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Chemo-radiotherapy is the standard treatment for locally advanced head-neck cancer (LA-HNC). However, about 30% of tumors do not respond or even progress shortly after the completion of radiotherapy. We investigated whether anti-PD1 immunotherapy can eradicate the irradiated tumor and reverse the ominous prognosis of these patients. We retrospectively analyzed a small series of 9 patients with LA-HNC who did not respond (6/9) or showed local disease progression (3/9) during chemo-radiotherapy and were treated with nivolumab anti-PD1 immunotherapy. Immunotherapy started 1.5 months after the end of radiotherapy. Out of 9 patients, 3 (33.3%) had a complete response and 3 (33.3%) partial response at 6 months after the onset of immunotherapy. Two patients are alive with no evidence of disease at 36 months. One more patient with partial response and without disease progression survived 16 months after therapy when he died from intercurrent disease. Immunotherapy showed an excellent tolerance profile. One patient developed an extensive skin rash on the 16th cycle. Anti-PD-1 immunotherapy after radiotherapy can lead to clearance of the remnant tumor and ameliorate the prognosis of patients. Randomized trials are necessary to establish post-irradiation immunotherapy as a standard of care in this ill-fated subgroup of HNC patients. [ABSTRACT FROM AUTHOR]

Background: Dose-dense sequential chemotherapy with anthracyclines and taxanes achieved an 18% reduction of recurrence risk in early breast cancer (BC). The optimal chemotherapy schedule and interval between cycles remain under investigation.Methods: Overall, 990 patients were randomised to receive either three cycles of epirubicin (E, 110 mg/m2) every 2 weeks followed by 3 cycles of paclitaxel (T, 200 mg/m2) every 2 weeks followed by three cycles of intensified CMF (Control Arm A, E-T-CMF) that was previously used in BC or three cycles of epirubicin followed by three cycles of CMF followed by nine consecutive weekly cycles of docetaxel (wD) 35 mg/m2 (Arm B, E-CMF-wD) or nine consecutive weekly cycles of paclitaxel (wT) 80 mg/m2 (Arm C, E-CMF-wT). Trastuzumab was administered for HER2-positive disease.Results: At a median follow-up of 13.3 years, 330 disease-free survival (DFS) events (33.3%) were reported. DFS and overall survival (OS) did not differ between patients in the combined B and C arms versus arm A either in the entire cohort (HR = 0.90, P = 0.38 and HR = 0.85, P = 0.20) or among trastuzumab-treated patients (HR = 0.69, P = 0.13 and HR = 0.67, P = 0.13). Thirty-four patients (3.4%) developed secondary neoplasms.Conclusions: Overall, no significant differences in survival were found amongst the studied regimens after a long-term observational period.Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12610000151033. [ABSTRACT FROM AUTHOR]

We consider goodness–of–fit tests for the distribution of the composed error in Stochastic Frontier Models. The proposed test statistic utilizes the characteristic function of the composed error term, and is formulated as a weighted integral of properly standardized data. The new test statistic is shown to be consistent and computationally convenient. Simulation results are presented whereby resampling versions of the new tests are compared to classical goodness–of–fit methods. [ABSTRACT FROM AUTHOR]

Purpose: Colorectal cancer is the fourth cause of cancer-related death. Drug toxicity and resistance remain concerns of major importance. miR-100 and miR-218 are micro-RNAs that regulate cellular proliferation, differentiation and apoptosis acting as oncogenes and tumour suppressors; their functions and have been linked with toxicity development and drug resistance. Methods: We investigated the correlation between rs11134527 miR-218 and rs1834306 miR-100 polymorphisms and irinotecan-based regimens with regard to drug efficacy and toxicity. A total of 105 mCRC patients receiving irinotecan-based regimens were included in our study and assessed in terms of toxicity development and response to treatment. Rs11134527 miR-218 and rs1834306 miR-100 polymorphism genotyping in the peripheral blood was performed with PCR-RFLP. Results: Neither rs11134527 miR-218 nor rs1834306 miR-100 are associated with toxicity risk to treatment regimens. GA/AA genotypes of rs11134527 and CT/TT genotypes of rs1834306 were associated with a significantly reduced time-to-progression (TTP) and overall survival (OS). Conclusions: GA/AA genotypes of rs11134527 miR-218 and CT/TT genotypes of rs1834306 miR-100 polymorphisms could serve as prognostic biomarkers of TTP and OS. Carriers of the A allele of the miR-218 rs11134527 and T allele of the miR-100 rs1834306 polymorphisms are more likely not to respond to irinotecan-based therapies. However, further studies in larger patient populations are required. [ABSTRACT FROM AUTHOR]

