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Additional Parameter (additional + parameter)
Selected AbstractsDeformation by examples: a density flow approachCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 2 2007Hoi-Chau Leung Abstract In this article, a shape transformation technique is introduced for deforming objects based on a given deformation example. The example consists of two reference shapes representing two different states of an object. The reference shapes are assumed to morph from one state to the other. The evolution between the two reference shapes determines the shape transformation function. Any given objects can then be deformed by the same transformation. A continuous 4D Radial Basis Function is used to construct a density flow field (an extension of the optical flow in computer vision) representing the shape transformation of the example in 3-space. Objects embedded in the density flow field are deformed by moving vertices of the objects along the density flow vectors. Additional parameters are introduced to control the process of the deformation. This provides explicit control on the shape of the object obtained in the deformation process. Copyright © 2007 John Wiley & Sons, Ltd. [source] Maternal sensitivity in interactions with three- and 12-month-old infants: Stability, structural composition, and developmental consequencesINFANT AND CHILD DEVELOPMENT, Issue 3 2004Arnold Lohaus This study addresses three topics related to the structural components of maternal sensitivity: (a) The stability of sensitivity over a nine-month period, (b) the predictability of maternal sensitivity assessed at 12 months from early parameters of parenting and (c) the relation between maternal sensitivity and developmental outcomes assessed at 12 months. Maternal sensitivity and its components (signal perception, correct interpretation, prompt, and appropriate reaction) were evaluated for 60 mother,infant-dyads when their infants were aged three and 12 months. Additional parameters of early parenting were maternal emotional warmth and behavioural contingency. Developmental outcome measures were the amount of infant crying and the quality of attachment at twelve months. The results showed close correlations between the sensitivity components suggesting a unidimensional structure for maternal sensitivity. The sensitivity assessments were significantly related to measures of maternal warmth. Stability of maternal sensitivity over time was, however, quite low. There was no relation between the early sensitivity assessments and later developmental outcomes, whereas there was a significant relation between the sensitivity parameters assessed at twelve months and developmental outcomes. The results indicate changes in the meaning of maternal sensitivity during infants' development. Copyright © 2004 John Wiley & Sons, Ltd. [source] Impact of parturition on iron status in nonanaemic iron deficiencyEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2003A. Krafft Abstract Background, Iron-deficient nonanaemic parturients risk underdiagnosis as a result of the reliance on postpartum ferritin and haemoglobin as markers of iron status. Ferritin is an acute-phase protein whose levels increase during the inflammatory response, as occurs after delivery. Our aims were to evaluate the impact of parturition on iron status, erythropoiesis and the inflammatory response, and identify the optimal parameters and timing for diagnosing iron deficiency in the presence of postpartum inflammation. Materials and methods, Conventional parameters of iron status, erythropoiesis and the inflammatory response (serum ferritin, serum iron, transferrin saturation, C-reactive protein) were compared with more recent parameters [soluble transferrin receptors (sTfR), hypochromic red cells, reticulocyte indices] within 48 h either side of delivery in 64 iron-deficient nonanaemic women (defined by a prepartum serum ferritin , 15 µg L,1, and a pre- and postpartum haemoglobin of , 11·0 g dL,1 and , 10·0 g dL,1, respectively). Results, Mean sTfR decreased pre to postpartum from 7·3 to 5·8 µg mL,1 (P < 0·01), while mean serum ferritin increased from 9·7 to 16·9 µg L,1 (P < 0·01). Serum ferritin did not correlate with haemoglobin pre or postpartum (r = 0·04, P = 0·7; r = 0·2, P = 0·09), but a correlation persisted postpartum between hypochromic red blood cells and haemoglobin (r = ,0·26; P < 0·05). The percentage of hypochromic red cells remained virtually unchanged pre- and postpartum (4·0% vs. 3·8%; NS). Postpartum mean reticulocyte haemoglobin content (CHr) was 27·1 ± 1·6 pg. Conclusion, Iron status should be tested prepartum, in the absence of an inflammatory response, rather than in the early postpartum. A valuable additional parameter, where available, might be the hypochromic red cell percentage, which is virtually uninfluenced by the inflammatory response. Furthermore, hypochromic red cell percentage, CHr and sTfR can be helpful to differentiate between functional iron deficiency and depleted iron stores. [source] Three-parameter discontinuous distributions for hydrological samples with zero valuesHYDROLOGICAL PROCESSES, Issue 15 2005Stanislaw Weglarczyk Abstract A consistent approach to the frequency analysis of hydrologic data in arid and semiarid regions, i.e. the data series containing several zero values (e.g. monthly precipitation in dry seasons, annual