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Direct Assessment (direct + assessment)
Selected AbstractsDirect Assessment of Electron Delocalization Using NMR Chemical Shifts,ANGEWANDTE CHEMIE, Issue 52 2009Stephan Festgenagelt: Mit dem neuen BLW-IGLO-Ansatz lassen sich die magnetischen Eigenschaften von Molekülen auswerten, in denen konjugative Wechselwirkungen ,unterdrückt" sind (rote Bindungen im Bild). Die NMR-spektroskopischen Parameter der lokalisierten Strukturen liefern ideale Referenzwerte für die Verschiebungen nichtaromatischer olefinischer Wasserstoffatome. [source] Direct assessment of structural resistance against pressurized fractureINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 5 2003G. Bolzon Abstract The determination of the load bearing capacity of hydraulic structures such as dams, reservoirs and retaining walls requires the consideration of mixed-mode fracture, possibly driven by the fluid pressure, in correspondence to artificial and natural joints (or cracks, in the latter case). A friction-cohesive softening interface model with coupled degradation of normal and tangential strength is introduced here to account for the essential features of the joint behaviour; its predictive capability is assessed through extensive calculations. Alternative numerical techniques resting on the discrete-crack approach are considered, focusing on simplified approaches for the direct appraisal of the structural resistance. Comparison is made with the results of evolutionary analyses, based on a priori piecewise linearization of the interface model and on ,exact integration'. Copyright © 2003 John Wiley & Sons, Ltd. [source] Children Enrolled in Public Pre-K: The Relation of Family Life, Neighborhood Quality, and Socioeconomic Resources to Early CompetenceAMERICAN JOURNAL OF ORTHOPSYCHIATRY, Issue 2 2006Oscar Barbarin PhD This article presents data on the family and social environments of 501 children enrolled in public sponsored pre-K in 5 states and tests the relation of these resources to child competence. Structured interviews and questionnaires provide information from parents about the family's social and economic status. Direct assessments and teacher reports provide data on children's literacy, numeracy, and behavioral problems. A majority of the children served in public pre-K lived in poverty and showed decrements in language but not in other domains. A socioeconomic resource factor consisting of parental education, household income, and material need predicted all domains of children's functioning. Children from households high in socioeconomic resources entered pre-K with more well developed language and math skill but fewer behavioral problems than their disadvantaged peers. Neighborhood quality status was related to language competence and mother's marital status to math competence. Neighborhood quality and income level may have their impact on child competence through their relation to dyadic quality and the health and the psychological well-being of the parents. [source] Dynamic centrifuge tests of concrete damEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 12 2005Y. Uchita Abstract Dynamic tests of a concrete gravity dam are, for the first time, performed inside a centrifuge. Details of the experimental procedure, data interpretation, and results are presented. It is shown (in conjunction with a parallel paper) that these tests cannot only provide a direct assessment of certain aspects of dam safety, but more importantly provide a data base for possible non-linear finite element code validation. Copyright © 2005 John Wiley & Sons, Ltd. [source] PCR DGGE and RT-PCR DGGE show diversity and short-term temporal stability in the Clostridium coccoides,Eubacterium rectale group in the human intestinal microbiotaFEMS MICROBIOLOGY ECOLOGY, Issue 3 2006Johanna Maukonen Abstract As the Clostridium coccoides,Eubacterium rectale (Erec; clostridial phylogenetic cluster XIVa) group is one of the major groups of the human intestinal microbiota, DNA- and RNA-based population analysis techniques (denaturing gradient gel electrophoresis; DGGE) were developed and applied to assess the diversity and temporal stability (6 months,2 years) of this faecal clostridial microbiota in 12 healthy adults. The stability of the Erec group was compared with the stability of the predominant bacterial microbiota, which was also assessed with PCR-DGGE. In addition, the Erec group was quantified with a hybridization-based method. According to our results, the Erec group was diverse in each subject, but interindividual uniqueness was not as clear as that of the predominant bacteria. The Erec group was found to be temporally as stable as the predominant bacteria. Over 200 clones obtained from two samples proved the developed method to be specific. However, the amount of bacteria belonging to the Erec group was not related to the diversity of that same bacterial group. In conclusion, the newly developed DGGE method proved to be a valuable and specific tool for the direct assessment of the stability of the Erec group, demonstrating diversity in addition to short-term stability in most of the subjects studied. [source] A large carbon pool and small sink in boreal Holocene lake sedimentsGLOBAL CHANGE BIOLOGY, Issue 10 2004Pirkko Kortelainen Abstract Model-based estimates suggest that lake sediments may be a significant, long-term sink for organic carbon (C) at regional to global scales. These models have used various approaches to predict sediment storage at broad scales from very limited data sets. Here, we report a large-scale direct assessment of the standing stock and sedimentation rate of C for a representative set of lakes in Finland. The 122 lakes were selected