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Purpose: This focus group study aimed to explore experiences and perceptions on post-stroke fatigue guidance in Dutch rehabilitation and follow-up care among people/patients with stroke and health professionals. Methods: Ten persons with stroke and twelve health professionals with different professions within stroke rehabilitation or follow-up care in the Netherlands were purposively sampled and included. Eight online focus group interviews were conducted. We analysed the data using reflexive thematic analysis. Results: Three themes were identified. Guidance in fatigue management did not always match the needs of people/patients with stroke. Professionals were positive about the provided fatigue guidance (e.g. advice on activity pacing), but found it could be better tailored to the situation of people/patients with stroke. Professionals believe the right time for post-stroke fatigue guidance is when people/patients with stroke are motivated to change physical activity behaviour to manage fatigue – mostly several months after stroke – while people/patients with stroke preferred information on post-stroke fatigue well before discharge. Follow-up care and suggestions for improvement described that follow-up support after rehabilitation by a stroke coach is not implemented nationwide, while people/patients with stroke and professionals expressed a need for it. Conclusions: The study findings will help guide improvement of fatigue guidance in stroke rehabilitation programmes and stroke follow-up care aiming to improve physical activity, functioning, participation, and health. IMPLICATIONS FOR REHABILITATION: We recommend fatigue guidance, including peer support, to be accessible to all people after stroke and for health professionals to pay attention to acceptance of the stroke. To improve fatigue guidance, we suggest providing information on post-stroke fatigue to people after stroke and their relatives well before discharge from stroke rehabilitation. Tailored advice on activity pacing during and after stroke rehabilitation is important to fill the current unmet need of people after stroke to manage fatigue and to gradually improve participation, physical activity behaviour and health. We recommend to health professionals working in stroke rehabilitation to tailor the rehabilitation schedule to their patients' energy level and perception of fatigue levels. [ABSTRACT FROM AUTHOR]

Aim: To examine the hypothesis that, based on their glucose curves during a seven‐point oral glucose tolerance test, people at elevated type 2 diabetes risk can be divided into subgroups with different clinical profiles at baseline and different degrees of subsequent glycaemic deterioration. Methods: We included 2126 participants at elevated type 2 diabetes risk from the Diabetes Research on Patient Stratification (IMI‐DIRECT) study. Latent class trajectory analysis was used to identify subgroups from a seven‐point oral glucose tolerance test at baseline and follow‐up. Linear models quantified the associations between the subgroups with glycaemic traits at baseline and 18 months. Results: At baseline, we identified four glucose curve subgroups, labelled in order of increasing peak levels as 1–4. Participants in Subgroups 2–4, were more likely to have higher insulin resistance (homeostatic model assessment) and a lower Matsuda index, than those in Subgroup 1. Overall, participants in Subgroups 3 and 4, had higher glycaemic trait values, with the exception of the Matsuda and insulinogenic indices. At 18 months, change in homeostatic model assessment of insulin resistance was higher in Subgroup 4 (β = 0.36, 95% CI 0.13–0.58), Subgroup 3 (β = 0.30; 95% CI 0.10–0.50) and Subgroup 2 (β = 0.18; 95% CI 0.04–0.32), compared to Subgroup 1. The same was observed for C‐peptide and insulin. Five subgroups were identified at follow‐up, and the majority of participants remained in the same subgroup or progressed to higher peak subgroups after 18 months. Conclusions: Using data from a frequently sampled oral glucose tolerance test, glucose curve patterns associated with different clinical characteristics and different rates of subsequent glycaemic deterioration can be identified. [ABSTRACT FROM AUTHOR]