peak flow discharges, etc.), requires using discontinuous probability distribution functions. Such an approach has received relatively limited attention. Along the lines of physically based models, the extensions of the Muskingum-based models to three parameter forms are considered. Using 44 peak flow series from the USGS data bank, the fitting ability of four three-parameter models was investigated: (1) the Dirac delta combined with Gamma distribution; (2) the Dirac delta combined with two-parameter generalized Pareto distribution; (3) the Dirac delta combined with two-parameter Weibull (DWe) distribution; (4) the kinematic diffusion with one additional parameter that controls the probability of the zero event (KD3). The goodness of fit of the models was assessed and compared both by evaluation of discrepancies between the results of both estimation methods (i.e. the method of moments (MOM) and the maximum likelihood method (MLM)) and using the log of likelihood function as a criterion. In most cases, the DWe distribution with MLM-estimated parameters showed the best fit of all the three-parameter models. Copyright © 2005 John Wiley & Sons, Ltd. [source] Splitting elastic modulus finite element method and its applicationINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 10 2001Dang Faning Abstract To establish the best precision FEM, the proportion of potential and complementary energy in the functional of the variational principles must be changeable. A new kind of variational principle in linear theory of solid mechanics, called the splitting elastic modulus variational principle, is introduced. Its distinctive feature is that the functional contains one arbitrary additional parameter, called splitting factor; the proportion of potential and complementary energy in the functional can be changed by the splitting factor. Finite element method, which is based on the new principle, is established. It is called splitting modulus FEM, its stiffness can be adjusted by properly selecting the splitting factors, some ill-conditioned problem can be conquered by it. The methods to choose the splitting factors, reduce the condition number of stiffness matrix and improve the precision of solutions are also discussed. The reason why the new method can transform the ill-conditioned problems into well-conditioned ones is analysed finally. Copyright © 2001 John Wiley & Sons, Ltd. [source] Seasonal patterns of growth, expenditure and assimilation in juvenile Atlantic salmonJOURNAL OF ANIMAL ECOLOGY, Issue 6 2002Wayne Jones Summary 1We report a modelling study of a data-set describing the growth of individual Atlantic salmon (Salmo salar L.) parr in the Girnock Burn (Scotland). A development of the compensatory growth model due to Broekhusien et al. (1994) was fitted to these data by numerical optimization. 2The model uses carbon mass as a surrogate for an energy currency. This mass is divided into structure and reserve components, so as to describe decoupled changes in length and wet-weight. 3Using the same parameters for all fish, our model explained 83% of the variability in length and weight at age. Adding a single additional parameter for each individual enabled the model to explain over 96% of length and weight variability. 4Weak negative correlation between size at first capture and within-study growth argues against genetic causality of observed growth variability. 5The energetic basis of our model enables us to infer time-series of net assimilation and basal maintenance rates for the observed individuals. Maximal growth occurs early in the season when high assimilation is accompanied by low temperatures and maintenance rates. In late season, continuing high assimilation is balanced by high maintenance rates consequent on summer temperatures. [source] Parameterization of charge model 3 for AM1, PM3, BLYP, and B3LYPJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 11 2003Jason D. Thompson Abstract We have recently developed a new Class IV charge model for calculating partial atomic charges in molecules. The new model, called Charge Model 3 (CM3), was parameterized for calculations on molecules containing H, Li, C, N, O, F, Si, S, P, Cl, and Br by Hartree,Fock theory and by hybrid density functional theory (DFT) based on the modified Perdew,Wang density functional with several basis sets. In the present article we extend CM3 to semiempirical molecular orbital theory, in particular Austin Model 1 (AM1) and Parameterized Model 3 (PM3), and to the popular BLYP and B3LYP DFT and hybrid DFT methods, respectively. For the BLYP extension, we consider the 6-31G(d) basis set, and for the B3LYP extension, we consider three basis sets: 6-31G(d), 6-31+G(d), and MIDI!6D. We begin with the previous CM3 strategy, which involves 34 parameters for 30 pairs of elements. We then refine the model to improve the charges in compounds that contain N and O. This modification, involving two new parameters, leads to improved dipole moments for amides, bifunctional H, C, N, O compounds, aldehydes, ketones, esters, and carboxylic acids; the improvement for compounds not containing N results from obtaining more physical parameters for carbonyl groups when the OCN conjugation of amides is addressed in the parameterization. In addition, for the PM3 method, we added an additional parameter to improve dipole moments of compounds that contain bonds between C and N. This additional parameter leads to improved accuracy in the dipole moments of aromatic nitrogen heterocycles with five-membered rings. