992 resultados para 338.962


Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper shows a simple, yet highly effective, tracking phase locked loop circuit which has applications for self steered antenna arrays. The tracking PLL has been demonstrated to accurately phase track signal levels as low as -120 dBm, making it suitable for applications such as SATCOM ground terminals. The implementation is simple requiring a low Q voltage controlled oscillator, a downconverting mixer and a PLL circuit.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The enzyme catechol-o-methyltransferase (COMT) transfers a methyl group from adenosylmethionine to catecholamines including the neurotransmitters dopamine, epinephrine and norepinephrine. This methylation results in the degradation of catecholamines. The involvement of the COMT gene in the metabolic pathway of these neurotransmitters has made it an attractive candidate gene for many psychiatric disorders. In this article, we reported our study of association of COMT with schizophrenia in Irish families with a high density of schizophrenia. Three single nucleotide polymorphisms (SNPs) were genotyped for the 274 such families and within-family transmission disequilibrium tests were performed. SNP rs4680, which is the functional Val/Met polymorphism, showed modest association with the disease by the TRANSMIT, FBAT and PDT programs, while the other two SNPs were negative. These SNPs showed lower level of LDs with each other in the Irish subjects than in Ashkenazi Jews. Haplotype analysis indicated that a haplotype, haplotype A-G-A for SNPs rs737865-rs4680-rs165599, was preferentially transmitted to the affected subjects. This was different from the reported G-G-G haplotype found in Ashkenazi Jews, but both haplotypes shared the Val allele. We concluded that COMT gene is associated with schizophrenia and carries a small but significant risk to the susceptibility in the Irish subjects.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper presents a preliminary study of developing a novel distributed adaptive real-time learning framework for wide area monitoring of power systems integrated with distributed generations using synchrophasor technology. The framework comprises distributed agents (synchrophasors) for autonomous local condition monitoring and fault detection, and a central unit for generating global view for situation awareness and decision making. Key technologies that can be integrated into this hierarchical distributed learning scheme are discussed to enable real-time information extraction and knowledge discovery for decision making, without explicitly accumulating and storing all raw data by the central unit. Based on this, the configuration of a wide area monitoring system of power systems using synchrophasor technology, and the functionalities for locally installed open-phasor-measurement-units (OpenPMUs) and a central unit are presented. Initial results on anti-islanding protection using the proposed approach are given to illustrate the effectiveness.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We study the behaviour of the glued trees algorithm described by Childs et al. in [1] under decoherence. We consider a discrete time reformulation of the continuous time quantum walk protocol and apply a phase damping channel to the coin state, investigating the effect of such a mechanism on the probability of the walker appearing on the target vertex of the graph. We pay particular attention to any potential advantage coming from the use of weak decoherence for the spreading of the walk across the glued trees graph. © 2013 Elsevier B.V.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Purpose of review: Cancer cachexia has a substantial impact on both patients and their family carers. It has been acknowledged as one of the two most frequent and devastating problems of advanced cancer. The impact of cachexia spans biopsychosocial realms. Symptom management in cachexia is fraught with difficulties and globally, there remains no agreed standard care or treatment for this client group. There is a need to address the psychosocial impact of cachexia for both patients and their family carers.

Recent findings: Patients living at home and their family carers are often left to manage the distressing psychosocial impacts of cancer cachexia themselves. Successful symptom management requires healthcare professionals to address the holistic impact of cancer cachexia. High quality and rigorous research details the existential impact of cachexia on patients and their family carers. This information needs to inform psychosocial, educational and communicative supportive healthcare interventions to help both patients and their family carers better cope with the effects of cachexia.