Background: To evaluate the expression of programmed cell death-ligand 1 (PD-L1) and CD8 in high-grade endometrial carcinomas and relate it to several clinicopathological parameters. Methods: One hundred and one (101) patients with high-grade endometrial carcinomas who were completely surgically staged were included in this study. PD-L1 and CD8 + expression was evaluated by immunohistochemistry. Results: In our cohort, 47 women (46.5%) had endometrioid carcinomas and 54 patients (53.5%) were diagnosed with non-endometrioid cancers. In endometrioid carcinomas, there was a significantly higher rate of positivity for PD-L1 expression (p = 0.042) and of intraepithelial CD8 + cell counts (p = 0.004) as opposed to non-endometrioid cancers. There were no significant relationships with any of the other clinicopathological features under study. Univariate and multivariate analysis revealed that only high intraepithelial CD8 + counts (p = 0.01) was associated with longer progression-free survival. Tumors positive for PD-L1 and high intraepithelial CD8 expression were mainly of endometrioid histology, whilst PD-L1-positive/CD8 low and PD-L1-negative/CD8 low tumors were mostly non-endometrioid carcinomas (p = 0.01). PD-L1 negative/CD8 high tumors had the longest progression-free survival (p = 0.032). Conclusions: In grade 3 endometrial carcinomas, both of endometrioid and non-endometrioid type, high intraepithelial CD8 + counts represent an independent favorable prognostic factor and when related to PD-L1-negative tumors, a longer progression-free survival can be predicted. Immunotherapy could probably be considered for PD-L1-positive/CD8 + high tumors, which were mostly of endometrioid histology. [ABSTRACT FROM AUTHOR]

For all $$n, \epsilon >0$$ , we show that the set of Poisson Binomial distributions on $$n$$ variables admits a proper $$\epsilon $$ -cover in total variation distance of size $$n^2+n \cdot (1/\epsilon )^{O(\log ^2 (1/\epsilon ))}$$ , which can also be computed in polynomial time. We discuss the implications of our construction for approximation algorithms and the computation of approximate Nash equilibria in anonymous games. [ABSTRACT FROM AUTHOR]

Purpose: The establishment of high dependency units (HDUs) has been an undoubted advance in the management of patients undergoing major oncological procedures. The aim of this study was to examine the impact of various preoperative and perioperative patients' characteristics on the prolonged HDU stay. Methods: We conducted a retrospective study including all gynecologic oncology patients who underwent surgical management and were admitted postoperatively to our hospitals' HDU from 2006 to 2010. Results: A total of 1,014 patients were transferred to the HDU and divided into two groups according to the length of HDU stay. Group A consisted of 840 (82.8 %) patients who stayed in the HDU for ≤24 h and Group B included 174 (17.2 %) patients who remained in the HDU under close observation for >24 h. Older age was the only preoperative characteristic that remained significantly associated with HDU prolonged stay. In addition, three intraoperative factors such as use of invasive hemodynamic monitoring, bowel resection and estimated blood loss were proved to be independently associated with prolonged HDU stay. Conclusion: Certain characteristics could identify those patients who are more likely to benefit most from HDU admission. [ABSTRACT FROM AUTHOR]