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 1291,1304, 2003 [source] Parameters related to lipid metabolism as markers of myelination in mouse brainJOURNAL OF NEUROCHEMISTRY, Issue 1 2001Evan D. Muse Myelination, during both normal development and with respect to disorders of myelination, is commonly studied by morphological and/or biochemical techniques that assay as their end-points the extent of myelination. The rate of myelination is potentially a more useful parameter, but it is difficult and time-consuming to establish, requiring a complete developmental study with labor-intensive methodology. We report herein development of methodology to assay the absolute rate of myelination at any desired time during development. This involves intraperitoneal injection of 3H2O to label body water pools, followed by determination of label in the myelin-specific lipid, cerebroside. The absolute amount of cerebroside synthesized can then be calculated from the specific radioactivity of body water and knowledge of the number of hydrogens from water incorporated into cerebroside. During development, the rate of cerebroside synthesis correlated well with the rate of accumulation of the myelin-specific components, myelin basic protein and cerebroside. For purposes of control, we also tested other putative, albeit less quantitative, indices of the rate of myelination. Levels of mRNA for ceramide galactosyltransferase (rate-limiting enzyme in cerebroside synthesis) and for myelin basic protein did not closely correlate with myelination at all times. Cholesterol synthesis closely matched the rate of cholesterol accumulation but did not track well with myelination. Synthesis of fatty acids did not correlate well with accumulation of either fatty acids (phospholipids) or myelin markers. We conclude that measurement of cerebroside synthesis rates provides a good measure of the rate of myelination. This approach may be useful as an additional parameter for examining the effects of environmental or genetic alterations on the rate of myelination. [source] Inductive effect of uncharged groups: dependence on electronegativityJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 7 2006Otto Exner Abstract Substituent effects in rigid non-conjugated systems were followed on the series of 3-substituted 1-fluoro-bicyclo[1.1.1]pentanes and 2-substituted 1-fluoroethanes in the fixed ap conformation. Their energies were calculated within the framework of the density functional theory at the B3LYP/6-311++G(3df,3pd)//B3LYP/6-311++G(3df,3pd) level and the substituent effects were expressed in terms of isodesmic homodesmotic reactions. The results were confirmed by the energies of 1,4-disubstituted bicyclo[2.2.2]octanes reported in the literature and calculated at a lower level. Interaction of two common substituents of low or medium polarity cannot be described as the classical inductive effect by one term, proportional in all series, but an additional parameter is necessary, which depends only on the first atom of the substituent and may be identified with its electronegativity. The second term decreases with the distance more steeply than the first term and is always much less important. Nevertheless its statistical significance was proved by several sensitive tests at the highest level used in statistics. When one of the substituents is charged (or at least strongly polar as NO2 or CN), the first term is much increased and the second becomes less significant or insignificant. Therefore, the standard definition of the inductive effect with a uniform, universally valid constant can be retained as far as one treats only the ionization equilibria, both in solution and in the gas phase, or kinetics with a strongly polar transition state. In contrast to the firm statistical proofs, the physical meaning of the electronegativity term was not established. Any relation to various group electronegativities does not exist, similarity to the 13C NMR shifts is merely qualitative. Copyright © 2006 John Wiley & Sons, Ltd. [source] Present state and perspectives of synchrotron radiation diffraction imagingJOURNAL OF SYNCHROTRON RADIATION, Issue 3 2002J. Baruchel The modern third-generation synchrotron radiation sources offer enhanced possibilities for all variants of imaging techniques. The quantitative and qualitative improvements with respect to previous synchrotron diffraction imaging work, which include the investigation in transmission of bulky samples, the use, as an additional parameter, of the sample-to-detector distance, and the use of the coherence of the beam, are illustrated by several examples. Emphasis is given to the possibilities associated with modern electronic detectors for this type of imaging. The new techniques implemented at the ESRF that take full advantage of new capabilities, and more particularly that of `topo-tomography', are presented. [source] Scaleable downstream recovery of nematodes used as biopesticidesBIOTECHNOLOGY & BIOENGINEERING, Issue 6 2001J.A. Wilson Abstract This study assesses the suitability of sieving as a scaleable technique for the separation of adult nematodes from infective juveniles, the latter is an effective bioinsecticide whereas the former is waste material resulting from the fermentation process. Batch