277 resultados para Modal intervals


Relevância:

10.00% 10.00%

Publicador:

Resumo:

We investigated the effect of hydrotherapy on time-trial performance and cardiac parasympathetic reactivation during recovery from intense training. On three occasions, 18 well-trained cyclists completed 60 min high-intensity cycling, followed 20 min later by one of three 10-min recovery interventions: passive rest (PAS), cold water immersion (CWI), or contrast water immersion (CWT). The cyclists then rested quietly for 160 min with R-R intervals and perceptions of recovery recorded every 30 min. Cardiac parasympathetic activity was evaluated using the natural logarithm of the square root of mean squared differences of successive R-R intervals (ln rMSSD). Finally, the cyclists completed a work-based cycling time trial. Effects were examined using magnitude-based inferences. Differences in time-trial performance between the three trials were trivial. Compared with PAS, general fatigue was very likely lower for CWI (difference [90% confidence limits; -12% (-18; -5)]) and CWT [-11% (-19; -2)]. Leg soreness was almost certainly lower following CWI [-22% (-30; -14)] and CWT [-27% (-37; -15)]. The change in mean ln rMSSD following the recovery interventions (ln rMSSD(Post-interv)) was almost certainly higher following CWI [16.0% (10.4; 23.2)] and very likely higher following CWT [12.5% (5.5; 20.0)] compared with PAS, and possibly higher following CWI [3.7% (-0.9; 8.4)] compared with CWT. The correlations between performance, ln rMSSD(Post-interv) and perceptions of recovery were unclear. A moderate correlation was observed between ln rMSSD(Post-interv) and leg soreness [r = -0.50 (-0.66; -0.29)]. Although the effects of CWI and CWT on performance were trivial, the beneficial effects on perceptions of recovery support the use of these recovery strategies.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Tenofovir has been associated with renal phosphate wasting, reduced bone mineral density, and higher parathyroid hormone levels. The aim of this study was to carry out a detailed comparison of the effects of tenofovir versus non-tenofovir use on calcium, phosphate and, vitamin D, parathyroid hormone (PTH), and bone mineral density. Methods: A cohort study of 56 HIV-1 infected adults at a single centre in the UK on stable antiretroviral regimes comparing biochemical and bone mineral density parameters between patients receiving either tenofovir or another nucleoside reverse transcriptase inhibitor. Principal Findings: In the unadjusted analysis, there was no significant difference between the two groups in PTH levels (tenofovir mean 5.9 pmol/L, 95% confidence intervals 5.0 to 6.8, versus non-tenofovir; 5.9, 4.9 to 6.9; p = 0.98). Patients on tenofovir had significantly reduced urinary calcium excretion (median 3.01 mmol/24 hours) compared to non-tenofovir users (4.56; p,0.0001). Stratification of the analysis by age and ethnicity revealed that non-white men but not women, on tenofovir had higher PTH levels than non-white men not on tenofovir (mean difference 3.1 pmol/L, 95% CI 5.3 to 0.9; p = 0.007). Those patients with optimal 25-hydroxyvitamin D (.75 nmol/L) on tenofovir had higher 1,25-dihydroxyvitamin D [1,25(OH)2D] (median 48 pg/mL versus 31; p = 0.012), fractional excretion of phosphate (median 26.1%, versus 14.6;p = 0.025) and lower serum phosphate (median 0.79 mmol/L versus 1.02; p = 0.040) than those not taking tenofovir. Conclusions: The effects of tenofovir on PTH levels were modified by sex and ethnicity in this cohort. Vitamin D status also modified the effects of tenofovir on serum concentrations of 1,25(OH)2D and phosphate.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This study was designed to determine the Intraocular Pressure (IOP) response to differing levels of dehydration. Seven males participated in a 90 minute treadmill walk (5 km/h and 1 % grade) in both a cool (22 °C) and hot (43 °C) climate. At Baseline and at 30 minute intervals measurements of IOP, by tonometery, and indicators of hydration status (nude weight and plasma osmolality (Posm)) were taken. Body temperature and heart rate were also measured at these time points. Statistically significant interactions (time point (4) by trial (2)) were observed for IOP (F = 10.747, p = 0.009) and body weight loss (F = 50.083, p < 0.001) to decrease, and Posm (F = 34.867, p < 0.001) to increase, by a significantly greater amount during the hot trial compared to the cool. A univariate general linear model showed a significant relationship between IOP and body weight loss (F = 37.63, p < 0.001) and Posm (F = 38.53, p < 0.001). A significant interaction was observed for body temperature (F = 20.908, p < 0.001) and heart rate (F = 25.487, p < 0.001) between the trials and time points, but there was negligible association between these variables and IOP (Pearson correlation coefficient < ±0.5). The present study provides evidence to suggest that IOP is influenced by hydration status.