Strong Correlation (strong + correlation)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Strong Correlation

  • very strong correlation


  • Selected Abstracts


    Study of selected quality and agronomic characteristics and their interrelationship in Kabuli-type chickpea genotypes (Cicer arietinum L.)

    INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2006
    Amal Badshah Khattak
    Summary Impact of genotype on quality, agronomic characteristics and their interrelationship in Kabuli-type chickpea was investigated to provide significant feedback to breeder for selection/evolution of the most suitable varieties. Seven genotypes were studied for seventeen physical, chemical and agronomic characteristics. The effect of Kabuli-type chickpea genotype on the physicochemical parameters, cooking time and agronomic characteristics were significant. Maximum seed size and volume were recorded for CC98/99 (0.32 g and 0.26 mL seed,1, respectively), density and swelling index for the genotype FLIP97-179C (having minimum seed size and volume), while the rest of the genotypes were statistically the same. Weight, volume after hydration, hydration capacity and swelling capacity followed the same pattern. Maximum moisture, protein and mineral concentration were noted in CC98/99. Seed protein concentration for the remaining genotypes was statistically non-significant from one another. Longer period was taken by CM 2000 for flowering and maturity (130 and 181 days, respectively). Minimum time to flowering and maturity was taken by CC98/99. Genotype CC 98/99 outyielded all other genotypes (2107 kg ha,1). Seed size and seed volume were strongly and positively correlated with protein content, weight after hydration, volume after hydration, hydration and swelling capacities (r = 0.83,1.0). Strong correlation was also noted among different agronomic characters. [source]


    Correlation of pre-breakdown sites and bulk defects in multicrystalline silicon solar cells

    PHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 2-3 2009
    Dominik Lausch
    Abstract Strong correlation between the pre-breakdown sites visible in dark lock-in thermography due to local heating and the intensity of spatially resolved electroluminescence of reverse-biased solar cells was observed. By comparing differently texturised solar cells we could show that the pre-breakdown sites are not correlated to the surface morphology, e.g. etch pits resulting in local field enhancement. The positions of the pre-breakdown sites are identical for acidic and alkaline texturised solar cells and therefore are directly related to bulk defects in the wafer. Nevertheless, the breakdown voltage is lower for acidic texturised solar cells; the parameters of breakdown are influenced by the texture in contrast to the position. Also pre-breakdown sites are observed in areas without specific surface features for alkaline texturised solar cells. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Predator behaviour and morphology mediates the impact of an invasive species: cane toads and death adders in Australia

    ANIMAL CONSERVATION, Issue 1 2010
    B. L. Phillips
    Abstract The arrival of an invasive species can have severe impacts on native species. The extent of the impact, as well as the speed at which native species may mount an adaptive response, depend upon the correlation between impact and the individual phenotypes of the native species. Strong correlation between phenotype and impact within the native species raises the possibility of rapid adaptive response to the invader. Here, we examine the impact of a dangerous newly arrived prey species (the highly toxic cane toad Bufo marinus) on naïve predators (death adders Acanthophis praelongus) in northern Australia. During laboratory trials and field radiotracking, toads killed 48% of the adders we studied. Long-term monitoring of the population also suggests a massive decline (>89%) in recent years concurrent with the arrival of toads. Variation in snake physiology (resistance to toad toxin) had little bearing on snake survival in the field. Snake behaviour (tendency to attack toads) and morphology (body size and head size), however, were strong predictors of snake survival. Smaller snakes with relatively small heads, and snakes that were unwilling to attack toads in the laboratory, had much higher survival rates in the field. These results show that toads have a massive impact on death adder populations, but that snake phenotypes strongly mediate this impact. Thus natural selection is operating on these adder populations and an adaptive response is a possibility. If these adders can rapidly shift toad-relevant morphological and behavioural traits (either through plastic or evolved means), they will ultimately face a lowered impact from this toxic invader. [source]


    Multilayer Substrate-Mediated Tuning Resonance of Plasmon and SERS EF of Nanostructured Silver,

    CHEMPHYSCHEM, Issue 12 2010
    Lian C. T. Shoute Dr.
    Abstract A thin-film of dielectric on a reflecting surface constituting a multilayer substrate modulates light intensity due to the interference effect. A nanostructure consisting of randomly oriented silver particles of different shapes, sizes, and interparticle spacings supports multiple plasmon resonances and is observed to have a broad extinction spectrum that spans the entire visible region. Combining the two systems by fabricating the nanostructure on the thin-dielectric film of the multilayer substrate yields a new composite structure which is observed to modulate both the extinction spectrum and the SERS EF (surface enhanced Raman scattering enhancement factor) of the nanostructure as the thickness of the thin-film dielectric is varied. The frequency and intensity of the visible extinction spectrum vary dramatically with the dielectric thickness and in the intermediate thickness range the spectrum has no visible band. The SERS EF determined for the composite structure as a function of the thin-film dielectric thickness varies by several orders of magnitude. Strong correlation between the magnitude of the SERS EF and the extinction intensity is observed over the entire dielectric thickness range indicating that the extinction spectrum corresponds to the excitation of the plasmon resonances of the nanostructure. A significant finding which has potential applications is that the composite structure has synergic effect to boost SERS EF of the nanostructure by an order of magnitude or more compared to the same nanostructure on an unlayered substrate. [source]


    Reproducibility, validity, and responsiveness of a disease-specific symptom questionnaire for gastroesophageal reflux disease

