173 research outputs found
Diversity and somatic hypermutation of the Ig VHDJH, V kappa J kappa, and V lambda J lambda gene segments in lymphoma B cells : relevance to the origin of the neoplastic B cell clone
No full textBurkitt’s lymphoma (BL) is a malignancy of B cells characterized by chromosomal translocations involving the immunoglobulin (Ig) and c-MYC gene loci. To address the putative role of antigen in the clonal expansion of these neoplastic B cells, we analyzed the VHDJH and VLJL gene segments expressed by the established cell lines derived from six endemic BL and six sporadic BL. Eight BL cell lines used genes of the VH3 family, two of the VH4, and two of the VH1. Eight VL chains were κ (four members of the Vκ3, two of the Vκ1, and two of the Vκ2 subgroups) and four λ (three members of the Vλ1 and one of the Vλ3 subgroup). The VH gene utilization was stochastic (i.e., it reflected the relative representation of the different VH gene family members in the human haploid genome). In contrast, the VL gene utilization was skewed toward the overutilization of the Vκ3 and Vλ1 gene subgroups. When compared with those of the respective germline genes, the sequences of the expressed Ig V(D)J genes displayed nucleotide differences that resulted from somatic hypermutation. In three endemic and three sporadic BL cells, nucleotide changes yielding amino acid substitutions segregated within the complementarity determining region, indicating the application of a positive pressure for replacement mutations and suggesting that these neoplastic lymphocytes underwent a process of clonal selection driven by antigen, perhaps emerging from or transitioning through germinal centers
Statistical computation for extreme bridge traffic load effects
No full textEighth International Conference on Computational Structures Technology, Las Palmas de Gran Canaria, Spain, from 12 to 15 September 2006The maintenance of highway infrastructure constitutes a major expenditure in many
countries. This cost can be reduced significantly by minimizing the repair or
replacement of highway bridges. In the assessment of existing bridges, the strength
estimate tends to be more accurate than that of traffic loading, due to the more
variable nature of loading. Recent advances in the statistical analysis of highway
bridge traffic loading have resulted in more accurate forecasts of the actual loading
to which a bridge is subject. While these advances require extensive numerical
computation, they can significantly improve the accuracy of the calculation. This
paper outlines the recent advances and describes the associated computational
aspects in detailDeposited by bulk importkpw26/2/1
The Effect of Lane Changing on Long-Span Highway Bridge Traffic Loading
No full textBridge Maintenance, Safety, Management, Resilience & Sustainability, Sixth International IABMAS Conference, Stresa, Lake Maggiore, Italy, 8-12 July 2012Maximum loading on long-span bridges typically occurs in congested traffic conditions. As
traffic becomes congested car drivers may change lane, increasing the tendency for trucks to travel in platoons.
For long-span bridges this phenomenon may increase the regularity and severity of bridge repair programs,
with potential significant associated costs. This research investigates the effect of lane changing by car
drivers on bridge loading. A Monte Carlo simulation model in which individual car drivers probabilistically
decide, based on a lane-changing bias probability, whether or not to change lane has been developed. The
sensitivity of bridge loading to this factor is investigated for different bridge lengths and traffic compositions.
This research concludes that the lane-changing behavior of car drivers has an effect on bridge loading for
long-span bridges, and the magnitude of this effect is quite sensitive to the percentage of trucks in the traffic.Deposited by bulk impor
The design of an intergenerational lifelog browser to support sharing within family groups
No full textAspetti OCT della regione maculare dopo intervento per distacco di retina con macula off
No full textUncertainties reduction on modal parameters estimation in existing bridges using ambient and free vibration test
No full textMacular Edema and Silicone Oil Tamponade
No full textPurpose: To analyze the risk factors for inflammatory macular edema (ME) in a series of patients undergoing vitreoretinal surgery using Silicone Oil (SO) as a long-term tamponade.
