Symmetry considerations and development of pinwheels in visual maps

Neurons in the visual cortex respond best to rod-like stimuli of given orientation. While the preferred orientation varies continuously across most of the cortex, there are prominent pinwheel centers around which all orientations a re present. Oriented segments abound in natural images, and tend to be collinear}; neurons are also more likely to be connected if their preferred orientations are aligned to their topographic separation. These are indications of a reduced symmetry requiring joint rotations of both orientation preference and the underl ying topography. We verify that this requirement extends to cortical maps of mo nkey and cat by direct statistical analysis. Furthermore, analytical arguments and numerical studies indicate that pinwheels are generically stable in evolving field models which couple orientation and topography

Identifying the severely injured benefitting from a specific level of trauma care in an inclusive network:A multicentre retrospective study

Introduction: Defining major trauma (MT) with an Injury Severity Score (ISS) &gt; 15 has limitations. This threshold is used for concentrating MT care in networks with multiple levels of trauma care. Objective: This study aims to identify subgroups of severely injured patients benefiting on in-hospital mortality and non-fatal clinical outcome measures in an optimal level of trauma care. Methods: A multicentre retrospective cohort study on data of the Dutch National Trauma Registry, region South West, from January 1, 2015 until December 31, 2019 was conducted. Patients ≥ 16 years admitted within 48 h after trauma transported with (H)EMS to a level I trauma centre (TC) or a non-level I trauma facility with a Maximum Abbreviated Injury Scale (MAIS) ≥ 3 were included. Patients with burns or patients of ≥ 65 years with an isolated hip fracture were excluded. Logistic regression models were used for comparing level I with non-level I. Subgroup analysis were done for MT patients (ISS &gt; 15) and non-MT patients (ISS 9–14). Results: A total of 7,493 records were included. In-hospital mortality of patients admitted to a non-level I trauma facility did not differ significantly from patients admitted to the level I TC (adjusted Odds Ratio (OR): 0.94; 95% confidence interval (CI) 0.68–1.30). This was also applicable for MT patients (OR: 1.06; 95% CI 0.73–1.53) and non-MT patients (OR: 1.30; 95% CI (0.56–3.03). Hospital and ICU LOS were significantly shorter for patients admitted to a non-level I trauma facilities, and patients admitted to a non-level I trauma facility were more likely to be discharged home. Findings were confirmed for MT and non-MT patients, per injured body region. Conclusion: All levels of trauma care performed equally on in-hospital mortality among severely injured patients (MAIS ≥ 3), although patients admitted to the level I TC were more severely injured. Subgroups of patients by body region or ISS, with a survival benefit or more favorable clinical outcome measures were not identified. Subgroups analysis on clinical outcome measures across different levels of trauma care in an inclusive trauma network is too simplistic if subgroups are based on injuries in specific body region or ISS only.</p

Instrumented Assessment of Physical Activity Is Associated With Muscle Function but Not With Muscle Mass in a General Population

Objectives: Self-reported physical activity has shown to affect muscle-related parameters. As self-report is likely biased, this study aimed to assess the association between instrumented assessment of physical activity (I-PA) and muscle-related parameters in a general population. Method: Included were 156 young-to-middle-aged and 80 older community-dwelling adults. Seven days of trunk accelerometry (DynaPort MoveMonitor, McRoberts B.V.) quantified daily physical activity (i.e., active/inactive duration, number and mean duration of active/inactive periods, and number of steps per day). Muscle-related parameters included muscle mass, handgrip strength, and gait speed. Results: I-PA was associated with handgrip strength in young-to-middle-aged adults and with gait speed in older adults. I-PA was not associated with muscle mass in either age group. Discussion: The association between I-PA and muscle-related parameters was age dependent. The lack of an association between I-PA and muscle mass indicates the relevance of muscle function rather than muscle mass

Identifying the severely injured benefitting from a specific level of trauma care in an inclusive network:A multicentre retrospective study