Lapatinib is approved in combination with capecitabine for treatment of patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) who have progressed on prior trastuzumab in the metastatic setting. Vinorelbine is an important chemotherapy option for MBC. We evaluated efficacy and safety of lapatinib plus vinorelbine, compared with lapatinib plus capecitabine, in women with HER2-positive MBC. In this open-label, multicenter, phase II study, eligible patients ( N = 112) were randomized 2:1 to lapatinib plus vinorelbine [( N = 75) 1,250 mg orally once daily (QD) continuously plus 20 mg/m/day intravenously] or lapatinib plus capecitabine [( N = 37) 1,250 mg orally QD continuously plus 2,000 mg/m/day orally, 2 doses]. The primary endpoint was progression-free survival (PFS). Other endpoints included overall survival (OS) and safety. Patients progressing within the study were given the option of crossover to the other treatment arm; time to second progression was an exploratory endpoint. Patient demographics, stratification, and prognostic factors were well balanced between treatments. Median PFS in both arms was 6.2 months [95 % confidence interval (CI) 4.2, 8.8 (lapatinib plus vinorelbine); 4.4, 8.3 (lapatinib plus capecitabine)]. Median OS on lapatinib plus vinorelbine was 24.3 months (95 % CI 16.4, NE) and 19.4 months (95 % CI 16.4, 27.2) on lapatinib plus capecitabine. In total, 42 patients opted to cross over; median PFS was 3.2 months (95 % CI 1.7, 5.1) on lapatinib plus vinorelbine and 4.0 months (95 % CI 2.1, 5.8) on lapatinib plus capecitabine. Lapatinib plus vinorelbine offers an effective treatment option for patients with HER2-overexpressing MBC, having displayed comparable efficacy and tolerability rates to lapatinib plus capecitabine. [ABSTRACT FROM AUTHOR]

This case control study aims to investigate the role of MMP- 2 − 1306C > T polymorphism as a potential risk factor and possible prognostic marker for breast cancer in a South European population. 113 consecutive incident cases of histologically confirmed ductal breast cancer and 124 healthy controls were recruited. MMP- 2 − 1306C > T polymorphism was genotyped; multivariate logistic regression as well as Cox regression analysis were performed. MMP-2 −1306C > T status was not associated with breast cancer risk either at the total sample or at the subanalyses on premenopausal and postmenopausal women. At the survival analysis, a trend towards a favorable association between MMP-2 −1306C > T allele and disease-free survival as well as overall survival was observed. Regarding subanalyses on ER-negative and ER-positive cases, the favorable association implicating MMP-2 −1306C > T allele was particularly evident among ER-positive cases; no significant associations emerged among ER-negative cases. MMP-2 −1306C > T polymorphism does not seem to be a risk factor for breast cancer in South European population; however, a trend towards a favorable association with survival has been observed. [ABSTRACT FROM AUTHOR]

Landmark studies have established trastuzumab in the treatment of HER2-positive breast cancer. The present systematic review and meta-analysis aims to synthesize all available data, so as to evaluate the safety of trastuzumab during pregnancy. This study was performed in accordance with the PRISMA guidelines. All studies that examined the safety of trastuzumab administered during pregnancy, regardless of sample size, were considered eligible. Overall, 17 studies (18 pregnancies; 19 newborns) were included. In 55.6 % of cases, trastuzumab was administered in the metastatic setting. The mean duration of trastuzumab administration was 14.8 weeks. Occurrence of oligohydramnios/anhydramnios (O/A) was the most common (61.1 %) adverse event. 73.3 % of pregnancies exposed to trastuzumab during the second/third trimester were complicated with O/A; the respective rate of pregnancies exposed to trastuzumab exclusively during the first trimester was 0 % ( P = 0.043). The mean GA at delivery was 33.8 weeks, and the mean weight of babies at delivery was 2,261 gr. In 52.6 % of cases, a healthy neonate was born. At the long-term evaluation, all children without problems at birth were healthy with a median follow-up of 9 months, while four out of nine children facing troubles at birth were dead within an interval ranging between birth and 5.25 months. All children exposed to trastuzumab in utero exclusively in the first trimester were completely healthy at birth. Trastuzumab should not be administered during pregnancy. However, for women who become accidentally pregnant during trastuzumab administration and wish to continue pregnancy, trastuzumab should be stopped and pregnancy could be allowed to continue. [ABSTRACT FROM AUTHOR]

