810 resultados para brain tumours, patient information, doctor-patient communication, cancer, carers
Resumo:
A one-time program is a hypothetical device by which a user may evaluate a circuit on exactly one input of his choice, before the device self-destructs. One-time programs cannot be achieved by software alone, as any software can be copied and re-run. However, it is known that every circuit can be compiled into a one-time program using a very basic hypothetical hardware device called a one-time memory. At first glance it may seem that quantum information, which cannot be copied, might also allow for one-time programs. But it is not hard to see that this intuition is false: one-time programs for classical or quantum circuits based solely on quantum information do not exist, even with computational assumptions. This observation raises the question, "what assumptions are required to achieve one-time programs for quantum circuits?" Our main result is that any quantum circuit can be compiled into a one-time program assuming only the same basic one-time memory devices used for classical circuits. Moreover, these quantum one-time programs achieve statistical universal composability (UC-security) against any malicious user. Our construction employs methods for computation on authenticated quantum data, and we present a new quantum authentication scheme called the trap scheme for this purpose. As a corollary, we establish UC-security of a recent protocol for delegated quantum computation.
Resumo:
Gemcitabine is indicated in combination with cisplatin as first-line therapy for solid tumours including non-small cell lung cancer (NSCLC), bladder cancer and mesothelioma. Gemcitabine is an analogue of pyrimidine cytosine and functions as an anti-metabolite. Structurally, however, gemcitabine has similarities to 5-aza-2-deoxycytidine (decitabine/Dacogen®), a DNA methyltransferase inhibitor (DNMTi). NSCLC, mesothelioma and prostate cancer cell lines were treated with decitabine and gemcitabine. Reactivation of epigenetically silenced genes was examined by RT-PCR/qPCR. DNA methyltransferase activity in nuclear extracts and recombinant proteins was measured using a DNA methyltransferase assay, and alterations in DNA methylation status were examined using methylation-specific PCR (MS-PCR) and pyrosequencing. We observe a reactivation of several epigenetically silenced genes including GSTP1, IGFBP3 and RASSF1A. Gemcitabine functionally inhibited DNA methyltransferase activity in both nuclear extracts and recombinant proteins. Gemcitabine dramatically destabilised DNMT1 protein. However, DNA CpG methylation was for the most part unaffected by gemcitabine. In conclusion, gemcitabine both inhibits and destabilises DNA methyltransferases and reactivates epigenetically silenced genes having activity equivalent to decitabine at concentrations significantly lower than those achieved in the treatment of patients with solid tumours. This property may contribute to the anticancer activity of gemcitabine.
Resumo:
Recent studies have demonstrated that angiogenesis and suppressed cell- mediated immunity (CMI) play a central role in the pathogenesis of malignant disease facilitating tumour growth, invasion and metastasis. In the majority of tumours, the malignant process is preceded by a pathological condition or exposure to an irritant which itself is associated with the induction of angiogenesis and/or suppressed CMI. These include: cigarette smoking, chronic bronchitis and lung cancer; chronic oesophagitis and oesophageal cancer; chronic viral infections such as human papilloma virus and ano-genital cancers, chronic hepatitis B and C and hepatocellular carcinoma, and Epstein- Barr virus (EBV) and lymphomas; chronic inflammatory conditions such as Crohn's disease and ulcerative colitis and colorectal cancer; asbestos exposure and mesothelioma and excessive sunlight exposure/sunburn and malignant melanoma. Chronic exposure to growth factors (insulin-like growth factor-I in acromegaly), mutations in tumour suppressor genes (TP53 in Li Fraumeni syndrome) and long-term exposure to immunosuppressive agents (cyclosporin A) may also give rise to similar environments and are associated with the development of a range of solid tumours. The increased blood supply would facilitate the development and proliferation of an abnormal clone or clones of cells arising as the result of: (a) an inherited genetic abnormality; and/or (b) acquired somatic mutations, the latter due to local production and/or enhanced delivery of carcinogens and mutagenic growth factors. With progressive detrimental mutations and growth-induced tumour hypoxia, the transformed cell, to a lesser or greater extent, may amplify the angiogenic process and CMI suppression, thereby facilitating further tumour growth and metastasis. There is accumulating evidence that long-term treatment with cyclo-oxygenase inhibitors (aspirin and indomethacin), cytokines such as interferon-α, anti-oestrogens (tamoxifen and raloxifene) and captopril significantly reduces the incidence of solid tumours such as breast and colorectal cancer. These agents are anti-angiogenic and, in the case of aspirin, indomethacin and interferon-α have proven immunomodulatory effects. Collectively these observations indicate that angiogenesis and suppressed CMI play a central role in the development and progression of malignant disease. (C) 2000 Elsevier Science Ltd.