Purpose: To identify Health-related Quality of Life (HR-QoL) trajectories in a large heterogeneous cohort of people with a physical disability and/or chronic disease during and after rehabilitation and to determine which factors before discharge are associated with longitudinal trajectory membership. Methods: A total of 1100 people with a physical disability and/or chronic disease were included from the longitudinal cohort study Rehabilitation, Sports and Active lifestyle. All participants participated in a physical activity promotion programme in Dutch rehabilitation care. HR-QoL was assessed using the RAND-12 Health Status Inventory questionnaire at baseline (T0: 3–6 weeks before discharge) and at 14 (T1), 33 (T2) and 52 (T3) weeks after discharge from rehabilitation. A data-driven approach using Latent Class Growth Mixture modelling was used to determine HR-QoL trajectories. Multiple binomial multivariable logistic regression analyses were used to determine person-, disease- and lifestyle-related factors associated with trajectory membership. Results: Three HR-QoL trajectories were identified: moderate (N = 635), high (N = 429) and recovery (N = 36). Trajectory membership was associated with person-related factors (age and body mass index), disease-related factors (perceived fatigue, perceived pain and acceptance of the disease) and one lifestyle-related factor (alcohol consumption) before discharge from rehabilitation. Conclusions: Most of the people who participated in a physical activity promotion programme obtained a relatively stable but moderate HR-QoL. The identified HR-QoL trajectories among our heterogeneous cohort are disease-overarching. Our findings suggest that people in rehabilitation may benefit from person-centred advice on management of fatigue and pain (e.g. activity pacing) and the acceptance of the disability. [ABSTRACT FROM AUTHOR]

Objectives: Health-related quality of life (HR-QoL) of patients with heart failure (HF) is low despite the aim of HF treatment to improve HR-QoL. To date, most studies have focused on medical and physical factors in relation to HR-QoL, few data are available on the role of emotional factors such as dispositional optimism. This study examines the prevalence of optimism and pessimism in HF patients and investigates how optimism and pessimism are associated with different patient characteristics and HR-QoL.Methods: Dispositional optimism was assessed in 86 HF patients (mean age 70 ± 9 years, 28% female, mean left ventricular ejection fraction 33%) with the Revised Life Orientation Test (LOT-R). HR-QoL was assessed with the Minnesota Living with Heart Failure Questionnaire and the EuroQol.Results: The (mean ± SD) total score on the LOT-R was 14.6 ± 2.9 (theoretical range 0-24) and the scores on the subscales optimism and pessimism were 8.1 ± 1.9 and 5.5 ± 2.5, respectively. Higher age was related to more optimism (r = 0.22, p < 0.05), and optimism was associated with higher generic HR-QoL (B = 0.04, p < 0.05).Significance of resultsThe association found between optimism and generic HR-QoL of HF patients can lead to promising strategies to improve HF patients' HR-QoL, particularly because the literature has indicated that optimism is a modifiable condition. [ABSTRACT FROM AUTHOR]

Summary: Background: Children with overweight or obesity are at risk for developing obesity in adulthood. Certain maternal characteristics, such as ethnicity, education, body mass index (BMI) or neighbourhood, are determinants for childhood overweight risk. There are large variations in how mothers differing in these characteristics feed their infants. Therefore, associations of age at complementary feeding, exclusive breast feeding duration with childhood overweight may differ in these groups. Understanding these associations would be essential to develop overweight prevention strategies. Objectives: The objective of this study is to study the associations of age at complementary feeding, exclusive breastfeeding duration with BMI‐standard deviation score (SDS) at 5–6 years within risk groups. Methods: Using data from the Amsterdam Born Children and their Development study, a population‐based birth cohort (n = 4495), we formed groups of children at varying risk of overweight according to maternal characteristics of ethnicity, education, pre‐pregnancy BMI and neighbourhood. Linear and logistic regression analyses were conducted. Results: Complementary feeding after 5 months of age was associated with lower BMI‐SDS in children of mothers of Dutch ethnicity (B: −0.12; 95% CI: −0.21, −0.04), medium‐level education (−0.19; −0.30, −0.08), normal BMI (−0.08; −0.16, −0.01) and high‐risk neighbourhood (−0.16; −0.29, −0.02). Compared with exclusive breastfeeding for <3 months, exclusive breastfeeding for ≥6 months was associated with lower BMI‐SDS in groups of medium‐level education (−0.28; 0.44, −0.11), normal BMI (−0.18; −0.29, −0.08) and medium‐risk (−0.18; −0.33, −0.04) and high‐risk (−0.22; −0.42, −0.02) neighbourhoods. Conclusions: Associations between infant feeding practices and childhood BMI may differ between risk groups, implying that overweight prevention strategies should be group‐specific. [ABSTRACT FROM AUTHOR]