    DISEASES OF THE ESOPHAGUS, Issue 4 2000
    C. J. Allen
    The purpose of this study was to establish the reproducibility, validity, and responsiveness of a symptom questionnaire to assess patients with gastroesophageal reflux disease (GERD). A total of 300 patients with GERD completed questionnaires before and 6 months after laparoscopic Nissen fundoplication. Forty-six GERD patients who continued on omeprazole served as controls. Lower esophageal sphincter pressure, 24-h pH, and quality of life (SF36) were measured at baseline and follow-up. Reproducibility was calculated as an intraclass correlation coefficient (ICC) from a repeated-measures analysis of variance on symptom scores (SS) on two consecutive days. Validity was established by correlating SS with 24-h pH and SF36 scores. Responsiveness was calculated as the the ratio of the mean paired difference in score in the surgical group to the within-subject variability in control subjects. Reproducibility was very high, as revealed by an ICC of 0.92. Strong correlations between SS and SF36 scores at baseline and after surgery demonstrated high cross-sectional validity. Correlation between change in SS and change in pH, SF36 pain, general health, and physical health scores demonstrated longitudinal validity. The mean (95% confidence interval) paired differences in SS were 25.6 (23.7, 27.5) in the study and 2.0 (,3.2, 7.3) in the control groups, and the responsive index was 1.0. The estimated minimally important clinical difference was 7. We conclude that the symptom score is a reproducible, valid, and responsive instrument for assessing symptoms caused by GERD. [source]


    Comparing agglomerative clustering and three weed classification frameworks to assess the invasiveness of alien species across spatial scales

    DIVERSITY AND DISTRIBUTIONS, Issue 6 2006
    Roger A. Lawes
    ABSTRACT To prioritize weed management at the catchment scale, information is required on the species present, their relatively frequency, abundance, and likely spread and impact. The objective of this study was to classify the invasiveness of alien species that have invaded the Upper Burdekin Catchment in Queensland, Australia, at three spatial scales. A combination of three published weed classification frameworks and multivariate techniques were employed to classify species based on their frequency and cover at a range of spatial scales. We surveyed the Upper Burdekin Catchment for alien species, and for each species determined the following distribution indices , site frequency, total cover, transect frequency per site frequency and quadrat frequency per site frequency, cover per quadrat when present, cover per transect when present, and cover per site when present. These indices capture the effect of species abundance and frequency between sites (site frequency and total cover), within sites (transect frequency per site and cover per transect when present), and within transects (quadrat frequency per site frequency and cover per site). They were used to classify the species into seven groups using a hierarchical cluster analysis. The relationship between the indices was explored to determine how effective the small scale, site-specific indices were at predicting the broader, landscape-scale patterns. Strong correlations were observed between transect frequency per site and frequency (r2 = 0.89) and cover per transect when present and total cover (r2 = 0.62). This suggests that if a weed is abundant at the site level, it has the potential to occupy large areas of the catchment. The species groupings derived from the application of the three published weed classification frameworks were compared graphically to the groupings derived from the cluster analysis. One of the frameworks classified species into three groups. The other two frameworks classified species into four groups. There was a high degree of subjectivity in applying the frameworks to the survey data. Some of the data were of no relevance to the classification frameworks and were therefore ignored. We suggest that the weed classification frameworks should be used in conjunction with existing multivariate techniques to ensure that classifications capture important natural variations in observed data that may reflect invasion processes. The combined use of the frameworks and multivariate techniques enabled us to aggregate species into categories appropriate for management. [source]


    HCV796: A selective nonstructural protein 5B polymerase inhibitor with potent anti-hepatitis C virus activity In Vitro, in mice with chimeric human livers, and in humans infected with hepatitis C virus,

    HEPATOLOGY, Issue 3 2009
    Norman M. Kneteman
    Anti-hepatitis C virus (HCV) drug development has been challenged by a lack of experience with inhibitors inclusive of in vitro, animal model, and clinical study. This manuscript outlines activity and correlation across such a spectrum of models and into clinical trials with a novel selective nonstructural protein 5B (NS5B) polymerase inhibitor, HCV796. Enzyme assays yielded median inhibitory concentration (IC50) values of 0.01 to 0.14 ,M for genotype 1, with half maximal effective concentration (EC50s) of 5 nM and 9 nM against genotype 1a and 1b replicons. In the chimeric mouse model, a 2.02 ± 0.55 log reduction in HCV titer was seen with monotherapy, whereas a suboptimal dose of 30 mg/kg three times per day in combination with interferon demonstrated a 2.44 log reduction (P = 0.001 versus interferon alone) Clinical outcomes in combination with pegylated interferon and ribavirin have revealed additive efficacy in treatment naïve patients. Abnormal liver function test results were observed in 8% of HCV-796 patients treated for over 8 weeks, resulting in suspension of further trial activity. Conclusion: The RNA-dependent RNA polymerase inhibitor HCV796 demonstrated potent anti-HCV activity consistently through enzyme inhibition assays, subgenomic replicon, and chimeric mouse studies. Strong correlations of outcomes in the mouse model were seen with subsequent clinical trials, including a plateau in dose-related antiviral activity and additive impact from combination therapy with interferon. These outcomes demonstrate the utility of the range of in vitro and in vivo models now available for anti-HCV drug development and support the potential utility of polymerase inhibitors in future combination therapies for HCV treatment. (HEPATOLOGY 2009.) [source]


    Use of turbidometry to characterize suspended sediment and phosphorus fluxes in the Lake Tahoe basin, California, USA

