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A photothermal technique for the characterization of semiconductor materials is presented, in combination with the theoretical description of the signal generation process of the effects of the charge carrier density on the IR optical properties. It relies on the excitation of charge carrier density waves by modulated laser irradiation in the visible spectrum, leading to periodical variations of the IR optical properties. The detection is based on sensing the ir transmission of the semiconductor sample. The modulated laser irradiation in the visible simultaneously leads to small temperature variations and additional signal contributions due to the modulation of the internal IR radiation, which can be minimized and eliminated by appropriate focussing conditions. A principal understanding of the signal generation mechanism has been achieved by timedependent measurements with a gradually increasing intensity of the external IR radiation source, while frequency-dependent measurements of the modulated IR transmission signal provide quantitative information on the semiconductor properties. [ABSTRACT FROM AUTHOR]

Objective: In rheumatoid arthritis (RA), chronic inflammation can enhance the development of sarcopenia with a depletion of muscle mass, strength and performance. Currently, a consensus definition for sarcopenia and solid results for the prevalence of sarcopenia in patients with RA are lacking., Methods: In this cross-sectional study, 289 patients ≥18 years with RA were recruited. Dual X-ray absorptiometry was performed to measure appendicular lean mass. Assessment of muscle function included grip strength, gait speed and chair rise time. Prevalence of sarcopenia was defined using the updated European Working Group on Sarcopenia in Older People (EWGSOP2) and the Foundation for the National Institutes of Health (FNIH) definition. In addition, the RA study population was compared with existing data of healthy controls (n=280)., Results: 4.5% of patients (59.4±11.3 years) and 0.4% of controls (62.9±11.9 years) were affected by sarcopenia according to the EWGSOP2 definition. Body weight (OR 0.92, 95% CI 0.86 to 0.97), body mass index (BMI) (OR 0.70, 95% CI 0.57 to 0.87), C reactive protein (CRP) (OR 1.05, 95% CI 1.01 to 1.10), disease duration (OR 1.08, 95% CI 1.02 to 1.36), current medication with glucocorticoids (OR 5.25, 95% CI 2.14 to 24.18), cumulative dose of prednisone equivalent (OR 1.04, 95% CI 1.02 to 1.05) and Health Assessment Questionnaire (HAQ) (OR 2.50, 95% CI 1.27 to 4.86) were associated with sarcopenia in patients with RA. In contrast, the prevalence was 2.8% in patients compared with 0.7% in controls when applying the FNIH definition, and body height (OR 0.75, 95% CI 0.64 to 0.88), BMI (OR 1.20, 95% CI 1.02 to 1.41), CRP (OR 1.06, 95% CI 1.01 to 1.11) and HAQ (OR 2.77, 95% CI 1.17 to 6.59) were associated with sarcopenia., Conclusion: Sarcopenia is significantly more common in patients with RA compared with controls using the EWGSOP2 criteria. The FNIH definition revealed sarcopenia in individuals with high BMI and fat mass, regardless of the presence of RA., Trial Registration Number: It was registered at the German Clinical Trials Registry (DRKS) as well as WHO Clinical Trials Registry (ICTRP) (DRKS00011873, registered on 16 March 2017)., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Postural control is associated with fall risk. Patients with rheumatoid arthritis (RA) have a higher risk to fall than healthy subjects. The objective of this study was to identify associations between variables of postural control with prospective falls in patients with RA., Methods: For the baseline, the balance performance of 289 men and women with RA, ages 24-85 years, was evaluated by SPPB, FICSIT-4 and Romberg tests. Postural sway for Romberg, semitandem, tandem and one-leg stands were measured with the Leonardo Mechanograph®. Self-reported disability was assessed using the Health Assessment Questionnaire (HAQ) and the Activity-specific Balance Confidence Scale (ABC-scale). Falls were reported in quarterly reports over a year. Univariate and multiple logistic regression analysis were used to explore any associations with falling. Receiver-operating characteristics were determined, and the area under the curve is reported., Results: A total of 238 subjects completed the 1-year follow-up, 48 (20.2%) experienced at least one fall during the observational period. Age (OR = 1.04, CI 1.01-1.07), HAQ (OR = 1.62, 1.1-2.38), FICSIT-4 scoring 0-4 (OR = 2.38, 1.13-5.0), and one-leg standing (OR = 2.14, 1.06-4.31) showed significant associations with falls. With regard to the SPPB and ABC-scale, no statistically significant associations with falls were found. The quartiles containing the worst results of medio-lateral sway of Romberg (OR = 2.63, CI 1.03-6.69), total sway of semitandem (OR = 3.07, CI 1.10-8.57) and tandem (OR = 2.86, CI 1.06-7.69), and area of sway of semitandem (OR = 2.80, CI 1.11-7.08) stands were associated with falls., Conclusions: The assessment of a one-leg stand seems to be a good screening tool to discriminate between high and low risk of falls in RA patients in clinical practice. A low FICSIT-4 score and several sway parameters are important predictors of falls., Trial Registration: The study has been registered at the German Clinical Trials Register and the WHO International Clinical Trials Registry Platform (ICTRP) since 16 March 2017 ( DRKS00011873 )., (© 2022. The Author(s).)

