460 research outputs found
Recommended from our members
An HDTV encoder for PALplus transmissions, supplemented with a digital residual signal
This paper discusses the design of a video encoder which will enable PALplus compatible HDTV transmission, by embedding a digital residual component within the standard analogue PALplus television signal. The design strategy includes a 2-D diagonal prefilter, together with a QMF band-splitting filter pair, from which the residual is initially derived. The performance of these filters is reviewed, especially in respect of the errors introduced by aliasing and crosstalk distortion. A number of different digital modulation techniques are then examined for the transmission of the residual signal and a qualitative appraisal of their effectiveness presente
Recommended from our members
A PALplus-Compatible HDTV Encoder System
The paper presents a new implementation for realising PALplus signals from high-definition television (HDTV) transmissions. A proposed encoder design is introduced, which decomposes the HDTV input into two separate channels, the first of which subsamples the input signal to produce the standard resolution TV signal, and the second derives a digitally compressed residual component. The problems of non-uniform line structure due to the decimation of an interlaced signal are addressed, as are the visible distortions caused by aliasing and cross-talk effects, with appropriate solutions presented. Finally the important issues of colour enhancement and the composition of the compatible signal are briefly discusse
A novel modulation strategy for integrating digital sub-channels within a PAL/PAL plus signal
This paper presents an original methodology which facilitates the modulation of digital signals within the active video portion of a conventional analogue PAL/PALplus television signal. The resultant crosstalk distortion errors which ensue are analysed and a model postulated that enables optimization of a number of important system parameters. It is also shown that applying this model enables a balancing of subjective quality with data-rat
Quadrature-Mirror Filter Design for the sub-band coding of Digital Video Signals
The paper firstly reviews the basic two-channel subband coding system and its implementation using both quadrature mirror filter (QMF) and conjugate quadrature filter (CQF) designs. Their features and performance characteristics for the one-dimensional case are examined and then using the principle of separability, 2-D QMF-CQF implementations are constructed, as the product of two l-D transfer functions. Examples of 2-D QMF-CQFs in band-splitting configurations for video applications are explored and discusse
Impact of Low-Dose Dronabinol Therapy on Cognitive Function in Cancer Patients Receiving Palliative Care: A Case-Series Intervention Study
BACKGROUND: Cannabis may offer therapeutic benefits to patients with advanced cancer not responding adequately to conventional palliative treatment. However, tolerability is a major concern. Cognitive function is a potential adverse reaction to tetrahydrocannabinol containing regimens. The aim of this study was to test cognitive function in patients being prescribed dronabinol as an adjuvant palliative therapy.METHODS: Adult patients with advanced cancer and severe related pain refractory to conventional palliative treatment were included in this case-series study. Patients were examined at baseline in conjunction with initiation of dronabinol therapy and at a two-week follow-up using three selected Wechsler's adult intelligence scale III neurocognitive tests: Processing Speed Index (PSI), Perceptual Organization Index (POI), and Working Memory Index (WMI). Patients were also assessed using pain visual analog scale, Major Depression Inventory, and Brief Fatigue Inventory.RESULTS: Eight patients consented to take part in the study. Two patients discontinued dronabinol therapy, one due to a complaint of dizziness and another critical progression of cancer disease, respectively. The remaining six patients were successfully treated with a daily dosage of 12.5âmg dronabinol (pâ=â0.039). PSI (pâ=â0.020), POI (pâ=â0.034.), and WMI (pâ=â0.039).CONCLUSIONS: Cognitive function improved in this group of patients with advanced cancer in conjunction with low-dose dronabinol therapy. The cause is likely multifactorial including reported relief of cancer-associated symptoms. Further clinical investigation is required.</p
Recommended from our members
The roles, resources and competencies of employee lay judges: A cross-national study of Germany, France and Great Britain
This research project analysed and compared the roles, resources and competencies of lay judges in Germany, France and Great Britain, where lay judges take up their role through nationally distinctive routes: nomination essentially by the social partners in Germany, self-nomination in Great Britain and election in France. The primary research consisted of qualitative data collected through interviews, set against contextual information on national institutional arrangements, industrial relations, This research project analysed and compared the roles, resources and competencies of lay judges in Germany, France and Great Britain, where lay judges take up their role through nationally distinctive routes: nomination essentially by the social partners in Germany, self-nomination in Great Britain and election in France. The primary research consisted of qualitative data collected through interviews, set against contextual information on national institutional arrangements, industrial relations, and court procedures. The key findings are as follows:
⢠The dominant influence on lay judgeâs reported perception of their role is their experience of the prevailing industrial relations system in each country, mediated by the labour court structure. Routes to nomination not only reflect national systems but may reinforce them and have a bearing on employee lay judgesâ sense of organisational allegiance.
