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Selected AbstractsImmediate antigen-specific effector functions byTCR-transgenic CD8+ NKT cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2006Gerhard Wingender Abstract Only recently have natural antigens for CD1d-dependent, invariant V,14+ natural killer T (iNKT) cells been identified. Similar data for CD1d-independent and CD8+ NKT cell populations are still missing. Here, we show that the MHC class,I-restricted CD8+ TCR-transgenic mouse lines OT-I, P14 and H-Y contain a significant proportion of transgenic CD8+ NK1.1+ T,cells. In liver, most of NK1.1+ T,cells express CD8,, homodimers. Transgenic NKT cells did not bind invariant V,14-to-J,18 TCR rearrangement (V,14i)-specific CD1d/,-galactosylceramide tetramers and the frequency of iNKT cells was severely reduced. The activated cell surface phenotype and the distribution of transgenic NKT cells in vivo were similar to that reported for iNKT cells. The OT-I and P14 CD8+ NKT cells recognized their cognate antigen in the context of H2-Kb and produced cytokines shortly after TCR stimulation. Importantly, transgenic NKT cells exerted immediate antigen-specific cytotoxicity in vitro and in vivo. Our results demonstrate the presence of transgenic CD8+ NKT cells in MHC class,I-restricted TCR-transgenic animals, which are endowed with rapid antigen-specific effector functions. These data imply that experiments studying naive T,cell function in TCR-transgenic animals should be interpreted with caution, and that such animals could be utilized for studying CD8+ NKT cell function in an antigen-specific manner. [source] Missense mutations of human homeoboxes: A reviewHUMAN MUTATION, Issue 5 2001Angela V. D'Elia Abstract The homeodomain (encoded by the homeobox) is the DNA-binding domain of a large variety of transcriptional regulators involved in controlling cell fate decisions and development. Mutations of homeobox-containing genes cause several diseases in humans. A variety of missense mutations giving rise to human diseases have been described. These mutations are an excellent model to better understand homeodomain molecular functions. To this end, homeobox missense mutations giving rise to human diseases are reviewed. Seventy-four independent homeobox mutations have been observed in 17 different genes. In the same genes, 30 missense mutations outside the homeobox have been observed, indicating that the homeodomain is more easily affected by single amino acids changes than the rest of the protein. Most missense mutations have dominant effects. Several data indicate that dominance is mostly due to haploinsufficiency. Among proteins having the homeodomain as the only DNA-binding domain, three "hot spot" regions can be delineated: 1) at codon encoding for Arg5; 2) at codon encoding for Arg31; and 3) at codons encoding for amino acids of recognition helix. In the latter, mutations at codons encoding for Arg residues at positions 52 and 53 are prevalent. In the recognition helix, Arg residues at positions 52 and 53 establish contacts with phosphates in the DNA backbone. Missense mutations of amino acids that contribute to sequence discrimination (such as those at positions 50 and 54) are present only in a minority of cases. Similar data have been obtained when missense mutations of proteins possessing an additional DNA-binding domain have been analyzed. The only exception is observed in the POU1F1 (PIT1) homeodomain, in which Arg58 is a "hot spot" for mutations, but is not involved in DNA recognition. Hum Mutat 18:361,374, 2001. © 2001 Wiley-Liss, Inc. [source] Sinus Pacemaker Function after Cardioversion of Chronic Atrial Fibrillation: Is Sinus Node Remodeling Related with Recurrence?JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2001EMMANUEL G. MANIOS M.D. Sinus Node Remodeling and Atrial Fibrillation. Introduction: The objective of this study was to investigate the temporal changes in sinus node function in postcardioversion chronic atrial fibrillation (AF) patients and their possible relation with the recurrence rates of AF. Methods and Results: In 37 chronic AF patients, internally cardioverted to sinus rhythm, corrected sinus node recovery time (CSNRT), and the pattern of corrected return cycle lengths were assessed 5 to 20 minutes and 24 hours after conversion. The last 20 consecutive patients also were evaluated after autonomic blockade. Twenty subjects with normal atrial structure and no history of AF served as the control group. Patients were followed-up for 1 month for recurrence, and the density of supraventricular ectopic beats per hour was obtained during the first 24 hours after conversion. Fifteen patients (40.5%) relapsed during follow-up. CSNRT values at 600 msec (371 ± 182 msec) and 500 ms (445 ± 338 msec) were significantly higher than those of control subjects (278 ± 157 msec, P = 0.050, and 279 ± 130 msec, P = 0.037, respectively). Significant temporal changes in CSNRT also were observed during the first 24 hours after conversion (600 msec: 308 ± 120 msec, P = 0.034; 500 msec: 340 ± 208 msec, P = 0.017). No significant interaction and temporal effects were observed with regard to corrected return cycle length pattern. Similar data regarding CSNRT and corrected return cycle length pattern were obtained after autonomic blockade. Patients with abnormal CSNRT after cardioversion had higher recurrence rates (50%) than those with normal function (37%; P = NS). Patients who relapsed had a higher density of supraventricular ectopic beats per hour (159 ± 120) compared with those who did not (35 ± 37; P = 0.001). Conclusion: Depressed sinus node function is observed after conversion of chronic AF. Recovery from this abnormality and its independence from autonomic function suggest that AF remodels the sinus node. Our data do not support a causative role of sinus node function in AF recurrence, but they do indicate such a role for the density of atrial ectopic beats. [source] Thrombin generation in acute coronary syndrome and stable coronary artery disease: dependence on plasma factor compositionJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2008K. BRUMMEL-ZIEDINS