Background: Patients with rheumatoid arthritis (RA) are at increased risk of falls and fractures. Sarcopenia occurs more frequently in RA patients due to the inflammatory processes. Early diagnosis and prevention programmes are essential to avoid serious complications. The present study aims to identify risk factors for falls related to sarcopenia and physical performance., Methods: In a 1-year prospective study, a total of 289 patients with RA, ages 24-85 years, were followed using quarterly fall diaries to report falls. At the baseline, medical data such as RA disease duration and Disease Activity Score (DAS28 CRP ) were collected. Self-reported disability was assessed using the Health Assessment Questionnaire (HAQ). Appendicular skeletal mass was determined by Dual X-ray-Absorptiometry (DXA). Physical performance was evaluated by handgrip strength, gait speed, chair rise test, Short Physical Performance Battery, and FICSIT-4. Muscle mechanography was measured with the Leonardo Mechanograph®. Sarcopenia was assessed according to established definitions by the European Working Group on Sarcopenia in Older People (EWGSOP2) and The Foundation for the National Institutes of Health (FNIH). Univariate and multiple logistic regression analysis were used to explore associations with falling. Receiver-operating characteristics (ROC) were performed, and the area under the curve is reported., Results: A total of 238 subjects with RA completed the 1-year follow-up, 48 (20.2%) experienced at least one fall during the observational period. No association was found between sarcopenia and prospective falls. Age (OR = 1.04, CI 1.01-1.07), HAQ (OR = 1.62, 1.1-2.38), and low FICSIT-4 score (OR = 2.38, 1.13-5.0) showed significant associations with falls., Conclusions: In clinical practice, a fall assessment including age, self-reported activities of daily life and a physical performance measure can identify RA patients at risk of falling., Trial Registration: The study has been registered at the German Clinical Trials Register and the WHO International Clinical Trials Registry Platform (ICTRP) since 16 March 2017 ( DRKS00011873 )., (© 2021. The Author(s).)

A modern day light microscope has evolved from a tool devoted to making primarily empirical observations to what is now a sophisticated , quantitative device that is an integral part of both physical and life science research. Nowadays, microscopes are found in nearly every experimental laboratory. However, despite their prevalent use in capturing and quantifying scientific phenomena, neither a thorough understanding of the principles underlying quantitative imaging techniques nor appropriate knowledge of how to calibrate, operate and maintain microscopes can be taken for granted. This is clearly demonstrated by the well-documented and widespread difficulties that are routinely encountered in evaluating acquired data and reproducing scientific experiments. Indeed, studies have shown that more than 70% of researchers have tried and failed to repeat another scientist's experiments, while more than half have even failed to reproduce their own experiments. One factor behind the reproducibility crisis of experiments published in scientific journals is the frequent underreporting of imaging methods caused by a lack of awareness and/or a lack of knowledge of the applied technique. Whereas quality control procedures for some methods used in biomedical research, such as genomics (e.g. DNA sequencing, RNA-seq) or cytometry, have been introduced (e.g. ENCODE), this issue has not been tackled for optical microscopy instrumentation and images. Although many calibration standards and protocols have been published, there is a lack of awareness and agreement on common standards and guidelines for quality assessment and reproducibility. In April 2020, the QUality Assessment and REProducibility for instruments and images in Light Microscopy (QUAREP-LiMi) initiative was formed. This initiative comprises imaging scientists from academia and industry who share a common interest in achieving a better understanding of the performance and limitations of microscopes and improved quality control (QC) in light microscopy. The ultimate goal of the QUAREP-LiMi initiative is to establish a set of common QC standards, guidelines, metadata models and tools, including detailed protocols, with the ultimate aim of improving reproducible advances in scientific research. This White Paper (1) summarizes the major obstacles identified in the field that motivated the launch of the QUAREP-LiMi initiative; (2) identifies the urgent need to address these obstacles in a grassroots manner, through a community of stakeholders including, researchers, imaging scientists, bioimage analysts, bioimage informatics developers, corporate partners, funding agencies, standards organizations, scientific publishers and observers of such; (3) outlines the current actions of the QUAREP-LiMi initiative and (4) proposes future steps that can be taken to improve the dissemination and acceptance of the proposed guidelines to manage QC. To summarize, the principal goal of the QUAREP-LiMi initiative is to improve the overall quality and reproducibility of light microscope image data by introducing broadly accepted standard practices and accurately captured image data metrics., (© 2021 The Authors. Journal of Microscopy published by JohnWiley & Sons Ltd on behalf of Royal Microscopical Society.)