Resumo:
We present a technique for delegating a short lattice basis that has the advantage of keeping the lattice dimension unchanged upon delegation. Building on this result, we construct two new hierarchical identity-based encryption (HIBE) schemes, with and without random oracles. The resulting systems are very different from earlier lattice-based HIBEs and in some cases result in shorter ciphertexts and private keys. We prove security from classic lattice hardness assumptions.
Resumo:
Implementation of an electronic tendering (e-tendering) systems requires careful attention to the needs of the system and its various participants. Fairness in an e-tendering is of utmost importance. Current proposals and implementations do not provide fairness and thus, are vulnerable to collusion and favourism. Dishonest participants, either the principal or tenderer may collude to alter or view competing tenders which would give the favoured tenderer a greater chance of winning the contract. This paper proposes an e-tendering system that is secure and fair to all participants. We employ the techniques of anonymous token system along with signed commitment approach to achieve a publicly verifiable fair e-tendering protocol. We also provide an analysis of the protocol that confirms the security of our proposal against security goals for an e-tendering system.
Resumo:
The contribution of creative occupations to Australian healthcare was examined using a mix of statistics and case studies. Creative occupations were found to be making widespread contributions in healthcare, in particular, to the development and delivery of healthcare goods and services, the initial training and ongoing professionalism of doctors and nurses and the effective functioning of healthcare buildings. Within most facets of healthcare, increasing employment over the period examined indicated that these contributions were growing. Key functions that creative activities addressed were information management and analysis and making complex information comprehensible, assisting communication and reducing psycho-social and distance-mediated barriers, and improving the efficiency and effectiveness of services.
Resumo:
Latinos living in the USA account for one third of the uninsured population and face numerous cultural, linguistic, and financial barriers to accessing healthcare services. Community health fairs have developed to address the unmet need for no- and low-cost services that target prevention and education among underserved communities. The current research describes an ongoing effort in a community in Southern California and examines the barriers to health care among participants registering to receive free breast health screenings, one of the major services offered at a 2010 health fair. A total of 186 adult Latina women completed a brief questionnaire assessing their healthcare utilization and self-reported barriers to engaging in preventive and screening services. Approximately two thirds of the participants reported never receiving or having more than 2 years passing since receiving a preventive health check-up. Participants identified cost (64.5 %) and knowledge of locations for services (52.3 %) as the primary barriers to engaging in routine healthcare services. Engaging with health professionals represents a leading way in which adults obtain health information; health fairs offering cancer health screenings represent a culturally appropriate venue for increased cancer health equity. Implications of the current research for future health fairs and their role in community cancer education are discussed.
Resumo:
The digital divide is the disparancy in access to information, in the ability to communicate, and in the capacity to make information and communication serve full participation in the information society. Indeed, the conversation about the digital divide has developed over the last decade from a focus on connectivity and access to information and communication technologies, to a conversation that encompasses the ability to use them and to the utility that usage provides (Wei et al., 2011). However, this conversation, while transitioning from technology to the skills of the people that use them and to the fruits of their use is limited in its ability to take into account the social role of information and communication technologies (ICTs). One successful attempt in conceptualizing the social impact of the differences in access to and utilization of digital communication technologies, was developed by van Dijk (2005) whose sequential model for analyzing the divide states that: 1. Categorical inequalities in society produce an unequal distribution of resources; 2. An unequal distribution of resources causes unequal access to digital technologies; 3. Unequal access to digital technologies also depends on the characteristics of these technologies; 4. Unequal access to digital technologies brings about unequal participation in society; 5. Unequal participation in society reinforces categorical inequalities and unequal distributions of resources.” (p. 15) As van Dijk’s model demonstrates, the divide’s impact is the exclusion of individuals from participation. Still left to be defined are the “categorical inequalities,” the “resources,” the “characteristics of digital technologies,” and the different levels of “access” that result in differentiated levels of participation, as these change over time due to the evolving nature of technology and the dynamics of society. And most importantly, the meaning of “participation” in contemporary society needs to be determined as it is differentiated levels of participation that are the result of the divide and the engine of the ever-growing disparities. Our argument is structured in the following manner: We first claim that contemporary digital media differ from the previous generation of ICTs along four dimensions: They offer an abundance of information resources and communication channels when compared to the relative paucity of both in the past; they offer mobility as opposed to the stationary nature of their predecessors; they are interactive in that they provide users with the capability to design their own media environments in contrast to the dictated environs of previous architectures; and, they allow users to communicate utilizing multi forms of mediation, unlike the uniformity of sound or word that limited users in the past. We then submit that involvement in the information society calls for egalitarian access to all four dimensions of the user experience that make contemporary media different from their predecessors and that the ability to experience all four affects the levels in which humans partake in the shaping of society. The model being cyclical, we then discuss how lower levels of participation contribute to the enhancement of social inequalities. Finally, we discuss why participation is needed in order to achieve full membership in the information society and what political philosophy should govern policy solutions targeting the re-inclusion of those digitally excluded.