⢠While acknowledging distinct employer and employee perspectives, there was an aspiration to be impartial and a commitment to fairness. This was most unambiguously expressed in Germany and Great Britain. In France, deliberations were sometimes reported as resembling a negotiation between employee and employer lay judges, but one that had to culminate in a legally correct judgment. Very few employee lay judge interviewees reported that they experienced enduring dissonance between sitting on the employee side in the court and their role as a lay judge, although this was noted by several at the outset.
⢠Our interview findings from lay and professional judges indicated that lay judges bring distinctive knowledge. Some of this knowledge is explicit and often specific. Lay knowledge is often tacit, however, and acquired through long exposure to workplace events. Such knowledge was valued by many professional judge interviewees as adding an extra dimension to decision-making and was seen by near-ly all our interviewees as the main contribution of lay judges to the judicial process. Crucially tacit knowledge is a form of understanding that needs to be elicited in the process of deliberations, rather than as evidence provided by an expert witness. As well as bringing knowledge to the court, lay judges also reported that they could enhance their representational and personal-professional skills by transferring knowledge and experience acquired in court back to the work-place.
⢠Gender played some role in the motivation to become a lay judge in Great Britain and in how lay judges assessed their contribution in Germany. Some female interviewees in Britain reported that work-place problems they had personally experienced had contributed to their motivation to become a lay judge. In Germany, there were some differences between men and women in their views of the nature of their contribution: whereas men tended to emphasise the specialist knowledge they could bring to bear in deliberations, women highlighted a âsocial perspectiveâ
Perception of Patients with Cancer Enquiring About Adjuvant Therapy with Cannabis Medicine for Palliation of Symptoms:An Interview Study among Danish Health Care Professionals
BACKGROUND: A medicinal cannabis pilot program was launched in Denmark in 2018 to support patients as countermeasure against self-medication by use of cannabis products from the illicit market. The aim was to facilitate patient access to adjuvate therapy using medicinal cannabis under the guidance of physicians. OBJECTIVE: The aim of this interview study was to elucidate how health care professionals (HCPs) perceive cancer patients enquiring about cannabis medicine (CM), including medicinal cannabis and cannabis-based medicine, for adjuvant palliative therapy. DESIGN: The program used semistructured qualitative research interviews with thematic analysis. SETTING/PARTICIPANTS: Fifty HCPs took part in the study with 10 informants in each of the following 5 groups: oncologists, palliative care specialists, general practitioners, registered nurses in oncology, and in palliative care. RESULTS: The informants reported that optional CM as adjuvant therapy was only discussed when initiated by the patient or relatives. Reluctance by HCPs to enter into a dialogue about CM with their patients was mainly explained by the lack of clinical evidence for the use of CM in palliative care of patients with cancer. None of the oncologists had ever prescribed CM, while three palliative care specialists and two general practitioners had issued prescriptions on rare occasions. CONCLUSION: HCPs involved in cancer treatment and palliative care are in general reluctant to discuss optional adjuvant CM therapy with their patients. The Danish health care authorities need to address this barrier to ensure that patients eligible for CM therapy are given this option as intended by the launch of the national pilot program
Phosphorylation-dependent inhibition of Cdc42 GEF Gef1 by 14-3-3 protein Rad24 spatially regulates Cdc42 GTPase activity and oscillatory dynamics during cell morphogenesis
Š The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Molecular Biology of the Cell 26 (2015): 3520-3534, doi:10.1091/mbc.E15-02-0095.Active Cdc42 GTPase, a key regulator of cell polarity, displays oscillatory dynamics that are anticorrelated at the two cell tips in fission yeast. Anticorrelation suggests competition for active Cdc42 or for its effectors. Here we show how 14-3-3 protein Rad24 associates with Cdc42 guanine exchange factor (GEF) Gef1, limiting Gef1 availability to promote Cdc42 activation. Phosphorylation of Gef1 by conserved NDR kinase Orb6 promotes Gef1 binding to Rad24. Loss of Rad24âGef1 interaction increases Gef1 protein localization and Cdc42 activation at the cell tips and reduces the anticorrelation of active Cdc42 oscillations. Increased Cdc42 activation promotes precocious bipolar growth activation, bypassing the normal requirement for an intact microtubule cytoskeleton and for microtubule-dependent polarity landmark Tea4-PP1. Further, increased Cdc42 activation by Gef1 widens cell diameter and alters tip curvature, countering the effects of Cdc42 GTPase-activating protein Rga4. The respective levels of Gef1 and Rga4 proteins at the membrane define dynamically the growing area at each cell tip. Our findings show how the 14-3-3 protein Rad24 modulates the availability of Cdc42 GEF Gef1, a homologue of mammalian Cdc42 GEF DNMBP/TUBA, to spatially control Cdc42 GTPase activity and promote cell polarization and cell shape emergence.Work in F.V.âs laboratory is supported by National Institutes