Objectives: The study reports longitudinal changes in grip strength, muscle mass and muscle power of lower extremities. The aim is to identify early muscular changes to improve the diagnosis and treatment of sarcopenia., Methods: Grip strength was measured by hand dynamometer, muscle mass by dual-energy X-ray absorptiometry and muscle power by performing a chair rise test and two-leg jumps (2LJP) on the Leonardo Mechanograph ® . Longitudinal changes were analysed using paired t-tests by age group and sex. Differences between groups in terms of the annual change were tested by Analysis of Variance and the Dunnett's test. Comparisons between the variables were performed using one sample t-tests., Results: Six-year changes were determined in 318 randomly selected healthy participants aged 20-90 years from Berlin. 2LJP declined significantly earlier in 20-39 years old women (-3.70 W/kg) and men (-5.97 W/kg, both p<0.001). This is an absolute annual decline of -0.46 W/kg in females and -0.75 W/kg in males. In the oldest age group, 2LJP showed the highest absolute annual loss with -0.99 W/kg in women and -0.88 W/kg in men. 2LJP was significantly different compared to all variables of muscle mass and strength (p<0.01)., Conclusions: The results underline the importance of assessing muscle power using 2LJP during aging., Competing Interests: The authors of the study received grants from The Danish Research Foundation during the conduct of the study.

Reference values of sway parameters have not been published for the Leonardo mechanograph ® so far. The aim of this cross-sectional study was to determine normative values on postural control measured by the force plate Leonardo Mechanograph ® and to analyze the influence of age and sex on balance performance. A set of standardized standing positions with eyes opened (Romberg, semi-tandem, tandem, unipedal standing) was carried out. Analysis of covariance (ANCOVA) was used to detect age-and sex-related differences in center of pressure (COP) parameters (path length, velocity, elliptical area, anterior-posterior, and medio-lateral directions). Measurements were available for 570 subjects aged 20-86 years. Statistical analysis showed a high effect of age group on postural control (partial n² between 0.1 and 0.4) with a U-shaped dependency between postural control and age for all area- and path-related COP parameters, with the largest sway in the youngest (aged 20-40) and the oldest age group (aged 60-86). For velocity of COP, a linear deterioration with increasing age was found. Medio-lateral components of COP are likely to indicate the extent of postural control. Significant sex differences were not clearly supported by current findings. Age- and sex-related normative values are a useful resource for diagnostic, research, and training.

The extracellular matrix (ECM) plays a vital role in maintaining normal tissue function. Collagens are major components of the ECM and there is a tight equilibrium between degradation and formation of these proteins ensuring tissue health and homeostasis. As a consequence of tissue turnover, small collagen fragments are released into the circulation, which act as important biomarkers in the study of certain tissue-related remodeling factors in health and disease. The aim of this study was to establish an age-related collagen turnover profile of the main collagens of the interstitial matrix (type I and III collagen) and basement membrane (type IV collagen) in healthy men and women. By using well-characterized competitive ELISA-assays, we assessed specific fragments of degraded (C1M, C3M, C4M) and formed (PINP, Pro-C3, P4NP7S) type I, III and IV collagen in serum from 617 healthy men and women ranging in ages from 22 to 86. Subjects were divided into 5-year age groups according to their sex and age. Groups were compared using Kruskal-Wallis adjusted for Dunn's multiple comparisons test and Mann-Whitney t-test. Age-specific changes in collagen turnover was most profound for type I collagen. PINP levels decreased in men with advancing age, whereas in women, the level decreased in early adulthood followed by an increase around the age of menopause (age 40-60). Sex-specific changes in type I, III and IV collagen turnover was present at the age around menopause (age 40-60) with women having an increased turnover. In summary, collagen turnover is affected by age and sex with the interstitial matrix and the basement membrane being differently regulated. The observed changes needs to be accounted for when measuring ECM related biomarkers in clinical studies.