Resumo:
This paper studies the problem of selecting users in an online social network for targeted advertising so as to maximize the adoption of a given product. In previous work, two families of models have been considered to address this problem: direct targeting and network-based targeting. The former approach targets users with the highest propensity to adopt the product, while the latter approach targets users with the highest influence potential – that is users whose adoption is most likely to be followed by subsequent adoptions by peers. This paper proposes a hybrid approach that combines a notion of propensity and a notion of influence into a single utility function. We show that targeting a fixed number of high-utility users results in more adoptions than targeting either highly influential users or users with high propensity.
Resumo:
The basis for this study was in poor attractiveness of the wood products industry among young people as a field to study and work in. The purpose was to produce new information of how to improve the relationship between young people and the wood products industry in order to better attract young people with different relational orientation. A survey was conducted among students of comprehensive schools and students of wood industry at vocational schools selected by systematic cluster sampling. The final sample consisted of 613 students. The study combined the theories and concepts of relationships, communication and trust of several disciplines. In addition, it applied theories of relationship marketing, stakeholders, publics, involvement and concepts of reputation and values. It studied the central relational elements in the form of antecedents, relationship state and its consequences. The study examined, how young people with different background and level of interest perceive wood industry as a field to study and work in from relational point of view, what are the central deficiencies in perceived relational elements and what are the public relations activities enhancing the relationship between wood industry and young people with less and high interest in the sector. The results indicate poor visibility of the wood industry among young people: unfamiliarity with the industry and unawareness of the opportunities to study in the field. It appeared that instead of increasing only information sharing, interactive communication in different forms is needed. The study also suggests that behaviors of the industry sector advancing perceived trustworthiness are of crucial importance. Moreover, the wood industry needs to pay attention to its behaviors and communication also among other stakeholder groups, especially the media, as reputation plays an important role in building up trust and satisfaction between young people and the sector. Finally, the less and highly interested young people were found to assess the relationship partly through different relational elements. In order to develop the relationship with highly interested young people they should be regarded clearly as future employees of the wood industry through activities affirming that they are desired and valued employees in the sector. Further, openness of information disclosure, whether concerning current situation or future prospects, seems to increase credibility and attractiveness of the wood industry. Highly interested young people were also found to appreciate socially responsible activities. The less interested young people seem to be insecure about the reliability of the wood industry as an employer, as well as, its ability and interest to invest in young people s skills. In addition,involvement in issues relevant for young people was found crucial in enhancing the relationship with the less interested young people.The conclusions of the study provide tools for enhancing the attractiveness of the wood industry among young people not only to the industry itself, but also to its advocates, teachers and student counselors of comprehensive and vocational schools, authorities and policy makers.
Resumo:
This paper provides a framework for understanding Twitter as a historical source. We address digital humanities scholars to enable the transfer of concepts from traditional source criticism to new media formats, and to encourage the preservation of Twitter as a cultural artifact. Twitter has established itself as a key social media platform which plays an important role in public, real-time conversation. Twitter is also unique as its content is being archived by a public institution (the Library of Congress). In this paper we will show that we still have to assume that much of the contextual information beyond the pure tweet texts is already lost, and propose additional objectives for preservation.
Resumo:
An atmospheric radio noise burst represents the radiation received from one complete lightning flash at the frequency to which a receiver is tuned and within the receiver bandwidth. At tropical latitudes, the principal source of interference in the frequency range from 0.1 to 10 MHz is the burst form of atmospheric radio noise. The structure of a burst shows several approximately rectangular pulses of random amplitude, duration and frequency of recurrence. The influence of the noise on data communication can only be examined when the value of the number of pulses crossing a certain amplitude threshold per unit time of the noise burst is known. A pulse rate counter designed for this purpose has been used at Bangalore (12°58′N, 77°35′E) to investigate the pulse characteristics of noise bursts at 3 MHz with a receiver bandwidth of 3.3 kHz/6d B. The results show that the number of pulses lying in the amplitude range between peak and quasi-peak values of the noise bursts and the burst duration corresponding to these pulses follow log normal distributions. The pulse rates deduced therefrom show certain correlation between the number of pulses and the duration of the noise burst. The results are discussed with a view to furnish necessary information for data communication.
