CDNs Content Outsourcing via Generalized Communities Katsaros, D.; Pallis, G.; Stamos, K. ...
IEEE transactions on knowledge and data engineering,
2009-Jan., 2009, 2009-01-00, 20090101, Letnik:
21, Številka:
1
Journal Article
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Content distribution networks (CDNs) balance costs and quality in services related to content delivery. Devising an efficient content outsourcing policy is crucial since, based on such policies, CDN ...providers can provide client-tailored content, improve performance, and result in significant economical gains. Earlier content outsourcing approaches may often prove ineffective since they drive prefetching decisions by assuming knowledge of content popularity statistics, which are not always available and are extremely volatile. This work addresses this issue, by proposing a novel self-adaptive technique under a CDN framework on which outsourced content is identified with no a-priori knowledge of (earlier) request statistics. This is employed by using a structure-based approach identifying coherent clusters of "correlated" Web server content objects, the so-called Web page communities. These communities are the core outsourcing unit and in this paper a detailed simulation experimentation has shown that the proposed technique is robust and effective in reducing user-perceived latency as compared with competing approaches, i.e., two communities-based approaches, Web caching, and non-CDN.
Transforming growth factor-
β
(TGF-
β
)-mediated signals play complicated roles in the development and progression of breast tumour. The purposes of this study were to analyse the genotype of
TGF-β1
...at T29C and TGF-
β
1 phenotype in breast tumours, and to evaluate their associations with IGFs and clinical characteristics of breast cancer. Fresh tumour samples were collected from 348 breast cancer patients. TGF-
β
1 genotype and phenotype were analysed with TaqMan® and ELISA, respectively. Members of the IGF family in tumour tissue were measured with ELISA. Cox proportional hazards regression analysis was performed to assess the association of TGF-
β
1 and disease outcomes. Patients with the T/T (29%) genotype at T29C had the highest TGF-
β
1, 707.9 pg mg
−1
, followed by the T/C (49%), 657.8 pg mg
−1
, and C/C (22%) genotypes, 640.8 pg mg
−1
, (
P
=0.210, T/T
vs
C/C and C/T). TGF-
β
1 concentrations were positively correlated with levels of oestrogen receptor, IGF-I, IGF-II and IGFBP-3. Survival analysis showed TGF-
β
1 associated with disease progression, but the association differed by disease stage. For early-stage disease, patients with the T/T genotype or high TGF-
β
1 had shorter overall survival compared to those without T/T or with low TGF-
β
1; the hazard ratios (HR) were 3.54 (95% CI: 1.21–10.40) for genotype and 2.54 (95% CI: 1.10–5.89) for phenotype after adjusting for age, grade, histotype and receptor status. For late-stage disease, however, the association was different. The T/T genotype was associated with lower risk of disease recurrence (HR=0.13, 95% CI: 0.02–1.00), whereas no association was found between TGF-
β
1 phenotype and survival outcomes. The study suggests a complex role of TGF-
β
1 in breast cancer progression, which supports the finding of
in vitro
studies that TGF-
β
1 has conflicting effects on tumour growth and metastasis.
A hybrid of node degree and k-shell index is more effective at identifying influential spreaders and has less computational overhead than either of these traditional measures.
The first joint European Society for Medical Oncology (ESMO), European SocieTy for Radiotherapy & Oncology (ESTRO) and European Society of Gynaecological Oncology (ESGO) consensus conference on ...endometrial cancer was held on 11–13 December 2014 in Milan, Italy, and comprised a multidisciplinary panel of 40 leading experts in the management of endometrial cancer. Before the conference, the expert panel prepared three clinically relevant questions about endometrial cancer relating to the following four areas: prevention and screening, surgery, adjuvant treatment and advanced and recurrent disease. All relevant scientific literature, as identified by the experts, was reviewed in advance. During the consensus conference, the panel developed recommendations for each specific question and a consensus was reached. Results of this consensus conference, together with a summary of evidence supporting each recommendation, are detailed in this article. All participants have approved this final article.
Background
The Accreditation Council for Graduate Medical Education (ACGME) requires an experience in hepatopancreatobiliary (HPB) surgery as part of general surgery residency training. The ...composition of this experience, however, is unclear. We set out to evaluate current trends in the HPB experience of US general surgery residents.
Methods
National ACGME operative case logs from 1990 to 2016 were examined with a focus on the HPB operative domains. Time-trend analysis was performed using ANOVA and linear regression analysis.
Results
Median biliary, liver, and pancreatic operative volumes increased by 30%, 33%, and 27% over the 27-year study period (all
p
< 0.05). Both core and advanced HPB cases increased, but the rate of increase for core was four times greater than that of advanced. However, when cholecystectomy was excluded, this trend reversed such that HPB core operations decreased by 11 cases over the study period. Further analysis demonstrated that laparoscopic cholecystectomy comprised 90% of all biliary cases and 77% of all HPB cases for graduates in 2016. Finally, operative volume variability—the difference in case numbers between high and low volume residents—increased by 16%, 21%, and 73% for the biliary, liver, and pancreatic domains, respectively (all
p
< 0.05).
Conclusions
Despite increases in overall HPB operative volume, the HPB experience is changing for today’s surgical trainees. Moreover, the HPB experience is comprised largely of a single operation—the cholecystectomy. Awareness of these trends is important for surgical educators to facilitate adequate exposure to HPB surgery among general surgery residents.
