Toward an architecture for quantum programming

It is becoming increasingly clear that, if a useful device for quantum computation will ever be built, it will be embodied by a classical computing machine with control over a truly quantum subsystem, this apparatus performing a mixture of classical and quantum computation. This paper investigates a possible approach to the problem of programming such machines: a template high level quantum language is presented which complements a generic general purpose classical language with a set of quantum primitives. The underlying scheme involves a run-time environment which calculates the byte-code for the quantum operations and pipes it to a quantum device controller or to a simulator. This language can compactly express existing quantum algorithms and reduce them to sequences of elementary operations; it also easily lends itself to automatic, hardware independent, circuit simplification. A publicly available preliminary implementation of the proposed ideas has been realized using the C++ language.Comment: 23 pages, 5 figures, A4paper. Final version accepted by EJPD ("swap" replaced by "invert" for Qops). Preliminary implementation available at: http://sra.itc.it/people/serafini/quantum-computing/qlang.htm

On the optimality of individual entangling-probe attacks against BB84 quantum key distribution

It is shown that an existing method to study ideal individual attacks on the BB84 QKD protocol using error discard can be adapted to reconciliation with error correction, and that an optimal attack can be explicitly found. Moreover, this attack fills Luetkenhaus bound, independently of whether error positions are leaked to Eve, proving that it is tight. In addition, we clarify why the existence of such optimal attacks is not in contradiction with the established ``old-style'' theory of BB84 individual attacks, as incorrectly suggested recently in a news feature.Comment: 12 pages, 3 figure

A lambda calculus for quantum computation with classical control

The objective of this paper is to develop a functional programming language for quantum computers. We develop a lambda calculus for the classical control model, following the first author's work on quantum flow-charts. We define a call-by-value operational semantics, and we give a type system using affine intuitionistic linear logic. The main results of this paper are the safety properties of the language and the development of a type inference algorithm.Comment: 15 pages, submitted to TLCA'05. Note: this is basically the work done during the first author master, his thesis can be found on his webpage. Modifications: almost everything reformulated; recursion removed since the way it was stated didn't satisfy lemma 11; type inference algorithm added; example of an implementation of quantum teleportation adde

Predictors of HER2 gene amplification in immunohistochemistry score 2+ Early Breast Cancer according to 2018 ASCO/CAP guidelines: a single institution analysis.

Background: HER2 overexpression occurs in approximately 15-20% of invasive breast cancers (BC). From a pathological point of view HER2 positivity is defined by intense circumferential membrane complete staining in more than 10% of tumour cells in immunohistochemistry (IHC score 3+). When complete circumferential staining is weak to moderate (IHC score 2+) double probe in situ ibridation (ISH) is mandatory to define HER2 status. In 2018 ASCO/CAP guidelines were updated to provide additional guidance in HER2 equivocal cases to allow a greater discrimination between positive and negative cases. Our aim is to find predictors of HER2 positivity among IHC score 2+ early breast cancer specimens analysed according to 2018 ASCO/CAP guidelines. Patients and methods: 253 cases of early BC diagnosed at Modena Cancer Center between November 2013 and August 2017 were identified. Stage, ISH result, hormonal receptor status (HR), proliferation index (MIB1), and histological grade were captured; menopausal status was available too. All IHC score 2+ cases were reclassified according to 2018 ASCO/CAP guidelines. The association between pathological tumour features, clinical characteristics and ISH positivity was assessed using Fisher test. Results: Overall, 25.7% IHC score 2+ BC resulted HER2 amplified in double probe ISH. High tumour grade (G3 vs G1-2) and MIB1 > 20% significantly predict HER2 ISH amplification (p=0,0001). No correlation was found according to HR, stage, or menopausal status. The majority (185; 98.4%) of HER2-ve BC were reclassified as group 5 (HER2/ CEP17 ratio <2 and HER2 copy number <4 signals/cell) except for 3 specimens classified as group 4 (HER2/CEP17 RATIO <2 and HER2 copy number \ub34 but <6 signals/cell). In HER2+ve group the majority (62; 95.3%) specimens were group 1 (HER2/CEP17 RATIO >2 and HER2 copy number =4 signals/cell), no specimen was group 2, and only 3 cases were classified as group 3 (HER2/CEP17 RATIO <2 and HER2 copy number >6 signals/cell). Conclusions: In this IHC score 2+ BC series, reclassification according to 2018 ASCO/CAP guidelines identified only 4.6% group 3 and 1.6% group 4 cases. The routinely assessment of grading and proliferation index could help to predict HER2 amplification in IHC score 2+ samples even if it must not substitute ISH assay in determining eligibility for HER2 targeted therapies

Poorly differentiated clusters (PDC) in colorectal cancer: what is and ought to be known.

