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PubMed1990

Research in physical medicine and rehabilitation. VIII. Preliminary data analysis.

This paper describes important aspects of preliminary data analysis to be taken after data are checked for clerical entry errors and before the primary statistical analysis is performed. These include description and graphic display of each variable, recoding categorical data, transforming continuous data into another continuous variable and recoding continuous to categorical data. Missing values and outlying data points are identified and several techniques are recommended to minimize mistakes in variable recoding. Related variables measured with different units may be combined by using the z transformation and converted back to one of the original units for ease of interpretation. Finally, both categorical and continuous variables are checked for reliability by using kappa or the intraclass R.

Data Collection↗
PubMed1983

Transformation of the structure of collagen. A time-resolved analysis of mechanochemical processes using synchrotron radiation.

Mechanochemically induced molecular transformations of collagen fibres were analysed using time-resolved small-angle diffraction spectra and histomechanical measurements. In particular, the influence of aqueous and methanolic perchlorate solutions was examined. According to a transformation continuing from the periphery towards the centre, the macroscopic contraction that is completed less than five minutes after incubation with perchlorate is caused by peripherally transformed fibrils only, whereas the centrally situated fibrils first undergo an accordion-like folding, but after more than 20 minutes are transformed similarly. The triple-helical transformation is preceded by a structure-breaking effect on structural water that can be monitored in time-resolved diffraction spectra. The combined loss of meridional low-angle reflections and cross-striated fibrils in micrographs is irreversible. By dialysis of colloidally dissolved collagen against a solution of ATP, however, segment-long spacing aggregates are obtained. Under isometric conditions, an instantaneous transformation of intermittent regions leads to an increase in the long period of adjacent, still structured regions of the same fibril that is correlated with a delayed increase in tension in the fibre. Increase of tension under isometric conditions as well as the flow-properties of a fibre relaxed in perchlorate are interpreted in terms of the parallel sliding of subunits of varying lengths, which has been demonstrated by diffraction analysis.

Animals↗
PubMed2006

An efficient content-adaptive motion-compensated 3-D DWT with enhanced spatial and temporal scalability.

We propose a novel, content adaptive method for motion-compensated three-dimensional wavelet transformation (MC 3-D DWT) of video. The proposed method overcomes problems of ghosting and nonaligned aliasing artifacts which can arise in regions of motion model failure, when the video is reconstructed at reduced temporal or spatial resolutions. Previous MC 3-D DWT structures either take the form of MC temporal DWT followed by a spatial transform ("t+2D"), or perform the spatial transform first ("2D + t"), limiting the spatial frequencies which can be jointly compensated in the temporal transform, and hence limiting the compression efficiency. When the motion model fails, the "t + 2D" structure causes nonaligned aliasing artifacts in reduced spatial resolution sequences. Essentially, the proposed transform continuously adapts itself between the "t + 2D" and "2D + t" structures, based on information available within the compressed bit stream. Ghosting artifacts may also appear in reduced frame-rate sequences due to temporal low-pass filtering along invalid motion trajectories. To avoid the ghosting artifacts, we continuously select between different low-pass temporal filters, based on the estimated accuracy of the motion model. Experimental results indicate that the proposed adaptive transform preserves high compression efficiency while substantially improving the quality of reduced spatial and temporal resolution sequences.

Algorithms↗
PubMed2000

Photoactive protochlorophyllide regeneration in cotyledons and leaves from higher plants.

Chlorophyll accumulation during greening implies the continuous transformation of photoactive protochlorophyllide (Pchlide) to chlorophyllide. Since this reaction is a light-dependent step, the study of regeneration of photoactive Pchlide under a continuous illumination is difficult. Therefore this process is best studied on etiolated plants during a period of darkness following the initial photoreduction of photoactive Pchlide. In this study, the regeneration process has been studied using spinach cotyledons, as well as barley and bean leaves, illuminated by a single saturating flash. The regeneration was characterized using 77 K fluorescence emission and excitation spectra and high-performance liquid chromatography. The fluorescence data indicated that the same spectral forms of photoactive Pchlide are regenerated by different pathways: (1) photoactive Pchlide regeneration starts immediately after the photoreduction through the formation of a nonphotoactive Pchlide form, emitting fluorescence at approximately 651 nm. This form is similar to the large aggregate of photoactive Pchlide present before the illumination, but it contains oxidized form of nicotinamide adenine dinucleotide phosphate, instead of the reduced form (NADPH), in the ternary complexes; and (2) after the dislocation of the large aggregates of chlorophyllide-light-dependent NADPH:Pchlide a photooxidoreductase-NADPH ternary complexes, the regeneration occurs at the expense of the several nonphotoactive Pchlide spectral forms present before the illumination.

