1,110 research outputs found

    Recursive Motion and Structure Estimation with Complete Error Characterization

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    We present an algorithm that perfom recursive estimation of ego-motion andambient structure from a stream of monocular Perspective images of a number of feature points. The algorithm is based on an Extended Kalman Filter (EKF) that integrates over time the instantaneous motion and structure measurements computed by a 2-perspective-views step. Key features of our filter are (I) global observability of the model, (2) complete on-line characterization of the uncertainty of the measurements provided by the two-views step. The filter is thus guaranteed to be well-behaved regardless of the particular motion undergone by the observel: Regions of motion space that do not allow recovery of structure (e.g. pure rotation) may be crossed while maintaining good estimates of structure and motion; whenever reliable measurements are available they are exploited. The algorithm works well for arbitrary motions with minimal smoothness assumptions and no ad hoc tuning. Simulations are presented that illustrate these characteristics

    Histopatología del osteosarcoma

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    El diagnóstico del osteosarcoma plantea una serie de problemas específicos. De hecho, se debe tener en cuenta la existencia de diversas variantes, con pronósticos diferentes y que requieren enfoques terapéuticos igualmente distintos. En este mismo sentido, la introducción de nuevos protocolos terapéuticos, incluyendo la quimioterapia preoperatoria, requiere una evaluación histopatológica cuidadosa del especimen a fin de cuantificar la necrosis inducida por la quimioterapia y los márgenes quirúrgicos. El presente estudio analiza las diferentes variantes histopatológicas y los problemas que se relacionan con la evaluación de los efectos de la quimioterapia preoperatoria sobre el especimen resecado.Diagnosis of osteosarcoma presents specific problems. In fact, several and different varieties, presenting different prognosis and requiring different treatments, have to be recognized. Moreover, the adoption of new therapeutic protocols including preoperative chemotherapy, requires a careful histopathological evaluation of the specimen to quantify the chemotherapy-induced necrosis and the surgical margins. This paper analyzes the different histopathological varieties and problems related to the evaluation of the effects on the resected specimen of preoperative chemotherapy

    Memory functions and Correlations in Additive Binary Markov Chains

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    A theory of additive Markov chains with long-range memory, proposed earlier in Phys. Rev. E 68, 06117 (2003), is developed and used to describe statistical properties of long-range correlated systems. The convenient characteristics of such systems, a memory function, and its relation to the correlation properties of the systems are examined. Various methods for finding the memory function via the correlation function are proposed. The inverse problem (calculation of the correlation function by means of the prescribed memory function) is also solved. This is demonstrated for the analytically solvable model of the system with a step-wise memory function.Comment: 11 pages, 5 figure

    Tratamiento del osteosarcoma localizado de las extremidades

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    En la década de los setenta, la introducción de la quimioterapia preoperatoria en el tratamiento del osteosarcoma proporcionó mejoras dramáticas en los resultados obtenidos a largo plazo, en cuanto a la supervivencia libre de enfermedad y los procedimientos de salvación de miembros. En el presente trabajo se describe la experiencia acumulada en el Instituto Rizzoli, con la aplicación de varios protocolos activados sucesivamente. Igualmente, se describen los distintos factores pronósticos, la necrosis inducida por quimioterapia, dosis/intensidad y niveles séricos de metotrexato.In the seventies, the introduction of preoperative chemotherapy in the treatment of osteosarcoma dramatically improved the results in terms of disease-free survival and limb salvage procedures. This paper reports the experience at the Rizzoli Institute showing the results obtained with several successively activated protocols. Different prognostic factors, including chemotherapy induced necrosis, dose/intensity, methotrexate serum concentration are also discussed

    Prognostic significance of miR-34a in Ewing sarcoma is associated with cyclin D1 and ki-67 expression

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    BACKGROUND: At diagnosis, identification of reliable biological indicators of prognosis to allow stratification of patients according to different risks is an important but still unresolved aspect in the treatment of Ewing sarcoma (EWS) patients. This study aimed to explore the role of miR-34A expression on prognosis of EWS patients.PATIENTS AND METHODS: Specimens from 109 patients with non-metastatic EWS treated at the Rizzoli Institute with neoadjuvant chemotherapy (protocols ISG/SSGIII, EW-1, EW-2, EW-REN2, EW-REN3, EW-PILOT) and 17 metastases were studied. Sixty-eight patients (62%) remained disease-free and 41 (38%) relapsed (median follow-up: 67 months, range 9-241 months). Expression of miR-34a and of some of its targets (cyclin D1, bcl-2, SIRT1 and YY1) was evaluated by qRT-PCR using TaqMan MicroRNA Assays and/or by immunohistochemistry on tissue microarrays from the same patients.RESULTS: High expression of miR-34a in localized tumors was significantly related to better event-free and overall survival (P = 0.004). Relevance of miR-34a was confirmed by using different calibrators (normal mesenchymal stem cells and different normal tissues). By multivariate Cox regression analysis, low miR-34a expression as well as nontotal necrosis and high levels of lactate dehydrogenase were all confirmed as independent risk factors associated with poor outcome. Expression of miR-34a was lower in metastases than in primary tumors. It inversely correlated with expression of cyclin D1 and Ki-67.CONCLUSIONS: By demonstrating its relationship with clinical outcome, we propose evaluation of miR-34a at diagnosis of EWS patients to allow early risk stratification. Validation of these results would nonetheless ultimately need a prospective assessment