Improved prediction of optimal N fertilizer rates for corn ( Zea mays L. ) can reduce N losses and increase profits. We tested the ability of the Agricultural Production Systems sIMulator (APSIM) to simulate corn and soybean ( Glycine max L. ) yields, the economic optimum N rate (EONR) using a 16-year field-experiment dataset from central Iowa, USA that included two crop sequences (continuous corn and soybean-corn) and five N fertilizer rates (0, 67, 134, 201, and 268 kg N ha -1 ) applied to corn. Our objectives were to: (a) quantify model prediction accuracy before and after calibration, and report calibration steps; (b) compare crop model-based techniques in estimating optimal N rate for corn; and (c) utilize the calibrated model to explain factors causing year to year variability in yield and optimal N. Results indicated that the model simulated well long-term crop yields response to N (relative root mean square error, RRMSE of 19.6% before and 12.3% after calibration), which provided strong evidence that important soil and crop processes were accounted for in the model. The prediction of EONR was more complex and had greater uncertainty than the prediction of crop yield (RRMSE of 44.5% before and 36.6% after calibration). For long-term site mean EONR predictions, both calibrated and uncalibrated versions can be used as the 16-year mean differences in EONR's were within the historical N rate error range (40-50 kg N ha -1 ). However, for accurate year-by-year simulation of EONR the calibrated version should be used. Model analysis revealed that higher EONR values in years with above normal spring precipitation were caused by an exponential increase in N loss (denitrification and leaching) with precipitation. We concluded that long-term experimental data were valuable in testing and refining APSIM predictions. The model can be used as a tool to assist N management guidelines in the US Midwest and we identified five avenues on how the model can add value toward agronomic, economic, and environmental sustainability.

Agricultural systems are being challenged to decrease water use and increase production while climate becomes more variable and the world's population grows. Low water use efficiency is traditionally characterized by high water use relative to low grain production and usually occurs under dry conditions. However, when a cropping system fails to take advantage of available water during wet conditions, this is also an inefficiency and is often detrimental to the environment. Here, we provide a systems-level definition of water use efficiency (sWUE) that addresses both production and environmental quality goals through incorporating all major system water losses (evapotranspiration, drainage, and runoff). We extensively calibrated and tested the Agricultural Production Systems sIMulator (APSIM) using 6 years of continuous crop and soil measurements in corn- and soybean-based cropping systems in central Iowa, USA. We then used the model to determine water use, loss, and grain production in each system and calculated sWUE in years that experienced drought, flood, or historically average precipitation. Systems water use efficiency was found to be greatest during years with average precipitation. Simulation analysis using 28 years of historical precipitation data, plus the same dataset with ± 15% variation in daily precipitation, showed that in this region, 430 mm of seasonal (planting to harvesting) rainfall resulted in the optimum sWUE for corn, and 317 mm for soybean. Above these precipitation levels, the corn and soybean yields did not increase further, but the water loss from the system via runoff and drainage increased substantially, leading to a high likelihood of soil, nutrient, and pesticide movement from the field to waterways. As the Midwestern United States is predicted to experience more frequent drought and flood, inefficiency of cropping systems water use will also increase. This work provides a framework to concurrently evaluate production and environmental performance of cropping systems., (© 2015 John Wiley & Sons Ltd.)