    HYDROLOGICAL PROCESSES, Issue 3 2007
    Andrew P. Stubblefield
    Abstract The efficacy of in-stream nephelometric turbidometry as a surrogate for total suspended solids (TSS) and total phosphorus (TP) concentrations was evaluated for use in low turbidity (<50 NTU) subalpine watersheds at Lake Tahoe, California,Nevada, USA. Continuous turbidity records for the 1999, 2000 and 2001 snowmelt seasons and data from water quality samples (1982,2000) were examined to determine watershed sediment delivery dynamics. Strong correlations were found between turbidity and both TSS and TP concentration. The strong correlation indicates that turbidity can serve as a good surrogate for direct measurement in these watersheds. The watersheds displayed clockwise hysteresis: sediment flushing and depletion, on daily, seasonal and decadal time-scales. The hysteresis curves had strong concave shapes, indicating a sensitive response to peak flow. A pronounced seasonal trend was observed for the ratio of suspended sediment concentration (SSC)/discharge over time, indicating early season flushing of available sediment. Significant linear relationships (p < 0·05) were found for 12 of 17 years. Comparison of annual sediment rating curve coefficients indicated smaller coefficients during high sediment loading years and in the years following. The smaller coefficients are evidence of sediment depletion during high flow years. The effect of hysteresis on monitoring methods was illustrated by comparing turbidity estimates of TSS load with sediment rating curve estimates of SSC. After accounting for differences in SSC/TSS methods of analysis, daily loads calculated with turbidity methods were 58,98% of rating curve estimates for the spring snowmelt seasons of 1999,2001. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Computational analysis of the cathepsin B inhibitors activities through LR-MMPBSA binding affinity calculation based on docked complex

    JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 14 2009
    Zhigang Zhou
    Abstract Cathepsin B, a ubiquitous lysosomal cysteine protease, is involved in many biological processes related to several human diseases. Inhibitors targeting the enzyme have been investigated as possible diseases treatments. A set of 37 compounds were recently found active in a high throughput screening assay to inhibit the catalytic activity of Cathepsin B, with chemical structures and biological test results available to the public in the PubChem BioAssay Database (AID 820). In this study, we compare these experimental activities to the results of theoretical predictions from binding affinity calculation with a LR-MM-PNSA approach based on docked complexes. Strong correlations (r2 = 0.919 and q2 = 0.887 for the best) are observed between the theoretical predictions and experimental biological activity. The models are cross-validated by four independent predictive experiments with randomly split compounds into training and test sets. Our results also show that the results based on protein dimer show better correlations with experimental activity when compared to results based on monomer in the in silico calculations. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2009 [source]


    A Blind Trial Evaluation of a Crime Scene Methodology for Deducing Impact Velocity and Droplet Size from Circular Bloodstains,

    JOURNAL OF FORENSIC SCIENCES, Issue 1 2007
    Lee Hulse-Smith M.S.
    ABSTRACT: In a previous study, mechanical engineering models were utilized to deduce impact velocity and droplet volume of circular bloodstains by measuring stain diameter and counting spines radiating from their outer edge. A blind trial study was subsequently undertaken to evaluate the accuracy of this technique, using an applied, crime scene methodology. Calculations from bloodstains produced on paper, drywall, and wood were used to derive surface-specific equations to predict 39 unknown mock crime scene bloodstains created over a range of impact velocities (2.2,5.7 m/sec) and droplet volumes (12,45 ,L). Strong correlations were found between expected and observed results, with correlation coefficients ranging between 0.83 and 0.99. The 95% confidence limit associated with predictions of impact velocity and droplet volume was calculated for paper (0.28 m/sec, 1.7 ,L), drywall (0.37 m/sec, 1.7 ,L), and wood (0.65 m/sec, 5.2 ,L). [source]


    A2. The carer's perception of dietitians' advice and its impact on the management of patients receiving haemodialysis

    JOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 5 2000
    M. A. Rezaie
    Background Patients with end stage renal disease and their carers suffer many changes in their daily life style as a result of haemodialysis (HD) treatment. Information and education concerning the management of dietary requirements and restrictions for renal patients should be aimed at both patients and their carers. Aim This study investigated the impact of dietitians' involvement and advice on the carers' ability to manage patients' dietary/fluid requirements. Method A total of 36 carers of renal patients receiving unit haemodialysis treatment were randomly recruited into this study from a hospital in Cardiff, Wales. All the carers completed the Haemodialysis carers questionnaire (HCQ), specifically designed for this study, delivered to them in the outpatient clinic by the dietitian. Results Of the 36 carers, 22 (61%) were female, six (16.7%) were male and eight (22%) did not report their gender. Thirteen (36%) of the carers were between the ages of 20,54 years and 23 (64%) were 55 years of age and older. Twenty-six (72%) of the carers involved in this study were spouses and 34 (94.4%) of the carers lived with the patient. The mean duration of haemodialysis treatment for the patient was found to be 20 months. The results indicated that although the majority of the carers were informed about patients' dietary and fluid restrictions, 45% had not received any dietary information. Dietitians' one-to,one interactions with the carer was the most effective way of providing information in enabling them to better manage the patient compared to other methods such as leaflet and information packs (P = 0.01). The majority of the carers knew how to contact the renal dietitian, however, many did not (P = 0.001). Almost all the carers considered receiving information about the purpose of HD, feed back on the patients' condition, fluid/dietary restriction and details of available community resources as very important. Those carers who had the benefit of a dietitian's involvement believed that their advice was very helpful and enabled them to cope better with the management and complications of patient fluid and dietary requirements (P < 0.02). Strong correlations were found (rs = 0.67; P < 0.01) between the amount of information received by the carers and the level of the carers satisfaction with this information. In contrast, there were no significant correlations between the amount of information received by the carers and different aspects of managing the patients' diet, because 45% of the carers received none or little information. Conclusions Dietitians should involve the carers in the management of HD patient's dietary/fluid requirements and restrictions in order to provide better quality of care and quality of life for both the patient and the carer. [source]


    Assessment of correlation between computerized tomography values of the bone, and maximum torque and resonance frequency values at dental implant placement