Summary.,Background:,Acute coronary syndrome (ACS) is associated with thrombin formation, triggered by ruptured or eroded coronary atheroma. We investigated whether thrombin generation based on circulating coagulation protein levels, could distinguish between acute and stable coronary artery disease (CAD). Methods and results:,Plasma coagulation factor (F) compositions from 28 patients with ACS were obtained after onset of chest pain. Similar data were obtained from 25 age- and sex-matched patients with stable CAD. All individuals took aspirin. Patients on anticoagulant therapy were excluded. The groups were similar in demographic characteristics, comorbidities and concomitant treatment. Using each individual's coagulation protein composition, tissue factor (TF) initiated thrombin generation was assessed both computationally and empirically. TF pathway inhibitor (TFPI), antithrombin (AT), factor II (FII) and FVIII differed significantly (P < 0.01) between the groups, with levels of FII, FVIII and TFPI higher and AT lower in ACS patients. When thrombin generation profiles from individuals in each group were compared, simulated maximum thrombin levels (P < 0.01) and rates (P < 0.01) were 50% higher with ACS while the initiation phases of thrombin generation were shorter. Empirical reconstructions of the populations reproduced the thrombin generation profiles generated by the computational model. The differences between the thrombin generation profiles for each population were primarily dependent upon the collective contribution of AT, FII and FVIII. Conclusion:,Simulations of thrombin formation based on plasma composition can discriminate between acute and stable CAD. [source] Semi-automated quantification of ivermectin in rat and human plasma using protein precipitation and filtration with liquid chromatography/tandem mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 12 2004Tony Pereira Ivermectin is a parasiticide commonly used in humans and livestock. It is currently under development for the treatment of pediculosis of humans (head lice) that does not respond to established treatments. A liquid chromatography/turbo ion spray tandem mass spectrometry (LC/TIS-MS/MS) method for the determination of ivermectin in rat and human plasma has been developed that uses emamectin [4,-epi-(methylamino)-4,-deoxyavermectin] as the internal standard. Sample preparation involved protein precipitation and filtration of fortified plasma in the 96-well format. Chromatographic separation was accomplished using fast gradient conditions on a C8 stationary phase. The analytes were detected with the mass spectrometer operated in the positive ion, multiple reaction monitoring mode. The method exhibited good intra- and interday accuracy and precision, and was linear over a dynamic range of 1,2000,ng/mL. In rat plasma, intraday accuracy ranged between 84,93% for the low quality control (QC) sample (1.5 ng/mL), and between 91,109% for the remaining QCs. Intraday precision ranged between 4.9,15% for the low QC, and 0.8,6.3% for the remaining QCs. Interday accuracy ranged between 88,107%, and precision between 4.1,11%. Similar data was obtained using human plasma. An investigation of matrix effects indicated that the ionization efficiency of ivermectin was favored by the presence of an ammonium ion in an aqueous environment. The implications of this observation toward assay sensitivity are discussed. Copyright © 2004 John Wiley & Sons, Ltd. [source] Systemic plant signal triggers genome instabilityTHE PLANT JOURNAL, Issue 1 2004Jody Filkowski Summary Previously, we have shown that infection of tobacco plants with a viral pathogen triggers local and systemic induction of homologous recombination (HR). Here, we have tested the hypothesis of whether free radicals are potentially involved in the induction of the systemic effect. We report a significant induction of HR in tobacco plants treated with radical-generating agents, UVC or rose Bengal (RB). Importantly, the recombination increase was observed in local (treated) as well as systemic (non-treated) tissue. The systemic increase in recombination implies the existence of a signal that is transmitted to non-treated tissue. Several sets of grafting experiments proved the generation of said signal by both RB and UVC exposure. A statistically significant increase in HR was observed in tissue that received a systemic signal via a grafted leaf. Similar data were obtained from transgenic plants naphthalene degrading salicylate 1-hydroxylase (NahG) unable to accumulate salicylic acid (SA). Interestingly, pre-treatment of plants with the radical-scavenging compound N -acetyl- l -cysteine (NAC) led to a significantly lower recombination increase upon grafting after treatment with UVC and RB. Moreover, leaves taken for grafting from NAC-pre-treated plants exhibited a lower level of oxidized organic compounds. Our data suggest the involvement of free radical production in either generation or maintenance of the recombination signal. We discuss potential mechanisms for generation of the signal and possible adaptive advantages of enhanced genomic flexibility following exposure to DNA-damaging agents. [source] Are common symptoms in childhood associated with chronic widespread body pain in adulthood?: Results from the 1958 british birth cohort studyARTHRITIS & RHEUMATISM, Issue 5 2007Gareth T. Jones Objective Studies have shown that common symptoms in childhood predict the onset of chronic widespread pain in the short term. However, it is unknown whether this association persists into adulthood. The aim of the current study was to examine, prospectively, whether children with common symptoms experience an increased risk of chronic widespread pain as adults. Methods Information on vomiting/bilious attacks, abdominal pain, and headaches/migraine was collected on 10,453 7-year-old children, by maternal report. Similar data were gathered when the children were ages 11 years and 16 years. Body pain at age 45 years was assessed by postal questionnaire. Poisson regression was used to examine chronic widespread pain in relation to