157 research outputs found

    Identification of marsh vegetation and coastal land use in ERTS-1 imagery

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    Coastal vegetation species appearing in the ERTS-1 images taken of Delaware Bay on August 16, and October 10, 1972 have been correlated with ground truth vegetation maps and imagery obtained from high altitude RB-57 and U-2 overflights. The vegetation maps of the entire Delaware Coast were prepared during the summer of 1972 and checked out with ground truth data collected on foot, in small boats, and from low-altitude aircraft. Multispectral analysis of high altitude RB-57 and U-2 photographs indicated that five vegetation communities could be clearly discriminated from 60,000 feet altitude including: (1) salt marsh cord grass, (2) salt marsh hay and spike grass, (3) reed grass, (4) high tide bush and sea myrtle, and (5) a group of fresh water species found in impoundments built to attract water fowl. All of these species are shown in fifteen overlay maps, covering all of Delaware's wetlands prepared to match the USGS topographic map size of 1:24,000

    Paradoxical roles of antioxidant enzymes:Basic mechanisms and health implications

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    Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated from aerobic metabolism, as a result of accidental electron leakage as well as regulated enzymatic processes. Because ROS/RNS can induce oxidative injury and act in redox signaling, enzymes metabolizing them will inherently promote either health or disease, depending on the physiological context. It is thus misleading to consider conventionally called antioxidant enzymes to be largely, if not exclusively, health protective. Because such a notion is nonetheless common, we herein attempt to rationalize why this simplistic view should be avoided. First we give an updated summary of physiological phenotypes triggered in mouse models of overexpression or knockout of major antioxidant enzymes. Subsequently, we focus on a series of striking cases that demonstrate “paradoxical” outcomes, i.e., increased fitness upon deletion of antioxidant enzymes or disease triggered by their overexpression. We elaborate mechanisms by which these phenotypes are mediated via chemical, biological, and metabolic interactions of the antioxidant enzymes with their substrates, downstream events, and cellular context. Furthermore, we propose that novel treatments of antioxidant enzyme-related human diseases may be enabled by deliberate targeting of dual roles of the pertaining enzymes. We also discuss the potential of “antioxidant” nutrients and phytochemicals, via regulating the expression or function of antioxidant enzymes, in preventing, treating, or aggravating chronic diseases. We conclude that “paradoxical” roles of antioxidant enzymes in physiology, health, and disease derive from sophisticated molecular mechanisms of redox biology and metabolic homeostasis. Simply viewing antioxidant enzymes as always being beneficial is not only conceptually misleading but also clinically hazardous if such notions underpin medical treatment protocols based on modulation of redox pathways

    Visual ecology of aphids – a critical review on the role of colours in host finding

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    We review the rich literature on behavioural responses of aphids (Hemiptera: Aphididae) to stimuli of different colours. Only in one species there are adequate physiological data on spectral sensitivity to explain behaviour crisply in mechanistic terms. Because of the great interest in aphid responses to coloured targets from an evolutionary, ecological and applied perspective, there is a substantial need to expand these studies to more species of aphids, and to quantify spectral properties of stimuli rigorously. We show that aphid responses to colours, at least for some species, are likely based on a specific colour opponency mechanism, with positive input from the green domain of the spectrum and negative input from the blue and/or UV region. We further demonstrate that the usual yellow preference of aphids encountered in field experiments is not a true colour preference but involves additional brightness effects. We discuss the implications for agriculture and sensory ecology, with special respect to the recent debate on autumn leaf colouration. We illustrate that recent evolutionary theories concerning aphid–tree interactions imply far-reaching assumptions on aphid responses to colours that are not likely to hold. Finally we also discuss the implications for developing and optimising strategies of aphid control and monitoring

    Therapeutic effects of the mitochondrial ROS-redox modulator KH176 in a mammalian model of Leigh Disease

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    Leigh Disease is a progressive neurometabolic disorder for which a clinical effective treatment is currently still lacking. Here, we report on the therapeutic efficacy of KH176, a new chemical entity derivative of Trolox, in Ndufs4 (-/-) mice, a mammalian model for Leigh Disease. Using in vivo brain diffusion tensor imaging, we show a loss of brain microstructural coherence in Ndufs4 (-/-) mice in the cerebral cortex, external capsule and cerebral peduncle. These findings are in line with the white matter diffusivity changes described in mitochondrial disease patients. Long-term KH176 treatment retained brain microstructural coherence in the external capsule in Ndufs4 (-/-) mice and normalized the increased lipid peroxidation in this area and the cerebral cortex. Furthermore, KH176 treatment was able to significantly improve rotarod and gait performance and reduced the degeneration of retinal ganglion cells in Ndufs4 (-/-) mice. These in vivo findings show that further development of KH176 as a potential treatment for mitochondrial disorders is worthwhile to pursue. Clinical trial studies to explore the potency, safety and efficacy of KH176 are ongoing