and semibatch experiments using conventional flow-assisted wet sieving and a novel cross-flow sieving technique were used to study the separation of juveniles from adult nematodes. The experiments were carried out using small-scale devices and the data were analyzed in terms of the screen effectiveness factor. The results were used to identify the sieve size and operating conditions for optimum juvenile recovery. It was found that, for a given species of nematode, optimum recovery was achieved when sieving was carried out in the cross-flow mode, the maximum recovery being a function of the size of the screen. Industrial-scale self-cleaning equipment capable of large-scale continuous screening was used to confirm the capacity of the small-scale operation for scale-up. Experimental results with this unit showed that in continuous operation sieving time is an additional parameter that influences separation performance. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 733,740, 2001. [source] Glare test as indicator for cataract surgeryACTA OPHTHALMOLOGICA, Issue 2008MJ TASSIGNON Purpose The concept of glare, as determined by the Oculus C-Quant device, can be useful in clinical practice as additional parameter to guide the surgeon in its decision for cataract surgery. Before to decide upon pathological conditions of glare, benchmarks of what is considered normal should be available. Methods The C-Quant device was calibrated in the Department of Ophthalmology of the Antwerp University Hospital in order to achieve benchmarks of what is "physiological" glare. Results Based on the results of the Gullstrand Benchmark study, glare in our "normal" population was found slightly higher than in other settings. Glare was also measured prior to each cataract operation as well as after cataract surgery. Conclusion Two conclusions can be drawn: it might be important to calibrate each individual machine before testing pathology, and glare is generally increased prior to cataract surgery and decreased after successful cataract surgery. [source] Posturographic description of the regaining of postural stability following strokeCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 1 2005Henrik Rogind Summary Background:, Failing balance and increased liability to falling are common complaints among hemiplegic subjects. During rehabilitation much effort is put into regaining postural stability. Purpose:, To describe the regaining of postural stability during rehabilitation for the first year following stroke in hemiplegic patients Materials and methods:, Twenty-six patients were included within 5 days of suffering a stroke resulting from a CT-verified clearly defined thromboembolic lesion, localized in the vascular bed of middle cerebral artery on either side. Posturographic evaluation of sway was performed on a commercially available force plate system (Balance Master Pro®). Measured parameters included per cent maximum stability (PMS), per cent ankle strategy (AST), and average angular velocity (AVE). An additional parameter was derived by calculating the slope (SLP) of the linear relationship between stability and ankle strategy. SLP reflects the predisposition of the stroke patient to keep using ankle strategy when faced with increasingly difficult balance tasks. The presence of familiarization to the measurement method was examined by including a preliminary measurement not otherwise included in the analysis of changes during the first year of follow-up. The temporal evolvement of sway was described by measuring sway parameters 1, 2, 4, 8 and 52 weeks following stroke. The proportions of the variation in sway caused by measurement error and between patients were compared. Results:, All parameters improved over time, as demonstrated by significant improvements from each of week 1, 2, 4 and 8 to week 52. There was evidence of familiarisation for PMS, AST and AVE, but not for SLP. Estimation of variance components showed that between patient variation accounts for between two-thirds and four-fifths of the total variation. A considerable part of this variation was caused by individual differences in the temporal improvement of sway over time. Patients considered the evaluation of postural sway demanding and time consuming resulting in a relatively large loss to follow-up: 15 patients completed the 8-week visit while seven completed the 1 year visit. Conclusion:, Postural stability increases for the first year following stroke. There is evidence of familiarization towards the measurements process for the traditional posturographic parameters PMS, AST and AVE, but not for the derived parameter SLP, which might make the latter a candidate for a sway parameter reflecting basic mechanisms of upholding upright stance in hemiplegic patients. The estimated variance components stress the considerable between-patient variation and question the ability of the force plate method to monitor individual sway performance of such patients during the rehabilitation process. [source] Quantitative analysis of InSAR digital elevation models for identification of areas with different tectonic activities in southern ItalyEARTH SURFACE PROCESSES AND LANDFORMS, Issue 1 2009Claudio Martino Abstract This work presents the results of a quantitative analysis of an interferometric SAR (InSAR) digital elevation model (DEM), obtained by the Shuttle Radar Topography Mission (SRTM). The