Background: Information on the course of neck pain (NP) and low back pain (LBP) typically relies on data collected at few time intervals during a period of up to 1 year.Methods: In this prospective, multicentre practice-based cohort study, patients consulting a chiropractor responded weekly for 52 weeks to text messages on their cell phones. Data from 448 patients (153 NP, 295 LBP) who had returned at least one set of answers in the first 26 weeks were used. Outcome measures were pain intensity (VAS) and functional outcome, assessed using four different questions: pain intensity, limitation in activities of daily living (ADL), number of days with pain in the previous week and number of days limited in ADL. Distinct patterns of pain were analysed with quadratic latent class growth analysis.Results: The final model was a 4-class model for NP and LBP. The 'recovering from mild baseline pain' is most common (76.3% of NP patients/58.3% of LBP patients) followed by the 'recovering from severe baseline pain' class (16.3% NP/29.8% LBP). They follow similar trajectories when considered over a period of 6 months. Pain at baseline, duration of complaints, functional status, limitations in ADL and the score on psychosocial scales were the variables that most contributed to distinguish between groups.Conclusions: Most patients with NP or LBP presenting in chiropractic care show a trajectory of symptoms characterized by persistent or fluctuating pain of low or medium intensity. Only a minority either experience a rapid complete recovery or develop chronic severe pain.Significance: Ninety percentage of patients with neck pain or low back pain presenting to chiropractors have a 30% improvement within 6 weeks and then show a trajectory of symptoms characterized by persistent or fluctuating pain of low or medium intensity. Only a minority either experience a rapid complete recovery or develop chronic severe pain. [ABSTRACT FROM AUTHOR]

Objectives: Impediments due to complaints of non-traumatic arm, neck and/or shoulder (CANS) during work often leads to consultation in primary care. This study examines the occurrence of sick leave among workers with new CANS, and evaluates sick leave trajectories and their characteristics.Methods: This prospective 2-year cohort study included workers with a new CANS presenting in general practice. Participants filled out postal questionnaires on sick leave at 6-monthly intervals. Latent class growth mixture modelling was used to identify distinct trajectories of sick leave. Multinomial regression analyses identified characteristics of the subgroups.Results: During follow-up, of the 533 participants 190 reported at least one episode of sick leave due to CANS. Three sick leave trajectories were distinguished: (1) 'low-risk' trajectory (n=366), with a constant low probability over time; (2) 'intermediate risk' trajectory, with a high probability at first consultation followed by a steep decrease in probability of sick leave (n=122); (3) 'high-risk' trajectory (n=45), with a constant high probability of sick leave. Compared to the 'low-risk' trajectory, the other trajectories were characterised by more functional limitations, less specific diagnoses, more work-related symptoms and low coworker support. Specific for the 'high-risk' subgroup were more recurrent symptoms, more musculoskeletal comorbidity, high score on somatisation and low score on job demands.Conclusions: Three trajectories of sick leave were distinguished, graded from favourable to unfavourable. Several complaint-related and work-related factors and somatisation contributed modestly to identify an unfavourable trajectory of sick leave when presenting in primary care with CANS. [ABSTRACT FROM AUTHOR]

Aims To identify HbA1c trajectories after the start of insulin treatment and to identify clinically applicable predictors of the response to insulin therapy. Methods The study population comprised 1203 people with Type 2 diabetes included in the Hoorn Diabetes Care System ( n = 9849). Inclusion criteria were: age ≥ 40 years; initiation of insulin during follow-up after failure to reach HbA1c levels ≤ 53 mmol/mol (7%) with oral glucose-lowering agents; and a follow up ≥ 2 years after initiating insulin. Latent class growth modelling was used to identify trajectories of HbA1c. Subjects considered to be 'off target' had HbA1c levels ≥ 53 mmol/mol (7.0%) during one-third or more of the follow-up time, and those considered to be 'on target' had HbA1c levels ≥ 53 mmol/mol (7.0%) during less than one-third of the follow-up time. Results Four HbA1c trajectories were identified. Most people (88.7%) were classified as having a stable HbA1c trajectory of ~57 mmol/mol (7.4%). Only 24.4% of the people were on target in response to insulin; this was associated with lower HbA1c levels and a higher age at the start of insulin treatment. Conclusions Using latent class growth modelling, four HbA1c trajectories were identified. A quarter of the people starting insulin were on target. Low HbA1c levels and advanced age at the start of insulin therapy were associated with better response to insulin therapy. Initiating insulin earlier improves the likelihood of achieving and sustaining glycaemic control. [ABSTRACT FROM AUTHOR]

