20 research outputs found

    The use of wavelet watermarking and statistical classification techniques for collusion detection and identification in multimedia forensics

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    This research proposes a wavelet-based multimedia fingerprint scheme and statistical clustering algorithm for collusion detection and identification. The use of digital multimedia has steadily increased using mediums like the Internet. Encryption is generally used to safeguard content while in transmission, but offers no protection against duplication. Tracing unauthorized content distributors has become an increasing concern for the media industry. Unauthorized duplication, piracy, and illegal redistribution of multimedia content account for several billion dollars in losses every year. It is important to design reliable investigative techniques against unauthorized duplication and propagation, and provide protection in the form of theft deterrence. Some fingerprint embedding schemes are robust against single-user modification attacks. However, a new breed of attacks, known as collusion attacks, have been used to defeat those underlying schemes. These attacks use the combination of multiple fingerprinted copies to create a new version where the underlying fingerprint is highly attenuated, becoming untraceable to the colluders. This research adopts the use of wavelet transforms and statistical classification techniques to effectively identify the set of colluders involved in a collusion attack while maintaining low miss rates and false accusation rates. The experimental results show that the solution is effective in identifying large colluder sets without the knowledge of the number of colluders involved in an attack and the collusion attack used

    The emotional labour of quality improvement work in end of life care : a qualitative study of Patient and Family Centred Care in England

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    Abstract: Background: There is a growing emphasis on understanding patient experience in order to inform efforts to support improvement. This paper reports findings from an implementation study of an evidence-based intervention called Patient and Family Centred Care (PFCC) designed to tap into patient experiences as a basis for improvement. In this study the PFCC intervention was spread to a new service area (end of life care) and delivered at scale in England. The findings presented here focus specifically on one key aspect of the intervention: staff shadowing of patients, and the experiences of staff carrying out shadowing for the purposes of service improvements. Methods: The study methods were ethnographic observations of key events, semi-structured interviews with members of participating teams and the programme implementation support team and managers, and a review of the documents used in the set up and running of the programme. Results: One of the key strengths of the PFCC approach is to encourage staff through shadowing to engage with patient experience of services. Many staff described the process of shadowing as a transformative experience that alerted them to immediate areas where their services could be improved. However, engaging with patient experience of end of life care services also had unintended consequences for some staff in the form of emotional labour. Furthermore, we observed difficulties encountered by staff that are not accounted for in the existing PFCC literature relating to how care service structures may unevenly distribute the amount of ‘emotional labour’ that staff members need to invest in implementing the programme. Conclusions: Connecting with patient experience is a crucial aspect of a number of quality improvement interventions that aim to help staff to engage with the lived experience of their services and reconnect their motivations for working in the health care system. However, there may be unintended consequences for health care service staff, particularly in sensitive areas of service delivery such as end of life care. The ‘emotional labour’ for staff of engaging in quality improvement work informed by patient experience should be considered in planning and supporting patient experience led quality improvement

    Cholesteatoma of the external ear canal: etiological factors, symptoms and clinical findings in a series of 48 cases

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    BACKGROUND: To evaluate symptoms, clinical findings, and etiological factors in external ear canal cholesteatoma (EECC). METHOD: Retrospective evaluation of clinical records of all consecutive patients with EECC in the period 1979 to 2005 in a tertiary referral centre. Main outcome measures were incidence rates, classification according to causes, symptoms, extensions in the ear canal including adjacent structures, and possible etiological factors. RESULTS: Forty-five patients were identified with 48 EECC. Overall incidence rate was 0.30 cases per year per 100,000 inhabitants. Twenty-five cases were primary, while 23 cases were secondary: postoperative (n = 9), postinflammatory (n = 5), postirradiatory (n = 7), and posttraumatic (n = 2). Primary EECC showed a right/left ratio of 12/13 and presented with otalgia (n = 15), itching (n = 5), occlusion (n = 4), hearing loss (n = 3), fullness (n = 2), and otorrhea (n = 1). Similar symptoms were found in secondary EECC, but less pronounced. In total the temporomandibular joint was exposed in 11 cases, while the mastoid and middle ear was invaded in six and three cases, respectively. In one primary case the facial nerve was exposed and in a posttraumatic case the atticus and antrum were invaded. In primary EECC 48% of cases reported mechanical trauma. CONCLUSION: EECC is a rare condition with inconsistent and silent symptoms, whereas the extent of destruction may be pronounced. Otalgia was the predominant symptom and often related to extension into nearby structures. Whereas the aetiology of secondary EECC can be explained, the origin of primary EECC remains uncertain; smoking and minor trauma of the ear canal may predispose

    31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

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    Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
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