Summary: Supportive interventions need to inform both patients and their family carers of the expected impacts of cachexia, and address how to cope with them to retain a functional, supported family unit who are informed about and equipped to care for a loved one with cachexia.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Although the international obligations and institutional frameworks for disaster response are not yet settled, as evidenced by the International Law Commission’s work on the protection of persons in the event of disasters and the on-going promotion of disaster laws by the Red Cross Movement; the diverse source and nature of such initiatives suggests that the international community is engaged in a process of norm creation, elaboration and interpretation reflecting a desire for legal clarity in humanitarian operations. Situated within the framework of transnational law, this paper argues that an acquis humanitaire, based on the principle of humanity, encapsulates the evolving body of law and practice specifically relating to the protection of persons in times of humanitarian crisis in both armed conflicts and natural or human-made disasters. Reflecting the non-traditional, non-statist, dynamic and normative basis of transnational legal process, as elaborated by Harold Koh, the constant flow of ideas and principles between the national, regional and international spheres provides an analytical framework for the on-going transnational dialogues on the social, political and legal internalization of humanitarian norms. Drawing on the internalization of humanitarian norms within the United Kingdom, this paper concludes that as the international community examines the codification of a universal legal framework for the protection of persons in the event of disasters it is necessary to understand the transnational process of interpretation and internalization of humanitarian norms, and how this may vary across different regions and countries.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