childhood symptom reporting. Results Of the 10,453 subjects on whom data were obtained when they were children, 7,470 participated at age 45 years (71.5%). Children with multiple symptoms at age 7 years experienced a 50% increased risk of chronic widespread pain (relative risk 1.5 [95% confidence interval 1.03, 2.3]). This relationship persisted after adjustment for sex, recent psychological distress, and childhood and current socioeconomic status, and after excluding children with major illnesses that might have explained early symptom reporting. A similar relationship with symptoms at ages 11 and 16 years was observed, although this was not associated with additional risk compared with that found with the presence of symptoms at age 7 years. However, despite a modest increase in risk, the presence of multiple symptoms at early ages was uncommon (<1.5%), and therefore, the associated population attributable risk was low (<1%). Conclusion Multiple common symptoms in childhood are associated with an increased risk of chronic widespread pain in adulthood. However, the magnitude of this increased risk is modest, and reports of multiple symptoms in childhood are uncommon. Thus the "early pain pathway" phenomenon is applicable only to a small proportion of individuals with chronic widespread pain. [source] Ultraviolet radiation exposure pattern in winter compared with summer based on time-stamped personal dosimeter readingsBRITISH JOURNAL OF DERMATOLOGY, Issue 1 2006E. Thieden Summary Background, Personal annual ultraviolet (UV) radiation data based on daily records are needed to develop protective strategies. Objectives, To compare UV radiation exposure patterns in the winter half-year (October,March) and the summer half-year (April,September) for Danish indoor workers. Methods, Nineteen indoor workers (age range 17,56 years) wore personal UV dosimeters, measuring time-stamped UV doses continuously during a year. The corresponding sun exposure behaviour was recorded in diaries. Similar data were collected for 28 volunteers during sun holidays in the winter half-year. The relationship between UV dose and sun exposure behaviour was analysed. Results, The ambient UV dose during the winter in Denmark (at 56°N) was 394 standard erythema doses (SED) or 10·5% of the annual ambient UV dose. In winter compared with summer the subjects had: (i) a lower percentage of ambient UV radiation, 0·82% vs. 3·4%; (ii) a lower solar UV dose in Denmark, 3·1 SED (range 0·2,52) vs. 133 SED (range 69,363); (iii) less time outdoors per day with positive dosimeter measurements, 10 min vs. 2 h; and (iv) no exposure (0 SED) per day on 77% vs. 19% of the days. Sun holidays outside Denmark in winter gave a median 4·3 SED per day (range 0·6,7·6) and 26 SED (range 3,71) per trip. Conclusions, In the winter half-year indoor workers received a negligible UV dose from solar exposure in Denmark and needed no UV precautions. No UV precautions are needed from November to February during holidays to latitudes above 45 °N, while precautions are needed the whole year around at lower latitudes. [source] A phenomenological study of ripening of salted herring.JOURNAL OF CHEMOMETRICS, Issue 2 2002Assessing homogeneity of data from different countries, laboratories Abstract Data from ripening experiments of herring carried out at three Nordic fishery research institutions in the period 1992,1995 were collected and analyzed by multivariate analysis. The experiments were carried out at different times, with different stocks as raw material, using different types of treatments and analyzed in different laboratories. The question considered here is whether these data can be assumed to be one homogeneous set of data pertaining to ripening of salted herring or whether data from different labs, stocks, etc. must be considered independently. This is of importance for further research into ripening processes with these and similar data. It is shown in this paper that all data can be considered as one homogeneous data set. This is verified using resampling where latent structures are compared between different sample sets. This is done indirectly by testing regression models, that have been developed on one sample set, on other sample sets. It is also done directly by monitoring the deviation in latent structure observed between different sample sets. No formal statistical test is developed for whether samples can be assumed to stem from the same population. Although this can easily be envisioned, it was exactly the need for a more intuitive and visual test that prompted this work, developing different exploration tools that visually make it clear how well the data can be assumed to derive from the same population. Subsequently analyzing the data as one homogeneous group provides new information about factors that govern the ripening of salted herring and can be used in new strategic research as well as in industrial practice. Copyright © 2002 John Wiley & Sons, Ltd. [source] Fatty acid composition and volatile compounds of selected marine oils and mealsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2009Ioannis Giogios Abstract BACKGROUND: Although volatile compounds characterising seafood have been studied extensively, no similar data are available regarding the volatiles of raw materials used in fish feed. Therefore the aim of this study was to make an initial screening of the volatiles of various common marine raw materials used in the aquaculture feed industry. Nine commercial marine oils (German (GFO1, GFO2 and GFO3) and Norwegian (NFO) fish oils and salmon (SO1 and SO2), tuna (TO), sardine (SRDO) and shrimp (SHO) oils) and eight commercial marine meals (Peruvian (PFM1 and PFM2), Danish (DFM1 and DFM2) and prime quality (PQFM1 and PQFM2) fish meals and Antarctic krill meals (KM1 and KM2)) were analysed for their fatty acid profiles and volatile flavour compounds. The relation between fatty acids and volatiles was examined. RESULTS: The highest polyunsaturated fatty acid and eicosapentaenoic acid (20:5,3) contents and ,3/,6 ratio were found in NFO. The fatty acid composition of all marine meals except krill meals