Introduction: Defining major trauma (MT) with an Injury Severity Score (ISS) &gt; 15 has limitations. This threshold is used for concentrating MT care in networks with multiple levels of trauma care. Objective: This study aims to identify subgroups of severely injured patients benefiting on in-hospital mortality and non-fatal clinical outcome measures in an optimal level of trauma care. Methods: A multicentre retrospective cohort study on data of the Dutch National Trauma Registry, region South West, from January 1, 2015 until December 31, 2019 was conducted. Patients ≥ 16 years admitted within 48 h after trauma transported with (H)EMS to a level I trauma centre (TC) or a non-level I trauma facility with a Maximum Abbreviated Injury Scale (MAIS) ≥ 3 were included. Patients with burns or patients of ≥ 65 years with an isolated hip fracture were excluded. Logistic regression models were used for comparing level I with non-level I. Subgroup analysis were done for MT patients (ISS &gt; 15) and non-MT patients (ISS 9–14). Results: A total of 7,493 records were included. In-hospital mortality of patients admitted to a non-level I trauma facility did not differ significantly from patients admitted to the level I TC (adjusted Odds Ratio (OR): 0.94; 95% confidence interval (CI) 0.68–1.30). This was also applicable for MT patients (OR: 1.06; 95% CI 0.73–1.53) and non-MT patients (OR: 1.30; 95% CI (0.56–3.03). Hospital and ICU LOS were significantly shorter for patients admitted to a non-level I trauma facilities, and patients admitted to a non-level I trauma facility were more likely to be discharged home. Findings were confirmed for MT and non-MT patients, per injured body region. Conclusion: All levels of trauma care performed equally on in-hospital mortality among severely injured patients (MAIS ≥ 3), although patients admitted to the level I TC were more severely injured. Subgroups of patients by body region or ISS, with a survival benefit or more favorable clinical outcome measures were not identified. Subgroups analysis on clinical outcome measures across different levels of trauma care in an inclusive trauma network is too simplistic if subgroups are based on injuries in specific body region or ISS only.</p

Robustness of In-Laboratory and Daily-Life Gait Speed Measures over One Year in High Functioning 61- To 70-Year-Old Adults

Introduction: Gait speed is a simple and safe measure with strong predictive value for negative health outcomes in clinical practice, yet in-laboratory gait speed seems not representative for daily-life gait speed. This study aimed to investigate the interrelation between and robustness of in-laboratory and daily-life gait speed measures over 12 months in 61- to 70-year-old adults. Methods: Gait speed was assessed in laboratory through standardized stopwatch tests and in daily life by 7 days of trunk accelerometry in the PreventIT cohort, at baseline, and after 6 and 12 months. The interrelation was investigated using Pearson's correlations between gait speed measures at each time point. For robustness, changes over time and variance components were assessed by ANOVA and measurement agreement over time by Bland-Altman analyses. Results: Included were 189 participants (median age 67 years [interquartile range: 64-68], 52.2% females). In-laboratory and daily-life gait speed measures showed low correlations (Pearson's r = 0.045-0.455) at each time point. Moreover, both in-laboratory and daily-life gait speed measures appeared robust over time, with comparable and smaller within-subject than between-subject variance (range 0.001-0.095 m/s and 0.032-0.397 m/s, respectively) and minimal differences between measurements over time (Bland-Altman) with wide limits of agreement (standard deviation of mean difference range: 0.12-0.34 m/s). Discussion/Conclusion: In-laboratory and daily-life gait speed measures show robust assessments of gait speed over 12 months and are distinct constructs in this population of high-functioning adults. This suggests that (a combination of) both measures may have added value in predicting health outcomes

Sildenafil for bronchopulmonary dysplasia and pulmonary hypertension: a meta-analysis

Bronchopulmonary dysplasia (BPD) is the most common complication in preterm infants and often complicated by pulmonary hypertension (PH), leading to substantial morbidity and mortality. Sildenafil is often used to treat PH and improve symptoms in this condition, even though evidence of safety and effectiveness is scarce. The aim of this study was to perform a systematic review and meta-analysis about the effectiveness and safety of chronic use of sildenafil in preterm infants with BPD-associated PH. Data sources were PubMed, EMBASE, and Medline. Studies reporting the effectiveness of sildenafil therapy in BPD-associated PH in newborns and infants were included. All-cause mortality, improvement in PH, improvement in respiratory scores, and adverse events were extracted. Five studies were included, yielding a total of 101 patients with 94.2 patient-years of total follow-up. The pooled mortality rate was 29.7%/year (95% confidence interval [CI] = 6.8–52.7). Estimated pulmonary arterial pressure improved > 20% in 69.3% (95% CI = 56.8–81.8) of patients within 1–6 months. Respiratory scores improved in 15.0% (95% CI = 0.0–30.4) of patients within 2–7 days. There were no serious adverse events during sildenafil therapy. This systematic review shows that in the treatment of BPD-associated PH in preterm infants, sildenafil may be associated with improvement in PAP and respiratory scores. However, there is no clear evidence of its effect on mortality rates. Considering BPD as a complex disease with variable expression patterns, these results support the need for a prospective registry and standardized approach

The association of objectively measured physical activity and sedentary behavior with skeletal muscle strength and muscle power in older adults: a systematic review and meta-analysis