Introduction: The clinical course after lumbar microdiscectomy is heterogenous. The primary aim was to evaluate the variability in long-term recovery and to identify outcome trajectories. The secondary aim was to assess whether factors at baseline could predict poor outcome trajectories. Methods: A latent class trajectory analysis was performed to identify outcome trajectories for leg pain (VAS), back pain (VAS), and disability (RMDQ). The best number of clusters was determined by using the Bayesian Information Criterion, Akaike's information criteria, entropy, and overall interpretability. Prediction models for poor outcome trajectories were assessed using multivariable logistic regression analyses. Results: We performed a prospective cohort study with 24 months follow-up and included 479 patients who underwent microdiscectomy. A four-class model provided the best fit for the data. Patients were assigned to the 'large improvement trajectory', the 'moderate improvement, the 'minimal improvement trajectory', and the 'relapse trajectory'. In total, 156 patients (32.6%) belonged to one or more than one poor outcome trajectory. Patients with previous treatment and those who had higher baseline pain and disability scores were more likely to belong to the poor outcome trajectories. Discussion: Patients who were classified as a member of the poor outcome trajectory for a specific outcome were not necessarily a member of a poor outcome trajectory for the other outcomes. Clinicians and patients should set appropriate expectations prior to surgery by illustrating the postoperative outcome trajectories that fit the patients' specific goals and expectations. Process evaluation: This study used commonly captured preoperative data. The role of other biomedical, personal and external factors should be further assessed. [ABSTRACT FROM AUTHOR]

Purpose: To validate a shortened version of the Participation Scale (P-scale) that will be quicker to use and to describe the factor structure found in the P-scale data in various study samples. Methods: A large multi-country and multi-cultural database was compiled consisting of 5125 respondents. Item analysis, explanatory factor analysis and confirmatory factor analysis were applied to identify items for deletion and investigate the factor structure of the P-scale. Results: The multi-country database included 11 databases from six different countries. Respondents were affected by a range of health conditions, including leprosy, HIV/AIDS, dermatological conditions and various disabilities. Of the respondents included 57% were male. The P-scale Short (PSS) contains 13 items. A two-factor structure, with factors named 'work-related participation' (three items) and 'general participation' (10 items), showed the best model fit (Comparative Fit Index = 0.983, Tucker Lewis Index = 0.979, Rooted Mean Square Error of Approximation = 0.061). The Cronbach's alphas were very good for both the whole scale and the subscales, 0.91, 0.83 and 0.90, respectively. Correlation between the two factors was high (r = 0.75) indicating that interpreting the P-scale as measuring an overall factor 'participation' is still valid. A very high correlation ( r = 0.99) was found between the full P-scale and the PSS. Conclusions:The findings suggest good validity of the P-scale across a range of languages and cultures. However, field testing needs to confirm the validity of the PSS to measure the level of social participation restrictions across cultures and health conditions. [ABSTRACT FROM AUTHOR]

Abstract: Background: Perspectives of nurses and patients on the intensity and content of disease management programmes (DMPs) in heart failure are seldom addressed but are important in optimizing these programmes. Aim: To describe the perspectives of patients and nurses on delivered care in two DMPs. Methods: In total 442 patients (62% male; age 68±12years; LVEF 33%±14), assigned to the intervention groups of the Coordinating Study Evaluating Outcomes of Advising and Counselling in HF (COACH), and 32 registered nurses, completed questionnaires on satisfaction with the intensity and components of the DMPs. Results: In spite of large differences in intensity and components, patients were satisfied with the content of both DMPs. In patients (NYHA III–IV), treatment and educational goals were more often achieved in those who received intensive support, compared to patients who received basic support (85% vs. 70%). Patients and nurses perceived that most home visits were adding significant value to the HF care, while 12% of the home visits were perceived as unnecessary by the nurses. Conclusion: Patients and nurses did not perceive the intense DMP as an emotional and physical burden for themselves. Patients with severe HF might be in need of more support to achieve optimal treatment and educational goals. [ABSTRACT FROM AUTHOR]

