1,043 research outputs found

    A knowledge based architecture for the virtual restoration of ancient photos

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    Historical images are essential documents of the recent past. Nevertheless, time and bad preservation corrupt their physical supports. Digitization can be the solution to extend their \u201clives\u201d, and digital techniques can be used to recover lost information. This task is often difficult and time-consuming, if commercial restoration tools are used for the purpose. A new solution is proposed to help non-expert users in restoring their damaged photos. First, we defined a dual taxonomy for the defects in printed and digitized photos. We represented our restoration domain with an ontology and we created some rules to suggest actions to perform in case of some specific events. Classes and properties of the ontology are included into a knowledge base, that grows dynamically with its use. A prototypal tool and a web application version have been implemented as an interface to the database, and to support non-expert users in the restoration process

    Visually-Grounded Language Model for Human-Robot Interaction

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    Visually grounded human-robot interaction is recognized to be an essential ingredient of socially intelligent robots, and the integration of vision and language increasingly attracts attention of researchers in diverse fields. However, most systems lack the capability to adapt and expand themselves beyond the preprogrammed set of communicative behaviors. Their linguistic capabilities are still far from being satisfactory which make them unsuitable for real-world applications. In this paper we will present a system in which a robotic agent can learn a grounded language model by actively interacting with a human user. The model is grounded in the sense that meaning of the words is linked to a concrete sensorimotor experience of the agent, and linguistic rules are automatically extracted from the interaction data. The system has been tested on the NAO humanoid robot and it has been used to understand and generate appropriate natural language descriptions of real objects. The system is also capable of conducting a verbal interaction with a human partner in potentially ambiguous situations

    A Posture Sequence Learning System for an Anthropomorphic Robotic Hand

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    The paper presents a cognitive architecture for posture learning of an anthropomorphic robotic hand. Our approach is aimed to allow the robotic system to perform complex perceptual operations, to interact with a human user and to integrate the perceptions by a cognitive representation of the scene and the observed actions. The anthropomorphic robotic hand imitates the gestures acquired by the vision system in order to learn meaningful movements, to build its knowledge by different conceptual spaces and to perform complex interaction with the human operator

    The eye in hand: predicting others' behavior by integrating multiple sources of information

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    The ability to predict the outcome of other beings' actions confers significant adaptive advantages. Experiments have assessed that human action observation can use multiple information sources, but it is currently unknown how they are integrated and how conflicts between them are resolved. To address this issue, we designed an action observation paradigm requiring the integration of multiple, potentially conflicting sources of evidence about the action target: the actor's gaze direction, hand preshape, and arm trajectory, and their availability and relative uncertainty in time. In two experiments, we analyzed participants' action prediction ability by using eye tracking and behavioral measures. The results show that the information provided by the actor's gaze affected participants' explicit predictions. However, results also show that gaze information was disregarded as soon as information on the actor's hand preshape was available, and this latter information source had widespread effects on participants' prediction ability. Furthermore, as the action unfolded in time, participants relied increasingly more on the arm movement source, showing sensitivity to its increasing informativeness. Therefore, the results suggest that the brain forms a robust estimate of the actor's motor intention by integrating multiple sources of information. However, when informative motor cues such as a preshaped hand with a given grip are available and might help in selecting action targets, people tend to capitalize on such motor cues, thus turning out to be more accurate and fast in inferring the object to be manipulated by the other's hand. </jats:p

    Organometallic iridium(III) anticancer complexes with new mechanisms of action: NCI-60 screening, mitochondrial targeting, and apoptosis

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    Platinum complexes related to cisplatin, cis-[PtCl2(NH3)2], are successful anticancer drugs; however, other transition metal complexes offer potential for combating cisplatin resistance, decreasing side effects, and widening the spectrum of activity. Organometallic half-sandwich iridium (IrIII) complexes [Ir(Cpx)(XY)Cl]+/0 (Cpx = biphenyltetramethylcyclopentadienyl and XY = phenanthroline (1), bipyridine (2), or phenylpyridine (3)) all hydrolyze rapidly, forming monofunctional G adducts on DNA with additional intercalation of the phenyl substituents on the Cpx ring. In comparison, highly potent complex 4 (Cpx = phenyltetramethylcyclopentadienyl and XY = N,N-dimethylphenylazopyridine) does not hydrolyze. All show higher potency toward A2780 human ovarian cancer cells compared to cisplatin, with 1, 3, and 4 also demonstrating higher potency in the National Cancer Institute (NCI) NCI-60 cell-line screen. Use of the NCI COMPARE algorithm (which predicts mechanisms of action (MoAs) for emerging anticancer compounds by correlating NCI-60 patterns of sensitivity) shows that the MoA of these IrIII complexes has no correlation to cisplatin (or oxaliplatin), with 3 and 4 emerging as particularly novel compounds. Those findings by COMPARE were experimentally probed by transmission electron microscopy (TEM) of A2780 cells exposed to 1, showing mitochondrial swelling and activation of apoptosis after 24 h. Significant changes in mitochondrial membrane polarization were detected by flow cytometry, and the potency of the complexes was enhanced ca. 5× by co-administration with a low concentration (5 μM) of the γ-glutamyl cysteine synthetase inhibitor L-buthionine sulfoximine (L-BSO). These studies reveal potential polypharmacology of organometallic IrIII complexes, with MoA and cell selectivity governed by structural changes in the chelating ligands