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Recent findings concerning exhaled aerosol size distributions and the regions in the respiratory tract in which they are generated could have significant implications for human to human spread of lower respiratory tract-specific infections. Even in healthy people, measurable quantities of aerosol are routinely generated from the Lower Respiratory Tract (LRT) during breathing(1-3). We have found that there at least three modes in the exhaled aerosol size distribution of healthy adults(4) (see Figure 1). These modes each have a characteristic size and arise from different parts of the respiratory tract. The respiratory bronchioles produce aerosol during breathing, the larynx during speech and the oral cavity also during speech. The model of the resulting droplet size distribution is therefore called the Bronchial Laryngeal Oral (B.L.O.) tri-modal model of expired aerosol.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Efficient management of domestic wastewater is a primary requirement for human well being. Failure to adequately address issues of wastewater collection, treatment and disposal can lead to adverse public health and environmental impacts. The increasing spread of urbanisation has led to the conversion of previously rural land into urban developments and the more intensive development of semi urban areas. However the provision of reticulated sewerage facilities has not kept pace with this expansion in urbanisation. This has resulted in a growing dependency on onsite sewage treatment. Though considered only as a temporary measure in the past, these systems are now considered as the most cost effective option and have become a permanent feature in some urban areas. This report is the first of a series of reports to be produced and is the outcome of a research project initiated by the Brisbane City Council. The primary objective of the research undertaken was to relate the treatment performance of onsite sewage treatment systems with soil conditions at site, with the emphasis being on septic tanks. This report consists of a ‘state of the art’ review of research undertaken in the arena of onsite sewage treatment. The evaluation of research brings together significant work undertaken locally and overseas. It focuses mainly on septic tanks in keeping with the primary objectives of the project. This report has acted as the springboard for the later field investigations and analysis undertaken as part of the project. Septic tanks still continue to be used widely due to their simplicity and low cost. Generally the treatment performance of septic tanks can be highly variable due to numerous factors, but a properly designed, operated and maintained septic tank can produce effluent of satisfactory quality. The reduction of hydraulic surges from washing machines and dishwashers, regular removal of accumulated septage and the elimination of harmful chemicals are some of the practices that can improve system performance considerably. The relative advantages of multi chamber over single chamber septic tanks is an issue that needs to be resolved in view of the conflicting research outcomes. In recent years, aerobic wastewater treatment systems (AWTS) have been gaining in popularity. This can be mainly attributed to the desire to avoid subsurface effluent disposal, which is the main cause of septic tank failure. The use of aerobic processes for treatment of wastewater and the disinfection of effluent prior to disposal is capable of producing effluent of a quality suitable for surface disposal. However the field performance of these has been disappointing. A significant number of these systems do not perform to stipulated standards and quality can be highly variable. This is primarily due to houseowner neglect or ignorance of correct operational and maintenance procedures. The other problems include greater susceptibility to shock loadings and sludge bulking. As identified in literature a number of design features can also contribute to this wide variation in quality. The other treatment processes in common use are the various types of filter systems. These include intermittent and recirculating sand filters. These systems too have their inherent advantages and disadvantages. Furthermore as in the case of aerobic systems, their performance is very much dependent on individual houseowner operation and maintenance practices. In recent years the use of biofilters has attracted research interest and particularly the use of peat. High removal rates of various wastewater pollutants have been reported in research literature. Despite these satisfactory results, leachate from peat has been reported in various studies. This is an issue that needs further investigations and as such biofilters can still be considered to be in the experimental stage. The use of other filter media such as absorbent plastic and bark has also been reported in literature. The safe and hygienic disposal of treated effluent is a matter of concern in the case of onsite sewage treatment. Subsurface disposal is the most common and the only option in the case of septic tank treatment. Soil is an excellent treatment medium if suitable conditions are present. The processes of sorption, filtration and oxidation can remove the various wastewater pollutants. The subsurface characteristics of the disposal area are among the most important parameters governing process performance. Therefore it is important that the soil and topographic conditions are taken into consideration in the design of the soil absorption system. Seepage trenches and beds are the common systems in use. Seepage pits or chambers can