The association between black tea consumption and iron status was investigated in a sample of African adults participating in the cross-sectional THUSA (Transition and Health during Urbanization of South Africans) study in the North West Province, South Africa. Data were analysed from 1605 apparently healthy adults aged 15–65 years by demographic and FFQ, anthropometric measurements and biochemical analyses. The main outcome measures were Hb and serum ferritin concentrations. No associations were seen between black tea consumption and concentrations of serum ferritin (men P = 0·059; women P = 0·49) or Hb (men P = 0·33; women P = 0·49). Logistic regression showed that tea consumption did not significantly increase risk for iron deficiency (men: OR 1·36; 95 % CI 0·99, 1·87; women: OR 0·98; 95 % CI 0·84, 1·13) nor for iron deficiency anaemia (men: OR 1·28; 95 % CI 0·84, 1·96; women: OR 0·93; 95 % CI 0·78, 1·11). Prevalence of iron deficiency and iron deficiency anaemia was especially high in women: 21·6 and 14·6 %, respectively. However, the likelihood of iron deficiency and iron deficiency anaemia was not significantly explained by tea consumption in sub-populations which were assumed to be at risk for iron deficiency. Regression of serum ferritin levels on tea consumption in women ≤ 40 years, adults with a daily iron intake ≤ 5·80 mg and adults with ferritin levels ≤ 26·60 μg/l, respectively, showed P values in the range of 0·28–0·88. Our findings demonstrate that iron deficiency and iron deficiency anaemia is not significantly explained by black tea consumption in a black adult population in South Africa. Tea intake was also not shown to be related to iron status in several sub-populations at risk for iron deficiency. [ABSTRACT FROM PUBLISHER]

BACKGROUND: Indications exist that deferral rates in blood donors are highest in summer. However, a detailed quantitative analysis is not available. The association between Hb values, deferral rates, and daily temperatures was investigated in a large data set of blood donors. STUDY DESIGN AND METHODS: The study population consisted of both plasma and whole-blood donors from the southeast region of the Netherlands. Individual Hb levels and other examination data between January 2002 and December 2004 were extracted from the donor file. Data on daily maximum temperatures were related to Hb levels and Hb deferrals. Results are reported separately for plasma and whole-blood donors as well as for men and women. RESULTS: Data were available from 106,398 whole blood donors and 6983 plasma donors, resulting in data of more than 600,000 examinations. Hb levels decreased with increasing daily temperature. Highest deferral rates were observed in summer months, which were consistent over the several groups and over the three years. The highest Hb deferral of 11.1 percent was observed for female whole-blood donors on days with a maximum temperature of 25 degrees and above. In all four donor categories a gradual increase with temperature was observed with 1.7-2.2 times higher deferral rates on hot days (≥25°C) compared to cold days (<5°C). CONCLUSION: A clear seasonal pattern in Hb levels and in the percentage of Hb deferrals was observed. The observed seasonal effect could not be explained by differences in donor characteristics. Our observations might have practical implications for donor management. [ABSTRACT FROM AUTHOR]

BACKGROUND: In the past decade, the number of blood donors has steadily declined in the Netherlands, and young adults are underrepresented among registered donors. An understanding of the correlates of donation intentions among nondonors could facilitate targeting psychological prerequisites of donation decisions in recruitment campaigns. STUDY DESIGN AND METHODS. A cross-sectional study with self-administered questionnaires based on an extension of the Theory of Planned Behavior (TPB; a social cognition model to study the determinants of volitional behavior) was conducted to assess potential cognitive determinants of willingness to donate blood in a student sample. A response rate of 50.5 percent yielded a sample of 311. RESULTS: Just over 7 percent of participants were registered blood donors but most (61.7%) had never seriously considered becoming donors. Self-efficacy (confidence in performing the behavior), attitude (the overall evaluation of the behavior), and personal moral norm (the perceived personal responsibility to perform the behavior) regarding blood donation were the most important correlates of the intention to become a blood donor. In total, 43 percent of the variance in the intentions toward blood donation could be explained by a TPB-based model. CONCLUSION: Among students, determinants of the intention to become a blood donor include self-efficacy, attitude, personal moral norm regarding blood donation, and subjective norm (perceived social support). Future research could establish whether campaigns targeting these psychological prerequisites would be more effective than current strategies. [ABSTRACT FROM AUTHOR]