was found to be more variable among batches than that of marine oils. Regarding volatiles, all marine raw materials were characterised by the complete absence or negligible levels of eight- and nine-carbon alcohols and carbonyls. All marine oils were found to have high 2-ethyl furan, 2-methylenebutyl cyclopropane, hexanal, 2,4-octadiene and 3,5-octadiene contents. Marine meals, unlike marine oils, were characterised by the almost complete absence of unsaturated and cyclic hydrocarbons and terpenes and very low levels of furans. CONCLUSION: Volatiles of marine meals differ from those of marine oils. Unlike fatty acids which give useful traceability information, volatiles seem to fail in this role owing to their strong variability. Copyright © 2008 Society of Chemical Industry [source] Gene transfer for hemophilia: can therapeutic efficacy in large animals be safely translated to patients?JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2005K. HIGH Summary., Gene transfer is a novel area of therapeutics in which the active agent is a nucleic acid rather than a protein or small molecule. As early as 1997, investigators reported long-term expression of therapeutic levels of factor IX using gene transfer techniques in hemophilia B mice, and similar data were thereafter reported in mice with hemophilia A. Efforts to translate these results to hemophilic dog models at first yielded only marginally therapeutic levels (1%,2% normal circulating levels), but within the past few years have achieved levels in the range of 10%,20% through multiple different gene transfer strategies. Early phase clinical testing has revealed that many aspects of gene transfer in humans were accurately predicted by studies in hemophilic dogs, but that other aspects were not, and were only appreciated as a result of clinical testing. Studies in the next few years will determine whether the problems identified in preclinical and early phase clinical testing can be solved to develop a therapeutic gene transfer approach to hemophilia. [source] Assessment and demarcation of trail degradation in a nature reserve, using GIS: case of Bukit Timah Nature ReserveLAND DEGRADATION AND DEVELOPMENT, Issue 5 2007K. Chatterjea Abstract With a significant rise in popularity of nature areas, particularly in urban settings like Singapore, Nature Reserves are being increasingly opened for public recreational use. In the Bukit Timah Nature Reserve (BTNR), the only remnant primary rain forest reserve in Singapore, trail networks are being expanded to meet this growing public demand. The physical condition of the present trail networks was assessed by monitoring the changes in surface compaction, soil moisture, infiltration rates, soil organic matter content, root density, litter cover and rill development. These parameters were compared with similar data obtained from undisturbed forested slopes to analyse the degree of changes brought about by trail usage. Significant changes occurred in all measured parameters, indicating observable degradation of the trails, particularly on vulnerable slopes. These changes are due to the heavy and increased use of the forest by visitors. Penetration resistance and shear strength of the top surface layers of the trails are important indicators of trail degradation status and these have been plotted, using GIS, to demarcate trails under different levels of stress. This field monitoring provides a relevant local assessment of trail conditions. It has potential for use in decision-making in future planning and forest management under similar site conditions. Copyright © 2007 John Wiley & Sons, Ltd. [source] Occult hepatitis B virus infection in patients with autoimmune liver diseasesLIVER INTERNATIONAL, Issue 3 2009Sarah P. Georgiadou Abstract Background: Occult hepatitis B virus (HBV) infection is characterized by undetectable serum HBV surface antigen (HBsAg) but detectable HBV-DNA in serum or liver. Aims: To determine the prevalence and clinical impact of occult HBV in autoimmune liver diseases as similar data are missing. Methods: One hundred and ninety-six sera samples from HBsAg-negative patients, including 66 autoimmune hepatitis (AIH), 93 primary biliary cirrhosis (PBC) and 37 primary sclerosing cholangitis (PSC), were investigated for HBV-DNA using the polymerase chain reaction (PCR) before treatment initiation. One hundred and three serial samples from 38 AIH patients under immunosuppression and 282 selected blood donors (HBsAg negative; antibodies to HBV-core antigen positive) were also investigated. Fourteen available paraffin-embedded AIH liver samples were also investigated for HBV-DNA by nested-PCR. Results: Hepatitis B virus DNA was detected in the serum of 24/196 patients (12.2%) and 0/282 donors (P=0.0000). Nine patients had AIH (13.6%), eight had PBC (8.6%) and seven had PSC (18.9%) (P=0.0000 vs healthy). HBV-DNA detection in AIH livers was higher than in serum. HBV-DNA was associated neither with HBV markers nor with epidemiological, laboratory and clinical data. Serial testing of AIH patients revealed two HBV-DNA-negative patients before treatment becoming positive during treatment, while all HBV-DNA-positive patients before immunosuppression became negative. Conclusion: Based mainly on serum HBV-DNA, we found a significant proportion of autoimmune liver disease patients with occult HBV compared with donors. However, taking into account our results in a small number of liver tissues, it should be emphasized that occult HBV could be even higher when both serum and liver specimens are investigated. Occult HBV does not seem to affect the clinical and laboratory features of the diseases, while AIH patients with occult HBV under immunosuppression do not deteriorate during follow-up. [source] Distribution of mountain hares Lepus timidus in Scotland: results from a questionnaireMAMMAL REVIEW, Issue 4 2010Vikki PATTON ABSTRACT A questionnaire survey of land owners, managers and gamekeepers was conducted in order to assess the distribution of mountain hares in Scotland, assess their current management, collate numbers harvested in 2006,07 and estimate distribution