analysis aims to identify additional parameters to recognize areas in southern Italy with different tectonic activities and behaviours. The axial zone of the Campania-Lucania Apennine and the Sila Massif in Calabria, Italy, characterized by quite different evolutionary histories, have been chosen as test areas sufficiently wide to validate observations on a sub-regional scale at least. Geomorphological information on the shape of palaeosurfaces has been used to estimate uplift and/or erosion amounts and rates. Palaeosurfaces are identified on the DEM as regions with an altitude higher than 1000 m a.s.l. and sub-planar land surfaces dipping less than 6°. Information about the shape of palaeosurfaces during the first stage of uplift and before the tectonic-induced block fragmentation has been extracted. A fragmentation index has been computed for these erosional surfaces. The first stage of this landscape evolution has been studied in terms of the geometric characteristics of fragmented blocks. The last erosional stage has been recognized in terms of both geometric characteristics and fragmentation index of the sub-horizontal land surfaces. Altitude and age of the palaeosurfaces, referred to ancient base-levels of the erosion, have been used to estimate the erosional rate. Copyright © 2008 John Wiley and Sons, Ltd. [source] Electrophysiological sensory demyelination in typical chronic inflammatory demyelinating polyneuropathyEUROPEAN JOURNAL OF NEUROLOGY, Issue 7 2010Y. A. Rajabally Background:, The presence of electrophysiological demyelination of sensory nerves is not routinely assessed in the evaluation of suspected chronic inflammatory demyelinating polyneuropathy (CIDP). Whether this can be useful is unknown. Methods:, We compared, using surface recording techniques, in 19 patients with typical CIDP and 26 controls with distal large fibre sensory axonal neuropathy, the forearm median sensory conductions, sensory nerve action potential (SNAP) amplitudes and durations and sensory nerve conduction velocities (SNCVs) of median, radial and sural nerves. Results:, Median nerve sensory conduction block (SCB) across the forearm was greater in CIDP patients than in controls (P = 0.005). SNAP durations were longer in CIDP patients for median (P = 0.001) and sural nerves (P = 0.004). Receiver operating characteristic (ROC) curves provided sensitive (>40%) and specific (>95%) cut-offs for median nerve SCB as well as median and sural SNAP durations. SNCVs were significantly slower for median and sural nerves in CIDP patients, but ROC curves did not demonstrate cut-offs with useful sensitivities/specificities. Median SCB or prolonged median SNAP duration or prolonged sural SNAP duration offered a sensitivity of 73.7% for CIDP and specificity of 96.2%. Used as additional parameters, they improved diagnostic sensitivity of the American Academy of Neurology (AAN) criteria for CIDP of 1991, from 42.1% to 78.9% in this population, with preserved specificity of 100%. Discussion:, Sensory electrophysiological demyelination is present and may be diagnostically useful in typical CIDP. SCB detection and SNAP duration prolongation appear to represent more useful markers of demyelination than SNCV reduction. [source] Dopamine challenge tests as an indicator of psychological traitsHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 2 2006P. Netter Abstract After discussing some introductory considerations about the value of challenge tests in general for discriminating personality dimensions which are considered extrapolations of psychopathological diseases, the present paper outlines the matter of responsivity to agonistic and antagonistic dopaminergic drugs or drugs of different mechanisms of action in the dopaminergic system, and elucidates that different hormones elicited by dopaminergic substances (prolactin, growth hormone) may indicate personality related differences in susceptibility of different brain areas. A further point was to demonstrate not only the well known relationship of dopaminergic hyperactivity with reward seeking and motivational factors associated with extraversion and novelty seeking, but also the relationship of dopaminergic hypofunction with the personality dimension of depression which had already been reported in studies on animals and psychiatric patients. A final point was to demonstrate that besides size of hormone responses additional parameters like time of response onset and initial prolactin increase can be used as biochemical indicators for identifying certain personality types, like highly depressive neurotic persons characterized by lower and later dopamine responses as compared to low depressives, and extraverted sensation-seeking types responding by an initial prolactin peak as opposed to low sensation seekers. Copyright © 2006 John Wiley & Sons, Ltd. [source] Advances in powder diffraction pattern indexing: N-TREOR09JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2009Angela Altomare Powder pattern indexing can still be a challenge, despite the great recent advances in theoretical approaches, computer speed and experimental devices. More plausible unit cells, belonging to different crystal systems, are frequently found by the indexing programs, and recognition of the correct one may not be trivial. The task is, however, of extreme importance: in case of failure a lot of effort and computing time may be wasted. The classical figures of merit for estimating the unit-cell reliability {i.e.M20 [de Wolff (1968). J. Appl. Cryst.1, 108,113] and FN [Smith & Snyder (1979). J. Appl. Cryst.12, 60,65]} sometimes fail. For this reason, a new figure of merit has been introduced in N-TREOR09, the updated version of the indexing package N-TREOR [Altomare, Giacovazzo, Guagliardi, Moliterni, Rizzi & Werner (2000). J. Appl. Cryst. 