be used where subsurface conditions warrant, whilst above grade mounds have been recommended for a variety of difficult site conditions. All these systems have their inherent advantages and disadvantages and the preferable soil absorption system should be selected based on site characteristics. The use of gravel as in-fill for beds and trenches is open to question. It does not contribute to effluent treatment and has been shown to reduce the effective infiltrative surface area. This is due to physical obstruction and the migration of fines entrained in the gravel, into the soil matrix. The surface application of effluent is coming into increasing use with the advent of aerobic treatment systems. This has the advantage that treatment is undertaken on the upper soil horizons, which is chemically and biologically the most effective in effluent renovation. Numerous research studies have demonstrated the feasibility of this practice. However the overriding criteria is the quality of the effluent. It has to be of exceptionally good quality in order to ensure that there are no resulting public health impacts due to aerosol drift. This essentially is the main issue of concern, due to the unreliability of the effluent quality from aerobic systems. Secondly, it has also been found that most householders do not take adequate care in the operation of spray irrigation systems or in the maintenance of the irrigation area. Under these circumstances surface disposal of effluent should be approached with caution and would require appropriate householder education and stringent compliance requirements. However despite all this, the efficiency with which the process is undertaken will ultimately rest with the individual householder and this is where most concern rests. Greywater too should require similar considerations. Surface irrigation of greywater is currently being permitted in a number of local authority jurisdictions in Queensland. Considering the fact that greywater constitutes the largest fraction of the total wastewater generated in a household, it could be considered to be a potential resource. Unfortunately in most circumstances the only pretreatment that is required to be undertaken prior to reuse is the removal of oil and grease. This is an issue of concern as greywater can considered to be a weak to medium sewage as it contains primary pollutants such as BOD material and nutrients and may also include microbial contamination. Therefore its use for surface irrigation can pose a potential health risk. This is further compounded by the fact that most householders are unaware of the potential adverse impacts of indiscriminate greywater reuse. As in the case of blackwater effluent reuse, there have been suggestions that greywater should also be subjected to stringent guidelines. Under these circumstances the surface application of any wastewater requires careful consideration. The other option available for the disposal effluent is the use of evaporation systems. The use of evapotranspiration systems has been covered in this report. Research has shown that these systems are susceptible to a number of factors and in particular to climatic conditions. As such their applicability is location specific. Also the design of systems based solely on evapotranspiration is questionable. In order to ensure more reliability, the systems should be designed to include soil absorption. The successful use of these systems for intermittent usage has been noted in literature. Taking into consideration the issues discussed above, subsurface disposal of effluent is the safest under most conditions. This is provided the facility has been designed to accommodate site conditions. The main problem associated with subsurface disposal is the formation of a clogging mat on the infiltrative surfaces. Due to the formation of the clogging mat, the capacity of the soil to handle effluent is no longer governed by the soil’s hydraulic conductivity as measured by the percolation test, but rather by the infiltration rate through the clogged zone. The characteristics of the clogging mat have been shown to be influenced by various soil and effluent characteristics. Secondly, the mechanisms of clogging mat formation have been found to be influenced by various physical, chemical and biological processes. Biological clogging is the most common process taking place and occurs due to bacterial growth or its by-products reducing the soil pore diameters. Biological clogging is generally associated with anaerobic conditions. The formation of the clogging mat provides significant benefits. It acts as an efficient filter for the removal of microorganisms. Also as the clogging mat increases the hydraulic impedance to flow, unsaturated flow conditions will occur below the mat. This permits greater contact between effluent and soil particles thereby enhancing the purification process. This is particularly important in the case of highly permeable soils. However the adverse impacts of the clogging mat formation cannot be ignored as they can lead to significant reduction in the infiltration rate. This in fact is the most common cause of soil absorption systems failure. As the formation of the clogging mat is inevitable, it is important to ensure that it does not impede effluent infiltration beyond tolerable limits. Various