Purpose: There is a controversy in the literature regarding the role and the prognostic significance of serum markers in uterine carcinosarcomas (CSs). We attempted to determine the utility of serum CA 125, CA 15-3, CA 19-9, and CEA as prognostic factors and disease follow-up in patients with CS of the uterus. Methods: Thirty-seven patients with CS of the uterus were included in this study. Information regarding demographic, clinical, pathologic, tumor marker data (CA 125, CA 19-9, CA 15-3, and CEA both pre- and postoperatively) treatment and outcome information was obtained, followed by Statistical analysis. Results: The mean follow-up period was 3.5 years. None of the study serum markers showed significant association with the outcome. Greater hazard was found for cases that staged from IIIA to IV compared to those staged from IA to IIB (HR = 4.75, 95 % CI: 1.99-11.3). Also, greater hazard was found for adenosquamous histological type compared to the other histological types. When multiple Cox regression analysis with stepwise approach was implied, it indicated stage as the only significant factor for the outcome. Elevated CA19-9 was more frequent in cases with heterologous sarcoma ( p = 0.036). Conclusion: In this retrospective study, none of the preoperative serum tumor markers, neither epithelial component, histological type, nor grade showed a significant association with prognosis. This null finding may have significant implications in the common clinical practice; given that there is a controversy in the literature regarding the role and the significance of the prognostic significance of serum CEA, CA 125, CA 19-9, and CA 15-3. [ABSTRACT FROM AUTHOR]

This case-control study aims to investigate the role of HTERT MNS16A polymorphism as a potential risk factors and/or a prognostic marker for breast cancer. 113 consecutive incident cases of histologically confirmed ductal breast cancer and 124 healthy controls were recruited. HTERT MNS16A polymorphism was genotyped (L: long allele, S: short allele); multivariate logistic regression was performed. No significant association was noted either at the overall analysis (OR = 1.57, 95 % CI 0.84-2.93 for heterozygous LS carriers; OR = 1.02, 95 % CI 0.54-1.95 for homozygous SS carriers) or at the subanalyses in premenopausal and postmenopausal women. With respect to survival analysis, HTERT MNS16A polymorphism was not associated with either disease-free survival or overall survival. HTERT MNS16A polymorphism does not seem to be a risk factor for breast cancer in the Caucasian Greek population. Further, larger studies from other countries and subjects seem to be needed as this novel polymorphism is being examined in depth. [ABSTRACT FROM AUTHOR]

This case control study aims to investigate the role of HSP90 Gln488His (C > G), HSP70-2 P1/P2, HIF-1 alpha C1772T and HSPA8 intronic 1541-1542delGT polymorphisms as potential risk factors and/or prognostic markers for breast cancer. 113 consecutive incident cases of histologically confirmed ductal breast cancer and 124 healthy cases were recruited. The above mentioned polymorphisms were genotyped; multivariate logistic regression was performed. HSP90 GG (His/His) genotype was associated with elevated breast cancer risk. Similarly, the allele dose-response model pointed to increase in breast cancer risk per G allele. HSP70-2 P1/P2, HSPA8 intronic 1541-1542delGT and HIF-1 alpha polymorphisms were not associated with breast cancer risk, as evidenced by the dose-response allele models. The positive association between HSP90 G allele and breast cancer risk seemed to pertain to both premenopausal and postmenopausal women. With respect to survival analysis, none of the aforementioned polymorphisms was associated with either disease-free survival or overall survival. HSP90α Gln488His polymorphism seems to be a risk factor for breast cancer. On the other hand, our study did not point to excess risk conferred by HSPA8 1541-1542delGT, Hsp70-2 P1/P2 and HIF-1α C1772T. [ABSTRACT FROM AUTHOR]

