Comparing methods for prescribing exercise for individuals with chronic heart failure

This study examined the accuracy of current recommended guidelines for prescribing exercise intensity using the methods of percentage of heart rate reserve (%HRR), percentage of VO2 peak (%VO2peak) and percentage of VO2 reserve (%VO2R) in a clinical population of chronic heart failure (CHF) patients. The precision of prescription of exercise intensity for 45 patients with stable CHF (39:6 M:F, 65&plusmn;9 yrs (mean&plusmn;SD)) was investigated. VO2peak testing is relatively common among patients with cardiac disease, but the assessment of VO2rest is not common practice and the accepted standard value of 3.5 mL/kg/min is assumed in the application of %VO2R (%VO2R3.5). In this study, VO2rest was recorded for 3 min prior to the start of a symptom-limited exercise test on a cycle ergometer. Target exercise intensities were calculated using the VO2 corresponding to 50 or 80 %HRR, VO2peak and VO2R. The VO2 values were then converted into prescribed speeds on a treadmill in km/hr at 1 %grade using ACSM&rsquo;s metabolic equation for walking. Target intensities and prescribed treadmill speeds were also calculated with the %VO2R method using the mean VO2rest value of participants (3.9 mL/kg/min) (%VO2R3.9). This was then compared to the exercise intensities and prescribed treadmill speeds using patient&rsquo;s measured VO2rest. Error in prescription correlates the difference between %VO2R3.5 and %VO2R3.9 compared to %VO2R with measured VO2rest. Prescription of exercise intensity through the %HRR method is imprecise for patients on medications that blunt the HR response to exercise. %VO2R method offers a significant improvement in exercise prescription compared to %VO2peak. However, a disparity of 10 % still exists in the %VO2R method using the standard 3.5 mL/kg/min for VO2rest in the %VO2R equation. The mean measured VO2rest in the 45 CHF patients was 11 % higher (3.9&plusmn;0.8 mL/kg/min) than the standard value provided by ACSM. Applying the mean measured VO2rest value of 3.9 mL/kg/min rather than the standard assumed value of 3.5 mL/kg/min proved to be closer to the prescribed intensity determined by the actual measured resting VO2. These results suggest that the %HRR method should not be used to prescribe exercise intensity for CHF patients. Instead, VO2 should be used to prescribe exercise intensity and be expressed as %VO2R with measured variables (VO2rest and VO2peak).<br /

Control of deviations and prediction of surface roughness from micro machining of THz waveguides using acoustic emission signals

By using acoustic emission (AE) it is possible to control deviations and surface quality during micro milling operations. The method of micro milling is used to manufacture a submillimetre waveguide where micro machining is employed to achieve the required superior finish and geometrical tolerances. Submillimetre waveguide technology is used in deep space signal retrieval where highest detection efficiencies are needed and therefore every possible signal loss in the receiver has to be avoided and stringent tolerances achieved. With a sub-standard surface finish the signals travelling along the waveguides dissipate away faster than with perfect surfaces where the residual roughness becomes comparable with the electromagnetic skin depth. Therefore, the higher the radio frequency the more critical this becomes. The method of time-frequency analysis (STFT) is used to transfer raw AE into more meaningful salient signal features (SF). This information was then correlated against the measured geometrical deviations and, the onset of catastrophic tool wear. Such deviations can be offset from different AE signals (different deviations from subsequent tests) and feedback for a final spring cut ensuring the geometrical accuracies are met. Geometrical differences can impact on the required transfer of AE signals (change in cut off frequencies and diminished SNR at the interface) and therefore errors have to be minimised to within 1 µm. Rules based on both Classification and Regression Trees (CART) and Neural Networks (NN) were used to implement a simulation displaying how such a control regime could be used as a real time controller, be it corrective measures (via spring cuts) over several initial machining passes or, with a micron cut introducing a level plain measure for allowing setup corrective measures (similar to a spirit level)