change by comparing with similar data collected in 1995,96. The land area covered by returned questionnaires was 71098km2 (90% of Scotland). Mountain hares were reported as present on 34359km2 (48%) and absent from 36739km2 (52%). Mountain hare presence was strongly associated with heather moorland managed for red grouse shooting. Moorland managed for driven grouse shooting had the highest percentage area of mountain hare presence (median 64%) followed by moorland managed for walked-up grouse shooting (median 9%) and moorland with no grouse shooting (median 0%). Approximately 25000 mountain hares were harvested in 2006,07. Based on the estimated UK population in 1995 of 350000 (range ±50%), this represents around 7% of the population (range 5,14%). Reasons given by respondents for harvesting hares were tick control (50%), sport (40%) and forestry or crop protection (10%). Comparison of the estates surveyed in both 2006,07 and 1995,96 (a total area of 20462km2) indicated no net gain or loss in hare distribution. Furthermore, there was no evidence that levels of harvest had reduced the range of mountain hares in this area. It is not possible to comment on any distribution change outside this area (58737km2). Similarly, as no data were collected on abundance, it is not possible to draw conclusions on changes in density. Regular monitoring of mountain hare distribution within Scotland is required to identify any distribution changes. Measures of abundance throughout the range are necessary to estimate the population size, investigate the relationship between harvest intensity and changes in abundance and further assess the conservation status of this UK Biodiversity Action Plan species. [source] The dust-eliminated shape of quasar spectra in the near-infrared: a hidden part of the big blue bumpMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2005Makoto Kishimoto ABSTRACT The near-infrared shape of the big blue bump component in quasar spectra has till now been essentially unknown. It usually cannot be observed directly, due to the strong hot dust emission that dominates quasar spectra longward of ,1 ,m. However, this is quite an important part of the spectrum theoretically. At least bare-disc models provide quite a robust prediction for the overall continuum shape in the near-infrared. Self-gravity should become important in the outer, near-infrared-emitting regions of the putative disc, possibly leaving a signature of disc truncation in the near-infrared. We propose here that this important part of the spectrum can be revealed for the first time by observing polarized flux from normal quasars. At least in some polarized quasars, the emission lines are all unpolarized and so the polarized flux should originate interior to the broad-line region, and therefore also interior to the dust-emitting region. This can then be used to eliminate the dust emission. We present the results of near-infrared polarimetry for three such quasars (Ton202, 4C 37.43 and B2 1208+32). The data for Ton202 have the highest signal-to-noise ratio, and the near-infrared polarized flux in this case is measured to have quite a blue shape, F,,,+0.42±0.29, intriguingly consistent with the simple multitemperature blackbody, bare-disc prediction of ,+1/3. All these data, although still with quite low signal-to-noise ratio for the other two objects, demonstrate the unique potential of the technique with future better data. We also present similar data for other quasars and radio galaxies, and briefly discuss the nature of the polarization. [source] Dispersion of QT Intervals: A Measure of Dispersion of Repolarization or Simply a Projection Effect?PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2000DIEGO DI BERNARDO QT interval dispersion may provide little information about repolarization dispersion. Some clinical measurements demonstrate an association between high QT interval dispersion and high morbidity and mortality, but what is being measured is not clear. This study was designed to help resolve this dilemma. We compared the association between different clinical measures of QT interval dispersion and the ECG lead amplitudes derived from a heart vector model of repolarization with no repolarization dispersion whatsoever. We compared our clinical QT interval dispersion data obtained from 25 subjects without cardiac disease with similar data from published studies, and correlated these QT dispersion results with the distribution of lead amplitudes derived from the projection of the heart vector onto the body surface during repolarization. Published results were available for mean relative QT intervals and mean differences from the maximum QT interval. The leads were derived from Uijen and Dower lead vector data. Using the Uijen lead vector data, the correlation between measurements of dispersion and derived lead amplitudes ranged from 0.78 to 0.99 for limb leads, and using the Dower values ranged from 0.81 to 0.94 for the precordial leads. These results show a clear association between the measured QT interval dispersion and the variation in ECG lead amplitudes derived from a simple heart vector model of repolarization with no regional information. Therefore, measured QT dispersion is related mostly to a projection effect and is not a true measure of repolarization dispersion. Our existing interpretation of QT dispersion must be reexamined, and other measurements that provide true repolarization dispersion data investigated. [source] Sex Redefined: The Reclassification Of Oral-Genital ContactPERSPECTIVES ON SEXUAL AND REPRODUCTIVE HEALTH, Issue 2 2010Jason D. Hans CONTEXT: Although partially anecdotal, some evidence suggests that oral-genital contact is increasingly excluded from young people's notions of what behaviors constitute sex. Such a shift may have implications for STD prevention. METHODS: In 2007, a convenience sample of 477 university students participated in a survey that included the question "Would you say you ,had sex' with someone if the most intimate behavior you engaged in was" each of 11 behaviors. Chi-square tests and independent samples t tests were used to assess