Universal singularity at the closure of a gap in a random matrix theory

We consider a Hamiltonian $H = H_0+ V$, in which $H_0$ is a given non-random Hermitian matrix,and $V$ is an $N \times N$ Hermitian random matrix with a Gaussian probability distribution.We had shown before that Dyson's universality of the short-range correlations between energy levels holds at generic points of the spectrum independently of $H_{0}$. We consider here the case in which the spectrum of $H_{0}$ is such that there is a gap in the average density of eigenvalues of $H$ which is thus split into two pieces. When the spectrum of $H_{0}$ is tuned so that the gap closes, a new class of universality appears for the energy correlations in the vicinity of this singular point.Comment: 20pages, Revtex, to be published in Phys. Rev.

Aberration-like cusped focusing in the post-paraxial Talbot effect

We present an analysis of self-imaging in a regime beyond the paraxial, where deviation from simple paraxial propagation causes apparent self-imaging aberrations. The resulting structures are examples of aberration without rays and are described analytically using post-paraxial theory. They are shown to relate to, but surprisingly do not precisely replicate, a standard integral representation of a diffraction cusp. Beyond the Talbot effect, this result is significant as it illustrates that the effect of aberration -- as manifested in the replacement of a perfect focus with a cusp-like pattern -- can occur as a consequence of improving the paraxial approximation, rather than due to imperfections in the optical system.Comment: 8 pages, 3 figures, IoP styl

An individual patient-data comparison of combined modality therapy and ABVD alone for patients with limited-stage Hodgkin lymphoma

Background Treatment options for patients with nonbulky stage IA-IIA Hodgkin lymphoma include combined modality therapy (CMT) using doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) plus involved-field radiation therapy (IFRT), and chemotherapy with ABVD alone. There are no mature randomized data comparing ABVD with CMT using modern radiation techniques. Patients and methods Using German Hodgkin Study Group HD10/HD11 and NCIC Clinical Trials Group HD.6 databases, we identified 588 patients who met mutually inclusive eligibility criteria from the preferred arms of HD10 or 11 (n = 406) and HD.6 (n = 182). We evaluated time to progression (TTP), progression-free (PFS) and overall survival, including in three predefined exploratory subset analyses. Results With median follow-up of 91 (HD10/11) and 134 (HD.6) months, respective 8-year outcomes were for TTP, 93% versus 87% [hazard ratio (HR) 0.44, 95% confidence interval (CI) 0.24-0.78]; for PFS, 89% versus 86% (HR 0.71, 95% CI 0.42-1.18) and for overall survival, 95% versus 95% (HR 1.09, 95% CI 0.49-2.40). In the exploratory subset analysis including HD10 eligible patients who achieved complete response (CR) or unconfirmed complete response (CRu) after two cycles of ABVD, 8-year PFS was 87% (HD10) versus 95% (HD.6) (HR 2.8; 95% CI 0.64-12.5) and overall survival 96% versus 100%. In contrast, among those without CR/CRu after two cycles of ABVD, 8-year PFS was 88% versus 74% (HR 0.35; 95% CI 0.16-0.79) and overall survival 95% versus 91%, respectively (HR 0.42; 95% CI 0.12-1.44). Conclusions In patients with nonbulky stage IA-IIA Hodgkin lymphoma, CMT provides better disease control than ABVD alone, especially among those not achieving complete response after two cycles of ABVD. Within the follow-up duration evaluated, overall survivals were similar. Longer follow-up is required to understand the implications of radiation and chemotherapy-related late effects. Clinical trials The trials included in this analysis were registered at ClinicalTrials.gov: HD10 - NCT00265018, HD11 - NCT00264953, HD.6 - NCT0000256

A phase II randomized trial comparing radiotherapy with concurrent weekly cisplatin or weekly paclitaxel in patients with advanced cervical cancer

<p>Abstract</p> <p>Purpose/Objective</p> <p>This is a prospective comparison of weekly cisplatin to weekly paclitaxel as concurrent chemotherapy with standard radiotherapy for locally advanced cervical carcinoma.</p> <p>Materials/Methods</p> <p>Between May 2000 and May 2004, 31 women with FIGO stage IB2-IVA cervical cancer or with postsurgical pelvic recurrence were enrolled into this phase II study and randomized to receive on a weekly basis either 40 mg/m²Cisplatin (group I; 16 patients) or 50 mg/m²paclitaxel (group II; 15 patients) concurrently with radiotherapy. Median total dose to point A was 74 Gy (range: 66-92 Gy) for group I and 66 Gy (range: 40-98 Gy) for group II. Median follow-up time was 46 months.</p> <p>Results</p> <p>Patient and tumor characteristics were similar in both groups. The mean number of chemotherapy cycles was also comparable with 87% and 80% of patients receiving at least 4 doses in groups I and II, respectively. Seven patients (44%) of group I and 8 patients (53%) of group II developed tumor recurrence. The Median Survival time was not reached for Group I and 53 months for group II. The proportion of patients surviving at 2 and 5 years was 78% and 54% for group I and 73% and 43% for group II respectively.</p> <p>Conclusions</p> <p>This small prospective study shows that weekly paclitaxel does not provide any clinical advantage over weekly cisplatin for concurrent chemoradiation for advanced carcinoma of the cervix.</p