Cotyledon↗
PubMedDate not supplied

Intrapolation and extrapolation of age-equivalent scores for the Bayley II: a comparison of two methods of estimation.

The Bayley Scales of Infant Development II (1) is a well established standardized test for assessing the mental ability of infants and young children. It provides an age-adjusted standard score as a summary measure, but for very low (or very high) functioning children the raw scores on this test may not allow the calculation of a standard score. The manual provides for the transformation of raw scores into age-equivalents but this translation is not unique and results in a step function. The availability of a unique and continuous transformation of raw scores to age-equivalents is critical when evaluating longitudinal mental development, particularly in the environment of controlled clinical trials or natural history studies. We compared two methods for deriving unique age equivalents: a local regression method, with estimates restricted to age-equivalents within the age range of the test, and a linear method, which also allows extrapolation outside the age range of the test. The linear method was found to be most useful and the values, which are provided in table format, can be used for assigning age equivalent scores to individual children. They are also useful in clinical trials which use the Bayley to assess the safety and efficacy of treatments with potential cognitive effects, when conducted in populations where the children are likely to record scaled scores below the limits of the test.

Age Factors↗
PubMed1978

Infection of human cell cultures with bovine visna virus.

Fibroblastoid cell cultures derived from leukaemic bone marrow were successfully infected with BVV. After 2 months of subcultivation the cultures showed the appearance of foci of altered cells, suggestive of malignant transformation. Such foci were absent in non-inoculated cultures. Both control and inoculated cultures had a limited life span, i.e. neither of them could be developed into continuous transformed cell lines. The presence of at least some BVV genome functions in the inoculated cells was demonstrated (i) by immunofluorescence using a reference BVV serum, (ii) by detection in the supernatant culture fluid of sedimentable particles bearing RNA-dependent DNA polymerase activity with preference for Mg2+ ions, and (iii) by electron microscopic detection of scarce cell-associated virus particles in one of the infected cultures. Infectious BVV could not be rescued. In contrast to leukaemic bone marrow cultures, diploid human embryonic fibroblasts of various origin could not be infected with BVV.

Animals↗
PubMed1994

Colored aftereffects contingent upon global transformations?

Dodwell and Humphrey (Psychol. Rev. 97, 78-79, 1990) have argued that colored aftereffects (CAEs) are contingent on the global geometries of local orientation and edge components in induction patterns. The spatiotopic dimensions underlying these geometries are derived from previous applications of the mathematics of continuous transformations (Lie groups) to the stimulus dynamics of perceptual invariance. In these terms, complementary CAEs induced by inspecting alternating colored bullseyes and spokes are attributed to the adaptation of orthogonal spatiotopic channels; the former characterized by vectorfields dealing with object invariance under rotation, and the latter by vectorfields dealing with object invariance under dilation. Importantly, the pattern-contingent CAEs induced in this pair of pattern channels are independent of CAEs induced in channels characterized by vectorfields dealing with object invariance under vertical and horizontal translations (e.g. vertical and horizontal gratings). The present investigation examined whether CAEs contingent on the stimulus dynamics originally used to define these spatiotopic channels exhibit comparable properties. It is confirmed that pairs of complementary CAEs can be induced simultaneously with radially expanding and contracting bullseyes, and clockwise- and counter-clockwise-rotating spokes (Experiment 1); and it is shown that these CAEs combine linearly in generalizing to and from the radial and rotational components of spiral motion (Experiments 2 and 3 respectively). In direct contrast to findings for CAEs induced with stationary versions of these patterns, however, it is demonstrated that complementary pairs of CAEs induced by expanding and contracting bullseyes interact with CAEs induced by left- and right-moving vertical gratings, suggesting that the components of motion underlying these contingent effects are locally and not globally determined (Experiment 4).