gender differences, and chi-square analyses were used to compare the data with similar data collected in 1991. Predictors of beliefs concerning the classification of oral-genital contact were assessed using logistic regression analysis. RESULTS: The majority of respondents indicated that penile-vaginal intercourse and penile-anal intercourse constitute sex (98% and 78%, respectively), but only about 20% believed the same was true of oral-genital contact. The proportion classifying oral-genital contact as sex in 2007 was about half that in 1991. This difference was consistent for both sexes and for both giving and receiving oral-genital stimulation. Responses did not vary by respondents' sexual experience or demographic characteristics. CONCLUSIONS: Sociocultural conceptualizations of oral-genital contact have shifted in a way that may leave people who engage in this activity unmindful of its potential health risks. Sex education programs, which generally focus on penile-vaginal contact, could help STD prevention efforts by explaining the risks associated with oral-genital stimulation and the measures that can be taken to minimize those risks. [source] Dynamics of water transport and storage in conifers studied with deuterium and heat tracing techniquesPLANT CELL & ENVIRONMENT, Issue 1 2006F. C. MEINZER ABSTRACT The volume and complexity of their vascular systems make the dynamics of long-distance water transport in large trees difficult to study. We used heat and deuterated water (D2O) as tracers to characterize whole-tree water transport and storage properties in individual trees belonging to the coniferous species Pseudotsuga menziesii (Mirb.) Franco and Tsuga heterophylla (Raf.) Sarg. The trees used in this study spanned a broad range of height (13.5,58 m) and diameter (0.14,1.43 m). Sap flow was monitored continuously with heat dissipation probes near the base of the trunk prior to, during and following injection of D2O. The transit time for D2O transport from the base of the trunk to the upper crown and the tracer residence time were determined by measuring hydrogen isotope ratios in water extracted from leaves sampled at regular intervals. Transit times for arrival of D2O in the upper crown ranged from 2.5 to 21 d and residence times ranged from 36 to 79 d. Estimates of maximum sap velocity derived from tracer transit times and path length ranged from 2.4 to 5.4 m d,1. Tracer residence time and half-life increased as tree diameter increased, independent of species. Species-independent scaling of tracer velocity with sapwood-specific conductivity was also observed. When data from this study were combined with similar data from an earlier study of four tropical angiosperm trees, species-independent scaling of tracer velocity and residence time with sapwood hydraulic capacitance was observed. Sapwood capacitance is an intrinsic tissue-level property that appears to govern whole-tree water transport in a similar manner among both tracheid- and vessel-bearing species. [source] The Polls: State-Level Presidential Approval: Results from the Job Approval ProjectPRESIDENTIAL STUDIES QUARTERLY, Issue 1 2003JEFFREY E. COHEN In this article, the author reports on the state job approval data set. Although the data set includes state-level job approval for governors and U. S. senators, it also contains similar data on the president. These data allow us to test propositions about public opinion toward the president at a level of aggregation lower than the national level but higher than the individual level. More than one thousand state-level presidential job approval readings exist in this data set. Such a large N allows us to test ideas and bypotheses that other limited N designs cannot accomplish. In the first part of this article, the author discusses the properties of these data. In the second part, he uses these data to test two competing theories of the impact of economic perceptions on presidential approval, the retrospection versus the prospection model, which provides one example of how these data can be put to use. [source] What to Do about Missing Values in Time-Series Cross-Section DataAMERICAN JOURNAL OF POLITICAL SCIENCE, Issue 2 2010James Honaker Applications of modern methods for analyzing data with missing values, based primarily on multiple imputation, have in the last half-decade become common in American politics and political behavior. Scholars in this subset of political science have thus increasingly avoided the biases and inefficiencies caused by ad hoc methods like listwise deletion and best guess imputation. However, researchers in much of comparative politics and international relations, and others with similar data, have been unable to do the same because the best available imputation methods work poorly with the time-series cross-section data structures common in these fields. We attempt to rectify this situation with three related developments. First, we build a multiple imputation model that allows smooth time trends, shifts across cross-sectional units, and correlations over time and space, resulting in far more accurate imputations. Second, we enable analysts to incorporate knowledge from area studies experts via priors on individual missing cell values, rather than on difficult-to-interpret model parameters. Third, because these tasks could not be accomplished within existing imputation algorithms, in that they cannot handle as many variables as needed even in the simpler cross-sectional data for which they were designed, we also develop a new algorithm that substantially expands the range of computationally feasible data types and sizes for which multiple imputation can be used. These developments also make it possible to implement the methods introduced here in freely available open source software that is considerably more reliable than existing algorithms. [source] INDIVIDUAL EQUITY RETURN DATA FROM THOMSON DATASTREAM: HANDLE WITH CARE!THE JOURNAL OF FINANCIAL RESEARCH, Issue 4 2006Ozgur S. Ince Abstract We compare individual U.S. equity return data from Thomson Datastream (TDS) with similar data from the Center for Research in