In the past decade, the number of blood donors has steadily declined in the Netherlands, and young adults are underrepresented among registered donors. An understanding of the correlates of donation intentions among nondonors could facilitate targeting psychological prerequisites of donation decisions in recruitment campaigns.A cross-sectional study with self-administered questionnaires based on an extension of the Theory of Planned Behavior (TPB; a social cognition model to study the determinants of volitional behavior) was conducted to assess potential cognitive determinants of willingness to donate blood in a student sample. A response rate of 50.5 percent yielded a sample of 311.Just over 7 percent of participants were registered blood donors but most (61.7%) had never seriously considered becoming donors. Self-efficacy (confidence in performing the behavior), attitude (the overall evaluation of the behavior), and personal moral norm (the perceived personal responsibility to perform the behavior) regarding blood donation were the most important correlates of the intention to become a blood donor. In total, 43 percent of the variance in the intentions toward blood donation could be explained by a TPB-based model.Among students, determinants of the intention to become a blood donor include self-efficacy, attitude, personal moral norm regarding blood donation, and subjective norm (perceived social support). Future research could establish whether campaigns targeting these psychological prerequisites would be more effective than current strategies. [ABSTRACT FROM AUTHOR]

The objective of this study was to gain a better understanding of the seclusion room experiences of chronic psychiatric patients, the way in which they cope with their seclusion room experience, and the effect of seclusion on subsequent relations with care providers. A qualitative research design was used, in line with the procedure of Grounded Theory. Semi-structured interviews were held with seven chronic psychiatric outpatients whose seclusion took place at a certain remove in time. The transcriptions were analyzed with the aid of Winmax. The following results were found. Most seclusion experiences by far are negative. However, patients whose experience took place a considerable time ago also mention positive experiences. It is hard to come to terms with the seclusion experience; this is a matter of learning to live with it (adaptation) rather than assimilating it (adjustment, or active coping and controlling). Factors conducive to the coping process are: understanding the reason why it took place, time, distraction, possibilities to discuss it with others, and quick recovery of control. Factors prohibitive to the coping process are: the danger of recurrence, iniquitous treatment by care providers during seclusion, confrontation with others being secluded, and lack of opportunity to talk about it. Seclusion does not affect subsequent relation with care providers, with two exceptions. When patients feel they have been treated iniquitously during seclusion, or when seclusion continues to be a daily threat, this has a negative effect on relations with care providers. The central themes of this study are autonomy, trust, and loneliness. [ABSTRACT FROM AUTHOR]

In this study we applied both linear and nonlinear spatial correlationmeasures to characterize epicardial activation patterns of sustained atrialfibrillation in instrumented conscious goats. It was investigated if nonlinearitywas involved in the spatial coupling of atrial regions and to what extentfibrillation was organized in the experimental model of sustained atrial fibrillation(AF) in instrumented goats. Data were collected in five goats during experiments to convert AF by continuousinfusion of cibenzoline. Spatial organization during AF was quantified withthe linear spatial cross correlation function and the nonlinear spatial crossredundancy which was calculated using the Grassberger-Procaccia correlationintegral. Two different types of correlation were evaluated to distinguishsimultaneous interaction from non-simultaneous interaction, for instance resultingfrom propagation of fibrillation waves. The nonlinear association length andthe linear correlation length were estimated along the principal axes of iso-correlationcontours in two-dimensional correlation maps of the nonlinear spatial redundancyand the linear spatial correlation function, respectively. To quantitatively assess the degree of nonlinearity, the association lengthwas also estimated from the linearized spatial redundancy using multivariatesurrogate data. The differences between the nonlinear and linearized associationlengths indicated that a nonlinear component in the spatial organization ofAF predominantly existed in the right atrium. The degree of organization characterizedby association length along the short principal axis was higher in the rightatrium (15 ± 7 mm) than in the left atrium (8 ± 4 mm). The spatialextension of coherent atrial patches was estimated from a surface of associationequal to the area spanned by the principal axes of iso-correlation contoursfrom the redundancy, including the effects from non-simultaneous interaction.Interpreting this area as the spati... [ABSTRACT FROM AUTHOR]

