Quantitative Elemental Analysis of a Single Cell by Using Inductively Coupled Plasma-Mass Spectrometry in Fast Time-Resolved Analysis Mode

The elemental composition of a single yeast, green alga, or red blood cell (RBC) was precisely determined by using inductively coupled plasma-mass spectrometry (ICP-MS) operating in fast time-resolved analysis (TRA) mode. The technique is known as single-cell (SC)-ICP-MS. Phosphorus, sulfur, magnesium, zinc, and iron were detected in the three types of cell. The elemental composition of yeast and green alga obtained by SC-ICP-MS was consistent with results obtained from conventional ICP-MS measurements following acid digestion of the cells. Slight differences were found in the measured values between SC-ICP-MS and the conventional ICP-MS results for RBC. However, the SC-ICP-MS results for S and Fe in RBC were closer to the estimated values for these elements that were calculated from the level of hemoglobin in RBCs. The data suggest that SC-ICP-MS is suitable for the analysis of various cell types, namely, fungus, plant, and animal cells.     

New trends: preperitoneal laparoscopic inguinal hernia repair

This paper focuses on the meaning and process of collaboration, particularly in the area of research and clinical practice. Much has been written about the existing gaps between research and the practice of nursing; however, action research is one mechanism that allows these elements to be drawn together. Research developed through collaborative participation has the potential to harness the energy, enthusiasm and talents of nurses at different levels and practice into a cohesive group motivated to achieve professional development and quality practice goals. Action research that is built on the philosophy of a quality within the process and significance of the group can lead to effective practice in nursing. Power can be found in partnership.     

Ethnography and Hermeneutics in Cybercultural Research Accessing IRC Virtual Communities

The Internet has penetrated China at a rapid rate. However, there exist a wide range of constraining forces, such as governmental control, inadequate infrastructure, economic affordability, cultural perceptions, and language barriers. This paper tests the impact of access to the Internet and other sources of information, perceived credibility of the Internet and conventional media, and cognitive sophistication of Chinese audiences on the choice of rival value orientations such as Communism, Materialism, and Post-materialism. The data come from a survey of 2,600 adults in Beijing and Guangzhou in November-December 2000. Multinomial logistic regression analyses show that perceived credibility of the Internet, cognitive sophistication, and access to Hong Kong-based television have a significant impact on the preference for particular value orientations. Analysis of the sub-sample of Internet users further reveals the importance of participation in online chatting. The findings bear important implications for the role of the Internet in the political development of transitional societies.     

CENTRIFUGAL FLUIDIZATION: EFFECTS OF PARTICLE DENSITY AND SIZE DISTRIBUTION

Based on the model of the centrifugal fluidized bed as a homogeneous viscous rotating fluid, the equation for conservation of momentum in the tangential direction is solved to obtain expressions for bed pressure drop and the radial variations of tangential velocity within the bed region. Comparisons with available data on bed pressure drop indicate that the fluidized bed rotates as a rigid body. Experimental data are also presented on minimum fluidization velocity and bed pressure drop with different particle densities and size distributions, verifying the validity of the available models for packed bed and fluidized bed pressure drop and minimum fluidization velocity in a centrifugal fluidized system.     

Mechanical Properties of First-Year Sea Ice at Tarsiut Island

This paper deals with the interpretation of small-scale first-year sea ice strength and property test data collected in 1982 during several field trips at Tarsiut Island N-44 location in the Canadian Beaufort Sea. Measurements of flexural, horizontal, and vertical uniaxial compressive and confined plane strain and borehole jack strengths are presented. Mathematical relationships representing the variation of these mechanical properties with temperature; salinity; strain and stress rates; and crystal structure (depth) are analyzed. Uniaxial unconfined compressive strength data of horizontal sea ice samples are compared with triaxially confined borehole jack strength data. Flexural strength data obtained from laboratory tests are compared with full-thickness cantilever beam tests performed in the field. The measured flexural strength of first-year sea ice is also provided in a statistical format. The apparent elastic modulus of sea ice is presented as a function of salinity and temperature.     

