1,721,040 research outputs found
Perfect state transfer in long-range interacting spin chains
Get PDFWe investigate the most general conditions under which a finite ferromagnetic long-range interacting spin chain achieves unitary fidelity and the shortest transfer time in transmitting an unknown input qubit. A deeper insight into system dynamics, allows us to identify an ideal system involving sender and receiver only. However, this two-spin ideal chain is unpractical due to the rapid decrease of the coupling strength with the distance. Therefore, we propose an optimization scheme for approaching the ideal behavior, while keeping the interaction strength still reasonably high. The procedure is scalable with the size of the system and straightforward to implement
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Metastatic basal cell carcinoma with squamous differentiation - Report of a case with response of cutaneous metastases to electrochemotherapy
No full textBackground: Metastatic basal cell carcinoma is a rare disease with poor prognosis. Palliative therapeutic approaches include surgery, radiotherapy, and/or chemotherapy. These treatment modalities are invasive and risky and associated with relevant adverse effects. Electrochemotherapy is a recently described therapy that relies on the permeation of cancer cell membranes by electrical pulses to enhance cytotoxic drug penetration. It has been successfully used in the treatment of primary and metastatic skin cancers. We report a case of metastatic basal cell carcinoma in which electrochemotherapy was effective in inducing local regression of skin metastases. Observations: A 75-year-old man presented with a pigmented, deeply infiltrating nodule in the right axilla manifesting as basal cell carcinoma with squamous differentiation at histopathologic examination. Despite 2 wide surgical resections involving lymphadenectomy with axillary vein substitution and systemic chemotherapy, a progressive metastatic spreading, both cutaneous and visceral, occurred in the following 2 years. Three successive sessions of electrochemotherapy with bleomycin sulfate were then performed on isolated skin metastases. The treatment was well tolerated and led to a rapid clinical and histologic regression of the treated lesions. Conclusion: Electrochemotherapy is an effective and well-tolerated adjunct to the therapeutic options in metastatic basal cell carcinoma, characterized by an advantageous risk-benefit ratio and minimal downtime
Multistage Particle Windows for Fast and Accurate Object Detection
No full textThe common paradigm employed for object detection is the sliding window (SW) search. This approach generates grid-distributed patches, at all possible positions and sizes, which are evaluated by a binary classifier: The tradeoff between computational burden and detection accuracy is the real critical point of sliding windows; several methods have been proposed to speed up the search such as adding complementary features. We propose a paradigm that differs from any previous approach since it casts object detection into a statistical-based search using a Monte Carlo sampling for estimating the likelihood density function with Gaussian kernels. The estimation relies on a multistage strategy where the proposal distribution is progressively refined by taking into account the feedback of the classifiers. The method can be easily plugged into a Bayesian-recursive framework to exploit the temporal coherency of the target objects in videos. Several tests on pedestrian and face detection, both on images and videos, with different types of classifiers (cascade of boosted classifiers, soft cascades, and SVM) and features (covariance matrices, Haar-like features,
integral channel features, and histogram of oriented gradients) demonstrate that the proposed method provides higher detection rates and accuracy as well as a lower computational burden w.r.t. sliding window detection
Problemi medico-sociali dell’evoluzione demografica e dell’occupazione nella po-polazione anziana.
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