strategies have been investigated to either control clogging mat formation or to remediate its severity. Intermittent dosing of effluent is one such strategy that has attracted considerable attention. Research conclusions with regard to short duration time intervals are contradictory. It has been claimed that the intermittent rest periods would result in the aerobic decomposition of the clogging mat leading to a subsequent increase in the infiltration rate. Contrary to this, it has also been claimed that short duration rest periods are insufficient to completely decompose the clogging mat, and the intermediate by-products that form as a result of aerobic processes would in fact lead to even more severe clogging. It has been further recommended that the rest periods should be much longer and should be in the range of about six months. This entails the provision of a second and alternating seepage bed. The other concepts that have been investigated are the design of the bed to meet the equilibrium infiltration rate that would eventuate after clogging mat formation; improved geometry such as the use of seepage trenches instead of beds; serial instead of parallel effluent distribution and low pressure dosing of effluent. The use of physical measures such as oxidation with hydrogen peroxide and replacement of the infiltration surface have been shown to be only of short-term benefit. Another issue of importance is the degree of pretreatment that should be provided to the effluent prior to subsurface application and the influence exerted by pollutant loadings on the clogging mat formation. Laboratory studies have shown that the total mass loadings of BOD and suspended solids are important factors in the formation of the clogging mat. It has also been found that the nature of the suspended solids is also an important factor. The finer particles from extended aeration systems when compared to those from septic tanks will penetrate deeper into the soil and hence will ultimately cause a more dense clogging mat. However the importance of improved pretreatment in clogging mat formation may need to be qualified in view of other research studies. It has also shown that effluent quality may be a factor in the case of highly permeable soils but this may not be the case with fine structured soils. The ultimate test of onsite sewage treatment system efficiency rests with the final disposal of effluent. The implication of system failure as evidenced from the surface ponding of effluent or the seepage of contaminants into the groundwater can be very serious as it can lead to environmental and public health impacts. Significant microbial contamination of surface and groundwater has been attributed to septic tank effluent. There are a number of documented instances of septic tank related waterborne disease outbreaks affecting large numbers of people. In a recent incident, the local authority was found liable for an outbreak of viral hepatitis A and not the individual septic tank owners as no action had been taken to remedy septic tank failure. This illustrates the responsibility placed on local authorities in terms of ensuring the proper operation of onsite sewage treatment systems. Even a properly functioning soil absorption system is only capable of removing phosphorus and microorganisms. The nitrogen remaining after plant uptake will not be retained in the soil column, but will instead gradually seep into the groundwater as nitrate. Conditions for nitrogen removal by denitrification are not generally present in a soil absorption bed. Dilution by groundwater is the only treatment available for reducing the nitrogen concentration to specified levels. Therefore based on subsurface conditions, this essentially entails a maximum allowable concentration of septic tanks in a given area. Unfortunately nitrogen is not the only wastewater pollutant of concern. Relatively long survival times and travel distances have been noted for microorganisms originating from soil absorption systems. This is likely to happen if saturated conditions persist under the soil absorption bed or due to surface runoff of effluent as a result of system failure. Soils have a finite capacity for the removal of phosphorus. Once this capacity is exceeded, phosphorus too will seep into the groundwater. The relatively high mobility of phosphorus in sandy soils have been noted in the literature. These issues have serious implications in the design and siting of soil absorption systems. It is not only important to ensure that the system design is based on subsurface conditions but also the density of these systems in given areas is a critical issue. This essentially involves the adoption of a land capability approach to determine the limitations of an individual site for onsite sewage disposal. The most limiting factor at a particular site would determine the overall capability classification for that site which would also dictate the type of effluent disposal method to be adopted.