Color Perception↗
PubMed1990

Expression of normal and cystic fibrosis phenotypes by continuous airway epithelial cell lines.

Continuous epithelial cell lines from individuals with cystic fibrosis (CF) and normal controls are required to understand the genetic and cellular defects in CF. We used retroviruses to transduce SV40 large T antigen into nasal epithelial cells. Transformed continuous cell lines were isolated that expressed epithelial markers, cytokeratin, and tight junctions. Northern blot analysis shows that all of the cell lines express the putative CF gene mRNA. Studies of transepithelial electrolyte transport show that CF and normal cell lines develop a transepithelial electrical resistance. Normal but not CF cell lines secreted Cl- in response to agonists that increase cellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) (isoproterenol, forskolin, and a membrane-permeant analogue of cAMP) or in response to a tumor-promoting phorbol ester that activates protein kinase C. In contrast, the Ca2(+)-elevating agonist bradykinin and the Ca2+ ionophore A23187 stimulated secretion in both normal and CF cell lines. The continuous cell lines we have produced maintain their proper phenotypes and will serve as useful tools in understanding the pathophysiology of CF.

Antigens, Polyomavirus Transforming↗
PubMed2006

Petunia (Petunia hybrida).

Petunia hybrida genetic transformation continues to be a valuable tool for genetic research into biochemical pathways and gene expression, as well as generating commercial products with varying floral colors. In this chapter, we describe a simple and reproducible genetic transformation protocol for generating transgenic petunia plants harboring a gene of interest and selectable marker. The system utilizes Agrobacterium tumefaciens for transgene integration with plant recovery via shoot organogenesis from leaf explant material. Selection for transgenic plants is achieved using the bar gene conferring resistance to glufosinate or nptII gene for resistance to kanamycin. Transformation efficiencies of around 10% are achievable with shoots being recovered about 8 wk after transgene insertion and rooted plants transferred to the greenhouse about twelve weeks after inoculation.

Agrobacterium tumefaciens↗
PubMed2004

[Using wavelet transform for information extraction from remote sensing FTIR spectra].

How to use wavelet transform technology to extract information from remote sensing FTIR spectra, which were weak or always interfered by others, was described in the present paper. The Mexican hat function was used as a wavelet function to continuously transform the signals of pure chloroform, pure acetone and their mixture. The results indicated that the small scales were the guarantee of the accuracy of corresponding position between maximum module of wavelet transform coefficients and break points of peaks. However, only one scale could not determine the position of break point because of the effect of noise in small scales. On the contrary, maximum module of wavelet transform coefficients was relatively stable in large scales when noise was smoothed. But smoothness always brought deviation of orientation. Therefore, multi-scales should be combined to observe the break points of signals when using wavelet transform technology. All in all, the break points of signals could be determined accurately and stably by the wavelet transform technology and useful information was extracted. The signals were smoothed and magnified at the same time. According to the analysis of maximum module of wavelet transform coefficients and their orientation in different scales, some spectra, such as mixed and non-strongly-overlapped remote sensing FTIR spectra, could be recognized magnificently.

English Abstract↗
PubMed1987

Studies on the introduction and mobility of the maize Activator element in Arabidopsis thaliana and Daucus carota.

We have co-transformed carrot (Daucus carota) and Arabidopsis thaliana with an Agrobacterium tumefaciens non-tumorigenic T-DNA carrying the maize transposable element Activator (Ac) and an Agrobacterium rhizogenes Ri T-DNA. We present evidence that the Ac element transposes in transformed root or root-derived callus cultures of both species. We show that fertile plants can be regenerated from transformed, root-derived callus cultures of Arabidopsis, demonstrating the utility of the Ri plasmid for introducing the maize Ac element into plants. We also present evidence that Ac elements that excise from the transforming T-DNA early after transformation continue to be mobile in carrot root cultures.

Cells, Cultured↗
PubMed2006

Analysis of amorphous and nanocrystalline solids from their X-ray diffraction patterns.