of Health R01 Grant GM095867. Part of this work was also supported
by National Science Foundation Grant 0745129. J.R.Y. is
supported by National Institutes of Health Grants P41 GM103533
and R01 MH 067880
Sinonasal B-cell lymphomas:A nationwide cohort study, with an emphasis on the prognosis and the recurrence pattern of primary diffuse large B-cell lymphoma
Lymphomas of the nasal cavity and paranasal sinuses (NPS) are rare. Knowledge on sinonasal Bâcell lymphoma (SNBCL) primarily comes from case series or singleâcenter studies on small cohorts. We sought to determine the subtype distribution, clinical characteristics, disease behavior, and prognosis on a nationwide scale, with an emphasis on prognostic factors for the most common sinonasal lymphoma, primary sinonasal diffuse large Bâcell lymphoma (PSDLBCL). We collated all data from medical records and national databases on patients registered with SNBCL from 1980 through 2018 in the national pathology registry and collected all tissue samples for validation of diagnosis. We included 205 patients and found 10 different subtypes of lymphoma. Diffuse large Bâcell lymphoma (DLBCL) was the predominant subtype (80%). The incidence of SNBCL was 0.14/100,000 personâyears. The fiveâyear progressionâfree survival (PFS) and overall survival rates for PSDLBCL were 50% and 56%, respectively. For PSDLBCL, Rituximab showed a statistically significant effect (Hazard Ratio 0.22, p < 0.001), whereas consolidative radiotherapy combined with immunochemotherapy was of limited value (PFS, p = 0.93). When treatment failure occurred, DLBCL showed a distinct pattern of recurrence/dissemination to the NPS, skin, breast, central nervous system (CNS), and/or testis. Collectively, DLBCL comprised a clear majority of SNBCLs, although nine other subtypes were represented. Data showed that immunochemotherapy increased survival for PSDLBCL and that the addition of radiotherapy did not benefit patients. Furthermore, treatment failure for sinonasal DLBCL showed a possible common pathogenesis with primary extranodal lymphomas of specific locations (e.g., CNS, skin, breast, and testis)
The time-profile of cell growth in fission yeast: model selection criteria favoring bilinear models over exponential ones
BACKGROUND: There is considerable controversy concerning the exact growth profile of size parameters during the cell cycle. Linear, exponential and bilinear models are commonly considered, and the same model may not apply for all species. Selection of the most adequate model to describe a given data-set requires the use of quantitative model selection criteria, such as the partial (sequential) F-test, the Akaike information criterion and the Schwarz Bayesian information criterion, which are suitable for comparing differently parameterized models in terms of the quality and robustness of the fit but have not yet been used in cell growth-profile studies. RESULTS: Length increase data from representative individual fission yeast (Schizosaccharomyces pombe) cells measured on time-lapse films have been reanalyzed using these model selection criteria. To fit the data, an extended version of a recently introduced linearized biexponential (LinBiExp) model was developed, which makes possible a smooth, continuously differentiable transition between two linear segments and, hence, allows fully parametrized bilinear fittings. Despite relatively small differences, essentially all the quantitative selection criteria considered here indicated that the bilinear model was somewhat more adequate than the exponential model for fitting these fission yeast data. CONCLUSION: A general quantitative framework was introduced to judge the adequacy of bilinear versus exponential models in the description of growth time-profiles. For single cell growth, because of the relatively limited data-range, the statistical evidence is not strong enough to favor one model clearly over the other and to settle the bilinear versus exponential dispute. Nevertheless, for the present individual cell growth data for fission yeast, the bilinear model seems more adequate according to all metrics, especially in the case of wee1Î cells
- âŚ