In spite the close association of the triple-negative breast cancer immunophenotype with hereditary breast cancers and the BRCA1 pathway, there is a lack of population studies that determine the frequency of BRCA1 mutations among triple-negative breast cancer patients. To address this, we have screened a large sample of 403 women diagnosed with triple-negative invasive breast cancer, independently of their age or family history, for germline BRCA1 mutations. Median age at diagnosis was 50 years (range 20-83). The overall prevalence of triple-negative cases among the initial patient group with invasive breast cancer was 8 %. BRCA1 was screened by direct DNA sequencing in all patients, including all exons where a mutation was previously found in the Greek population (exons 5, 11, 12, 16, 20, 21, 22, 23, 24-77 % of the BRCA1 coding region), including diagnostic PCRs to detect the three Greek founder large genomic rearrangements. Sixty-five deleterious BRCA1 mutations were identified among the 403 triple-negative breast cancer patients (16 %). Median age of onset for mutation carriers was 39 years. Among a total of 106 women with early-onset triple-negative breast cancer (<40 years), 38 (36 %) had a BRCA1 mutation, while 27 % of women with triple-negative breast cancer diagnosed before 50 years (56/208) had a BRCA1 mutation. A mutation was found in 48 % (50/105) of the triple-negative breast cancer patients with family history of breast or ovarian cancer. It is noteworthy, however, that of the 65 carriers, 15 (23 %) had no reported family history of related cancers. All but one of the carriers had grade III tumors (98 %). These results indicate that women with early-onset triple-negative breast cancer, and ideally all triple-negative breast cancer patients, are candidates for BRCA1 genetic testing even in the absence of a family history of breast or ovarian cancer. [ABSTRACT FROM AUTHOR]

To explore the impact of dose intensity (DI) in the adjuvant setting of breast cancer, a randomized phase III trial was conducted comparing postoperative dose-dense sequential chemotherapy with epirubicin, paclitaxel, and cyclophosphamide, methotrexate and fluorouracil (CMF)in high-risk breast cancer patients. From Oct 2000 to June 2005, 1,121 node-positive patients were randomized to dose-dense sequential epirubicin 110 mg/m and paclitaxel (Taxol, Bristol Myers-Squibb, Princeton, NJ) 250 mg/m (group A), or concurrent epirubicin 83 mg/m and paclitaxel 187 mg/m (group B), both followed by three cycles of 'intensified' combination chemotherapy with CMF. By protocol design total cumulative dose and duration of treatment were identical in both groups. Dose intensity of epirubicin and paclitaxel was double in the dose-dense arm. Prophylactic treatment with granulocyte colony-stimulating factor was given with the dose-dense treatments. Disease-free survival (DFS) was the primary endpoint. At a median follow-up of 76 months, 253 patients (23%) had documented disease relapse (123 vs. 130 in groups A and B, respectively) and 208 deaths (101, group A and 107, group B) had been observed. The 5-year DFS rate of 74 and 74% and OS rate of 86 and 85% were observed for group A and group B, respectively. No differences were found in DFS or OS between the two treatment groups ( P = 0.78 and P = 0.45 for DFS and OS, respectively). Safety analysis results showing that both regimens were well tolerated and safe have been previously published (Fountzilas et al. Ann Oncol 2008). No DFS or OS benefit from the dose-dense sequential epirubicin and paclitaxel was detected when compared to the concurrent administration of the same drugs. No additional safety issues were raised with long-term follow-up. [ABSTRACT FROM AUTHOR]

Embryonal rhabdomyosarcoma (RMS) of the uterine cervix is a rare and extremely malignant entity. Generally, embryonal RMS originating in the uterine cervix is usually diagnosed in adolescence. Before the introduction of effective adjuvant chemotherapy, the prognosis of these lesions was poor. We have treated a young woman suffering from this disease using a combination of surgery, chemotherapy and radiation therapy (RT) with excellent results. The medical community should keep in mind that embryonal RMS of the uterine cervix, despite its malignancy and rarity, can be cured if adequate treatment is given. A case of a young woman aged 20, presenting with vaginal bleeding, is reported. The histological examination revealed embryonal RMS of uterine cervix. The patient was treated with a combination of surgery, chemotherapy and RT. A review in the literature, which is also presented, shows that the combined treatment of embryonal RMS using surgery and multidrug chemotherapy has significantly improved survival. Patients with favourable prognostic parameters, such as localised disease without deep myometrial invasion, single polyp and embryonal histologic subtype, can effectively be treated by surgery. Patients with unfavourable prognostic parameters seem to benefit from a multimodality approach including surgery, adjuvant chemotherapy and RT. [ABSTRACT FROM AUTHOR]