    JOURNAL OF ORAL REHABILITATION, Issue 12 2006
    I. TURKYILMAZ
    summary, The aim of this study was to determine the bone density in the designated implant sites using computerized tomography (CT), the fastening torque values of dental implants, and the implant stability values using resonance frequency analysis. Further aim was to evaluate a possible correlation between bone density, fastening torque and implant stability. Eighty-five patients were treated with 158 Brånemark System implants. CT machine was used for preoperative evaluation of the jawbone for each patient, and bone densities were recorded in Hounsfield units (HU). The fastening torque values of all implants were recorded with the OsseoCare equipment. Implant stability measurements were performed with the Osstell machine. The average bone density and fastening torque values were 751·4 ± 256 HU and 39·7 ± 7 Ncm for 158 implants. The average primary implant stability was 73·2 ± 6 ISQ for seventy implants. Strong correlations were observed between the bone density, fastening torque and implant stability values of Brånemark System TiUnite MKIII implants at implant placement (P < 0·001). These results strengthen the hypothesis that it may be possible to predict and quantify initial implant stability and bone quality from pre-surgical CT diagnosis. [source]


    Climate and human induced hydrological change since AD 800 in an ombrotrophic mire in Pomerania (N Poland) tracked by testate amoebae, macro-fossils, pollen and tree rings of pine

    BOREAS, Issue 2 2009
    MARIUSZ LAMENTOWICZ
    This high-resolution, multiproxy, palaeoenvironmental study of the S,owi,skie B,ota raised bog in N Poland, 10 km from the Baltic Sea, covering the last 1200 years reveals different aspects of environmental change in a range of spatial scales from local to regional. Testate amoebae allowed quantitative reconstruction of the local water table using a transfer function based on a training set from N and W Poland. Special attention is paid to the testate amoeba Arcella discoides, which responds to rapid water-table fluctuations more than to average surface wetness. Macrofossils supported by local pollen tracked the local vegetation dynamics caused by local human impact and disturbance, including nutrients. Regional pollen showed human-induced landscape change outside the bog. Tree rings of Pinus sylvestris reflected the history of tree establishment and desiccation of the bog. Strong correlations between DCA axes 1 of regional pollen, of macrofossils and of testate amoebae, and a testate-amoebae-based water-table reconstruction that excludes A. discoides, indicate that changes on all spatial scales are linked, which is explained by a strong hydrologic connection between bog and surroundings. The combination of proxies shows that groundwater levels were modified by both human impact and climate change. [source]


    Norms for grip strength in children aged 4,16 years

    ACTA PAEDIATRICA, Issue 6 2002
    C Häger-Ross
    The aim of this study was to provide norms for grip strength in children. A total of 530 Swedish 4,16-y-olds was tested with the instrument Grippit®. The instrument estimates peak grip strength over a 10 s period, and sustained grip strength averaged across the 10 s. The increase in grip strength with age was approximately parallel for boys and girls until 10 y of age, after which boys were significantly stronger than girls. Strong correlations existed between grip strength and the anthropometric measures weight, height and, in particular, hand length. Right-handed children were significantly stronger in their dominant hand, while left-handers did not show any strength difference between the hands. It is therefore suggested that when evaluating grip strength in left-handed children both hands should be assumed to be about equally strong, while right-handed children are expected to be up to 10% stronger with their right hand. Sustained grip strength was consistently about 80,85% of peak grip strength, with somewhat lower values in younger children. The present normative data for peak grip strength were slightly lower than 1980s' data from the USA and Australia, probably because of divergences in age grouping and in instruments used. Conclusion: Norms for grip strength including estimates of variation were provided for children aged 4,16 y. These data will enable therapists and physicians to compare a patient's score with the scores of normally developed children according to age, gender, handedness and body measures. [source]


    Nonlinear Damping Identification in Precast Prestressed Reinforced Concrete Beams

    COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 8 2009
    P. Franchetti
    Integrated static and dynamic experiments were carried out on three precast PRC beam specimens. The static loading induced different levels of damage to the beams. At each damage level, impulsive loading was applied to the beams and the free vibration response was measured. The dynamic response data were processed using different methods including the multi-input multi-output (MIMO) curve fitting and the Hilbert transform techniques. A strong correlation is observed between the level of concrete damage (cracks) and the amount of nonlinear energy dissipation that can be modeled by means of quadratic damping. The nonlinear damping can be extracted from the free vibration response for each vibration mode. The proposed method is suited for quality control when manufacturing precast PRC members, and can be further extended for in situ detection of damage in concrete structures under ambient vibration. [source]


    Fluctuating Helium Emission in Optically Thick Divertor Plasmas

    CONTRIBUTIONS TO PLASMA PHYSICS, Issue 1-3 2008
    F. B. Rosmej
    Abstract Simulations of the helium radiative properties carried out with the recently developed multi-level meta-stable resolved collisional-radiative code SOPHIA discovered new unique emission lines to analyze optically thick divertor plasmas relevant for ITER. The comparison of their time dependent line emission obtained from the NAGDIS-II plasma simulator experiments with time dependent temperature probe measurements shows a strong correlation. This indicates that line intensity fluctuations can be transformed to the important quantities of density and temperature fluctuations. A transformation method based on integral line intensity ratios which can be recorded with high time resolution is discussed. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Slit-flow ektacytometry: Laser diffraction in a slit rheometer

    CYTOMETRY, Issue 1 2005
    Sehyun Shin
    Abstract Background Deformability of red blood cells (RBCs) is a determinant of blood flow resistance as RBCs pass through small capillaries of the microcirculation. Available techniques for measuring RBC deformability often require a washing process after each measurement, which is not optimal for day-to-day clinical use. Methods A laser diffraction technique has been combined with slit-flow rheometry, which shows significant advances in ektacytometric design, operation, and data analysis. The essential features of this design are its simplicity (ease of operation and no moving parts) and a disposable element that is in contact with the blood sample. Results With slit ektacytometry, the deformation of RBCs subjected to continuously decreasing shear stress in a slit flow can be quickly measured with extremely small quantities of blood. The measurements with the slit ektacytometer were compared with those of LORCA and a strong correlation was apparent. The deformability of the hardened RBCs was markedly lower than that of the normal RBCs. In addition, the young cells showed higher values of the elongation index than did the old cells. Conclusions The newly developed slit ektacytometer can measure RBC deformability with ease and accuracy. In addition, the slit ektacytometer can be easily used in a clinical setting owing to the incorporation of a disposable element that holds the blood sample. © 2005 Wiley-Liss, Inc. [source]


    A CRITICAL LOOK AT PAP ADEQUECY: ARE OUR CRITERIA SATISFACTORY?