Materials and methods: We examined 118 consecutive eyes of 115 patients, mean age 57.8 years (range 39-79), suffering from various types of severe retinal detachment. Surgical procedures were carried out on all patients, and SO 1000cs was injected into the eye at the end of surgery to permit stable retinal reattachment. ME was classified as initial, medium and severe. The characteristics of ME were compared with various preoperative, intra-surgical and postoperative parameters. Statistical analyses were carried out using the T test and the Pearson correlation coefficient.
Results: Twenty-six eyes were excluded. Twenty out of 92 eyes (22%) presented various types of ME. No significant correlation was found between ME and age or complication and duration of surgery. Significant correlation was found between ME and macular status before surgery and time length of intraocular permanence of SO.
Conclusion: SO should be removed as soon as possible, in particular when the preoperative macular status is compromised. Decreased molecular transport in the vitreous space, permanence of inflammatory substances between SO and the macula, mechanical floating of SO and dangerous light exposure might be involved in the pathogenesis of ME
Vitreous Substitutes: The Present and the Future.
No full textVitreoretinal surgery has advanced in numerous directions during recent years. The removal of the vitreous body is one of the main characteristics of this surgical procedure. Several molecules have been tested in the past to fill the vitreous cavity and to mimic its functions. We here review the currently available vitreous substitutes, focusing on their molecular properties and functions, together with their adverse effects. Afterwards we describe the characteristics of the ideal vitreous substitute. The challenges facing every ophthalmology researcher are to reach a long-term intraocular permanence of vitreous substitute with total inertness of the molecule injected and the control of inflammatory reactions. We report new polymers with gelification characteristics and smart hydrogels representing the future of vitreoretinal surgery. Finally, we describe the current studies on vitreous regeneration and cell cultures to create new intraocular gels with optimal biocompatibility and rheological properties
The structural reliability of bridges subject to time-dependent deterioration
No full textPaper presented at the 11th International Conference on Civil, Structural and Environmental Engineering Computing, Malta, 18-21 September 2007The reliability of the structural performance of any given structure is affected by both in-service loading and material deterioration due to environmental attack. They must be evaluated at any given time in order to compute lifetime probability of failure. This paper presents an innovative methodology to derive the structure lifetime load effect due to existing traffic using a statistical tool known as Predictive Likelihood. Loss of resistance due to corrosion originated by chloride ingression is also taken into account. Finally the lifetime probability of failure is evaluated via the application of a time-discretization strategyNot applicableConference detailshttp://www.civil-comp.com/conf/cc07.htmConference website at http://www.civil-comp.com/conf/cc07.htm. Record must include a full reference to the published paper and a DOI weblink to the final published version - http://dx.doi.org/10.4203/ccp.86.189. DG
06/07/10
au,ti, ke - AL 23/07/201
Assessment dynamic ratio for traffic loading on highway bridges
No full textThe determination of characteristic bridge load effect is a complex problem. Usually,
statistical extrapolation of simulated static load effects is used to derive a lifetime
characteristic static load effect. However, when a vehicle crosses a bridge, dynamic
interaction occurs which often causes a greater total load effect. This total load effect is
related to the static load effect through a dynamic amplification factor (DAF).
Specifications often recommend a conservative level for DAF, based on bridge length,
number of lanes, and type of load effect only. Therefore significant improvements in the
accuracy of this calculation are possible if a DAF, specific to the considered bridge, is
applied. In this paper, the authors develop a novel method that considers site-specific
bridge and traffic load conditions and allows for the reduced probability of both high
static loading and high dynamic interaction occurring simultaneously. This approach
utilises multivariate extreme value theory, in conjunction with static simulations and
finite element vehicle-bridge dynamic interaction models. It is found that the dynamic
allowance for the sample bridge and traffic considered, is significantly less than
recommended by bridge codes. This finding can have significant implications for the
assessment of existing bridge stock.Not applicableCan't locate article. 12M embargo from date of publication. On publication, add citation to set text in Rights field - AV 2/08/2011
Citation added - OR 10/1/201
- …
