Historical Features (historical + feature)

Distribution by Scientific Domains


Selected Abstracts


From gene amplification to V(D)J recombination and back: A personal account of my early years in B cell biology

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue S1 2007
Frederick
Abstract I have been invited to write a short historical feature in the context of being a co-recipient with Klaus Rajewsky and Fritz Melchers of the 2007,Novartis Prize in Basic Immunology that was given in the general area of the molecular biology of B cells. In this feature, I cover the main points of the short talk that I presented at the Award Ceremony at the International Immunology Congress in Rio de Janeiro, Brazil. This talk focused primarily on the work and people involved early on in generating the models and ideas that have formed the basis for my ongoing efforts in the areas of V(D)J recombination and B cell development. [source]


Parents and Practitioners Are Poor Judges of Young Children's Pain Severity

ACADEMIC EMERGENCY MEDICINE, Issue 6 2002
Adam J. Singer MD
Objective: Visual analog pain scales are reliable measures in older children and adults; however, pain studies that include young children often rely on parental or practitioner assessments for measuring pain severity. The authors correlated patient, parental, and practitioner pain assessments for young children with acute pain. Methods: This was a prospective, descriptive study of a convenience sample of 63 emergency department patients aged 4-7 years, with acute pain resulting from acute illness or painful invasive procedures. A trained research assistant administered a structured pain survey containing demographic and historical features to all parents/guardians. Children assessed their pain severity using a validated ordinal scale that uses five different faces with varying degrees of frowning (severe pain) or smiling (no pain). Each face was converted to a numeric value from 0 (no pain) to 4 (severe pain). Parents and practitioners independently assessed their child's pain using a validated 100-mm visual analog scale (VAS) marked "most pain" at the high end. Pairwise correlations between child, parent, and practitioner pain assessments were performed using Spearman's or Pearson's test as appropriate. The association between categorical data was assessed using ,2 tests. Results: Sixty-three children ranging in age from 4 to 7 were included. Mean age (±SD) was 5.7 (±1.1); 42% were female. Fifty-seven successfully completed the face scale. The distribution of the children's scores was 0-17%, 1-9%, 2-30%, 3-14%, and 4-30%. Mean parental and practitioner scores (±SD) on the VAS were 61 (±26) mm and 37 (±26) mm, respectively (maximal = 100 mm). Correlation between child and parent scores was 0.47 (p < 0.001). Correlation between child and practitioner scores was 0.08 (p = 0.54). Correlation between parent and practitioner scores was 0.04 (p = 0.001). Conclusions: There is poor agreement between pain ratings by children, parents, and practitioners. It is unclear which assessment best approximates the true degree of pain the child is experiencing. [source]


Ability of Patients to Accurately Recall the Severity of Acute Painful Events

ACADEMIC EMERGENCY MEDICINE, Issue 3 2001
Adam J. Singer MD
Abstract. Objective: Pain studies require prospective patient enrollment to ensure accurate pain assessment. The authors correlated pain assessments of an acute painful episode over a one-week period and determined the accuracy of patient pain severity recall over time. Methods: This was a prospective, descriptive, longitudinal study. Participants were a convenience sample of 50 emergency department patients with acute pain resulting from injuries or painful invasive procedures. A trained research assistant administered a structured pain survey containing demographic and historical features to all patients. Patients sequentially assessed their pain severity using a vertical 100-mm visual analog scale marked "most pain" at the top, a verbal numeric rating scale ranging from 0 to 100 from none to worst (NRS100), and a verbal numeric rating scale ranging from 0 to 10 from none to worst (NRS10). Patients were contacted by phone and asked to reassess their initial pain severity one and seven days later using the two verbal numeric rating scales. Analysis of pain assessments using the various scales at the three time intervals was performed with Pearson's and Spearman's coefficients and repeated-measures analysis of variance (ANOVA). Results: There were 50 patients with a mean age of 41 years. Correlation between initial pain assessments on the three scales ranged from 0.83 to 0.92. Correlations between the initial and 24-hour assessments were NRS100-0.98 and NRS10-0.98. Correlations between the initial and one-week assessments were NRS100-0.96 and NRS10-0.97. Repeated-measures ANOVA showed no significant change in pain assessments over time for both verbal numeric scales. Conclusions: Pain severity assessments of acute painful events one and seven days later were similar and highly correlated with initial assessments using both verbal numeric scales. Patients accurately recall the severity of an acute painful episode for at least one week after its occurrence, which may allow retrospective pain assessments. [source]