    CYTOPATHOLOGY, Issue 2006
    D.R. Bolick
    Liquid based Pap (LBP) specimen adequacy is a highly documented, yet poorly understood cornerstone of our GYN cytology practice. Each day, as cytology professionals, we make adequacy assessments and seldom wonder how the criteria we use were established. Are the criteria appropriate? Are they safe? What is the scientific data that support them? Were they clinically and statistically tested or refined to achieve optimal patient care? In this presentation, we will take a fresh look at what we know about Pap specimen adequacy and challenge some of the core assumptions of our daily practice. LBP tests have a consistent, well-defined surface area for screening, facilitating the quantitative estimates of slide cellularity. This provides an unprecedented opportunity to establish reproducible adequacy standards that can be subjected to scientific scrutiny and rigorous statistical analysis. Capitalizing on this opportunity, the TBS2001 took the landmark step to define specimen adequacy quantitatively, and set the threshold for a satisfactory LBP at greater than 5,000 well visualized squamous epithelial cells. To date, few published studies have attempted to evaluate the validity or receiver operator characteristics for this threshold, define an optimal threshold for clinical utility or assess risks of detection failure in ,satisfactory' but relatively hypocellular Pap specimens. Five years of cumulative adequacy and cellularity data of prospectively collected Pap samples from the author's laboratory will be presented, which will serve as a foundation for a discussion on ,Pap failure'. A relationship between cellularity and detection of HSIL will be presented. Risk levels for Pap failure will be presented for Pap samples of different cellularities. The effect of different cellularity criterion on unsatisfactory Pap rates and Pap failure rates will be demonstrated. Results from this data set raise serious questions as to the safety of current TBS2001 adequacy guidelines and suggest that the risk of Pap failure in specimens with 5,000 to 20 000 squamous cells on the slide is significantly higher than those assumed by the current criteria. TBS2001 designated all LBP to have the same adequacy criterion. Up to this point, it has been assumed that ThinPrep, SurePath, or any other LBP would be sufficiently similar that they should have the same adequacy criteria. Data for squamous cellularity and other performance characteristics of ThinPrep and SurePath from the author's laboratory will be compared. Intriguing data involving the recently approved MonoPrep Pap Test will be reviewed. MonoPrep clinical trial data show the unexpected finding of a strong correlation between abundance of endocervical component and the detection of high-grade lesions, provoking an inquiry of a potential new role for a quantitative assessment of the transition zone component. The current science of LBP adequacy criteria is underdeveloped and does not appear to be founded on statistically valid methods. This condition calls us forward as a body of practitioners and scientists to rigorously explore, clarify and define the fundamental nature of cytology adequacy. As we forge this emerging science, we will improve diagnostic performance, guide the development of future technologies, and better serve the patients who give us their trust. Reference:, Birdsong GG: Pap smear adequacy: Is our understanding satisfactory? Diagn Cytopathol. 2001 Feb; 24(2): 79,81. [source]


    Long-term follow-up of patients following negative colposcopy: a new gold standard and its implications for cervical screening

    CYTOPATHOLOGY, Issue 5 2003
    P. D. Da Forno
    From 1189 colposcopy referrals in 1997 at a single cervical screening centre, 88 women who had no biopsy taken at colposcopy (negative colposcopy) were identified. We followed up these women for a maximum of 4 years and calculated the positive predictive value (PPV) of a single smear before and after follow-up. Using slide review we attempted to correlate the grade of smear leading to colposcopy referral with final outcome. Our results showed that long-term follow-up alters the PPV of cervical cytology. Analysis showed a strong correlation between the review grade of the referring smear and the final outcome after follow-up. From these results we suggest an evidence-based protocol for cervical screening follow-up after negative colposcopy. [source]


    Localization of Indian hedgehog and PTH/PTHrP receptor expression in relation to chondrocyte proliferation during mouse bone development

    DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 2 2005
    Helen E. MacLean
    We have developed a useful approach to examine the pattern of gene expression in comparison to cell proliferation, using double in situ hybridization and immunofluorescence. Using this system, we examined the expression of Indian hedgehog (Ihh) and PTH/PTHrP receptor (PPR) mRNA in relation to chondrocyte proliferation during embryonic mouse bone development. Both genes are expressed strongly in prehypertrophic and early hypertrophic chondrocytes, and there is a strong correlation between upregulation of both Ihh and PPR expression and chondrocyte cell cycle arrest. At embryonic day (E14.5), PPR mRNA upregulation begins in the columnar chondrocytes just prior to cell cycle exit, but at later time points expression is only observed in the postproliferative region. In contrast, Ihh mRNA expression overlaps slightly with the region of columnar proliferating chondrocytes at all stages. This study provides further evidence that in the developing growth plate, cell cycle exit and upregulation of Ihh and PPR mRNA expression are coupled. [source]


    Developmental changes in the modulation of respiratory rhythm generation by extracellular K+ in the isolated bullfrog brainstem

