State and output feedback design for robust tracking of linear systems with rate limited actuators

A design technique (Control of Uncertain Systems with Bounded Inputs, Tarbouriech S, Garcia G, (Eds), Lecture Notes in Control and Information Sciences, vol. 227 , Springer: Berlin, 1997; 173–186) recently proposed for stabilization of a linear system with rate‐limited actuators is utilized to design feedback laws that cause the system output to track a desired command signal. This design technique combines two design techniques recently developed for linear systems with position limited actuators, piecewise‐linear LQ control (Automatica, 1994; 30 : 403–416) and low‐and‐high gain feedback (IEEE Trans. Automat. Control, 1996; 41 : 368–378), and hence takes advantage of both design techniques, while avoiding their disadvantages. In the case that only the output is available for feedback, the performance of the state feedback law is preserved by the use of a fast observer. An open‐loop exponentially unstable fighter aircraft is used to demonstrate the effectiveness of the proposed control design method. Copyright © 2002 John Wiley & Sons, Ltd.     

In vivo 23Na NMR studies of myotonic dystrophy

Myotonic dystrophy is an inherited multi-system disease. Its pathophysiology leading to muscle malfunction and damage is not well understood. ²³Na NMR spectroscopy was applied here for an in vivo comparative study of the calf muscles of 7 myotonic dystrophy patients at various stages of the disease and 11 healthy volunteers. Both the total sodium content, expressed as the ratio of the ²³Na and ¹H water signals, and the fast transverse relaxation time, T₂₁, determined from the triple quantum-filtered spectra, increased in correlation with the severity of the disease. The results demonstrate that ²³Na NMR enables the quantitation of myotonic dystrophy progression.     

Childhood Malignant Thymoma: Clinical, Therapeutic, and Immunohistochemical Considerations

Malignant thymomas are among the least common mediastinal tumors in the pediatric age group. Thymomas are considered malignant on the basis of macroscopic and microscopic invasiveness. As only 20 well-documented cases involving children have been reported in the literature, the pattern of responsiveness to therapy and the value of prognostic signs is obscure. Two cases of malignant pediatric thymomas are reported with pathognomonic histoimmunological features of aggressive thymoma. One was cured, with a follow-up of 70 months, and one died while on therapy. Analysis of the histological features and the immunoperoxidase staining displays the complexity of pediatric thymomas and the inability to prognosticate the outcome, respectively.     

Psychiatric Comorbidity in Women with Disordered Eating Behavior: A National Study

ABSTRACT

This study used data collected by Statistics Canada in the Mental Health and Well-being cycle of the Canadian Community Health Survey (N = 20,211) to examine the associations between disordered eating behavior and selected mood, anxiety and substance use disorders in adult women grouped in three age groups. Significant associations between disordered eating behaviors and major depression, substance dependence and psychological distress were found for women in all three age ranges. Prevalence of specific classes of anxiety disorders in women who reported disordered eating behaviors differed according to their age. Having disordered eating behaviors was significantly associated with both 12-month and lifetime prevalence of social phobia for women above 25 years of age. Lifetime prevalence of agoraphobia was associated with disordered eating behaviors in women 15–44 years old, and the 12-month prevalence was associated with disordered eating behaviors only in women 15–24 years of age. Disordered eating behaviors were significantly associated with lifetime prevalence of panic disorder in women in all three age ranges and with 12-month prevalence of panic disorder in women in two age ranges, 15–24 and 45 and above. The findings highlight the importance of taking age into consideration when developing assessment instruments and treatment strategies to address the co-occurrence of eating disorders and other psychiatric disorders.     

Cardiovascular impact of testosterone therapy for hypogonadism

Introduction: Since 2010 some evidence supporting the possible increased cardiovascular (CV) risk related to testosterone treatment (TTh) has created much debate in the scientific community. Based on these results, the US Food and Drug Administration agency has questioned TTh for aging men recognizing its value only for classical hypogonadism due to genetic or organic causes. To better clarify this topic, we scrutinized and summarized, also by using meta-analytic methods, the data generated during the last 7 years, as derived from the analysis of randomized controlled trials (RCTs) on TTh and CV risk.