Security Prices (CRSP) to evaluate TDS for use in studies involving large numbers of individual equities in markets outside the United States. We document important issues of coverage, classification, and data integrity and find that naive use of TDS data can have a large impact on economic inferences. We show that after careful screening of the TDS data, inferences drawn from TDS data are similar to those drawn from CRSP. We illustrate the importance of the screens we develop using U.S. TDS data by applying the screens to TDS data from four European equity markets. [source] Hand-Assisted Laparoscopic Living-Donor Nephrectomy as an Alternative to Traditional Laparoscopic Living-Donor NephrectomyAMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2002Joseph F. Buell The benefits of laparoscopic living-donor nephrectomy (LDN) are well described, while similar data on hand-assisted laparoscopic living-donor nephrectomy (HALDN) are lacking. We compare hand-assisted laparoscopic living-donor nephrectomy with open donor nephrectomy. One hundred consecutive hand-assisted laparoscopic living-donor nephrectomy (10/98,8/01) donor/recipient pairs were compared to 50 open donor nephrectomy pairs (8/97, 1/00). Mean donor weights were similar (179.6 ± 40.8 vs. 167.4 ± 30.3 lb; p =,NS), while donor age was greater among hand-assisted laparoscopic living-donor nephrectomy (38.2 ± 9.5 vs. 31.2 ± 7.8 year; p <,0.01). Right nephrectomies was fewer in hand-assisted laparoscopic living-donor nephrectomy [17/100 (17%) vs. 22/50 (44%); p <,0.05]. Operative time for hand-assisted laparoscopic living-donor nephrectomy (3.9 ± 0.7 vs. 2.9 ± 0.5 h; p <,0.01) was longer; however, return to diet (6.9 ± 2.8 vs. 25.6 ± 6.1 h; p <,0.01), narcotics requirement (17.9 ± 6.3 vs. 56.3 ± 6.4 h; p <,0.01) and length of stay (51.7 ± 22.2 vs. 129.6 ± 65.7 h; p <,0.01) were less than open donor nephrectomy. Costs were similar ($11 072 vs. 10 840). Graft function and 1-week Cr of 1.4 ± 0.9 vs. 1.6 ± 1.1 g/dL (p =,NS) were similar. With the introduction of HALDN, our laparoscopic living-donor nephrectomy program has increased by 20%. Thus, similar to traditional laparoscopic donor nephrectomy, hand-assisted laparoscopic living-donor nephrectomy provides advantages over open donor nephrectomy without increasing costs. [source] Immunohistochemical Characterization of Neurones in the Hypoglossal Nucleus of the PigANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2010W. Sienkiewicz Summary With 4 figures and 1 table In this study, the presence of several neurotransmitters and transmitter synthesizing enzymes was studied in hypoglossal nucleus (HN) of the juvenile (4 months old) female pigs (n = 3). Double-labeling immunofluorescence revealed neurones expressing cholinacetyltranspherase (ChAT), calcitonin gene-related peptide (CGRP), nitric oxide synthase (NOS), and somatostatin (SOM). Nerve fibers within HN were ChAT, CGRP, NOS, SOM, substance P (SP), Leu-5-enkephalin (Leu-5-Enk), ß-dopamine hydroxylase (DßH), neuropeptide Y (NPY) positive. Virtually all the perikarya contained ChAT, whereas CGRP was present in 47% of the neurones. Nerve cell bodies containing NOS or SOM were only occasionally observed. Immunoreactive nerve fibers were found in a close vicinity of the perikarya, often forming baskets around nerve cell bodies. The results obtained were compared with similar data obtained in other species. The presence of immunoreactive structures, origin of the nerve fibers, and functional significance of the findings are discussed. [source] Fluid flow in an impacting symmetrical tee junction II: two-phase air/water flowASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2009A. P. Doherty Abstract A universal flow regime map was presented for two-phase flow in a horizontal pipe. Data were given on two-phase gas/liquid flow in a symmetrical impacting tee junction. The flow regimes in the inlet arm of the tee were those expected for a straight pipe. This was not so for the outlet arm where, in most cases, flow regimes occurred earlier than expected. At low liquid outlet flows the stratified regime was reinforced into higher gas flows than expected. The liquid hold-up exhibited variations over the tee junction. The pressure drop in the inlet arm agreed with similar data for the straight pipe, but in the tee outlets was below that expected for the straight pipe. The tee junction pressure drop showed some parallels to the corresponding single-phase flow data but the le/d dimensionless values for the junction pressure drop showed a wide variation, in contrast to the single-phase junction data. A model was presented based on the Lockhard,Martinelli theory that enabled the tee pressure drop to be predicted. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Mayr's view of Darwin: was Darwin wrong about speciation?BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2008JAMES MALLET We commonly read or hear that Charles Darwin successfully convinced the world about evolution and natural selection, but did not answer the question posed by his most famous book, ,On the Origin of Species ,'. Since the 1940s, Ernst Mayr has been one of the people who argued for this point of view, claiming that Darwin was not able to answer the question of speciation because he failed to define species properly. Mayr undoubtedly had an important and largely positive influence on the study of evolution by stimulating much evolutionary work, and also by promoting a ,polytypic species concept' in which multiple, geographically separated forms may be considered as subspecies within a larger species entity. However, Mayr became seduced by the symmetry of a pair of interlocking ideas: (1) that coexistence of divergent populations was not possible without reproductive isolation and (2) reproductive isolation could not evolve in populations that coexist. These beliefs led Mayr in 1942 to reject evidence of the importance of intermediate stages in speciation, particularly introgression between hybridizing species, which demonstrates that complete reproductive isolation is not necessary, and the existence of ecological races, which shows