Regionale kennisarrangementen: verslag van quickscan en kennisdag 2009

In veel regio’s zijn burgers, bestuurders en ondernemers actief betrokken bij de ontwikkeling van hun omgeving. In het kader van gebiedsplannen wordt gewerkt aan doelen op het terrein van landschap, natuur, landbouw en plattelandsontwikkeling. Hierbij komen uiteenlopende (kennis)vragen naar boven. De kennisvragen worden vaak ad hoc gesteld en men weet vaak niet waar men terecht kan. In een aantal regio’s in Nederland wordt dit verschijnsel onderkend en groeit het besef dat het zoeken naar de antwoorden op deze kennisvragen een serieuze bijdrage levert aan gebiedsontwikkeling. Hier wordt een verbinding met onderwijs en onderzoek gemaakt. Omdat ook bij de kennisinstellingen steeds vaker wordt gezocht naar manieren om meer praktijkgerichte werken, ontstaan er samenwerkingsverbanden. Deze verbindingen tussen regio en onderwijs en onderzoek rond kennisvragen, noemen we een regionaal kennisarrangemen

Dexamethasone for the prevention of a pain flare after palliative radiotherapy for painful bone metastases:a multicenter double-blind placebo-controlled randomized trial

Background: Radiotherapy has a good effect in palliation of painful bone metastases, with a pain response rate of more than 60%. However, shortly after treatment, in approximately 40% of patients a temporary pain flare occurs, which is defined as a two-point increase of the worst pain score on an 11-point rating scale compared to baseline, without a decrease in analgesic intake, or a 25% increase in analgesic intake without a decrease in worst pain score, compared to baseline. A pain flare has a negative impact on daily functioning and mood of patients. It is thought to be caused by periostial edema after radiotherapy. Dexamethasone might diminish this edema and thereby reduce the incidence of pain flare. Two non-randomized studies suggest that dexamethasone reduces the incidence of a pain flare by 50%. The aim of this trial is to study the effectiveness of dexamethasone to prevent a pain flare after palliative radiotherapy for painful bone metastases and to determine the optimal dose schedule. Methods and design: This study is a three-armed, double-blind, placebo-controlled multicenter trial. We aim to include 411 patients with uncomplicated painful bone metastases from any type of primary solid tumor who receive short schedule radiotherapy (all conventional treatment schedules from one to six fractions). Arm 1 consists of daily placebo for four days, arm 2 starts with 8 mg dexamethasone before the (first) radiotherapy and three days placebo thereafter. Arm 3 consists of four days 8 mg dexamethasone. The primary endpoint is the occurrence of a pain flare. Secondary endpoints are pain, quality of life and side-effects of dexamethasone versus placebo. Patients complete a questionnaire (Brief Pain Inventory with two added questions about side-effects of medication, the EORTC QLQ-C15-PAL and QLQ-BM22 for quality of life) at baseline, daily for two weeks and lastly at four weeks. Discussion: This study will show whether dexamethasone is effective in preventing a pain flare after palliative radiotherapy for painful bone metastases and, if so, to determine the optimal dose

Randomized controlled study of pain education in patients receiving radiotherapy for painful bone metastases

BACKGROUND: Although short-course radiotherapy is an effective treatment for patients with painful bone metastases, pain is not always sufficiently controlled. We therefore investigated the additional effect of a nurse-led pain education program on pain control and quality of life (QoL).PATIENTS AND METHODS: In this multicenter study, patients with solid tumor bone metastases and a worst pain intensity of ≥5 on a 0-10 numeric rating scale (NRS) were randomized between care as usual (control-group) and care as usual plus the Pain Education Program (PEP-group). PEP consisted of a structured interview and personalized education with follow-up phone calls. Patients completed the Brief Pain Inventory, EORTC QLQ-C15-PAL and BM22 at week 0, 1, 4, 8 and 12. The primary outcome was pain control, defined as the number of patients whose worst pain intensity was &lt;5 on a 0-10 NRS after 12 weeks. Secondary outcomes were time to reach control of pain (NRS &lt; 5), mean worst pain and average pain, and QoL at weeks 1, 4, 8 and 12.RESULTS: Of 308 included patients, 182 (92 PEP-group) completed 12 weeks follow-up. At 12 weeks, more patients in the PEP-group (71%) compared to the control-group (52%) reported pain control (P =.008). In the PEP-group, pain control was reached earlier than in the control-group (median 29 days versus 56 days; P =.003). Mean worst and average pain decreased in both groups but decreased more in the PEP-group. QoL did not differ between the groups.CONCLUSION: The addition of PEP to care as usual for patients treated with radiotherapy for painful bone metastases resulted in less pain and faster pain control.</p