Currently, randomized phase III trials have demonstrated that docetaxel is an effective strategy in the adjuvant treatment of breast cancer. However, previous attempts to incorporate docetaxel with an anthracycline in a dose-dense regimen have been unsuccessful. Therefore, new schedules containing both drugs should be explored. Forty-four patients with high-risk operable breast cancer entered this feasibility study. They were treated with three cycles of epirubicin 110 mg/m2 every 2 wk with G-CSF followed by three cycles of "intensified" CMF (840 mg/m2 cyclophosphamide; 57 mg/m2 methotrexate; 840 mg/m2 fluorouracil) every 2 wk with G-CSF followed 3 wk later by nine weekly cycles of 35 mg/m2 docetaxel (E-CMF-doc). Totally, 39 patients (89%) received all cycles of chemotherapy. The vast majority (92%) of cycles were administered at full dose. Therefore, dose intensity was sufficiently maintained for all drugs. Toxicity was generally mild to moderate. Most frequently recorded side effects apart from alopecia were neutropenia (54%) and nausea/vomiting (89%). Infection developed in nine patients. Two cases of febrile neutropenia were reported. The E-CMF-doc regimen, as used in this study, is feasible and well tolerated. Its impact on survival should be evaluated in phase III trials. [ABSTRACT FROM AUTHOR]

The routing of traffic between Interact domains, or Autonomous Systems (ASs), a task known as interdomain routing, is currently handled by the Border Gateway Protocol (BGP). In this paper, we address the problem of interdomain routing from a mechanism-design point of view. The application of mechanism-design principles to the study of routing is the subject of earlier work by Nisan and Ronen [16] and Hershberger and Suri [12]. In this paper, we formulate and solve a version of the routing-mechanism design problem that is different from the previously studied version in three ways that make it more accurately reflective of real-world interdomain routing: (1) we treat the nodes as strategic agents, rather than the links; (2) our mechanism computes lowest-cost routes for all source-destination pairs and payments for transit nodes on all of the routes (rather than computing routes and payments for only one source-destination pair at a time, as is done in [12, 16]); (3) we show how to compute our mechanism with a distributed algorithm that is a straightforward extension to BGP and causes only modest increases in routing-table size and convergence time (in contrast with the centralized algorithms used in [12, 16]). This approach of using an existing protocol as a substrate for distributed computation may prove useful in future development of Internet algorithms generally, not only for routing or pricing problems. Our design and analysis of a strategyproof, BGP-based routing mechanism provides a new, promising direction in distributed algorithmic mechanism design, which has heretofore been focused mainly on multicast cost sharing. [ABSTRACT FROM AUTHOR]

Background: Capecitabine and oxaliplatin are both effective and well-tolerated monotherapies for the treatment of advanced colorectal cancer (CRC). Oxaliplatin has also been shown to be very effective when combined with 5-FU/LV in the first-line setting. Aim of the Study: Assess the efficacy and safety of capecitabine plus oxaliplatin (XELOX) in patients with previously untreated advanced CRC. Methods: Fifty-three patients with measurable disease received capecitabine 1,000 mg/m2 twice daily on d 1–14 and oxaliplatin 130 mg/m2 on d 1, every 3 wk. Of these, 52 were evaluable for safety and 49 for antitumor response. Results: There was a low rate of grade 1/2 adverse events; grade 3/4 events included leukopenia (10%), neutropenia (6%), thrombocytopenia (2%), nausea/vomiting (4%), and diarrhea (4%). The overall response rate was 39% (95% CI, 25–54%) and median time to disease progression was 7.8 mo. Conclusions: XELOX is an active and well-tolerated first-line treatment for advanced CRC. Randomized phase III studies are ongoing to compare XELOX with FOLFOX in view of the comparable efficacy and safety but superior convenience of XELOX therapy. [ABSTRACT FROM AUTHOR]