    Mitochondrially targeted ceramide LCL-30 inhibits colorectal cancer in mice

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    The sphingolipid ceramide is intimately involved in the growth, differentiation, senescence, and death of normal and cancerous cells. Mitochondria are increasingly appreciated to play a key role in ceramide-induced cell death. Recent work showed the C16-pyridinium ceramide analogue LCL-30 to induce cell death in vitro by mitochondrial targeting. The aim of the current study was to translate these results to an in vivo model. We found that LCL-30 accumulated in mitochondria in the murine colorectal cancer cell line CT-26 and reduced cellular ATP content, leading to dose- and time-dependent cytotoxicity. Although the mitochondrial levels of sphingosine-1-phosphate (S1P) became elevated, transcription levels of ceramide-metabolising enzymes were not affected. In mice, LCL-30 was rapidly absorbed from the peritoneal cavity and cleared from the circulation within 24 h, but local peritoneal toxicity was dose-limiting. In a model of subcutaneous tumour inoculation, LCL-30 significantly reduced the proliferative activity and the growth rate of established tumours. Sphingolipid profiles in tumour tissue also showed increased levels of S1P. In summary, we present the first in vivo application of a long-chain pyridinium ceramide for the treatment of experimental metastatic colorectal cancer, together with its pharmacokinetic parameters. LCL-30 was an efficacious and safe agent. Future studies should identify an improved application route and effective partners for combination treatment

    How to train surgical residents to perform laparoscopic roux-en-Y gastric bypass safely

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    Background As a result of increasing numbers of patients with morbid obesity there is a worldwide demand for bariatric surgeons. The Roux-en-Y gastric bypass, nowadays performed mostly laparoscopically (LRYGB), has been proven to be a highly effective surgical treatment for morbid obesity. This procedure is technically demanding and requires a long learning curve. Little is known about implementing these demanding techniques in the training of the surgical resident. The aim of this study was to evaluate the safety and feasibility of the introduction of LRYGB into the training of surgical residents. Methods All patients who underwent LRYGB between March 2006 and July 2010 were retrospectively analyzed. The procedure was performed by a surgical resident under strict supervision of a bariatric surgeon (group I) or by a bariatric surgeon (group II). The primary end point was the occurrence of complications. Secondary end points included operative time, days of hospitalization, rate of readmission, and reappearance in the emergency department (ED) within 30 days. Results A total of 409 patients were found eligible for inclusion in the study: 83 patients in group I and 326 in group II. There was a significant difference in operating time (129 min in group I vs. 116 min in group II; p<0.001) and days of hospitalization. Postoperative complication rate, reappearance in the ED, and rate of readmission did not differ between the two groups. Conclusions Our data suggest that under stringent supervision and with sufficient laparoscopic practice, implementation of LRYGB as part of surgical training is safe and results in only a slightly longer operating time. Complication rates, days of hospitalization, and the rates of readmission and reappearance in the ED within 30 days were similar between the both groups. These results should be interpreted by remembering that all procedures in group I were performed in a training environment so occasional intervention by a bariatric surgeon, when necessary, was inevitable

    Role of Portal Vein Embolization in Hepatocellular Carcinoma Management and Its Effect on Recurrence: A Case-control Study

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    Background Liver regeneration that occurs after portal vein embolization (PVE) may have adverse effects on the microscopic tumor foci in the residual liver mass in patients with hepatocellular carcinoma (HCC). Methods Fifty-four HCC patients with inadequate functional residual liver volume were offered PVE during a seven-year period. Among them, 34 (63%) patients underwent curative resection. They were compared with a matched control group (n = 102) who underwent surgery without PVE. Postoperative complications, pattern of recurrence, and survival were compared between groups. Results In the PVE group, a pre-embolization functional residual liver volume of 23% (12-33.5%) improved to 34% (20-54%) (p = 0.005) at the time of surgery. When the two groups were compared, minor (PVE, 24%; control, 29%; p = 0.651) and major (PVE, 18%; control, 15%; p = 0.784) complications were similar. After a follow-up period of 35 months (standard deviation 25 months), extrahepatic recurrences were detected in 10 PVE patients (29%) and 41 control patients (40%) (p = 0.310). Intrahepatic recurrences were seen in 10 (29%) and 47 (46%) cases (p = 0.109) in the PVE and control groups, respectively. In the PVE group, 41% (n = 14) of the recurrences were detected before one year, compared with 42% (n = 43) in the control group (p = 1). Disease-free survival rates at 1, 3, and 5 years were 57, 29, and 26% in the control group and 60, 42, and 42% in the PVE group (log-rank, p = 0.335). On multivariate analysis, PVE was not a factor affecting survival (p = 0.821). Conclusions Portal vein embolization increases the resectability of initially unresectable HCC due to inadequate functional residual liver volume, and it has no deleterious oncological effect after major resection of HCC. © The Author(s) 2012.published_or_final_versionSpringer Open Choice, 28 May 201
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