Areas covered: Analysis included 31 RCTs published between 2010 and 2018. Retrieved trials included 2675 and 2308 patients in TTh and placebo groups, respectively. The analysis documented that TTh was not associated with an increased CV mortality or morbidity either when overall or major adverse CV events were considered.

Expert commentary: Despite present evidence it is important to recognize that the duration of the available trials is short (lower that 3 years) limiting final conclusions on this topic. In particular, the available information on possible long-term effects of TTh on CV risk is limited. Long-term safety studies are advisable to better clarify these points.     

Feminist identity,body image,and disordered eating

ABSTRACT

Using data from a community-based sample (Project EAT-III), this study (N = 1241; mean age = 25.2) examined the relationship of feminist identity with body image and disordered eating. Feminist-identified women reported significantly higher body satisfaction than non-feminist women and women who did not identify as feminists but held feminist beliefs. However, feminist-identified women did not differ from non-feminist women in disordered eating. Women holding feminist beliefs and non-feminist women did not differ in body satisfaction. Our findings suggest that self-identification as a feminist may promote positive body image in young adult women, but may be insufficient to change behaviors.     

Frequency of hand movements as a possible diagnostic tool for parkinsonian bradykinesia. Proposal of a simple bedside test

Neurological Sciences - Bradykinesia, dysrhythmia, and decrement in hand movements (HM) are core symptoms of Parkinson’s disease (PD). The maximal rate of repetitive rhythm-preserving HM can...     

Effect of Rivastigmine on Mobility of Patients with Higher-Level Gait Disorder: A Pilot Exploratory Study

Background

Higher-level gait disorder (HLGD) in older adults is characterized by postural instability, stepping dysrhythmicity, recurrent falls and progressive immobility. Cognitive impairments are frequently associated with HLGD.

Objectives

The aim of this study was to compare gait and cognitive performance before and after the use of rivastigmine in patients with HLGD, free from cognitive impairment or Parkinsonism.

Methods

Fifteen non-demented patients with HLGD (age 79.2 ± 5.9 years; 11 women; Mini-Mental State Examination [MMSE] 28.3 ± 1.4) received escalating doses of rivastigmine for 12 weeks in an open-label, pilot study. They were assessed before and after treatment (week 0 and week 12), and after a 4-week washout period (week 16). Assessments included the Mindstreams computerized neuropsychological battery, Activities-specific Balance Confidence Scale, State-Trait Anxiety Inventory, Geriatric Depression Scale, Timed Up and Go (TUG) test, gait speed and stride time variability. One-way multiple analysis of variance tests for repeated measures were used, and Pillai’s trace test was considered as robust to investigate significant differences.

Results

The mean dose of rivastigmine during the 8–12 week period was 5.1 ± 2.3 mg/day. A positive effect was observed on the Mindstreams memory subscale and anxiety scores [Pillai’s trace: F(6,724) = 0.508, p = 0.010; and F(7,792) = 0.545, p = 0.006, respectively, over the course of the study] as well as on mobility (TUG test) [Pillai’s trace: F(4,863) = 0.448; p = 0.028], whereas gait speed and stride time variability did not change.

Conclusions

The use of relatively low-dose rivastigmine did not affect gait speed and stride time variability; however, the general mobility and anxiety were improved. These preliminary results warrant a larger, randomized, placebo-controlled study.     

Evaluation of a day hospital program for eating disorders

The study describes the outcome results of the first 53 patients with an eating disorder referred to a day hospital program, an innovative group treatment for patients requiring hospital treatment. Among the program's completers, 19 fulfilled criteria for anorexia nervosa (AN), and 35 fulfilled criteria for bulimia nervosa (BN). There was a significant weight gain for the AN patients; 73.6% gained over 1 lb/week during the average 12 weeks of stay in the program. There was a significant decrease in the average number of binges per week in the BN group; a reduction of 75% in binges was present in 88% of patients within the study period, 9 AN and 12 BN patients completed a detailed assessment 1, 3, and 6 months postdischarge; for these patients clinical gains were maintained. Factors related to dropout and outcome, as well as clinical implications, are discussed.