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background Hallux valgus (HV) is a very common deformity of the first metatarsophalangeal joint that often requires surgical correction. However, the association between structural HV deformity and related foot pain and disability is unclear. Furthermore, no previous studies have investigated concerns about appearance and difficulty with footwear in a population with HV not seeking surgical correction. The aim of this cross-sectional study was to investigate foot pain, functional limitation, concern about appearance and difficulty with footwear in otherwise healthy adults with HV compared to controls. Methods Thirty volunteers with HV (radiographic HV angle >15 degrees) and 30 matched controls were recruited for this study (50 women, 10 men; mean age 44.4 years, range 20 to 76 years). Differences between groups were examined for self-reported foot pain and disability, satisfaction with appearance, footwear difficulty, and pressure-pain threshold at the first metatarsophalangeal joint. Functional measures included balance tests, walking performance, and hallux muscle strength (abduction and plantarflexion). Mean differences (MD) and 95% confidence intervals (CI) were calculated. Results All self-report measures showed that HV was associated with higher levels of foot pain and disability and significant concerns about appearance and footwear (p < 0.001). Lower pressure-pain threshold was measured at the medial first metatarsophalangeal joint in participants with HV (MD = -133.3 kPa, CI: -251.5 to -15.1). Participants with HV also showed reduced hallux plantarflexion strength (MD = -37.1 N, CI: -55.4 to -18.8) and abduction strength (MD = -9.8 N, CI: -15.6 to -4.0), and increased mediolateral sway when standing with both feet with eyes closed (MD = 0.34 cm, CI: 0.04 to 0.63). Conclusions These findings show that HV negatively impacts on self-reported foot pain and function, and concerns about foot appearance and footwear in otherwise healthy adults. There was also evidence of impaired hallux muscle strength and increased postural sway in HV subjects compared to controls, although general physical functioning and participation in physical activity were not adversely affected.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Airports are currently being pressured to operate in a more environmentally-sensitive manner; as a response, airports have integrated environmental policies into their operations. However, environmental concerns regarding automobile traffic and related emissions have yet to be addressed. While the automobile is the dominant air passenger ground transportation mode at US airports, services facilitating automobile usage including public parking and car rentals are a major airport revenue source. Less than 20 US hub airports have direct access to rail-based transportation modes. New rail transportation projects serving additional airports are either being consideration or under construction. Regardless of whether an airport has direct access to rail-based transportation modes, the air passenger ground transportation modal split at US airports remain low in comparison to those in Asia and Europe. The high cost of providing additional US airports with direct rail connections in an era of severe governmental budgetary cutbacks is making the “build it and they will come” mindset untenable. Governmental policies are but one factor determining whether programs increasing transit usage results in automobile traffic reductions and related emissions. This study reveals that a significant percentage of the busiest US airports do not have policies fostering increases in the air passenger ground transportation modal split. A case study of one US airport is presented that has successfully adopted a transit first policy to achieve a high air passenger ground transportation modal split and facilitate the availability of rail-based transportation services.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background and aims: Lower-limb lymphoedema is a serious and feared sequela after treatment for gynaecological cancer. Given the limited prospective data on incidence of and risk factors for lymphoedema after treatment for gynaecological cancer we initiated a prospective cohort study in 2008. Methods: Data were available for 353 women with malignant disease. Participants were assessed before treatment and at regular intervals after treatment for two years. Follow-up visits were grouped into time-periods of six weeks to six months (time 1), nine months to 15 months (time 2), and 18 months to 24 months (time 3). Preliminary data analyses were undertaken up to time 2 using generalised estimating equations to model the repeated measures data of Functional Assessment of Cancer Therapy-General (FACT-G) quality of life (QoL) scores and self-reported swelling at each follow-up period (best-fitting covariance structure). Results: Depending on the time-period, between 30% and 40% of patients self-reported swelling of the lower limb. The QoL of those with self-reported swelling was lower at all time-periods compared with those who did not have swelling. Mean (95% CI) FACT-G scores at time 0, 1 and 2 were 80.7 (78.2, 83.2), 83.0 (81.0, 85.0) and 86.3 (84.2, 88.4), respectively for those with swelling and 85.0 (83.0, 86.9), 86.0 (84.1, 88.0) and 88.9 (87.0, 90.7), respectively for those without swelling. Conclusions: Lower-limb swelling adversely influences QoL and change in QoL over time in patients with gynaecological cancer.