12 resultados para L indicator
em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast
Resumo:
Most cytotoxic drugs kill cells by instigating the process of apoptosis and it has been suggested that apoptotic markers may provide an indication of tumour chemosensitivity. The aim of this study was to determine if such a relationship exists in acute myeloid leukaemia (AML). The levels of spontaneous apoptosis, bcl-2 and bax were evaluated in 56 newly diagnosed AML patients to determine if they correlated with a response to cytotoxic therapy. Spontaneous apoptosis was lower, but bcl-2, bax and the bcl-2/bax ratio were higher in AML compared with normal individuals. AML patients with high bax expression at diagnosis had significantly better prognosis for disease-free survival, event-free survival and overall survival (P = 0.016). In the standard risk group, high bax expression was in keeping with significantly improved survival. Multivariate analysis revealed bax to be an independent predictor of survival. There was a significant reduction in bcl-2 and bax expression when AML patients entered complete remission and also in relapsed AML patients who entered a second remission. This study suggests that bax is a useful prognostic indicator in AML and may assist with therapeutic decision-making for patients in the standard risk category.
Resumo:
Durability of concrete is a great concern to all designers, owners and users of reinforced concrete structures. As a result, more restrictive regulations are being introduced in various Codes of Practice dealing with the design of these structures. Attempts are being made by various researchers to develop performance based specification. For this to be successful standard non destructive tests are required which will be used to assess the durability of concretes. In parallel with this approach, a research team in Queen’s University Belfast, U. K., investigated the effect of different mix parameters on workability, strength and various permeation properties. Furthermore, durability parameters such as freeze-thaw salt scaling resistance and carbonation depth were also investigated. The research was part funded by the Department of Environment, Transport and the Regions (DETR). This paper reports of the findings from this study. The results from this investigation showed that some of the non destructive tests used were reasonably well correlated with carbonation and freeze-thaw salt scaling resistance of CEM I concrete. If the mix parameters such as aggregate-cement ratio or water-cement ratio are known, better correlation can be obtained. Further investigation is required varying other mix parameters including various aggregates, admixtures and air entrainments before the result can be used for developing mix design methods for durable concretes. Also long term site tests are required to validate the results obtained from the accelerated laboratory tests used to study the carbonation resistance and freeze-thaw salt scaling resistance.
Resumo:
The formation of arsenic-phytochelatin (As-PC) complexes is thought to be part of the plant detoxification strategy for arsenic. This work examines (i) the arsenic (As) concentration-dependent formation of As-PC complex formation and (ii) redistribution and metabolism of As after arrested As uptake in Helianthus annuus. HPLC with parallel ICP-MS/ES-MS detection was used to identify and quantify the species present in plant extracts exposed to arsenate (As(V)) (between 0 and 66.7 micromol As l-1 for 24 h). At As concentrations below the EC50 value for root growth (22 micromol As l-1) As uptake is exponential, but it is reduced at concentrations above. Translocation between root and shoot seemed to be limited to the uptake phase of arsenic. No redistribution of As between root and shoot was observed after arresting As exposure. The formation of As-PC complexes was concentration-dependent. The amount and number of As-PC complexes increased exponentially with concentration up to 13.7 micromol As l-1. As(III)-PC3 and GS-As(III)-PC2 complexes were the dominant species in all samples. The ratio of PC-bound As to unbound As increased up to 1.3 micromol As l-1 and decreased at higher concentrations. Methylation of inorganic As was only a minor pathway in H. annuus with about 1% As methylated over a 32 d period. The concentration dependence of As-PC complex formation, amount of unbound reduced and oxidized PC2, and the relative uptake rate showed that As starts to influence the cellular metabolism of H. annuus negatively at As concentrations well below the EC50 value determined by more traditional means. Generally, As-PC complexes and PC-synthesis rate seem to be the more sensitive parameters to be studied when As toxicity values are to be estimated.
Resumo:
Little is known about the microevolutionary processes shaping within river population genetic structure of aquatic organisms characterized by high levels of homing and spawning site fidelity. Using a microsatellite panel, we observed complex and highly significant levels of intrariver population genetic substructure and Isolation-by-Distance, in the Atlantic salmon stock of a large river system. Two evolutionary models have been considered explaining mechanisms promoting genetic substructuring in Atlantic salmon, the member-vagrant and metapopulation models. We show that both models can be simultaneously used to explain patterns and levels of population structuring within the Foyle system. We show that anthropogenic factors have had a large influence on contemporary population structure observed. In an analytical development, we found that the frequently used estimator of genetic differentiation, F-ST, routinely underestimated genetic differentiation by a factor three to four compared to the equivalent statistic Jost's D-est (Jost 2008). These statistics also showed a near-perfect correlation. Despite ongoing discussions regarding the usefulness of "adjusted" F-ST statistics, we argue that these could be useful to identify and quantify qualitative differences between populations, which are important from management and conservation perspectives as an indicator of existence of biologically significant variation among tributary populations or a warning of critical environmental damage.
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 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. We also show the effects of modelling shocks, such as World War Two and the Great Depression.
