Is the adiposity rebound a rebound in adiposity?

OBJECTIVE: Early adiposity rebound ([AR], when body mass index [BMI] rises after reaching a nadir) strongly predicts later obesity. We investigated whether the upswing in BMI at AR is accompanied by an increase in body fat. DESIGN: Community-based cohort study. SUBJECTS: A total of 299 first-born children (49% male). Measurements. Six-monthly anthropometry and bioelectrical impedance, 4-6.5 years; lean and fat mass index (kg/m(2)) for direct comparison with BMI. Supplementary (0-2 years) weight and length measures (needed for growth curve modelling) were drawn from subjects' child health records. METHODS: AR was estimated from individually modelled BMI curves from birth to 6.5 years. Two main analyses were performed: 1) cross-sectional comparisons of BMI, fat mass index (FMI), lean mass index (LMI) and percent body fat in children with early (<5 years) and later (>5 years) rebound; and 2) investigation of linear trends in BMI, FMI, LMI and percent body fat before and after AR. Results. The 81 children (27%) experiencing early AR had higher BMI, FMI, LMI and percent fat at 6.5 years. Overall, FMI decreased steeply pre-AR, at -0.56 (0.02) kg/m(2) per year (mean [Standard Error]), then flattened post-AR to 0.07 (0.05) kg/m(2) per year. In contrast, LMI increased pre-AR (0.34 [0.01]) and steepened post-AR (0.47 [0.03] kg/m(2) per year). CONCLUSION: The 'adiposity rebound' is characterised by increasing lean mass index, coupled with cessation of the decline in fat mass index. Understanding what controls the dynamics of childhood body composition and mechanisms that delay AR could help prevent obesity.

Dharma and grief: secularisation of a sacred emotion

The presentation begins with the moving scene of Va¯lmi¯ki's grief over the bereavement of the survivor of the two birds in amorous union as one of them is pierced by a hunter's arrow. After considering Abhinavagupta's doubt about the genuineness of Va¯lmi¯ki's grief, the paper moves to Maha¯bha¯rata as the women from the warring clans bear witness to the horrendous carnage ensuing from the battle, and the constant rebuke that Yudhisthira, head of the Pa¯ndava clan, faces from Draupadi¯ for wandering the earth without finding a stable foundation for Dharma or grounding it in firm absolutes. We liken Yudhisthira to Mahatma Gandhi facing the near-collapse of the Indian subcontinent as it was being rent apart with communal violence on the eve of its Independence. But we also compare Yudhisthira with Hamlet, the tragic grief-ridden character, who is equally bewildered and confused by the array of emotions and sensations that overwhelm his lingering body upon news of the death of and ghostly encounter with his murdered father. With this as the context, we take the occasion to explore recent thinking on the 'hard emotions', in particular, grief, sorrow and mourning, and link the challenging inner and social condition to the calling of Dharma (righteous law, normatively worthy action). Drawing from some comparative work (academic and personal) in the study of grief, mourning and empathy, we shall discuss the treatment of this tragic pathos in classical Indic literature and modern-day psychotherapy. We shall demonstrate, despite being secularised, these emotions continue to serve as the sites of imagination at a much more personal and inter-personal level that are not antithetical to a Dharmic (sacred) quest despite their haunting presence even when 'the four walls collapse around one in the intensity of duhkha (suffering, sorrow)' (Tagore).

Unknown input observer design for one-sided Lipschitz discrete-time systems subject to time-delay

In this paper, we address the problem of unknown input observer design, which simultaneously estimates state and unknown input, of a class of nonlinear discrete-time systems with time-delay. A novel approach to the state estimation problem of nonlinear systems where the nonlinearities satisfy the one-sided Lipschitz and quadratically inner-bounded conditions is proposed. This approach also allows us to reconstruct the unknown inputs of the systems. The nonlinear system is first transformed to a new system which can be decomposed into unknown-input-free and unknown-input-dependent subsystems. The estimation problem is then reduced to designing observer for the unknown-input-free subsystem. Rather than full-order observer design, in this paper, we propose observer design of reduced-order which is more practical and cost effective. By utilizing several mathematical techniques, the time-delay issue as well as the bilinear terms, which often emerge when designing observers for nonlinear discrete-time systems, are handled and less conservative observer synthesis conditions are derived in the linear matrix inequalities form. Two numerical examples are given to show the efficiency and high performance of our results.

Exponential stability of time-delay systems via new weighted integral inequalities

In this paper, new weighted integral inequalities (WIIs) are first derived based on Jensen's integral inequalities in single and double forms. It is theoretically shown that the newly derived inequalities in this paper encompass both the Jensen inequality and its most recent improvement based on Wirtinger's integral inequality. The potential capability of WIIs is demonstrated through applications to exponential stability analysis of some classes of time-delay systems in the framework of linear matrix inequalities (LMIs). The effectiveness and least conservativeness of the derived stability conditions using WIIs are shown by various numerical examples.

Passivity analysis of memristor-based complex-valued neural networks with time-varying delays

In this paper, the model of memristor-based complex-valued neural networks (MCVNNs) with time-varying delays is established and the problem of passivity analysis for MCVNNs is considered and extensively investigated. The analysis in this paper employs results from the theory of differential equations with discontinuous right-hand side as introduced by Filippov. By employing the appropriate Lyapunov–Krasovskii functional, differential inclusion theory and linear matrix inequality (LMI) approach, some new sufficient conditions for the passivity of the given MCVNNs are obtained in terms of both complex-valued and real-value LMIs, which can be easily solved by using standard numerical algorithms. Numerical examples are provided to illustrate the effectiveness of our theoretical results.

Observer design for one-sided Lipschitz discrete-time systems subject to delays and unknown inputs

In this paper, we address the problem of observer design for a class of nonlinear discrete-time systems in the presence of delays and unknown inputs. The nonlinearities studied in this work satisfy the one-sided Lipschitz and quadratically inner-bounded conditions which are more general than the traditional Lipschitz conditions. Both H∞ observer design and asymptotic observer design with reduced-order are considered. The designs are novel compared to other relevant nonlinear observer designs subject to time delays and disturbances in the literature. In order to deal with the time-delay issue as well as the bilinear terms which usually appear in the problem of designing observers for discrete-time systems, several mathematical techniques are utilized to deduce observer synthesis conditions in the linear matrix inequalities form. A numerical example is given to demonstrate the effectiveness and high performance of our results.

Robust observer design for a class of one-sided Lipschitz systems subject to time delays and disturbances in both plants and outputs

In this paper, we consider the problem of designing state observers for a class of one-sided Lipschitz time-delay systems subject to disturbances. Not only the plants but also the outputs of the systems are subject to time delays and disturbances. The one-sided Lipschitz and quadraticallyinner-bounded conditions, which are more general than the traditional Lipschitz condition, are utilized to cover a broader class of nonlinearities. Based on the Lyapunov-Krasovskii approach, a robust observer design is proposed where synthesis condition is derived in terms of linear matrixinequality (LMI). A numerical example is given to show the effectiveness of the obtained results.