Ad hoc networks designed for deployment in modern battlefields need to take care of traditional requirements related to their backbone’s size, their energy efficiency, their scalability in terms of ...network size, but also of their nature which allows for combining networks of different units that act altogether towards a common operational goal. This article develops a distributed algorithm for developing an energy-aware backbone for military ad hoc network composed of multiple layers, namely E2CLB. The algorithm is based on the concepts of connected dominating sets and also on node centrality concepts, and results as a heuristic solution to the problem of calculating a maximum energy, minimum connected dominating set for a multilayer network by including into the dominating set those nodes which are highly connected to their and other layers (i.e., they have large centrality value) and moreover they are energy-rich. The computation and communication complexities of the algorithm are analyzed, and a thorough simulation-based evaluation of it against six competitors is presented. The results show that E2CLB is either the best performing algorithm across the examined performance measures or it is able to trade a very small increase in the size of the backbone’s network in order to reap improved performance in the energy realm.
Kallikrein gene 5 (KLK5, also known as KLK-L2), located on chromosome 19q13.4, is one of the newly identified members of the kallikrein gene family, which is a subgroup of the serine protease enzyme ...family. In normal human tissues, KLK5 is highly expressed in skin, mammary gland and testis. Preliminary RT-PCR analysis has indicated that KLK5 is expressed in a subset of ovarian tumours. We have thus hypothesized that KLK5 may be a new prognostic indicator in ovarian cancer. We have examined the mRNA expression of KLK5 in 142 malignant ovarian tissues. Tumours were pulverized, total RNA was extracted, and cDNA was prepared by reverse transcription. KLK5 was amplified by PCR using gene specific primers, and the identity of the PCR product was verified by sequencing. Ovarian tissues were then classified as KLK5 positive or negative, based on ethidium bromide staining of the PCR product on agarose gels. KLK5 was found to be highly expressed in 58/142 (41%) of ovarian cancer samples while its level of expression was very low in normal ovarian tissues. We found a strong positive relation between KLK5 expression and tumour grade (P = 0.006) and disease stage (P = 0.027). Univariate survival analysis revealed that patients with ovarian tumours positive for KLK5 expression had an increased risk for relapse and death (P = 0.018 and 0.022, respectively). In multivariate analysis, KLK5 expression showed independent prognostic value only in the subset of tumours with lower grade disease (grades I and II). We conclude that KLK5 expression is associated with more aggressive forms of epithelial ovarian carcinoma and has indepdent prognostic value in low grade tumours.
Background Pelvic lymph nodes are the most common site of extrauterine tumor spread in early-stage endometrial cancer, but the clinical impact of lymphadenectomy has not been addressed in randomized ...studies. We conducted a randomized clinical trial to determine whether the addition of pelvic systematic lymphadenectomy to standard hysterectomy with bilateral salpingo-oophorectomy improves overall and disease-free survival. Methods From October 1, 1996, through March 31, 2006, 514 eligible patients with preoperative International Federation of Gynecology and Obstetrics stage I endometrial carcinoma were randomly assigned to undergo pelvic systematic lymphadenectomy (n = 264) or no lymphadenectomy (n = 250). Patients’ clinical data, pathological tumor characteristics, and operative and early postoperative data were recorded at discharge from hospital. Late postoperative complications, adjuvant therapy, and follow-up data were collected 6 months after surgery. Survival was analyzed by use of the log-rank test and a Cox multivariable regression analysis. All statistical tests were two-sided. Results The median number of lymph nodes removed was 30 (interquartile range = 22–42) in the pelvic systematic lymphadenectomy arm and 0 (interquartile range = 0–0) in the no-lymphadenectomy arm (P < .001). Both early and late postoperative complications occurred statistically significantly more frequently in patients who had received pelvic systematic lymphadenectomy (81 patients in the lymphadenectomy arm and 34 patients in the no-lymphadenectomy arm, P = .001). Pelvic systematic lymphadenectomy improved surgical staging as statistically significantly more patients with lymph node metastases were found in the lymphadenectomy arm than in the no-lymphadenectomy arm (13.3% vs 3.2%, difference = 10.1%, 95% confidence interval CI = 5.3% to 14.9%, P < .001). At a median follow-up of 49 months, 78 events (ie, recurrence or death) had been observed and 53 patients had died. The unadjusted risks for first event and death were similar between the two arms (hazard ratio HR for first event = 1.10, 95% CI = 0.70 to 1.71, P = .68, and HR for death = 1.20, 95% CI = 0.70 to 2.07, P = .50). The 5-year disease-free and overall survival rates in an intention-to-treat analysis were similar between arms (81.0% and 85.9% in the lymphadenectomy arm and 81.7% and 90.0% in the no-lymphadenectomy arm, respectively). Conclusion Although systematic pelvic lymphadenectomy statistically significantly improved surgical staging, it did not improve disease-free or overall survival.
This article presents a survey of ad hoc networking protocols that have used concepts such as centrality metrics and community formation from the area of social network analysis, which is seen as a ...network measurement task that deals with structural properties of the network graph. We recognize the synergy among social network analysis and ad hoc networking as a fertile research area that can provide significant advances for the design of network protocols, especially in environments where the communication is opportunistic in nature and therefore cannot be easily or efficiently described as an optimization problem, and other systematic approaches like cross-layer optimization are more difficult to apply.
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