Resumo:
The monitoring of oral disease is important, not alone for oral health, but for the detection and prevention of
systemic disease. The link between oral health and systemic disease is the focus of many studies, with
indications emerging of a causal link [1]. For disease diagnostics, blood has typically been the fluid of choice
for analysis, the retrieval of which is invasive and therefore unsuitable for wearable technology. Analysis of
saliva, however, is less invasive than that of blood, requires little or no pre-treatment and is abundantly
available. A strong correlation has been found between the analytes of blood and saliva [2] with saliva
containing biomarkers for diseases such as diabetes, oral cancer and cardiovascular disease. The development of
an implantable multi-parametric wireless sensor, to monitor both salivary analytes and changes in gingival
temperature, is the aim of this research project.
The aim of our current study is to detect changes in salivary pH, using a gold electrode with a pHsensitive
iridium oxide layer, and an Ion Sensitive Field Effect Transistor probe. Characterisation studies were
carried out in artificial saliva (AS). A salivary pH of between 4.5pH-7.5pH [3], and gingival temperature
between 35°C-38°C [4], were identified as the target range of interest for the human oral environment. Sensor
measurements were recorded in solutions of varying pH and temperature. An ISFET probe was then implanted
into a prototype denture and characterised in AS. This study demonstrates the suitability of ISFET and gold
electrode pH sensors for incorporation into implantable oral sensors.
[1] G. Taylor and W. Borgnakke, “Periodontal disease: associations with diabetes, glycemic control and
complications,” Oral Dis., vol. 14, no. 3, pp. 191–203, Apr. 2008.
[2] E. Tékus, M. Kaj, E. Szabó, N. L. Szénási, I. Kerepesi, M. Figler, R. Gábriel, and M. Wilhelm,
“Comparison of blood and saliva lactate level after maximum intensity exercise,” Acta Biol. Hung., vol. 63
Suppl 1, pp. 89–98, 2012.
[3] S. Naveen, M. L. Asha, G. Shubha, A. Bajoria, and A. Jose, “Salivary Flow Rate, pH and Buffering
Capacity in Pregnant and Non Pregnant Women - A Comparative Study,” JMED Res., pp. 1–8, Feb. 2014.
[4] A. F. Holthuis and F. S. Chebib, “Observations on temperature and temperature patterns of the gingiva. I.
The effect of arch, region and health,” J. Periodontol., vol. 54, no. 10, pp. 624–628, Oct. 1983
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.
Resumo:
We assessed motor laterality in sheep to explore species-specific brain hemi-field dominance and how this could be affected by genetic or developmental factors. Further, we investigated whether directionality and strength of laterality could be linked to emotional stress in ewes and their lambs during partial separation. Forty-three ewes and their singleton lambs were scored on the (left/right) direction of turn in a y-maze to rejoin a conspecific (laterality test). Further, their behavioural response (i.e. time spent near the fence, vocalisations, and activity level) during forced separation by an open-mesh fence was assessed (separation test). Individual laterality was recorded for 44.2 % ewes (significant right bias) and 81.4 % lambs (equally biased to the left and the right). There was no significant association in side bias between dams and offspring. The Chi-squared test revealed a significant population bias for both groups (p < 0.05). Evolutionary adaptive strategies or stimuli-related visual laterality may provide explanation for this decision-making process. Absolute strength of laterality (irrespective of side) was high (Kolmogorov–Smirnov test, dams: D = 0.2; p < 0.001; lambs: D = 0.36, p < 0.0001). The Wilcoxon test showed that lateralised lambs and dams spent significantly more time near each other during separation than non-lateralised animals (p < 0.05), and that lateralised dams were also more active than non-lateralised ones. Arguably, the lateralised animals showed a greater attraction to their pair because they were more disturbed and thus required greater reassurance. The data show that measures of laterality offer a potential novel non-invasive indicator of separation stress.
Resumo:
Introduction
Evaluating quality of palliative day services is essential for assessing care across diverse settings, and for monitoring quality improvement approaches.
Aim
To develop a set of quality indicators for assessment of all aspects (structure, process and outcome) of care in palliative day services.
Methods
Using a modified version of the RAND/UCLA appropriateness method (Fitch et al., 2001), a multidisciplinary panel of 16 experts independently completed a survey rating the appropriateness of 182 potential quality indicators previously identified during a systematic evidence review. Panel members then attended a one day, face-to-face meeting where indicators were discussed and subsequently re-rated. Panel members were also asked to rate the feasibility and necessity of measuring each indicator.
Results
71 indicators classified as inappropriate during the survey were removed based on median appropriateness ratings and level of agreement. Following the panel discussions, a further 60 were removed based on appropriateness and feasibility ratings, level of agreement and assessment of necessity. Themes identified during the panel discussion and findings of the evidence review were used to translate the remaining 51 indicators into a final set of 27.
Conclusion
The final indicator set included information on rationale and supporting evidence, methods of assessment, risk adjustment, and recommended performance levels. Further implementation work will test the suitability of this ‘toolkit’ for measurement and benchmarking. The final indicator set provides the basis for standardised assessment of quality across services, including care delivered in community and primary care settings.
Reference
• Fitch K, Bernstein SJ, Aguilar MD, et al. The RAND/UCLA Appropriateness Method User’s Manual. Santa Monica, CA: RAND Corporation; 2001. http://www.rand.org/pubs/monograph_reports/MR1269