PERSPECTIVE: GENE DIVERGENCE, POPULATION DIVERGENCE, AND THE VARIANCE IN COALESCENCE TIME IN PHYLOGEOGRAPHIC STUDIES

EVOLUTION, Issue 6 2000
ScottV.
Abstract Molecular methods as applied to the biogeography of single species (phylogeography) or multiple codistributed species (comparative phylogeography) have been productively and extensively used to elucidate common historical features in the diversification of the Earth's biota. However, only recently have methods for estimating population divergence times or their confidence limits while taking into account the critical effects of genetic polymorphism in ancestral species become available, and earlier methods for doing so are underutilized. We review models that address the crucial distinction between the gene divergence, the parameter that is typically recovered in molecular phylogeographic studies, and the population divergence, which is in most cases the parameter of interest and will almost always postdate the gene divergence. Assuming that population sizes of ancestral species are distributed similarly to those of extant species, we show that phylogeographic studies in vertebrates suggest that divergence of alleles in ancestral species can comprise from less than 10% to over 50% of the total divergence between sister species, suggesting that the problem of ancestral polymorphism in dating population divergence can be substantial. The variance in the number of substitutions (among loci for a given species or among species for a given gene) resulting from the stochastic nature of DNA change is generally smaller than the variance due to substitutions along allelic lines whose coalescence times vary due to genetic drift in the ancestral population. Whereas the former variance can be reduced by further DNA sequencing at a single locus, the latter cannot. Contrary to phylogeographic intuition, dating population divergence times when allelic lines have achieved reciprocal monophyly is in some ways more challenging than when allelic lines have not achieved monophyly, because in the former case critical data on ancestral population size provided by residual ancestral polymorphism is lost. In the former case differences in coalescence time between species pairs can in principle be explained entirely by differences in ancestral population size without resorting to explanations involving differences in divergence time. Furthermore, the confidence limits on population divergence times are severely underestimated when those for number of substitutions per site in the DNA sequences examined are used as a proxy. This uncertainty highlights the importance of multilocus data in estimating population divergence times; multilocus data can in principle distinguish differences in coalescence time (T) resulting from differences in population divergence time and differences in T due to differences in ancestral population sizes and will reduce the confidence limits on the estimates. We analyze the contribution of ancestral population size (,) to T and the effect of uncertainty in , on estimates of population divergence (,) for single loci under reciprocal monophyly using a simple Bayesian extension of Takahata and Satta's and Yang's recent coalescent methods. The confidence limits on , decrease when the range over which ancestral population size , is assumed to be distributed decreases and when increases; they generally exclude zero when /(4Ne) > 1. We also apply a maximum-likelihood method to several single and multilocus data sets. With multilocus data, the criterion for excluding = 0 is roughly that l/(4Ne)> 1, where l is the number of loci. Our analyses corroborate recent suggestions that increasing the number of loci is critical to decreasing the uncertainty in estimates of population divergence time. [source]


Magnetic and seismic investigations of historic features in the Suchon area, Kongju, Korea

ARCHAEOLOGICAL PROSPECTION, Issue 3 2008
Jinyong Oh
Abstract Integrated geophysical surveys including magnetometer, gradiometer and seismic refraction were performed in the Suchon area, Kongju, Korea, which revealed three locations of buried architectural features. The magnetometer survey identified four main anomalies that were further tested using the gradiometer. Application of the second vertical derivative and the high-pass filtering techniques to the magnetometer data isolated the deeper sources and enhanced the near-surface features. Depth was estimated using magnetometer data and seismic refraction analysis. The study identified three promising areas that are strongly recommended for excavation, which can be seen in the northeastern and southwestern parts of the study area. They are strongly linked to shallow historical features, i.e. brick tomb structure, pottery collection and stone-mound tomb, that were dominant during Baekche rule in Suchon area and therefore are believed to be from the Baekche period. Copyright © 2008 John Wiley & Sons, Ltd. [source]