Falls remain a challenge for ageing societies. Strong evidence indicates that a previous fall is the strongest single screening indicator for a subsequent fall and the need for assessing fall risk without accounting for fall history is therefore imperative. Testing in three functional domains (using a total 92 measures) were completed in 84 older women (60-85 years of age), including muscular control, standing balance, and mean and variability of gait. Participants were retrospectively classified as fallers (n = 38) or non-fallers (n = 42) and additionally in a prospective manner to identify first-time fallers (FTFs) (n = 6) within a 12-month follow-up period. Principal component analysis revealed that seven components derived from the 92 functional measures are sufficient to depict the spectrum of functional performance. Inclusion of only three components, related to mean and temporal variability of walking, allowed classification of fallers and non-fallers with a sensitivity and specificity of 74% and 76%, respectively. Furthermore, the results indicate that FTFs show a tendency towards the performance of fallers, even before their first fall occurs. This study suggests that temporal variability and mean spatial parameters of gait are the only functional components among the 92 measures tested that differentiate fallers from non-fallers, and could therefore show efficacy in clinical screening programmes for assessing risk of first-time falling.

Objectives: The aim of this cross-sectional study was to examine the influence of age and sex on neuromuscular function of the lower limbs using mechanography. 704 adults aged 20-85 years from Germany participated in this study., Methods: Ground reaction force and power were assessed with countermovement jumps and the chair rising test on a ground reactions force plate., Results: While ground reaction force per unit body mass declined by about 20% from the third to the ninth decade, the decline of power per unit body mass was much greater, varying between 40-50%. Men and women are affected equally by the decline. Age and sex explained the variability of the power parameters to a much greater extent (R(2)=0.54 to R(2)=0.70) than the force parameters (R(2)=0.18 to R(2)=0.36)., Conclusions: Our reference values can help to identify those who might be affected by the development of sarcopenia. Preventive exercise programs should focus on preserving muscle power in addition to the training of muscle force.

Background: As part of a Berlin-based research consortium on health in old age, the OMAHA (Operationalizing Multimorbidity and Autonomy for Health Services Research in Aging Populations) study aims to develop a conceptual framework and a set of standardized instruments and indicators for continuous monitoring of multimorbidity and associated health care needs in the population 65 years and older., Methods/design: OMAHA is a longitudinal epidemiological study including a comprehensive assessment at baseline and at 12-month follow-up as well as brief intermediate telephone interviews at 6 and 18 months. In order to evaluate different sampling procedures and modes of data collection, the study is conducted in two different population-based samples of men and women aged 65 years and older. A geographically defined sample was recruited from an age and sex stratified random sample from the register of residents in Berlin-Mitte (Berlin OMAHA study cohort, n = 299) for assessment by face-to-face interview and examination. A larger nationwide sample (German OMAHA study cohort, n = 730) was recruited for assessment by telephone interview among participants in previous German Telephone Health Surveys. In both cohorts, we successfully applied a multi-dimensional set of instruments to assess multimorbidity, functional disability in daily life, autonomy, quality of life (QoL), health care services utilization, personal and social resources as well as socio-demographic and biographical context variables. Response rates considerably varied between the Berlin and German OMAHA study cohorts (22.8% vs. 59.7%), whereas completeness of follow-up at month 12 was comparably high in both cohorts (82.9% vs. 81.2%)., Discussion: The OMAHA study offers a wide spectrum of data concerning health, functioning, social involvement, psychological well-being, and cognitive capacity in community-dwelling older people in Germany. Results from the study will add to methodological and content-specific discourses on human resources for maintaining quality of life and autonomy throughout old age, even in the face of multiple health complaints.

The specificity and stability of a set of assumptions hypothesized to be characteristic of Borderline Personality Disorder (BPD) was investigated. BPD patients (n = 16) were compared to cluster-C personality disorder patients (n = 12) and to normal controls (n = 15). All subjects were female and diagnosed with SCID-I and -II. Subjects rated a short version of the Personality Disorder Beliefs Questionnaire (PDBQ), with six sets of 20 assumptions each, hypothesized to be characteristic of avoidant, dependent, obsessive-compulsive, paranoid, histrionic and borderline personality disorder. The BPD assumptions (Cronbach alpha = 0.95) proved to be the most specific to BPD patients. Subjects rated the shortened PDBQ again after viewing an emotional video fragment one week later. Despite increased negative emotions, the PDBQ ratings remained relatively stable. Confirming the cognitive hypothesis, regression analyses indicated that the BPD assumptions mediate the relationship between self-reported etiological factors from childhood (sexual abuse and emotional/physical abuse) and BPD pathology assessed with the SCID-II. It is suggested that a set of assumptions is characteristic of BPD, and is relatively stable despite the instability of the behaviour of people diagnosed as having BPD.