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Since 2007, KITE Arts Education Program @ QPAC has been engaged in a series of arts and drama-based experiences for students in selected primary schools on the edges of Brisbane and in regional Queensland. The in-school workshop experiences of the program have culminated in a performance by the children for their school community, parents and carers at the Queensland Performing Arts Centre or a regional cultural venue. In conducting an analysis of the Yonder project, the researcher aimed to provide evidence of outcomes brought about through participation by schools, school staff, students and their communities in the Yonder project. To develop longitudinal data project initiators, participants were interviewed at six-monthly intervals to establish patterns of engagement and participation. The report analyses arts-based workshops conducted by the teacher artist in edge-city Brisbane and a regional centre; interviews with teachers and school administrators from the participating schools; interviews with teacher artist and professional artists; interviews with community partners; teacher professional development workshops; community-based workshops; performance outcomes that were the culminating events of the workshop program; student work samples and student reflections on the program. This document covers data and project outputs from February 2010 to July 2012. There have been five iterations of the Yonder project since its commencement in mid-2009 — three in regional Queensland (February–April 2010; February–May 2011; February–May 2012) and two in edge-city1 Brisbane (July–September 2010; August–October 2011). This report is a result of a research partnership between Queensland Performing Arts Centre and Queensland University of Technology (QUT) Creative Industries Faculty(Drama).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Recent research indicates that brief periods (60 minutes) of monocular defocus lead to small but significant changes in human axial length. However, the effects of longer periods of defocus on the axial length of human eyes are unknown. We examined the influence of a 12 hour period of monocular myopic defocus on the natural daily variations occurring in axial length and choroidal thickness of young adult emmetropes. A series of axial length and choroidal thickness measurements (collected at ~3 hourly intervals, with the first measurement at ~9 am and the final measurement at ~9 pm) were obtained for 13 emmetropic young adults over three consecutive days. The natural daily rhythms (Day 1, baseline day, no defocus), the daily rhythms with monocular myopic defocus (Day 2, defocus day, +1.50 DS spectacle lens over the right eye), and the recovery from any defocus induced changes (Day 3, recovery day, no defocus) were all examined. Significant variations over the course of the day were observed in both axial length and choroidal thickness on each of the three measurement days (p<0.0001). The magnitude and timing of the daily variations in axial length and choroidal thickness were significantly altered with the monocular myopic defocus on day 2 (p<0.0001). Following the introduction of monocular myopic defocus, the daily peak in axial length occurred approximately 6 hours later, and the peak in choroidal thickness approximately 8.5 hours earlier in the day compared to days 1 and 3 (with no defocus). The mean amplitude (peak to trough) of change in axial length (0.030 ± 0.012 on day 1, 0.020 ± 0.010 on day 2 and 0.033 ± 0.012 mm on day 3) and choroidal thickness (0.030 ± 0.007 on day 1, 0.022 ± 0.006 on day 2 and 0.027 ± 0.009 mm on day 3) were also significantly different between the three days (both p<0.05). The introduction of monocular myopic defocus disrupts the daily variations in axial length and choroidal thickness of human eyes (in terms of both amplitude and timing) that return to normal the following day after removal of the defocus.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective: To determine factors associated with symptom detected breast cancers in a population offered screening. Methods We interviewed 1,459 Australian women aged 40–69, 946 with symptom detected and 513 with mammogram detected invasive breast cancers ≥1.1 cm in diameter, about their personal, mammogram and breast histories before diagnosis and reviewed medical records for tumour characteristics and mammogram dates, calculating ORs and 95% confidence intervals (CIs) for symptom- vs mammogram-detected cancers in logistic regression models. Results: Lack of regular mammograms (<2 mammograms in the 4.5 years before diagnosis) was the strongest correlate of symptom detected breast cancer (OR=3.04 for irregular or no mammograms). In women who had regular mammograms (≥2 mammograms in the 4.5 years before diagnosis), the independent correlates of symptom detected cancers were low BMI (OR <25kg/m2 vs ≥30kg/m2=2.18, 95% CI 1.23-3.84; p=0.008), increased breast density (available in 498 women) (OR highest quarter vs lowest =3.50, 95% CI 1.76-6.97; ptrend=0.004), high grade cancer and a larger cancer (each p<0.01). In women who did not have regular mammograms, the independent correlates were age <50 years, a first cancer and a ≥2cm cancer. Smoking appeared to modify the association of symptom detected cancer with low BMI (higher ORs for low BMI in current smokers) and estrogen receptor (ER) status (higher ORs for low BMI in ER− cancers). Conclusion: Women with low BMI may benefit from a tailored approach to breast cancer detection, particularly if they smoke.