It is widely documented that nurses experience work-related stress [Quine, L., 1998. Effects of stress in an NHS trust: a study. Nursing Standard 13 (3), 36-41; Charnley, E., 1999. Occupational stress in the newly qualified staff nurse. Nursing Standard 13 (29), 32-37; McGrath, A., Reid, N., Boore, J., 2003. Occupational stress in nursing. International Journal of Nursing Studies 40, 555-565; McVicar, A., 2003. Workplace stress in nursing: a literature review. Journal of Advanced Nursing 44 (6), 633-642; Bruneau, B., Ellison, G., 2004. Palliative care stress in a UK community hospital: evaluation of a stress-reduction programme. International Journal of Palliative Nursing 10 (6), 296-304; Jenkins, R., Elliott, P., 2004. Stressors, burnout and social support: nurses in acute mental health settings. Journal of Advanced Nursing 48 (6), 622-631], with cancer nursing being identified as a particularly stressful occupation [Hinds, P.S., Sanders, C.B., Srivastava, D.K., Hickey, S., Jayawardene, D., Milligan, M., Olsen, M.S., Puckett, P., Quargnenti, A., Randall, E.A., Tyc, V., 1998. Testing the stress-response sequence model in paediatric oncology nursing. Journal of Advanced Nursing 28 (5), 1146-1157; Barnard, D., Street, A., Love, A.W., 2006. Relationships between stressors, work supports and burnout among cancer nurses. Cancer Nursing 29 (4), 338-345]. Terminologies used to capture this stress are burnout [Pines, A.M., and Aronson, E., 1988. Career Burnout: Causes and Cures. Free Press, New York], compassion stress [Figley, C.R., 1995. Compassion Fatigue. Brunner/Mazel, New York], emotional contagion [Miller, K.I., Stiff, J.B., Ellis, B.H., 1988. Communication and empathy as precursors to burnout among human service workers. Communication Monographs 55 (9), 336-341] or simply the cost of caring (Figley, 1995). However, in the mental health field such as psychology and counselling, there is terminology used to captivate this impact, vicarious traumatisation. Vicarious traumatisation is a process through which the therapist's inner experience is negatively transformed through empathic engagement with client's traumatic material [Pearlman, L.A., Saakvitne, K.W., 1995a. Treating therapists with vicarious traumatization and secondary traumatic stress disorders. In: Figley, C.R. (Ed.), Compassion Fatigue: Coping with Secondary Traumatic Stress Disorder in Those Who Treat the Traumatized. Brunner/Mazel, New York, pp. 150-177]. Trauma not only affects individuals who are primarily present, but also those with whom they discuss their experience. If an individual has been traumatised as a result of a cancer diagnosis and shares this impact with oncology nurses, there could be a risk of vicarious traumatisation in this population. However, although Thompson [2003. Vicarious traumatisation: do we adequately support traumatised staff? The Journal of Cognitive Rehabilitation 24-25] suggests that vicarious traumatisation is a broad term used for workers from any profession, it has not yet been empirically determined if oncology nurses experience vicarious traumatisation. This purpose of this paper is to introduce the concept of vicarious traumatisation and argue that it should be explored in oncology nursing. The review will highlight that empirical research in vicarious traumatisation is largely limited to the mental health professions, with a strong recommendation for the need to empirically determine whether this concept exists in oncology nursing.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Epithelial ovarian carcinoma (EOC) is characterised by late diagnosis and recurrences, both of which contribute to the high morbidity and mortality of this cancer. Unfortunately, EOC has an innate susceptibility to become chemo-resistant. Specifically, up to 30% of patients may not respond to current standard chemotherapy (paclitaxel and platinum in combination) and of those who have an initial response, some patients relapse within a few months. Therefore, in order to improve patient outcome it is crucial to establish what factors influence a patients' individualised response to chemotherapy. We analysed MAD2 protein expression in a patient cohort of 35 ovarian tumours and a panel of 5 ovarian cancer cell lines. We have demonstrated that low nuclear MAD2 expression intensity was significantly associated with chemo-resistant ovarian tumours (p=0.0136). Moreover, in vitro studies of the 5 ovarian cancer cell lines revealed that reduced MAD2 expression was associated with paclitaxel resistance. In silico analysis identified a putative miR-433 binding domain in the MAD2 3′UTR and expression profiling of miR-433 in the ovarian cancer cell lines showed that low MAD2 protein expression was associated with high miR-433 levels. In vitro over-expression of miR-433 attenuated MAD2 protein expression with a concomitant increase in cellular resistance to paclitaxel. Over-expression of a morpholino oligonucleotide that blocks miR-433 binding to MAD2 3′UTR stabilised MAD2 protein expression and protects from miR-433 induced degradation. Furthermore, miR-433 expression analysis in 35 ovarian tumour samples revealed that high miR-433 expression was associated with advanced stage presentations (p=0.0236). In conclusion, ovarian tumours that display low nuclear MAD2 intensity are chemo-resistant and stabilising MAD2 expression by antagonising miR-433 activity is a potential mechanism for restoring chemo-responsiveness in these tumours.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Genuine Savings has emerged as a widely used indicator of sustainable development. In this paper, we use long -term data stretching back to 1870 to undertake empirical tests of the relationship between Genuine Savings (GS) and future well-being for three countries: Britain, the USA and Germany. Our tests are based on an underlying theoretical relationship between GS and changes in the present value of future consumption. Based on both single country and panel results, we find evidence supporting the existence of javascript:void(0);a cointegrating (long run equilibrium) relationship between GS and future well-being, and fail to reject the basic theoretical result on the relationship between these two macroeconomic variables. This provides some support for the GS measure of weak sustainability.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This is a novel investigation of whether, and how, a single close supportive friendship may facilitate psychological resilience in socio-economically vulnerable British adolescents. A total of 409 adolescents (160 boys, 245 girls, four unknown), aged between 11 and 19 years, completed self-report measures of close friendship quality, psychological resilience, social support, and other resources. Findings revealed a significant positive association between perceived friendship quality and resilience. This relationship was facilitated through inter-related mechanisms of developing a constructive coping style (comprised of support-seeking and active coping), effort, a supportive friendship network, and reduced disengaged and externalising coping. While protective processes were encouragingly significantly present across genders, boys were more vulnerable to the deleterious effects of disengaged and externalizing coping than girls. We suggest that individual close friendships are an important potential protective mechanism accessible to most adolescents. We discuss implications of the resulting Adolescent Friendship and Resilience Model for resilience theories and integration into practice.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Small adenomas may be missed during colonoscopy, but chromoscopy has been reported to enhance detection. The aim of this randomized-controlled trial was to determine the effect of total colonic dye spray on adenoma detection during routine colonoscopy.

Methods: Consecutive outpatients undergoing routine colonoscopy were randomized to a dye-spray group (0.1% indigo carmine used to coat the entire colon during withdrawal from the cecum) or control group (no dye).