The accessory gene regulator (agr) controls Staphylococcus aureus virulence in a murine arthritis model

We have studied the role of the accessory gene regulator (agr) of Staphylococcus aureus as a virulence determinant in the pathogenesis of septic arthritis. At least 15 genes coding for potential virulence factors in Staphylococcus aureus are regulated by a putative multicomponent signal transduction system encoded by the agr/hld locus. agr and hld mutants show a decreased synthesis of extracellular toxins and enzymes, such as alpha-, beta-, and delta-hemolysin, leucocidin, lipase, hyaluronate lyase, and proteases, and at the same time an increased synthesis of coagulase and protein A as compared with the wild-type counterpart. We have used a recently described murine model of S. aureus-induced arthritis to study the virulence of S. aureus 8325-4 and two agr/hld mutants derived from it. Sixty percent of the mice injected with the wild-type strain developed arthritis, whereas agrA and hld mutants displayed joint involvement in only 10 and 30%, respectively. In addition, 40% of the mice inoculated with the wild-type strain displayed an erosive arthropathy; such changes were not detectable at all in mice inoculated with the agrA mutant. Serum levels of interleukin-6, a potent B-cell differentiation factor, were significantly higher (P < 0.001) in the mice inoculated with the wild-type strain than in those inoculated with the agrA mutant counterpart. Overall, our results suggest that the agr system of S. aureus is an important virulence determinant in the induction and progression of septic arthritis in mice.     

Symmetric nearly shift-invariant tight frame wavelets

K-regular two-band orthogonal filterbanks have been applied to image processing. Such filters can be extended into a case of downsampling by two and more than two filters provided that they satisfy a set of conditions. Such a setup allows for more degrees of freedom but also at the cost of higher redundancy. The latter depends directly on the number of the wavelet filters involved. Tight frame filters allow the design of smooth scaling functions and wavelets with a limited number of coefficients. Moreover, such filters are nearly shift invariant, a desirable feature in many applications. We explore a family of symmetric tight frame finite impulse response (FIR) filters characterized by the relations H/sub 3/(z)=H/sub 0/(-z) and H/sub 2/(z)=H/sub 1/(-z). They are simple to design and exhibit a degree of near orthogonality, in addition to near shift invariance. Both properties are desirable for noise removal purposes.     

Symmetric tight frame wavelets with dilation factor M=4

In this paper we discuss a new set of symmetric tight frame wavelets with the associated filterbank outputs downsampled by four at each stage. The frames consist of seven generators obtained from the lowpass filter using spectral factorization, with the lowpass filter obtained via a simple method using Taylor polynomials. The filters are simple to construct, and offer smooth scaling functions and wavelets. Additionally, the filterbanks presented in this paper have limited redundancy while maintaining the smoothness of underlying limit functions. The filters are linear phase (symmetric), FIR, and the resulting wavelets possess vanishing moments.     

An Approach to the Evaluation of Usefulness as a Social Construct Using Technological Frames

Abstract

This article describes an investigation of the way usefulness of an information system is shaped by sociocultural factors in a work context. It presents technological frames as a conceptual tool that helps to understand usefulness from this point of view. It suggests that developers and users shape their experience of the usefulness of a system through these technological frames. This is illustrated with a qualitative study, in which developers' expectations of the usefulness of an enterprise resource planning system differed from those of users, who experienced the usefulness of the same system in diverse ways. Technological frames are proposed as an analysis framework for assessing how context and local culture shape the utility and usability of systems in situ, that is, once they are deployed to their actual contexts of use.     

Classification of mammogram images using the energy probability in frequency domain and most discriminative power coefficients

The purpose of this work is to develop a computer-aided diagnosis (CAD) system to assist radiologists in the classification of mammogram images. The CAD system is composed of three main steps. The first step is image preprocessing and segmentation with the seeded region growing algorithm applied on a localized triangular region to remove only the muscle. In the second step of the CAD system, we proposed a novel features extraction method, which consists of three stages. In the first, the discrete cosine transform (DCT) is applied on all obtained regions of interest and then only the upper left corner (ULC) of DCT coefficients is retained. Second, we have applied the energy probability to the ULCs that is used as a criterion for selecting discriminant information. At the last stage, a new Most Discriminative power coefficient algorithm has been proposed to select the most significant features. In the final step of the CAD, the support vector machines, Naive Bayes, and artificial neural network (ANN) classifiers are used to make an effective classification. The evaluation of the proposed algorithm on the mini-Mammographic Image Analysis Society database shows its efficiency over other recently proposed CAD systems in the literature, whereas an accuracy of 100% can be achieved using ANN with a small number of features.