    Targeting GSTP1-1 induces JNK activation and leads to apoptosis in cisplatin-sensitive and -resistant human osteosarcoma cell lines

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    The effect of the glutathione transferase P1-1 (GSTP1-1) targeting has been investigated in both sensitive (U-2OS) and cisplatin-resistant (U-2OS/CDDP4μg) human osteosarcoma cell lines. Despite the different enzyme’s content, inhibition of GSTP1-1 by 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX) causes the activation of c-Jun N-terminal kinase (JNK) and apoptosis in both cell lines. However, different time courses of JNK activation and cell responses are observed. Whereas in the U-2OS/CDDP4μg cell line drug treatment results in an early increase of caspase activity and secondary necrosis, in the U-2OS cells it mainly causes cell cycle arrest followed by apoptosis. Thereafter, we detailed the action mechanism of NBDHEX in the U-2OS cell line. We report evidence of the interaction between GSTP1-1 and the TNF receptor associated factor 2 (TRAF2) and we demonstrate that NBDHEX is able to dissociate the GSTP1-1:TRAF2 complex. This restores the TRAF2:ASK1 signaling, thereby leading to the simultaneous and prolonged activation of JNK and p38. These mitogen-activated protein kinases (MAPKs) mediate different effects: JNK is crucial for apoptosis, whereas p38 causes an increase in the p21 level and a concomitant cell cycle arrest. Our study shows that GSTP1-1 plays an important regulatory role in TRAF signaling of osteosarcoma and discloses new features of the action mechanism of NBDHEX that suggest potentially practical consequences of these finding

    Struggling with happiness: A pathway leading depression to gambling disorder

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    A number of studies have suggested that depressive mood might lead to the development and/or maintenance of a gambling disorder (GD). The pathways by which such relationships are fostered may involve deficits in emotional regulation capacity and dysfunctional coping styles. This study aims to explore the role played by depressive symptomatology and the regulation of positive emotion in GD. We administered the South Oaks Gambling Inventory (SOGS, Lesieur and Blume in Am J Psychiatry 144(9):1184\u20131188, 1987), the 21-item Depression Anxiety Stress Scale (DASS-21, Lovibond and Lovibond in Manual for the depression anxiety stress scales. Psychology Foundation, Sydney, 1995) and the Kill-joy Thinking subscale of the Ways of Savouring Checklist (WOSC, Bryant and Veroff in Savoring: a new model of positive experience. Lawrence Erlbaum, Mahwah, 2007) to a sample of pathological gamblers (n = 91) and a sample of community participants (n = 105). The pathological gamblers scored higher on the DASS-21 subscales and obtained higher scores on the Kill-joy Thinking subscale of the WOSC compared to the controls. Moreover, the SOGS scores positively correlate with the DASS-21 subscales, and with the Kill-Joy Thinking measure. Finally, it is evident that Kill-joy Thinking fully mediates the relationship between depressive symptomatology and GD severity. Our results further confirm the roles of depression, anxiety and stress in GD. Moreover, this is the first study to explore the mediating role of dampening processes in the relationship between depression and GD. Future lines of research are also discussed

    Extensive carrier testing and CF birth prevalence: evidence for a negative correlation

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    Aim of the study was to evaluate if extensive CF carrier testing may be connected with the progressive decrease of CF birth incidence recorded in North Eastern Italy. From 1993 to 2007 an average 52,000 newborns per year underwent Neonatal Screening (NS), and 198 newborns with CF were detected (1/3937). A time related contraction in birth prevalence was confirmed, with an average annual percent decrease of 0.15 per 10,000 neonates (Poisson regression analysis p 0.003). In the NS area two sections were identified: the Western Region (WR), where CF carrier testing is not offered to couples from the general population, and the Eastern Region (ER), where CF carrier testing is widely offered to couples from the general population. In ER from 1995 to 2007 such testing practice has been steadily expanding, with a total of 87,721 CF carrier tests performed, 3460 carriers identified, and 238 carrier couples detected (data collection in progress). The prevalence of CF decreased by time (p<0.001) but the rate of decrease was more enhanced in ER as suggested by the existence of a statistically significant (p = 0.014) interaction term between time and region in the Poisson regression model. The overall negative trend in North Eastern Italy is due to a contraction of CF births in its Eastern part. In ER a negative correlation was found between CF incidence and the number of carrier tests (p 0.012). Prenatal diagnosis data collection is in progress. These data support the hypothesis that carrier screening may modify the incidence of CF
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