from the statistically selected Nordic Lake Survey database, they cover the entire country and the water quality represents the average lake water quality in Finland. Unlike all prior estimates, these data use sediment cores that comprise the entire sediment record. The data show that within Finland, aquatic ecosystems contain the second largest areal C stocks (19 kg C m,2) after peatlands (72 kg C m,2), and exceed by significant amounts stocks in the forest soil (uppermost 75cm; 7.2 kg C m,2) and woody biomass (3.4 kg C m,2). Kauppi et al. (1997). The Finnish estimate extrapolated over the boreal region gives a total C pool in lakes 19,27 Pg C, significantly lower than the previous model-based estimates. [source] The temperament of pre-term, low birth weight infants and its potential biological substratesRESEARCH IN NURSING & HEALTH, Issue 6 2004Sandra J. Weiss Abstract Temperament profiles of pre-term, low birth weight (LBW) infants were assessed at 6 months of age using standardized norms from the Revised Infant Temperament Questionnaire (RITQ). The contributions of perinatal risk, ethnicity, and gender to various temperament dimensions were examined. The sample included 152 infants with a mean birth weight of 1687 g and a mean gestational age of 31 weeks. Eighty percent of the infants were classified as having temperaments that were difficult to manage. Irregularity of the infants' biorhythms, slowness in their ability to adapt to changes, and distractibility were the most problematic. Birth weight, gestational age, and gender were not associated with temperament. Perinatal morbidity was related to the temperament dimension of infant persistence, with implications for the infant's attention span and task performance. Euro American infants were rated as more persistent and less intense in emotional expression than were infants of other ethnic groups. Results suggest the need for a more direct assessment of the effects of neurobiological processes on development of temperament phenotypes and for measurement of temperament that is socioculturally appropriate. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:392,402, 2004 [source] Role of Nitric Oxide in the Development of Distant Metastasis From Squamous Cell Carcinoma,THE LARYNGOSCOPE, Issue 2 2007Richard L. Scher MD Abstract Background: Metastasis, the dissemination of malignant cells to distant sites, remains one of the most significant factors responsible for death from cancer. Recent studies have shown some improvement in the rate of distant metastasis (DM) with the addition of chemotherapy to surgery and radiation for treatment of head and neck squamous cell carcinoma (HNSCC). However, diagnosis and treatment at an early stage ultimately leads to a better prognosis. The prediction of which patients will develop metastasis and the selection of treatment most effective at preventing and treating metastasis remains dependent on an incomplete understanding of prognostic factors and the biological and molecular basis for metastatic development. This study was undertaken using an in vivo model to investigate the possible role of nitric oxide (NO) in the development of metastasis from HNSCC. The findings will result in better understanding of the metastatic process for HNSCC, with the potential to develop and implement therapies that could prevent and treat metastasis in patients. Objectives/Hypothesis: 1) To analyze whether in vivo videomicroscopy (IVVM) is useful for the study of DM from squamous cell carcinoma of the head and neck; 2) with use of IVVM, investigate the effect of the biological mediators NO and interleukin (IL)-1 on the adhesion of circulating human HNSCC cells in the hepatic microcirculation. Study Design: Prospective study using an animal model. Methods: Phase 1: athymic nude rats and mice were used for IVVM experiments. The cremaster muscle and liver, used as arterial and venous flow models, were tested to determine whether IVVM was useful for the study of human HNSCC interactions with the microcirculation. A human squamous cell carcinoma cell line (FaDu) labeled with the intracytoplasmic fluorescent marker BCECF-am. was used for all experiments. Videomicroscopic images of FaDu cells in the microcirculation were analyzed for cell adhesion, morphology, deformation, circulation, location of adhesion within the microcirculation, and alteration of microvascular circulation. Phase 2: the effect of IL-1, NO, and NO inhibitors on HNSCC cell adhesion in the hepatic microcirculation of nude mice was analyzed by IVVM. This was followed by histologic determination of the ratio of FaDu cells present for liver area analyzed. Nude mice were treated with 1) IL-1; 2) L-arginine (an NO substrate); or 3) L-N-monomethyl-L-arginine (an NO synthase inhibitor) alone or in combination. These data were analyzed statistically to determine the effect on cell adhesion in the liver. Results: IVVM provided a method for the study of circulating HNSCC with the microcirculation in both the cremaster and liver models. FaDu cells were arrested at the inflow side of the circulation, with maintenance of cell integrity. L-arginine and IL-1 both increased FaDu cell arrest in the liver above baseline (P = .00008 and P = .03), and the combination of these agents potentiated the effect (P = .000009). Conclusions: IVVM allows direct assessment of circulating HNSCC with the microcirculation and is a powerful model for the study of DM. NO and IL-1 play a role in increasing the arrest of HNSCC in the liver and are important in the generation of DM in patients with HNSCC. [source] Identification of immunodominant CD4+ T cell epitopes in patients with Yersinia -induced reactive arthritis by cytometric cytokine secretion assayARTHRITIS & RHEUMATISM, Issue 11 2006Andreas Thiel Objective In reactive arthritis (ReA), a bacteria-specific T cell response to the triggering microbe is detected in synovial fluid. So far, direct characterization of bacteria-specific T cells and identification of the immunodominant fine specificities remain difficult due to the lack of appropriate techniques. The aim of the present study was to directly determine the fine specificity of CD4+ T cells specific to ReA-associated bacteria-derived protein. Methods In 2 patients with Yersinia -induced ReA, live Yersinia Hsp60,specific CD4+ T cells were directly isolated from synovial fluid after stimulation with Yersinia -derived protein Hsp60 using a cytometric cytokine secretion assay. Generated short-term T cell lines were then tested in vitro for their peptide epitope specificity. Also, direct cross-reactivity of one line with Chlamydia - and human-derived Hsp60 was assessed. Results Generated short-term CD4+ T cell lines were highly antigen-specific and revealed single immunodominant peptide epitopes that were confirmed by direct testing with single peptides in both peripheral blood and synovial fluid cells. Yersinia Hsp60,specific T cells of one patient cross-reacted directly with human Hsp60. Conclusion Our results demonstrate the feasibility of direct assessment of live, potentially pathogenic, antigen-specific interferon-,+ CD4+ T cells taken from inflammatory lesions of patients with rheumatic diseases such as ReA. This might have implications not only regarding pathogenesis, but also in the design of new immunotherapies. [source] A novel in vitro co-culture system for the study of maternal decidual endothelial cell,trophoblast interactions in human pregnancyBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 6 2001Eileen D.M. Gallery Investigation of the pathophysiology of pre-eclampsia (characterised by insufficient invasion of the intrauterine vasculature by cytotrophoblasts) has been hampered by the absence of a suitable animal model, and ethical constraints in clinical studies. We have developed a novel in vitro human cell co-culture system allowing direct assessment of cytotrophoblast invasion of a decidual endothelial cell monolayer from the abluminal side, as occurs in vivo. This model will facilitate detection, at the cellular level, of abnormal endothelial cell,trophoblast functional interactions in pre-eclampsia and other pregnancy disorders with abnormal placentation. [source] Pulmonary venous wedge pressure provides a safe and accurate estimate of pulmonary arterial pressure in children with shunt-dependent pulmonary blood flow,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 5 2009Kevin D. Hill MD Abstract Objectives: To compare two methods of pulmonary arterial pressure measurement in children with shunt-dependent pulmonary blood flow. Background: In children with shunt-dependent pulmonary blood flow, direct assessment of pulmonary arterial pressure requires passage of a catheter across the shunt. This can be technically difficult and dangerous. Use of the pulmonary venous wedge pressure offers an alternative but has not been validated in this patient population. Methods: We prospectively studied 18 children with shunt-dependent pulmonary blood flow. Pulmonary venous wedge pressure and directly measured pulmonary arterial pressures were independently assessed by two blinded cardiologists. Results: Directly measured mean pulmonary arterial pressure and pulmonary venous wedge pressure are closely correlated (R2 = 0.80, P < 0.01). Agreement between the two measures is improved at lower mean pressures with greater differences at higher pressures. For 20 of 24 ipsilateral measurements, pulmonary venous wedge pressure was , directly measured pulmonary arterial pressure. Pulmonary venous wedge pressure never underestimated pulmonary arterial pressure by more than 3 mm Hg. Conclusions: Pulmonary venous wedge pressure provides a safe and accurate means of estimating pulmonary arterial pressure in children with shunt-dependent pulmonary blood flow. The slightly lower pressures seen on direct measurement compared with the reverse pulmonary vein may reflect impairment of flow across the shunt by the catheter. © 2009 Wiley-Liss, Inc. [source] Wrinkles in the rare biosphere: pyrosequencing errors can lead to artificial inflation of diversity estimatesENVIRONMENTAL MICROBIOLOGY, Issue 1 2010Victor Kunin Summary Massively parallel pyrosequencing of the small subunit (16S) ribosomal RNA gene has revealed that the extent of rare microbial populations in several environments, the ,rare biosphere', is orders of magnitude higher than previously thought. One important caveat with this method is that sequencing error could artificially inflate diversity estimates. Although the per-base error of 16S rDNA amplicon pyrosequencing has been shown to be as good as or lower than Sanger sequencing, no direct assessments of pyrosequencing errors on diversity estimates have been reported. Using only Escherichia coli MG1655 as a reference template, we find that 16S rDNA diversity is grossly overestimated unless relatively stringent read quality filtering and low clustering thresholds are applied. In particular, the common practice of removing reads with unresolved bases and anomalous read lengths is insufficient to ensure accurate estimates of microbial diversity. Furthermore, common and reproducible homopolymer length errors can result in relatively abundant spurious phylotypes further confounding data interpretation. We suggest that stringent quality-based trimming of 16S pyrotags and clustering thresholds no greater than 97% identity should be used to avoid overestimates of the rare biosphere. [source] | ||||||||||||||||