Results: Two hundred fifty-nine patients were randomized, 124 to the dye-spray and 135 to the control group; demographics, indication for colonoscopy, and quality of the preparation were similar between the groups. Extubation from the cecum took a median of 9:05 minutes (range: 2:4824:44 min) in the dye-spray group versus 4:52 minutes (range: 1:42-15:21 min] in the control group (p <0.0001). The proportion of patients with at least 1 adenoma and the total number of adenomas were not different between groups. However, in the dye-spray group significantly more diminutive adenomas (

Conclusions: Dye-spray increases the detection of small adenomas in the proximal colon and patients with multiple adenomas, but long-term outcomes should be studied to determine the clinical value of these findings.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The photonic efficiencies of films of Evonik (formerly Degussa) P25 TiO2 and carbon-modified TiO2 Kronos VLP 7000 samples are reported as a function of excitation wavelength (300–430 nm; FWHM ∼ 7.5 nm), i.e. the action spectra, for the degradation of stearic acid, a model organic for the photocatalytic destruction of solid surface organic pollutants. For each of these semiconductor photocatalysts, at 365 nm (FWHM = 18 nm), the dependence of the rate of degradation of stearic acid, upon the irradiance, I, is determined and the rate is found to be proportional to I0.65 and I0.82 for P25 and Kronos titania, respectively. Assuming this relationship holds at all wavelengths, the action spectra for two different semiconductor photocatalysts is modified by plotting, (RSA (rate of stearic acid destruction, units: molecules cm−2 s−1)/Iθ) vs. wavelength of excitation (λexcit), and both differ noticeably from those of the original (unmodified) action spectra, which are plots of (RSA/I = photonic efficiency, ξ) vs. λexcit. The shape of the modified action spectrum for P25 TiO2 is consistent with that reported by others for other organic mineralisation reactions and correlates well with diffuse reflectance data for P25 TiO2 (Kubelka–Munk plot), although there is some evidence that the active phase, in the photodegradation of stearic acid, is the anatase form present in P25. The unmodified and modified action spectra of the beige Kronos VLP 7000 TiO2 compound exhibits little or no activity in the visible i.e. (λexcit > 400 nm) and a peak at 350 nm. The Kronos powder contains a yellow/brown conjugated, extractable, organic sensitiser which has been identified by others as the species responsible for its reported photocatalytic visible light activity. But, irradiation of the Kronos powder film, with and without a stearic acid coating, in air, using UVA or visible light, bleaches rapidly (<60 min) most, if not all, of the little colour exhibited by the original Kronos powder. The photobleached form of the Kronos has a similar action spectrum to that of the unbleached form, which, in turn, appears very similar to that of P25 titania, at wavelengths >350 nm. It is proposed that the difference between the Kronos and P25 powder films at wavelengths <350 nm is due to a photodegradation-resistant, previously unidentified (but extractable using MeCN) UV-absorbing organic species in the former which screens the titania particles at these lower wavelengths. The implications of these observations are discussed briefly.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Promoter hypermethylation is central in deregulating gene expression in cancer. Identification of novel methylation targets in specific cancers provides a basis for their use as biomarkers of disease occurrence and progression. We developed an in silico strategy to globally identify potential targets of promoter hypermethylation in prostate cancer by screening for 5' CpG islands in 631 genes that were reported as downregulated in prostate cancer. A virtual archive of 338 potential targets of methylation was produced. One candidate, IGFBP3, was selected for investigation, along with glutathione-S-transferase pi (GSTP1), a well-known methylation target in prostate cancer. Methylation of IGFBP3 was detected by quantitative methylation-specific PCR in 49/79 primary prostate adenocarcinoma and 7/14 adjacent preinvasive high-grade prostatic intraepithelial neoplasia, but in only 5/37 benign prostatic hyperplasia (P < 0.0001) and in 0/39 histologically normal adjacent prostate tissue, which implies that methylation of IGFBP3 may be involved in the early stages of prostate cancer development. Hypermethylation of IGFBP3 was only detected in samples that also demonstrated methylation of GSTP1 and was also correlated with Gleason score > or =7 (P=0.01), indicating that it has potential as a prognostic marker. In addition, pharmacological demethylation induced strong expression of IGFBP3 in LNCaP prostate cancer cells. Our concept of a methylation candidate gene bank was successful in identifying a novel target of frequent hypermethylation in early-stage prostate cancer. Evaluation of further relevant genes could contribute towards a methylation signature of this disease.