    DEVELOPMENTAL NEUROBIOLOGY, Issue 3 2003
    Rachel E. Winmill
    Abstract This study tested the hypothesis that voltage-dependent, respiratory-related activity in vitro, inferred from changes in [K+]o, changes during development in the amphibian brainstem. Respiratory-related neural activity was recorded from cranial nerve roots in isolated brainstem,spinal cord preparations from 7 premetamorphic tadpoles and 10 adults. Changes in fictive gill/lung activity in tadpoles and buccal/lung activity in adults were examined during superfusion with artificial CSF (aCSF) with [K+]o ranging from 1 to 12 mM (4 mM control). In tadpoles, both fictive gill burst frequency (fgill) and lung burst frequency (flung) were significantly dependent upon [K+]o (r2 > 0.75; p < 0.001) from 1 to 10 mM K+, and there was a strong correlation between fgill and flung (r2 = 0.65; p < 0.001). When [K+]o was raised to 12 mM, there was a reversible abolition of fictive breathing. In adults, fictive buccal frequency (fbuccal), was significantly dependent on [K+]o (r2 = 0.47; p < 0.001), but [K+]o had no effect on flung (p > 0.2), and there was no significant correlation between fbuccal and flung. These data suggest that the neural networks driving gill and lung burst activity in tadpoles may be strongly voltage modulated. In adults, buccal activity, the proposed remnant of gill ventilation in adults, also appears to be voltage dependent, but is not correlated with lung burst activity. These results suggest that lung burst activity in amphibians may shift from a "voltage-dependent" state to a "voltage-independent" state during development. This is consistent with the hypothesis that the fundamental mechanisms generating respiratory rhythm in the amphibian brainstem change during development. We hypothesize that lung respiratory rhythm generation in amphibians undergoes a developmental change from a pacemaker to network-driven process. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 278,287, 2003 [source]


    Relationship between mean blood glucose and glycated haemoglobin in Type 2 diabetic patients

    DIABETIC MEDICINE, Issue 2 2008
    K. Makris
    Abstract Aims To correlate the values of MBG to HbA1c in Greek patients with Type 2 diabetes and/or metabolic syndrome. Methods We followed up 140 Greek adult patients: 92 patients with Type 2 diabetes treated with insulin or oral glucose-lowering medication, and 48 patients with newly diagnosed Type 2 diabetes or metabolic syndrome not receiving any treatment. MBG was calculated for each patient from self-measurements of blood glucose using a portable glucometer, made six times a day (before eating and 2 h after a meal), three times a week for 1 month. HbA1c was determined by HPLC at 0 and 12 weeks. Results, HbA1c at 0 (x) and 12 weeks (y) correlated strongly (y = 0.790x + 1.115, r = 0.92), confirming that the patient's glycaemic status remained stable during the whole period of follow-up. Linear regression was performed on MBG values; HbA1c at 12 weeks, sex, age, body mass index (BMI) and patient status (Type 2 diabetes treated or not) were used as independent variables. None of the independent variables reached statistical significance in the model, with the exception of HbA1c at 12 weeks. The final model was: MBG (mg/dl) = (34.74 × HbA1c) , 79.21, r = 0.93; or MBG (mmol/l) = 1.91 × HbA1c , 4.36, r = 0.93. Conclusions Our results establish for the first time a strong correlation between MBG and HbA1c in Type 2 diabetic patients and support the idea of expressing HbA1c results as MBG. This will help patients to gain a clearer interpretation of the result, with less confusion. This simplification will allow every person with diabetes using home glucose-monitoring to understand his or her own target level. [source]


    Relationship of lipoprotein(a) with intimal medial thickness of the carotid artery in Type 2 diabetic patients in south India

    DIABETIC MEDICINE, Issue 6 2003
    K. Velmurugan
    Abstract Objective The objective of this study was to investigate the association of lipoprotein(a) [Lp(a)] levels with intimal medial thickness (IMT) in Type 2 diabetic patients in south India. Study design We studied 587 consecutive Type 2 diabetic patients at the M.V. Diabetes Specialities Centre, Chennai. The mean age of the study group was 55 ± 10 years and 71.2% were males. IMT of the right common carotid artery was determined using high-resolution B mode ultrasonography. Lp(a) levels were measured using ELISA. Since the frequency distribution of Lp(a) was skewed, Lp(a) values were log transformed and the geometric mean was used for statistical analysis. The tertiles of IMT were determined to analyse the association of Lp(a) and other factors with IMT. Result The mean Lp(a) level in the study patients was 18.9 ± 3.1 mg/dl (geometric mean ± sd) and the mean IMT of the study subjects was 0.93 ± 0.19 mm (mean ± sd). The prevalence of carotid atherosclerosis (defined as IMT > 1.1 mm) among subjects with elevated Lp(a) levels > 20 mg/dl was significantly higher compared with those with Lp(a) levels , 20 mg/dl (26.9% vs. 16.3%, P = 0.003). Lp(a) levels increased with increase in tertiles of IMT (anova, P < 0.05). Pearson correlation analysis of carotid IMT with other cardiovascular risk factors revealed strong correlation of IMT with age (P < 0.0001), duration of diabetes (P < 0.0001), systolic blood pressure (P < 0.0001), diastolic blood pressure (P = 0.006), LDL-cholesterol (P = 0.023), HbA1c (P = 0.017) and Lp(a) (P < 0.0001). Multiple logistic regression analysis showed age (P = 0.010), LDL-cholesterol (P = 0.032) and Lp(a) (P = 0.021) to be associated with carotid atherosclerosis. Conclusion The results suggest that Lp(a) has a strong association with IMT of carotid arteries in Type 2 diabetic subjects in south India. Diabet. Med. 20, 455,461 (2003) [source]


    Right Heart Function and Scleroderma: Insights from Tricuspid Annular Plane Systolic Excursion