Resumo:
This research focused on indicators with the aim of recognizing the main characters of this particular tool. The planning and use of Finnish sustainability indicators for natural resource management was examined as well as the experiences about the international sets of agri-environmental indicators were described. In both cases, the actual utilization of information was found to be quite minimal. Indicators have succeeded in bringing more of environmental information into the processes of decision making, but information has not been directly shifted into the actions of natural resource management. The concept of technical use of indicators was presented and considered as a possible explanation for the failures of information transfer and communication. Traditionally indicators have been used in order to recognize and describe the performance of certain system; to provide clear operative message for the actors. In policy planning, the situation is essentially different. We may lack both the jointly shared and accepted objectives of development as well the reliable and representative methods for measuring the issue under attention. Therefore, the technical orientation of using indicators may cause several problems at the policy forum. The study identified the risks of 1) reduced informative basis of decision-making, 2) narrowed approach of interpreting the data, 3) the focus on the issues that already are best documented and provides the most representative data series, and 4) the risks of losing the systemic viewpoints while focusing on measurable details of the system. Technical use of indicators may also result the excessive focus on information while being detached from the actions. With sustainability indicators, the major emphasis was indeed paid with producing information while the reality of agricultural practices was left mostly unaffected. Therefore, the essential process of social learning, where actions and producing of relevant information are alternating was neither realized. This study underlines the complexity of information transfer, mutual communication and the learning of new practices. Besides the information and measurable number people also need personal experiences and interesting stories, which make them to understand the meaning of information in their own lives. Particularly important this is for thechildren, who are studying for to be the future decision-makers of food system; in production as well as the in consumption of food. Numbers will be useful tools of management as soon there exists the awareness of the direction, where to strive for.
Resumo:
Gliomas are the most frequent primary brain tumours. The cardinal features of gliomas are infiltrative growth pattern and progression from low-grade tumours to a more malignant phenotype. These features of gliomas generally prevent their complete surgical excision and cause their inherent tendency to recur after initial treatment and lead to poor long-term prognosis. Increasing knowledge about the molecular biology of gliomas has produced new markers that supplement histopathological diagnostics. Molecular markers are also used to evaluate the prognosis and predict therapeutic response. The purpose of this thesis is to study molecular events involved in the malignant progression of gliomas. Gliomas are highly vascularised tumours. Contrast enhancement in magnetic resonance imaging (MRI) reflects a disrupted blood-brain barrier and is often seen in malignant gliomas. In this thesis, 62 astrocytomas, oligodendrogliomas and oligoastrocytomas were studied by MRI and immunohistochemistry. Contrast enhancement in preoperative MRI was associated with angiogenesis, tumour cell proliferation and histological grade of gliomas. Activation of oncogenes by gene amplification is a common genetic aberration in gliomas. EGFR amplification on chromosome 7p12 occurs in 30-40% of glioblastomas. PDGFRA, KIT and VEGFR2 are receptor tyrosine kinase genes located on chromosome 4q12. Amplification of these genes was studied using in situ hybridisation in the primary and recurrent astrocytomas, oligodendrogliomas and oligoastrocytomas of 87 patients. PDGFRA, KIT or VEGFR2 amplification was found in 22% of primary tumours and 36% of recurrent tumours including low-grade and malignant gliomas. The most frequent aberration was KIT amplification, which occurred in 10% of primary tumours and in 27% of recurrent tumours. The expression of ezrin, cyclooxygenase 2 (COX-2) and HuR was studied immunohistochemically in a series of primary and recurrent gliomas of 113 patients. Ezrin is a cell membrane-cytoskeleton linking-protein involved in the migration of glioma cells. The COX-2 enzyme is implicated in the carcinogenesis of epithelial neoplasms and is overexpressed in gliomas. HuR is an RNA-stabilising protein, which regulates the expression of several proteins including COX-2. Ezrin, COX-2 and HuR were associated with histological grade and the overall survival of glioma patients. However, in multivariate analysis they were not independent prognostic factors. In conclusion, these results suggest that contrast enhancement in MRI can be used as a surrogate marker for the proliferative and angiogenic potential of gliomas. Aberrations of PDGFRA, KIT and VEGFR2 genes, as well as the dysregulated expression of ezrin, COX-2 and HuR proteins, are linked to the progression of gliomas.
Resumo:
In this paper, we show that it is possible to reduce the complexity of Intra MB coding in H.264/AVC based on a novel chance constrained classifier. Using the pairs of simple mean-variances values, our technique is able to reduce the complexity of Intra MB coding process with a negligible loss in PSNR. We present an alternate approach to address the classification problem which is equivalent to machine learning. Implementation results show that the proposed method reduces encoding time to about 20% of the reference implementation with average loss of 0.05 dB in PSNR.