The counting of poorly differentiated clusters of 5 or more cancer cells lacking a gland-like structure in a tumor mass has recently been identified among the histological features predictive of poor prognosis in colorectal cancer. Poorly differentiated clusters can easily be recognized in the histological sections of colorectal cancer routinely stained with haematoxylin and eosin. Despite some limitations related to specimen fragmentation, counting can also be assessed in endoscopic biopsies. Based on the number of poorly differentiated clusters that appear under a microscopic field of a ×20 objective lens (i.e., a microscopic field with a major axis of 1 mm), colorectal cancer can be graded into malignancies as follows: tumors with <5 clusters as grade 1, tumors with 5 to 9 clusters as grade 2, and tumors with ≥10 clusters as grade 3. High poorly differentiated cluster counts are significantly associated with peri-neural and lympho-vascular invasion, the presence of nodal metastases or micrometastases, as well as shorter overall and progression free survival to colorectal cancer. The morphological aspects and clinical relevance of poorly differentiated clusters counting in colorectal cancer are discussed in this review

Photon bunching in parametric down-conversion with continuous wave excitation

The first direct measurement of photon bunching (g2 correlation function) in one output arm of a spontaneous-parametric-down-conversion source operated with a continuous pump laser in the single-photon regime is demonstrated. The result is in agreement with the statistics of a thermal field of the same coherence length, and shows the feasibility of investigating photon statistics with compact cw-pumped sources. Implications for entanglement-based quantum cryptography are discussed.Comment: 7 pages, 4 figures, expanded introduction and experimental details added. Accepted for publication in Phys.Rev.

Clinical impact and prognostic role of KRAS/BRAF/PIK3CA mutations in stage I colorectal cancer

Stage I colorectal carcinoma has excellent prognosis, with 5-year survival rate up to 95%. The occurrence of lymphovascular invasion, tumor budding, high number of PDC, or lymph node micrometastases is associated with tumor progression. The aim of this study was to evaluate the mutational status of 62 stage I colorectal carcinomas (CRC) (taken from 37 patients surviving more than five years since the initial diagnosis and from 25 patients who died of disease) and to correlate it with histopathological features and the clinical outcome. Mutations of KRAS, NRAS, BRAF, and PIK3CA genes were analyzed through Myriapod Colon Status Kit, using the high-throughput genotyping platform Sequenom MassARRAY System. Mutations in those genes were found in 31 cases (50%) and mainly in those with poor prognosis. The most frequent mutations occurred at codons 12 and 13 of the KRAS gene (40% of cases). We found concomitant PIK3CA mutations in 5 cases (8%). The presence of PIK3CA mutations was mainly observed in tumors with poor prognosis and with unfavorable histopathological prognostic features. High PDC grade (P = 0 0112), the presence of tumor budding (P = 0 0334), LVI (P < 0 0001), KRAS mutations (P = 0 0228), PIK3CA mutations (P = 0 0214), multiple genetic mutations in KRAS and PIK3CA genes (P = 0 039), and nodal micrometastases (P < 0 0001) were significant prognostic variables for CSS. The presence of LVI was the only independent and statistically significant prognostic variable for CSS in our cohort of pTNM stage I CRCs. The analysis of KRAS/PIK3CA mutational status may be used to identify patients with stage I CRC at high risk of bad outcome and who may need additional treatments, including biological therapies

Global Superdiffusion of Weak Chaos

A class of kicked rotors is introduced, exhibiting accelerator-mode islands (AIs) and {\em global} superdiffusion for {\em arbitrarily weak} chaos. The corresponding standard maps are shown to be exactly related to generalized web maps taken modulo an ``oblique cylinder''. Then, in a case that the web-map orbit structure is periodic in the phase plane, the AIs are essentially {\em normal} web islands folded back into the cylinder. As a consequence, chaotic orbits sticking around the AI boundary are accelerated {\em only} when they traverse tiny {\em ``acceleration spots''}. This leads to chaotic flights having a quasiregular {\em steplike} structure. The global weak-chaos superdiffusion is thus basically different in nature from the strong-chaos one in the usual standard and web maps.Comment: REVTEX, 4 Figures: fig1.jpg, fig2.ps, fig3.ps, fig4.p