    ECHOCARDIOGRAPHY, Issue 2 2007
    Chiu-Yen Lee M.D.
    Objective: The purpose of this study was to evaluate the use of echocardiographic parameters as predictors of rehospitalization in scleroderma patients. Methods: Echocardiographic studies were conducted in 38 patients with systolic scleroderma (SSc) to assess cardiopulmonary function. Forty-five age-matched volunteers without any sign of heart failure served as the control group. Transmitral flow pattern, tricuspid annular plane systolic excursion (TAPSE), left ventricular ejection fraction (LVEF), and right ventricular ejection fraction (RVEF) were evaluated. All patients were subsequently followed for one year. Results: Peak transmitral early-diastolic velocity (mitral E) and TAPSE measurements were significantly different between SSc and control patients (mitral E: 74.1 ± 16.3 vs. 83.5 ± 17.0 cm/s with P = 0.012; TAPSE: 2.4 ± 0.43 vs. 1.9 ± 0.39 cm with P < 0.0001). LVEF was similar, but RVEF was lower in the SSc group (LVEF: 61.7 ± 9.7 vs. 61.7 ± 5.8% with P = 0.962; RVEF: 49.6 ± 6.8 vs. 39.2 ± 6.7% with P < 0.0001). A strong correlation was found between TAPSE and RVEF. A TAPSE less than 1.96 cm indicted a RVEF less than 40% with a sensitivity of 81% and specificity of 78%. Contrary to expectation, pulmonary artery systolic pressure (PASP) did not correlate well with RV function (r = 0.261, r2= 0.068, P = 0.016). Finally, the frequency of rehospitalization was inversely correlated with RVEF and TAPSE in SSc patients. Conclusions: We can predict the rehospitalization rate of SSc patients by TAPSE and RVEF, suggesting the involvement of heart, skin, lung, and other organs in scleroderma patients. [source]


    Visual Quantitative Estimation: Semiquantitative Wall Motion Scoring and Determination of Ejection Fraction

    ECHOCARDIOGRAPHY, Issue 5 2003
    M.D., Steven J. Lavine
    Ejection fraction (EF) is the most commonly used parameter of left ventricular (LV) systolic function and can be assessed by echocardiography. Quantitative echocardiography is time consuming and is as accurate as visual estimation, which has significant variability. We hypothesized that each echocardiographer has developed a mental set of guidelines that relate to how much individual segment shortening constitutes normal function or hypokinesis of varying extents. We determined the accuracy of applying these guidelines to an accepted technique of EF determination using a retrospective analysis of consecutive two-dimensional echocardiographic studies performed on patients who had radioventriculography (RVG) within 48 hours. Using a 12 segment model, we scored each segment at the base and mid-ventricular level based on segmental excursion and thickening. The apex was scored similarly but with 1/3 of the value based on a cylinder-cone model. EF was determined from the sum of segment scores and was estimated visually. We termed this approach visual quantitative estimation (VQE). We correlated the EF derived from VQE and visual estimation with RVG EF. In the training set, VQE demonstrated a strong correlation with RVG(r = 0.969), which was significantly greater than visual estimation(r = 0.896, P < 0.01). The limits of agreement for VQE (+12% to ,7%) were similar to the limits of RVG agreement with contrast ventriculography (+10% to ,11%) with similar intraobserver and interobserver variabilities. Similar correlation was noted in the prediction set between VQE and RVG EF(r = 0.967, P < 0.001). We conclude that VQE provides highly correlated estimates of EF with RVG. (ECHOCARDIOGRAPHY, Volume 20, July 2003) [source]


    Oviposition preferences of Maculinea alcon as influenced by aphid (Aphis gentianae) and fungal (Puccinia gentianae) infestation of larval host plants

    ECOLOGICAL ENTOMOLOGY, Issue 1 2009
    ERVIN ÁRNYAS
    Abstract 1.,The influence of infestation of the larval host plant Gentiana cruciata on the egg-laying preferences of the xerophilous ecotype of Alcon Blue butterfly (Maculinea alcon) was studied in a semi-dry grassland area (Aggtelek Karst Region, Northern Hungary). 2.,We examined whether oviposition patterns of females differed when G. cruciata stems were uninfested compared with when they were infested by an aphid (Aphis gentianae) or a rust (Puccinia gentianae) species. 3.,Females laid more than 90% of their eggs on fertile, uninfested G. cruciata stems, although these stems comprised only , 50% of the total stems available. Stems infested by aphids were similar to uninfested ones in properties that had a strong correlation with egg numbers, and yet there were significantly fewer eggs on infested stems than on intact ones. 4.,Females never laid eggs on parts of Gentiana stems infested by aphids, and the presence of Lasius paralienus ants, which have a mutualistic interaction with Aphis gentianae, did not increase the repulsive effect of aphids. Infection of Gentiana by Puccinia did not influence the egg-laying behaviour of females, even though the flowers and buds of infested stems exhibited a delayed development. 5.,Aphid infestation can influence butterfly oviposition patterns through both direct and indirect effects. The presence of aphids directly excluded oviposition, but our data also indicated the possibility of an indirect effect of aphid infestation. Stems that had no aphids at the last egg counting, but were infested prior to it, had significantly fewer eggs than those that were never infested. [source]


    Enantioselectivity of alcohol-modified polymeric surfactants in micellar electrokinetic chromatography