Background Engaging in physical activity (PA) and avoiding sedentary behavior (SB) are important for healthy ageing with benefits including the mitigation of disability and mortality. Whether benefits extend to key determinants of disability and mortality, namely muscle strength and muscle power, is unclear. Aims This systematic review aimed to describe the association of objective measures of PA and SB with measures of skeletal muscle strength and muscle power in community-dwelling older adults. Methods Six databases were searched from their inception to June 21st, 2020 for articles reporting associations between objectively measured PA and SB and upper body or lower body muscle strength or muscle power in community dwelling adults aged 60 years and older. An overview of associations was visualized by effect direction heat maps, standardized effect sizes were estimated with albatross plots and summarized in box plots. Articles reporting adjusted standardized regression coefficients (β) were included in meta-analyses. Results A total of 112 articles were included representing 43,796 individuals (range: 21 to 3726 per article) with a mean or median age from 61.0 to 88.0 years (mean 56.4 % female). Higher PA measures and lower SB were associated with better upper body muscle strength (hand grip strength), upper body muscle power (arm curl), lower body muscle strength, and lower body muscle power (chair stand test). Median standardized effect sizes were consistently larger for measures of PA and SB with lower compared to upper body muscle strength and muscle power. The meta-analyses of adjusted β coefficients confirmed the associations between total PA (TPA), moderate-to-vigorous PA (MVPA) and light PA (LPA) with hand grip strength (β = 0.041, β = 0.057, and β = 0.070, respectively, all p ≤ 0.001), and TPA and MVPA with chair stand test (β = 0.199 and β = 0.211, respectively, all p ≤ 0.001). Conclusions Higher PA and lower SB are associated with greater skeletal muscle strength and muscle power, particularly with the chair stand test

The prevalence of malnutrition according to the new ESPEN definition in four diverse populations

© 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism.Background & aims: Consensus on the definition of malnutrition has not yet been reached. Recently, The European Society for Clinical Nutrition and Metabolism (ESPEN) proposed a consensus definition of malnutrition. The aim of the present study was to describe the prevalence of malnutrition according to the ESPEN definition in four diverse populations. Methods: In total, 349 acutely ill middle-aged patients, 135 geriatric outpatients, 306 healthy old individuals and 179 healthy young individuals were included in the study. Subjects were screened for risk of malnutrition using the SNAQ. The ESPEN definition of malnutrition, i.e. low BMI (< 18.5 kg/m2) or a combination of unintentional weight loss and low FFMI or low BMI was applied to all subjects. Results: Screening identified 0, 0.5, 10 and 30% of the healthy young, the healthy old, the geriatric outpatients and the acutely ill middle-aged patients as being at risk of malnutrition. The prevalence of malnutrition ranged from 0% in the healthy young, 0.5% in healthy old individuals, 6% in the geriatric outpatients to 14% in the acutely ill middle-aged patients. Prevalence of low FFMI was observed in all four populations (14-33%), but concurred less frequently with weight loss (0-13%). Conclusions: Using the ESPEN definition, 0%-14% malnutrition was found in the diverse populations. Further work is needed to fully address the validity of a two-step approach, including risk assessment as an initial step in screening and defining malnutrition. Furthermore, assessing the predictive validity of the ESPEN definition is needed

Distinct Trajectories of Individual Physical Performance Measures Across 9 Years in 60-to 70-Year-Old Adults

BACKGROUND: Physical performance is an important factor for successful aging. This study aimed to identify distinct trajectories of multiple physical performance measures over 9 years in individuals aged 60-70 years and to evaluate their characteristics and the overlap between measures. METHODS: Four physical performance measures were assessed in 440 participants of the Longitudinal Aging Study Amsterdam: tandem stand, gait speed, chair stand, and handgrip strength. Gender-specific latent class models were conducted to obtain distinct trajectories and their degree of overlap. RESULTS: Mean age at baseline was 67.9 (SD 1.7) years for males and 68.0 (SD 1.7) years for females. The optimal number of trajectories differed across measures. For tandem stand, no distinct trajectories were found (all 179 males, 198 females). For gait speed, three trajectories were identified, dependent on baseline speed: high-stable (47 males, 27 females), intermediate-stable (132 males, 130 females), and low-declining performance (6 males, 48 females). Two trajectories were identified for the chair stand: a stable (168 males, 150 females) and declining trajectory (10 males, 38 females). For handgrip strength, three declining trajectories were identified differing in baseline performance: high (55 males, 75 females), intermediate (111 males, 118 females), and low (17 males, 10 females). Overall, 11.9% of males and 5.7% of females were classified in similar trajectories across measures. CONCLUSIONS: Trajectories of physical performance were heterogeneous, but showed similar patterns for males and females. Little overlap between measures was shown, suggesting different mechanisms for decline. This study emphasizes the use of multiple domains to assess physical performance