On recent developments in the theory of abstract differential equations with fractional derivatives

This note is motivated from some recent papers treating the problem of the existence of a solution for abstract differential equations with fractional derivatives. We show that the existence results in [Agarwal et al. (2009) [1], Belmekki and Benchohra (2010) [2], Darwish et al. (2009) [3], Hu et al. (2009) [4], Mophou and N`Guerekata (2009) [6,7], Mophou (2010) [8,9], Muslim (2009) [10], Pandey et al. (2009) [11], Rashid and El-Qaderi (2009) [12] and Tai and Wang (2009) [13]] are incorrect since the considered variation of constant formulas is not appropriate. In this note, we also consider a different approach to treat a general class of abstract fractional differential equations. (C) 2010 Elsevier Ltd. All rights reserved.

Fractional Photothermolysis for the Treatment of Hypertrophic Scars: Clinical Experience of Eight Cases

Hypertrophic scars are common problems and represent a challenging condition to treat. Fractional photothermolysis has been effective at resurfacing photodamaged skin, acne scars, and atrophic scars, but there are few reports on its use for hypertrophic scars. To evaluate the safety and efficacy of 1,550-nm erbium-doped fiber laser treatment of hypertrophic scars in eight patients. Eight patients (skin phototypes II-IV) with hypertrophic scars received monthly treatments with a 1,550-nm erbium-doped fiber laser. Energy settings ranged from 35 to 50 mJ, and eight to 10 passes were applied with treatment levels 6 to 8. An independent physician evaluator assessed the treatment response by comparing pre- and posttreatment clinical photographs using a quartile grading scale (grade 1, <= 25%=minimal to no improvement; grade 2, 26-50%=moderate improvement; grade 3, 51-75%=marked improvement; grade 4, > 75%=near total improvement. At four weeks after the last treatment session, a mean grade of 2.4 was achieved based on an independent physician`s clinical assessment. Improvement in pigmentation occurred in all hyperpigmented scars. Hypertrophic scars can be effectively and safely improved with 1,550-nm erbium-doped fiber laser treatment. The authors have indicated no significant interest with commercial supporters.

Elevated left and reduced right orbitomedial prefrontal fractional anisotropy in adults with bipolar disorder revealed by tract-based spatial statistics

Context Diffusion tensor imaging (DTI) studies in adults with bipolar disorder (BD) indicate altered white matter (WM) in the orbitomedial prefrontal cortex (OMPFC), potentially underlying abnormal prefrontal corticolimbic connectivity and mood dysregulatioin in BD. Objective: To use tract-based spatial statistics (TBSS) to examine VVM skeleton (ie, the most compact whole-brain WM) in subjects with BD vs healthy control subjects. Design: Cross-sectional, case-control, whole-brain DTI using TBSS. Setting: University research institute. Participants: Fifty-six individuals, 31 having a DSM-IV diagnosis of BD type 1 (mean age, 35.9 years [age range, 24-52 years]) and 25 controls (mean age, 29.5 years [age range, 19-52 years]). Main Outcome Measures: Fractional anisotropy (FA) longitudinal and radial diffusivities in subjects with BD vs controls (covarying for age) and their relationships with clinical and demographic variables. Results: Subjects with BD vs controls had significantly greater FA (t > 3.0, P <=.05 corrected) in the left uncinate fasciculus (reduced radial diffusivity distally and increased longitudinal diffusivity centrally), left optic radiation (increased longitudinal diffusivity), and right anterothalamic radiation (no significant diffusivity change). Subjects with BD vs controls had significantly reduced FA (t > 3.0, P <=.05 corrected) in the right uncinate fasciculus (greater radial diffusivity). Among subjects with BD, significant negative correlations (P <.01) were found between age and FA in bilateral uncinate fasciculi and in the right anterothalamic radiation, as well as between medication load and FA in the left optic radiation. Decreased FA (P <.01) was observed in the left optic radiation and in the right anterothalamic radiation among subjects with BD taking vs those not taking mood stabilizers, as well as in the left optic radiation among depressed vs remitted subjects with BD. Subjects having BD with vs without lifetime alcohol or other drug abuse had significantly decreased FA in the left uncinate fasciculus. Conclusions: To our knowledge, this is the first study to use TBSS to examine WM in subjects with BD. Subjects with BD vs controls showed greater WM FA in the left OMPFC that diminished with age and with alcohol or other drug abuse, as well as reduced WM FA in the right OMPFC. Mood stabilizers and depressed episode reduced WM FA in left-sided sensory visual processing regions among subjects with BD. Abnormal right vs left asymmetry in FA in OMPFC WM among subjects with BD, likely reflecting increased proportions of left-sided longitudinally aligned and right-sided obliquely aligned myelinated fibers, may represent a biologic mechanism for mood dysregulation in BD.

Factorizations of and by powers of complete graphs

Let K-k(d) denote the Cartesian product of d copies of the complete graph K-k. We prove necessary and sufficient conditions for the existence of a K-k(r)-factorization of K-pn(s), where p is prime and k > 1, n, r and s are positive integers. (C) 2002 Elsevier Science B.V. All rights reserved.

Climate governance in an international system under conservative hegemony: the role of major powers

In the last five years, climate change has been established as a central civilizational driver of our time. As a result of this development, the most diversified social processes - as well as the fields of science which study them - have had their dynamics altered. In International Relations, this double challenge could be explained as follows: 1) in empirical terms, climate change imposes a deepening of cooperation levels on the international community, considering the global common character of the atmosphere; and 2) to International Relations as a discipline, climate change demands from the scientific community a conceptual review of the categories designed to approach the development of global climate governance. The goal of this article is to discuss in both conceptual and empirical terms the structure of global climate change governance, through an exploratory research, aiming at identifying the key elements that allow understanding its dynamics. To do so, we rely on the concept of climate powers. This discussion is grounded in the following framework: we now live in an international system under conservative hegemony that is unable to properly respond to the problems of interdependence, among which - and mainly -, the climate issue.

Muddle or march: China and the 21st century Concert of Powers

Concert of Powers has emerged as an attractive modality in global governance. As an emerging power, China must seriously take this template into account. This article seeks to analyze the incentives, possibilities, and uncertainties for China to participate in Concert with reference to China's history memory on Concert, China's intellectual endeavors, as well as China's evolving foreign preferences. It concludes that China is generally qualified and capable of being a key participant in Concert of Powers with increasing willingness. Yet, China's involvement depends on 1) if Concert template can overcome its own deficiencies; 2) if Concert have competitive advantages compared with other governance alternatives for China; and 3) if China can keep its momentum on both willingness and capacity in power transition.

Wandering decarbonization: the BRIC countries as conservative climate powers

Abstract This article discusses the role of China, Russia, India and Brazil in the climate regime. It describes the trajectory of their emissions, of their domestic policies and of their international commitments, and argues that, despite their responsibility in causing the problem, they have been conservative forces in the climate regime.

A Pitch Control Malfunction Analysis for Wind Turbines with Permanent Magnet Synchronous Generator and Full-power Converters: Proportional Integral Versus Fractional-order Controllers

A transient analysis for two full-power converter wind turbines equipped with a permanent magnet synchronous generator is studied in this article, taking into consideration, as a new contribution to earlier studies, a pitch control malfunction. The two full-power converters considered are, respectively, a two-level and a multi-level converter. Moreover, a novel control strategy based on fractional-order controllers for wind turbines is studied. Simulation results are presented; conclusions are in favor of the novel control strategy, improving the quality of the energy injected into the electric grid.