    ELECTROPHORESIS, Issue 15 2003
    Jepkoech Tarus
    Abstract A novel method of modifying sodium undecanoyl- L -leucinate (SUL) micelles employed in chiral separation of analytes in micellar electrokinetic chromatography (MEKC) to enhance selectivity toward specific analytes is discussed. The current study aimed at modifying the SUL micelles by introducing different alcohols into the mono-SUL micelles. The micellar solutions were then polymerized in the presence of alcohols followed by postpolymerization extraction of the alcohols to yield alcohol-free polymeric surfactants (poly- L -SUL). The effects of hexanol (C6OH) and undecylenyl alcohol (C11OH) on micellar properties of this surfactant were investigated by use of surface tensiometry, fluorescence spectroscopy, pulsed field gradient-nuclear magnetic resonance (PFG-NMR), and MEKC. The surface tension and PFG-NMR studies indicated an increase in the critical micelle concentration (cmc) and micellar size upon increasing the alcohol concentration. Fluorescence measurements suggested that alcohols induce closely packed micellar structures. Coumarinic and benzoin derivatives, as well as (±)-1, 1'-binaphthyl-2,2'-dihydrogen phosphate (BNP) were used as test analytes for MEKC experiments. Examination of MEKC data showed remarkable resolutions and capacity factors of coumarinic derivatives obtained with modified poly- L -SUL as compared to the unmodified poly- L -SUL. Evaluation of fluorescence, PFG-NMR, and MEKC data suggest a strong correlation between the polarity and hydrodynamic radii of alcohol-modified micelles and the resolution of the test analytes. [source]


    Microbial community dynamics in a humic lake: differential persistence of common freshwater phylotypes

    ENVIRONMENTAL MICROBIOLOGY, Issue 6 2006
    Ryan J. Newton
    Summary In an effort to better understand the factors contributing to patterns in freshwater bacterioplankton community composition and diversity, we coupled automated ribosomal intergenic spacer analysis (ARISA) to analysis of 16S ribosomal RNA (rRNA) gene sequences to follow the persistence patterns of 46 individual phylotypes over 3 years in Crystal Bog Lake. Additionally, we sought to identify linkages between the observed phylotype variations and known chemical and biological drivers. Sequencing of 16S rRNA genes obtained from the water column indicated the presence of phylotypes associated with the Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria, TM7 and Verrucomicrobia phyla, as well as phylotypes with unknown affiliation. Employment of the 16S rRNA gene/ARISA method revealed that specific phylotypes varied independently of the entire bacterial community dynamics. Actinobacteria, which were present on greater than 95% of sampling dates, did not share the large temporal variability of the other identified phyla. Examination of phylotype relative abundance patterns (inferred using ARISA fragment relative fluorescence) revealed a strong correlation between the dominant phytoplankton succession and the relative abundance patterns of the majority of individual phylotypes. Further analysis revealed covariation among unique phylotypes, which formed several distinct bacterial assemblages correlated with particular phytoplankton communities. These data indicate the existence of unique persistence patterns for different common freshwater phylotypes, which may be linked to the presence of dominant phytoplankton species. [source]


    Monitoring of DNA breakage in embryonic stages of the African catfish Clarias gariepinus (Burchell, 1822) after exposure to lead nitrate using alkaline comet assay

    ENVIRONMENTAL TOXICOLOGY, Issue 6 2008
    Alaa G. M. Osman
    Abstract Increasing lead contamination in Egyptian ecosystems and high lead concentrations in food items have raised concern for human health and stimulated studies on monitoring ecotoxicological impact of lead-caused genotoxicity. In this work, the alkaline comet assay was modified for monitoring DNA strand breakage in sensitive early life stages of the African catfish Clarias gariepinus. Following exposure to 100, 300, and 500 ,g/L lead nitrate, DNA strand breakage was quantified in embryos at 30, 48, 96, 144, and 168 h post-fertilization (PFS). For quantitative analysis, four commonly used parameters (tail % DNA, %TDNA; head % DNA, %HDNA; tail length, TL; tail moment, TM) were analyzed in 96 nuclei (in triplicates) at each sampling point. The parameter %TDNA revealed highest resolution and lowest variation. A strong correlation between lead concentration, time of exposure, and DNA strand breakage was observed. Here, genotoxicity detected by comet assay preceded the manifested malformations assessed with conventional histology. Qualitative evaluation was carried out using five categories are as follows: undamaged (%TDNA , 10%), low damaged (10% < %TDNA , 25%), median damaged (25 < %TDNA , 50%), highly damaged (50 < %TDNA , 75%), and extremely damaged (%TDNA > 75%) nuclei confirming a dose and time-dependent shift towards increased frequencies of highly and extremely damaged nuclei. A protective capacity provided by a hardened chorion is a an interesting finding in this study as DNA damage in the prehatching stages 30 h-PFS and 48 h-PFS was low in all treatments (qualitative and quantitative analyses). These results clearly show that the comet assay is a sensitive tool for the detection of genotoxicity in vulnerable early life stages of the African catfish and is a method more sensitive than histological parameters for monitoring genotoxic effects. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. [source]


    Detection of environmental androgens: A novel method based on enzyme-linked immunosorbent assay of spiggin, the stickleback (Gasterosteus aculeatus) glue protein

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2002
    Ioanna Katsiadaki
    Abstract We report the development and validation of a novel in vivo biomarker test for waterborne androgens. During breeding, male sticklebacks (Gasterosteus aculeatus) manufacture a glue protein, spiggin, in their kidneys that they use to build their nests. Spiggin production is under the control of androgens. Until now, however, it has only been possible to quantify its production by measurement of the height of kidney epithelial cells. In the present study, we report the development of an enzyme-linked immunosorbent assay (ELISA) for spiggin and demonstrate its application to the measurement of spiggin in the kidneys of female sticklebacks that have been exposed to androgens in water. Results from the ELISA procedure revealed a strong correlation with measurement of kidney epithelial cell height (r2 = 0.93). However, the ELISA was much quicker and had a considerably higher response range (100,000-fold vs fourfold). Clear, graded responses in spiggin production were obtained by exposing intact females to increasing concentrations of 17,-methyltestosterone and 5,-dihydrotestosterone over three-week test periods. The lowest effective concentrations for these two steroids were 100 ng/L and 3 ,g/L, respectively. Female sticklebacks that were exposed to pulp mill effluent also produced spiggin in their kidneys. Possession of an androgen-regulated protein by the female stickleback makes it a unique bioassay organism for detecting androgenic contamination in the aquatic environment. [source]