that ecological divergence can be maintained below the level of species, in the face of gene flow. Mayr's train of thought led him to the view that Darwin misunderstood species, and that species were fundamentally different from subspecific varieties in nature. Julian Huxley, reviewing similar data at the same time, came to the opposite conclusion, and argued that these were the intermediate stages of speciation expected under Darwinism. Mayr's arguments were, however, more convincing than Huxley's, and this caused a delay in the acceptance of a more balanced view of speciation for many decades. It is only now, with new molecular evidence, that we are beginning to appreciate more fully the expected Darwinian intermediates between coexisting species. © The Author. Journal compilation © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95, 3,16. [source] Rare occurrence of CD30+ circulating cells in patients with cutaneous CD30+ anaplastic large cell lymphoma: a study of nine patientsBRITISH JOURNAL OF DERMATOLOGY, Issue 2 2003O. Dereure SummaryBackground The presence of a significant percentage of circulating atypical lymphocytes in peripheral blood has already been demonstrated in systemic CD30+ anaplastic large cell lymphoma (ALCL), which implies that a leukaemic component may be present in this subset of lymphomas. However, no similar data are available for the cutaneous counterpart of this particular lymphoproliferation. Objectives To assess the presence of atypical cells, CD30+ lymphocytes and of a dominant T-cell clone in peripheral blood in a series of patients with cutaneous CD30+ ALCL. Materials and methods Nine patients with either primary (four) or secondary (five) cutaneous CD4+ CD30+ ALCL were selected. The percentage of CD30+ CD4+ lymphocytes among peripheral blood mononuclear cells (PBMC) was determined by flow cytometry and the presence of a dominant circulating T-cell clone was assessed by polymerase chain reaction targeting the T-cell receptor , chain. A control group composed of apparently healthy individuals was similarly studied at the same time. Results The mean percentage of CD30+ cells in PBMC was slightly higher in patients than in controls (3·9% vs. 2·7%) but the difference was not statistically significant. Only two patients displayed more than 5% CD30+ cells, both of whom had a minor tumour burden. A dominant circulating T-cell clone was detected in only three cases, including these two latter patients. Conclusions The occurrence of a significant percentage of CD30+ CD4+ circulating cells is rare in active cutaneous CD30+ ALCL, either primary or secondary. This percentage is not related to the apparent skin tumour burden but a significant figure appeared to be correlated with the detection of a dominant T-cell clone in peripheral blood. Overall, these data show that, unlike mycosis fungoides, peripheral blood involvement seems infrequent in cutaneous CD30+ ALCL. The hypothesis that a high percentage of CD30+ circulating cells might be related to the presence of a cryptic systemic disease cannot be ruled out. [source] Sleep habits in Nigerian undergraduatesACTA NEUROLOGICA SCANDINAVICA, Issue 1 2010O. S. A. Oluwole Background,,, Quantity of night sleep is shorter than 8 h in several developed countries, but similar data is not available for most African countries. The objective of this study was to describe the quantity of night sleep, factors that are associated with non-restorative sleep, and sleep habits in a population of undergraduates in Nigeria. Methods,,, Questionnaires were used to collect information about bedtimes, waketimes, intra-night awakenings, non-restorative sleep, and afternoon naps over a period of 14 days. Results,,, Mean duration of night sleep was 6.2 h (median 6.0, range 4.5,9.3), while mean duration of daytime naps was 70 min (median 75, range 10,315). Duration of night sleep was associated with day of the week and gender, but not with BMI. Non-restorative sleep, which occurred 25% of total sleep times, was associated with night sleep ,5 h, hypnotic use, alarm to wake, heavy workload, and afternoon naps. Intra-night sleep awakening occurred 58.5% of total sleep times. Afternon naps were taken by 225 (82%) of subjects. Conclusion,,, Duration of night sleep in this African population is not longer than the duration in Western countries. Intra-night awakening and non-restorative sleep; however, occur more frequently, and afternoon nap is usually in excess of 1 h. [source] How clinicians in neonatal care see the introduction of neonatal nurse practitionersACTA PAEDIATRICA, Issue 2 2002ME Redshaw The aim of this study was to investigate the views of UK clinicians in neonatal care who were working with nurses trained as neonatal nurse practitioners (NNPs). A questionnaire survey was used with a total sample of senior clinicians in the 66 neonatal units with one or more qualified NNPs. The main outcome measures were type and frequency of response, and similar data from NNPs were used to make comparisons. Data were returned from 57 of the 66 clinicians contacted (86%). NNP clinical practice as perceived by them was largely similar to that recorded by NNPs, though the clinicians expected more NNP involvement in some procedures (inserting central venous lines, umbilical arterial catheters, chest drains and peripheral arterial cannulae) than was actually found. Perceptions of the NNP role were similar, though the clinicians were significantly less likely to see taking a case-load, conducting a ward round, accepting outside referrals and taking charge of emergency transfers as integral elements. Reflections on the utilization of NNPs in neonatal care and the impact on junior medical staff education referred to NNPs filling gaps, a reduction in the intensity of work, improvements in training and in the quality of care. Conclusion: The introduction of NNPs is seen positively from the perspective of clinicians working alongside them in neonatal care. The development of similar models of care in countries where the introduction of NNPs is being considered is likely to be similarly supported. [source] | ||||||||||||||||||||||