33, 1180,1186], combining the information supplied by M20 with additional parameters such as the number of unindexed lines, the degree of overlap in the pattern (the so-called number of statistically independent observations), the symmetry deriving from the automatic evaluation of the extinction group, and the agreement between the calculated and observed profiles. The use of the new parameters requires a dramatic modification of the procedures used worldwide: in the approach presented here, extinction symbol and unit-cell determination are simultaneously estimated. N-TREOR09 benefits also from an improved indexing procedure in the triclinic system and has been integrated into EXPO2009, the updated version of EXPO2004 [Altomare, Caliandro, Camalli, Cuocci, Giacovazzo, Moliterni & Rizzi (2004). J. Appl. Cryst. 37, 1025,1028]. The application of the new procedure to a large set of test structures is described. [source] Controlling diffusion of 3He by buffer gases: A structural contrast agent in lung MRIJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2006Rodolfo H. Acosta PhD Abstract Purpose To study the influence of admixing inert buffer gases to laser-polarized 3He in terms of resulting diffusion coefficients and the consequences for image contrast and resolution. Materials and Methods The diffusion coefficient of 3He was altered by admixing buffer gases of various molecular weights (4He, N2, and SF6). The influence of the pulse sequence and the diffusion coefficient on the appearance of MRI of (laser-polarized) gases was analyzed by comparison of basic theoretical concepts with demonstrative experiments. Results Excellent agreement between theoretical description and observed signal in simple gradient echoes was observed. A maximum signal gain can be predicted and was experimentally validated. Images acquired under such conditions revealed improved resolution. The nature and concentration of the admixed gas defines a structural threshold for the observed apparent diffusion coefficient (ADC) as demonstrated with diffusion-weighted MRI on a pig's lung flooded with suitable gas mixtures. Conclusion A novel procedure is proposed to control the diffusion coefficient of gases in MRI by admixture of inert buffer gases. Their molecular mass and concentration enter as additional parameters into the equations that describe structural contrast. This allows for setting a structural threshold up to which structures contribute to the image. For MRI of the lung this enables images of very small structural elements (alveoli) only, or in the other extreme, all airways can be displayed with minimal signal loss due to diffusion. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source] Microsystems for Optical Cell Detection: Near versus Far FieldPARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 1 2008Stefan Kostner Abstract Optical flow cytometry is a process where physical and (bio-) chemical parameters of single biological cells can be obtained in a flow-through setup by optical measurement techniques. Unlike conventional systems, where measurements are conducted in the optical far field, the proposed system senses the cell's optical projection in the near field by using integrated photodiodes. This allows for the attainment of additional parameters, e.g., size and shape, which are usually hidden in the far field. In addition, parameters such as refractive index and absorption of the cell influence the sensor signal. Additionally, with another setup, a different approach is followed to measure similar parameters with external detection using a DVD laser pickup head and a microchannel equipped with a mirror. This low-cost setup does not measure in the near field, and therefore, is dedicated to different parameters. In this contribution, results from measurements with polystyrene particles and biological cells (yeast and Chinese hamster ovary) are presented and the advantages and limitations of both systems are outlined. [source] Application of the Ion-interaction Model to the Solubility Prediction of LiCl-HCl-MgCl2 -H2O System at 20 °CCHINESE JOURNAL OF CHEMISTRY, Issue 8 2005Li Ya-Hong Abstract Component solubility in HCl-LiCl-MgCl2 -H2O system of high ionic strength at 20 °C was predicted by using the Pitzer's ion-interaction model. The results indicated that the model supplied a very good prediction of the component solubility of the system mentioned above. The values of parameters of ,0, ,1 and C, of HCl, LiCl and MgCl2 were obtained from optimization of literature data, while those of ,MN and ,MNX were calculated from a least-squares optimization procedure to couple activity coefficient with solubility data. According to the ion-interaction model, no additional parameters need to be determined for more complex systems. The study provided theoretical basis for the manufacture process, which was proposed by Gao and employed to extract LiCl and MgCl2·6H2O from salt lake brine. 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