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The three-component reaction-diffusion system introduced in [C. P. Schenk et al., Phys. Rev. Lett., 78 (1997), pp. 3781–3784] has become a paradigm model in pattern formation. It exhibits a rich variety of dynamics of fronts, pulses, and spots. The front and pulse interactions range in type from weak, in which the localized structures interact only through their exponentially small tails, to strong interactions, in which they annihilate or collide and in which all components are far from equilibrium in the domains between the localized structures. Intermediate to these two extremes sits the semistrong interaction regime, in which the activator component of the front is near equilibrium in the intervals between adjacent fronts but both inhibitor components are far from equilibrium there, and hence their concentration profiles drive the front evolution. In this paper, we focus on dynamically evolving N-front solutions in the semistrong regime. The primary result is use of a renormalization group method to rigorously derive the system of N coupled ODEs that governs the positions of the fronts. The operators associated with the linearization about the N-front solutions have N small eigenvalues, and the N-front solutions may be decomposed into a component in the space spanned by the associated eigenfunctions and a component projected onto the complement of this space. This decomposition is carried out iteratively at a sequence of times. The former projections yield the ODEs for the front positions, while the latter projections are associated with remainders that we show stay small in a suitable norm during each iteration of the renormalization group method. Our results also help extend the application of the renormalization group method from the weak interaction regime for which it was initially developed to the semistrong interaction regime. The second set of results that we present is a detailed analysis of this system of ODEs, providing a classification of the possible front interactions in the cases of $N=1,2,3,4$, as well as how front solutions interact with the stationary pulse solutions studied earlier in [A. Doelman, P. van Heijster, and T. J. Kaper, J. Dynam. Differential Equations, 21 (2009), pp. 73–115; P. van Heijster, A. Doelman, and T. J. Kaper, Phys. D, 237 (2008), pp. 3335–3368]. Moreover, we present some results on the general case of N-front interactions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Daylight availability data are essential for designing effectively day lighted buildings. In respect to no available daylight availability data in Iran, illuminance data on the south facing vertical surfaces were estimated using a proper method. Methods: An illuminance measuring set was designed for measuring vertical illuminances for standard times over 15 days at one hour intervals from 9 a.m. to 3 p.m. at three measuring stations (Hamadan, Eshtehard and Kerman). Measuring data were used to confirm predicted by the IESNA method. Results: Measurement of respective illuminances on the south vertical surfaces resulted in minimum values of 10.5 KLx, mean values of 33.59 KLx and maximum values of 79.6 KLx. Conclusion: In this study was developed a regression model between measured and calculated data of south facing vertical illuminance. This model, have a good linear correlation between measured and calculated values (r= 0.892).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper develops and applies a multi-criteria procedure, incorporating changes in natural frequencies, modal flexibility and the modal strain energy, for damage detection in slab-on-girder bridges. The proposed procedure is first validated through experimental testing of a model bridge. Numerically simulated modal data obtained through finite element analyses are then used to evaluate the vibration parameters before and after damage and used as the indices for assessment of the state of structural health. The procedure is illustrated by its application to full scale slab-on-girder bridges under different damage scenarios involving single and multiple damages on the deck and girders.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Mobile devices are becoming indispensable personal assistants in people's daily life as these devices support work, study, play and socializing activities. The multi-modal sensors and rich features of smartphones can capture abundant information about users' life experience, such as taking photos or videos on what they see and hear, and organizing their tasks and activities using calendar, to-do lists, and notes. Such vast information can become useful to help users recalling episodic memories and reminisce about meaningful experiences. In this paper, we propose to apply autobiographical memory framework to provide an effective mechanism to structure mobile life-log data. The proposed model is an attempt towards a more complete personal life-log indexing model, which will support long term capture, organization, and retrieval. To demonstrate the benefits of the proposed model, we propose some design solutions for enabling users-driven capture, annotation, and retrieval of autobiographical multimedia chronicles tools.