Landscape level associations between birds, mosquitoes and microclimates: possible consequences for disease transmission?

oai:scholarlypublications.universiteitleiden.nl:item_3731020Environmental Biolog

Carbohydrate Intake in the Etiology of Crohn's Disease and Ulcerative Colitis

Background: Diet may have a role in the etiology of inflammatory bowel disease. In previous studies, the associations between increased intakes of carbohydrates, sugar, starch, and inflammatory bowel disease are inconsistent. However, few prospective studies have investigated the associations between these macronutrients and incident Crohn's disease (CD) or ulcerative colitis (UC). Methods: A total of 401,326 men and women were recruited between 1991 and 1998. At recruitment, dietary intakes of carbohydrate, sugar, and starch were measured using validated food frequency questionnaires. The cohort was monitored identifying participants who developed incident CD or UC. Cases were matched with 4 controls, and odds ratios were calculated for quintiles of total carbohydrate, sugar, and starch intakes adjusted for total energy intake, body mass index, and smoking. Results: One hundred ten participants developed CD, and 244 participants developed UC during follow-up. The adjusted odds ratio for the highest versus the lowest quintiles of total carbohydrate intake for CD was 0.87, 95% CI = 0.24 to 3.12 and for UC 1.46, 95% CI = 0.62 to 3.46, with no significant trends across quintiles for either (CD, Ptrend = 0.70; UC, Ptrend = 0.41). Similarly, no associations were observed with intakes of total sugar (CD, Ptrend = 0.50; UC, Ptrend = 0.71) or starch (CD, Ptrend = 0.69; UC, Ptrend = 0.17). Conclusions: The lack of associations with these nutrients is in agreement with many case–control studies that have not identified associations with CD or UC. As there is biological plausibility for how specific carbohydrates could have an etiological role in inflammatory bowel disease, future epidemiological work should assess individual carbohydrates, although there does not seem to be a macronutrient effect

The Influence of Scale Preferences on the Design of a Water Innovation: A Case in Dutch River Management

The debate on scale use in river management focuses primarily on the (lack of) fit between the bio-geophysical and institutional systems. However, in this article we focus on the ‘subjective’ aspect of scale preferences in water governance. We apply an adapted version of the Integrated Scale Hierarchy for Rivers to determine the degree of fit between the scale preferences of the actors involved in a Dutch case study and the scale requirements of the innovative river management concept. This allows us to understand which riverine processes and characteristics are regarded as important by the different actors and to identify mismatches in scale perspectives as they manifest themselves in water management practice. We discover that inflexibility in scale use on the part of the involved actors places bounds on the design and quality of interventions and demonstrate that a more flexible use of scales in the design phase of a river management intervention has the potential to lead to more effective solutions

Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine

In the field of predictive, preventive and personalised medicine, researchers are keen to identify novel and reliable ways to predict and diagnose disease, as well as to monitor patient response to therapeutic agents. In the last decade alone, the sensitivity of profiling technologies has undergone huge improvements in detection sensitivity, thus allowing quantification of minute samples, for example body fluids that were previously difficult to assay. As a consequence, there has been a huge increase in tear fluid investigation, predominantly in the field of ocular surface disease. As tears are a more accessible and less complex body fluid (than serum or plasma) and sampling is much less invasive, research is starting to focus on how disease processes affect the proteomic, lipidomic and metabolomic composition of the tear film. By determining compositional changes to tear profiles, crucial pathways in disease progression may be identified, allowing for more predictive and personalised therapy of the individual. This article will provide an overview of the various putative tear fluid biomarkers that have been identified to date, ranging from ocular surface disease and retinopathies to cancer and multiple sclerosis. Putative tear fluid biomarkers of ocular disorders, as well as the more recent field of systemic disease biomarkers, will be shown

Het versterken van ondernemerschap in de regio : ervaringen vanuit regionale kennisarrangementen

Het kenniswerkplaatsmodel als kennisarrangement is niet als een blauwdruk door te vertalen van regio naar regio. Dit vergt een aanpak op maat. Wel kunnen regio's onderling leren van de verschillende aanpakken. Om de continuïteit voor de kenniswerkplaats te borgen is het van belang dat de kennisagenda die leidt tot de uitvoering van projecten, opgehangen wordt aan de kapstok van een regionale langetermijnvisie