The nonlinear spatial redundancy and the linear spatial correlationfunction were used to investigate to what extent non-linearity was involvedin the coupling of atrial regions and how organization in activation patternsof sustained atrial fibrillation (AF) had been modified by administrationof the class IC agent cibenzoline in the experimental model of sustained AFin instrumented conscious goats. Electrograms were measured in five goats during sustained AF and when thefibrillation interval had been prolonged to about 25%, 50% and 85% (CIB25,CIB50, CIB85) with respect to control. The nonlinear association length andlinear correlation length were estimated along the principal axes of two-dimensionalcorrelation maps estimated from the spatial redundancy and the spatial correlationfunction, respectively. The estimated short axis association length in the right atrium increasedalready shortly after the start of infusion (CIB25, +61%), and remained significantlydifferent from control during the experiment, including the effects of non-simultaneousinteraction. At CIB85 the association length had almost become twice as longwith respect to control (increase from 16 to 29 mm, 89%), while in the leftatrium changes were less pronounced (increase from 9 to 12 mm, +32%). Thelinearized association length which was estimated using multivariate surrogatedata increased more gradually and was less sensitive to changes in spatialorganization. The results of the spatial correlation analysis suggest thatthe drug-induced nonlinearity in the spatio-temporal dynamics of sustainedAF is related to activation patterns which are characterized by extended uniformlypropagating fibrillation wavefronts (AF type I). We conclude that cibenzoline enhanced the spatial organization of sustainedAF associated with a transition from type II to type I AF activation patterns.This may destabilize the perpetuation of AF since an increase in associationlength is equivalent to a reduction of atrial ti... [ABSTRACT FROM AUTHOR]

Historically, societies have been abandoned when management invoked complicated infrastructure that diminished returns on effort. Some societies survived by redefining their relationship to the resource base through emergence of a new, more elaborate level of organization. Organization may elaborate when resources are expanded or used more efficiently. The new situation favorably resets the cost/benefit ratio of problem solving. With six billion people, our critical problem is the capture of natural resources while maintaining ecosystem function to keep them renewable. Presently resource management is too complicated at too low a level, and suffers diminishing returns. Supply-side sustainability recommends management from the context for the function of the whole ecosystem, not the resource. Then ecosystems integrate materials and energy sustainability, while generating resources that humans can take. To achieve a global level of organization of resource management we see a new relationship between the feedback of commerce, greened by the social and environmental resource sciences in the academy, with governmental catalysis. Copyright © 1999 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The treatment of linseed oil by the action of electric discharges (voltolization) in a hydrogen atmosphere (80 mm. Hg, 70°C.) is described. It has been known for a long time that voltolization of linseed oil brings about a polymerization of the oil. Now it has been proven that the nature of the polymerization product thus obtained is absolutely different from that of thermally or catalytically polymerized linseed oils. In contrast to the latter, voltolized linseed oils contain only small amounts of cyclic compounds. Their viscosity is relatively low, even at a high polymerization degree, and considerably less than that of thermally polymerized oils of a corresponding degree of polymerization. Atomic hydrogen seems to play an important part in the voltolization process. Coupling of fatty acid chains is made possible by combining radicals, formed primarily by the action of hydrogen atoms. Coupling reaction occurs almost exclusively intermolecularly. The possibility of transforming linseed oil and other drying oils into polymerization products of a completely different chemical structure, depending on the applied polymerization process, opens new possibilities for their manufacture. [ABSTRACT FROM AUTHOR]

A response from the author of the article "Patients with heart failure with preserved ejection fraction and low levels of natriuretic peptides" is presented.

Erbium-doped YO integrated optical amplifiers are designed for low-threshold operation and 3 dB amplification. The most important design parameter for minimal threshold, the erbium concentration, is found to have an optimum value of 0.35 at% for a given waveguide structure with 1.0 dB cm background loss. The corresponding threshold power is 7 mW. The pump power to obtain 3 dB gain is found to be 22 mW for an amplifier with an optimum erbium concentration of 0.6 at% and 2.8 cm length. At 30 mW pump power the maximum gain is shown to be 5 dB. Designing is done using a comprehensive numerical model of an erbium-doped integrated optical amplifier. In the model two-dimensional intensity-dependent overlap integrals are used, which allow arbitrary erbium dopant profiles and waveguide crosssections. Concentration-dependent effects such as quenching and upconversion are also included in the model. Input parameters for the model are determined from measurements on an unoptimized Er: YO optical waveguide amplifier. Amplification simulations and gain measurements of the unoptimized waveguides are found to be in close agreement, providing a sound basis for the design calculations. [ABSTRACT FROM AUTHOR]