PURPOSE: The purpose of this paper is to provide a physical description of the amorphous state for pharmaceutical materials and to investigate the pharmaceutical implications. Techniques to elucidate structural differences in pharmaceutical solids exhibiting characteristic X-ray amorphous powder patterns are also presented. MATERIALS AND METHODS: The X-ray amorphous powder diffraction patterns of microcrystalline cellulose, indomethacin, and piroxicam were measured with laboratory XRPD instrumentation. Analysis of the data were carried out using a combination of direct methods, such as pair distribution functions (PDF), and indirect material modeling techniques including Rietveld, total scattering, and amorphous packing. RESULTS: The observation of X-ray amorphous powder patterns may indicate the presence of amorphous, glassy or disordered nanocrystalline material in the sample. Rietveld modeling of microcrystalline cellulose (Avicel PH102) indicates that it is predominantly disordered crystalline cellulose Form Ibeta with some amorphous contribution. The average crystallite size of the disordered nanocrystalline cellulose was determined to be 10.9 nm. Total scattering modeling of ground samples of alpha, gamma, and delta crystal forms of indomethacin in combination with analysis of the PDFs provided a quantitative picture of the local structure during various stages of grinding. For all three polymorphs, with increased grinding time, a two-phase system, consisting of amorphous and crystalline material, continually transformed to a completely random close packed (RCP) amorphous structure. The same pattern of transformation was detected for the Form I polymorph of piroxicam. However, grinding of Form II of piroxicam initially produced a disordered phase that maintained the local packing of Form II but over a very short nanometer length scale. The initial disordered phase is consistent with continuous random network (CRN) glass material. This initial disordered phase was maintained to a critical point when a transition to a completely amorphous RCP structure occurred. CONCLUSIONS: Treating X-ray amorphous powder patterns with different solid-state models, ranging from disordered nanocrystalline to glassy and amorphous, resulted in the assignment of structures in each of the systems examined. The pharmaceutical implications with respect to the stability of the solid are discussed.

Cellulose↗
PubMed2005

Articulated rigid registration for serial lower-limb mouse imaging.

This paper describes a new piecewise rotational transformation model for capturing the articulation of joints such as the hip and the knee. While a simple piecewise rigid model can be applied, such models suffer from discontinuities at the motion boundary leading to both folding and stretching. Our model avoids both of these problems by constructing a provably continuous transformation along the motion interface. We embed this transformation model within the robust point matching framework and demonstrate its successful application to both synthetic data, and to serial x-ray CT mouse images. In the later case, our model captures the articulation of six joints, namely the left/right hip, the left/right knee and the left/right ankle. In the future such a model could be used to initialize non-rigid registrations of images from different subjects, as well as, be embedded in intensity-based and integrated registration algorithms. It could also be applied to human data in cases where articulated motion is an issue (e.g. image guided prostate radiotherapy, lower extremity CT angiography).

Algorithms↗
PubMedDate not supplied

[Live immobilized cells as biocatalysts of transformation and biosynthesis of organic compounds: a review].

The paper reviews the data concerning immobilization of liver microorganisms obtained by the author and found in the literature. The paper discusses different immobilization techniques maintaining cell viability (at least, in part): adsorption, covalent binding, incorporation into different gels (alginates, collagen, polyacrylamide gel, carrageens, etc). The paper summarizes the information about physiology and morphology of resting and growing immobilized cells. It describes the relationship between the level of stability of enzymic activity and cell viability in the course of semi--continuous and continuous transformations. It is emphasized that live immobilized cells can be widely used as highly active polyenzymic systems requiring no exogenous cofactors.

Bacteria↗
PubMed2003

On the nature of intuitive and delusional thought: its implications in clinical work with psychotic patients.

