based on an economically justifiable formula. Opposition to formulary apportionment is generally based on the argument that it is not a theoretically superior (or optimal) model because of the implementation difficulties. The conclusion that the unitary taxation model may be theoretically superior to the current arm's-length model that applies to multinational banks, despite significant implementation, compliance, and enforcement issues, is based on the unitary taxation model providing greater alignment with the unique features of these banks. The formulary apportionment model looks to the economic substance of the multinational entity and, in this sense, adopts a substance-over- form approach. Formulary apportionment further recognizes the impossibility of using arm's-length pricing for economically interdependent multinational entities. A final advantage to formulary apportionment, which is also a consequence of this model achieving greater inter-nation equity, is the elimination of double taxation.