Given a set of communication tasks (best described in terms of a weighted bipartite graph where one set of nodes denotes the senders, the other set the receivers, edges are communication tasks, and the weight of an edge is the time required for transmission), we wish to minimize the total time required for the completion of all communication tasks assuming that tasks can be preempted (that is, each edge can be subdivided into many edges with weights adding up to the edge's original weight) and that preemption comes with a cost. In this paper, we first prove that one cannot approximate this problem within a factor smaller than $$\frac{7}{6}$$ unless P=NP. It is known that a simple approximation algorithm achieves within a ratio of two (H. Choi and S.L. Hakimi, Algorithmica, vol. 3, pp. 223–245, 1988). However, our experimental results show that its performance is worse than the originally proposed heuristic algorithm (I.S. Gopal and C.K. Wong, IEEE Transactions on Communications, vol. 33, pp. 497–501, 1985). We devise a more sophisticated algorithm, called the potential function algorithm which, on the one hand, achieves a provable approximation ratio of two, and on the other hand, shows very good experimental performance. Moreover, the way in which our more sophisticated algorithm derives from the simple one, suggests a hierarchy of algorithms, all of which have a worst-case performance at most two, but which we suspect to have increasingly better performance, both in worst case and with actual instances. [ABSTRACT FROM AUTHOR]

Reaction of CuII salts with phenanthroline and oxalate (ox) or oxamate (oxm) gives [Cu(phen)(ox)(H2O)] · H2O or [Cu(phen)(oxm)(H2O)] · H2O complexes while direct treatment of CuII salts with oxalate or oxamate gives [NH4]2[Cu(ox)2] and [Cu(oxm)2(H2O)2] respectively. The X-ray structures of one example of each system, aquo-oxamato-phenanthroline-copper(II)-dihydrate and the polymeric ammonium-bis(aquo)-tetraoxalato-dicopper(II)-dihydrate, are reported. [ABSTRACT FROM AUTHOR]

The construction of a liquid triphenyltetrazolium cation (TT+) ion-selective electrode (ISE) based on [TT+]3[P(W3O10)4] salt dissolved in 2-nitrotoluene is described. The liquid membrane electrode exhibits a rapid and almost Nernstian response to triphenyltetrazolium cations in the concentration range from 2×10−4 to 1×10−2 mol l−1. The Nernstian slope is 56–58 mV decade−1 which remains constant for at least two months. The response is virtually unaffected by pH changes in the range 3–12. Major interferents are periodate and malate. Deviation from linearity is also observed in the presence of bromide, iodide and thiocyanate, due to their precipitation with triphenyltetrazolium cations. Analytical applications such as direct potentiometry for the determination of TT+ in aqueous solutions and indirect potentiometry for the assay of ascorbic acid (vitamin C) in pharmaceutical preparations are described. Ascorbic acid in the range of 150–500 mg l−1, under specified experimental conditions, can be determined with mean relative error of 1.9%. [ABSTRACT FROM AUTHOR]

Abstract. We study the following decision-making scenario: A linear program is solved by a set of agents arranged hierarchically in a tree, where each agent decides the level of certain variables, and has a distinct objective function, known to all agents. Authority is reflected in two ways: Agents higher in the tree set their variables first; and agents that are siblings in the tree resolve their game by focusing on the Nash equilibrium that is optimum for the agent above them. We give a necessary and sufficient condition for such a hierarchy to be efficient (i.e., to have perfect coordination, to ultimately optimize the objective of the firm). We study problems related to designing a hierarchy (assigning decision makers to positions in the tree) in order to achieve efficiency or otherwise optimize coordination. [ABSTRACT FROM AUTHOR]

We present a rigorous framework, based on optimization, for evaluating data mining operations such as associations and clustering, in terms of their utility in decision-making. This framework leads quickly to some interesting computational problems related to sensitivity analysis, segmentation and the theory of games. [ABSTRACT FROM AUTHOR]

We consider the problem of determining whether two traveling salesman tours correspond to non-adjacent vertices of the convex polytope associated with the traveling salesman problem. This problem is shown to be NP-Complete for both the symmetric and nonsymmetric traveling salesman problem. Several implications are discussed. [ABSTRACT FROM AUTHOR]

We define a notation (specification language) for describing desired patterns of communication among components of a distributed system through multiport, unreliable channels. Our language specifies the network topology, and the kinds of information transmission desired. We give a polynomial-time algorithm for determining whether a specification is satisfiable; our algorithm can actually construct a protocol that achieves the specified exchange of information, optimized with respect to two possible criteria. Examples suggest that our method can automatically synthesize reasonably complex protocols. [ABSTRACT FROM AUTHOR]