The author tries to differentiate intuitive imagination from delusional imagination and hypothesises that psychosis alters the system of intuitive thinking, which consequently cannot develop in a dynamic and selective way. Scholars of different disciplines, far removed from psychoanalysis, such as Einstein, Hadamard or Poincaré, believe that intuitive thinking works in the unconscious by means of hidden processes, which permit a creative meeting of ideas. Thanks to Bion's work, psychoanalysts have begun to understand that waking thinking is unconsciously intertwined with dream-work. The delusional construction is similar to a dreamlike sensorial production but, unlike a real dream, it remains in the waking memory and creates characters which live independently of the 'dreamer's' awareness. It is a dream that never ends. On the contrary, the real dream disappears when it has brought its communicative task to an end. In the analysis of psychotic patients it is very important to analyse the delusional imagination which dominates the personality and continuously transforms the mental state, twisting emotional truth. The delusional imagination is so deeply rooted in the patient's mental functioning that, even after systematic analysis, the delusional world, which had seemed to disappear, re-emerges under new configurations. The psychotic core remains encapsulated; it produces unsteadiness and may induce further psychotic states in the patient. The author reports some analytic material of a patient, who, after a delusional episode treated with drugs, shows a vivid psychotic functioning. Some considerations are added on the nature of the psychotic state and on the therapeutic approach used to transform the delusional structure. This paper particularly deals with the difficulty in working through the psychotic episode and in 'deconstructing'the delusional experience because of the terror connected with it. In the reported case, the analytic work changed the delusional construction into a more benign one characterised by phobic qualities. The analysis of the psychotic transference allowed the focus to be on the hidden work which had been continuously influencing the transferential picture of the analyst and the patient's psychic reality.

Delusions↗
PubMed1999

Aging and cancer of the stomach and colon.

Although the incidence of most human malignancies including cancer of the gastrointestinal tract increases dramatically with advancing age, the precise role of aging in that increase remains a matter of continued controversy. Many probable explanations for the age-related rise in cancer incidence have been offered including altered carcinogen metabolism and the cumulative effects of protracted exposure to cancer-causing agents. Neoplasia of the stomach or colon is a multi-stage process with hyperproliferation being central to the initiation of carcinogenesis. Since aging is associated with increased gastrointestinal mucosal cell proliferation, the possibility that aging itself may render target cells more susceptible to carcinogenic transformation continues to be an area of intense interest and study. This review will examine the evidence for age-related alterations in the structural and functional properties of the gastric and colonic mucosa in an effort to further elucidate the potential mechanisms of carcinogenesis which may be involved during the aging process.

Aging↗
PubMed1987

A vector based approach to age-related changes of Doppler velocity waveforms in the brachial artery.

The shape of blood flow velocity wave has been correlated with age. The continuous wave Doppler ultrasound technique was used to obtain the blood flow velocity from the brachial arteries in 40 subjects of different age. The blood flow velocity was analysed by means of the Fourier method. The changes of relative values of harmonics were observed according to age. The second harmonic was maximum for the young and the first one for the old. To quantify these changes the vector formed from the first eight moduli was introduced. The angle between the vector so defined and a certain reference vector was accepted as a measure of the Fourier transform. Continuous alteration of wave shape described by angle has been observed according to age. The correlation between angle and age was r = 0.79 (p less than 0.001).

Adult↗
PubMed2005

[Post-mortem diagnosis of Alzheimer's disease].

Alzheimer's disease is a slowly but continuously progressive degenerative disorder of the human central nervous system seen in approximately 15% of elderly people over the age of 65 years. Morphological hallmarks of this process are intra- and extracellular protein aggregates. The intraneuronal protein aggregates are primarily made up of abnormal phosphorylated tau-protein, which builds neurofibrillary tangles, neuropil threads and dystrophic neurites in neuritic plaques. The extracellular deposits consist of amyloid beta-protein (Abeta) aggregates showing the characteristics of amyloid fibrils. The evolution of neurofibrillary changes as well as Abeta-deposition in brain regions follows a distinct hierarchical sequence spanning many decades. Abeta deposition begins in the neocortex whereas neurofibrillary pathology starts in the allocortical nerve cells of the transentorhinal region. Both transformations continue to increase in severity and expand into further areas and regions. The hierarchical pattern allows an easily understandable staging of neurofibrillary and Abeta pathology which in turn reflects the clinical gravity of the disease. According to these stages a dementing disorder can be diagnostically attributed to Alzheimer's disease.

Aged↗