    Editors’ Introduction: An Overview of the Educational Administration and Leadership Curriculum: Traditions of Islamic Educational Administration and Leadership in Higher Education

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    This chapter provides an overview of several topics relevant to constructing an approach to teaching educational administration and leadership in Muslim countries. First, it places the topic in the context of the changing nature and critiques of the field that argue for a greater internationalisation to both resist some of the negative aspects of globalisation and to represent countries’ traditions in the professional curriculum. Then, it identifies literature that presents the underlying principles and values of Islamic education that guide curriculum and pedagogy and shape its administration and leadership including the Qur’an and Sunnah and the classical educational literature which focuses on aims, values and goals of education as well as character development upon which a ‘good’ society is built. This is followed by a section on the Islamic administration and leadership traditions that are relevant to education, including the values of educational organisations and how they should be administered, identifying literature on the distinctive Islamic traditions of leadership and administrator education and training as it applies to education from the establishment of Islam and early classical scholars and senior administrators in the medieval period who laid a strong foundation for a highly sophisticated preparation and practice of administration in philosophical writings and the Mirrors of Princes writings, and subsequent authors who have built upon it up to the contemporary period. The final section provides an overview of the chapters in this collection

    Translating the oxidative stress hypothesis into the clinic: NOX versus NOS

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    Cardiovascular diseases remain the leading cause of death in industrialised nations. Since the pathomechanisms of most cardiovascular diseases are not understood, the majority of therapeutic approaches are symptom-orientated. Knowing the molecular mechanism of disease would enable more targeted therapies. One postulated underlying mechanism of cardiovascular diseases is oxidative stress, i.e. the increased occurrence of reactive oxygen species such as superoxide. Oxidative stress leads to a dysfunction of vascular endothelium-dependent protective mechanisms. There is growing evidence that this scenario also involves impaired nitric oxide (NO)-cyclic GMP signalling. Out of a number of enzyme families that can produce reactive oxygen species, NADPH oxidases stand out, as they are the only enzymes whose sole purpose is to produce reactive oxygen species. This review focuses on the clinically validated targets of oxidative stress, NO synthase (NOS) and the NO receptor, soluble guanylate cyclase as well as the source of ROS, e.g. NADPH oxidases. We place recent knowledge in the function and regulation of these enzyme families into clinical perspective. For a comprehensive overview of the biology and pharmacology of oxidative stress and possible other sources and targets, we refer to other literature overviews

    The humanistic roots of Islamic administration and leadership for education : philosophical foundations for cross-cultural and transcultural teaching

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    For a number of decades, a humanistic approach has been a minor but persistent one in the Western field of administrative and leadership studies, and only recently has been broadening to include other humanist traditions (Dierksmeier et al., 2011) and has yet to be fully explored in educational administration and its pedagogy and curriculum although some foundational work has been done (e.g., Samier, 2005). The focus in this chapter is on the Islamic humanist tradition as it relates to the teaching of educational administration and leadership in a Muslim context, with implications for cross-cultural and transcultural use. The second purpose of the chapter is to show the correspondences that exist between the Islamic and Western humanist traditions in terms of human values, knowledge and educational ideal, which in this chapter are argued to be close to the Western Idealist tradition and the German Bildung conception of education as well as the strong interpretive and hermeneutic foundations that originated in the Islamic tradition and which influenced the foundations of many relevant European schools of thought, particularly in the Enlightenment.The initial section of the chapter is a comparative examination of the central principles of the Islamic humanist tradition from the classical through to contemporary times with the Western humanist tradition as they relate to conceptions of the good, ethics, the construction of meaning and a set of higher order values predicated upon human dignity, integrity, empathy, well-being, and the public good (Goodman, 2003) covering a number of important scholars like Al Farabi, al Isfanhani, and Edward Said (e.g., Kraemer, 1986). In both, professions are viewed as meaningful work that allow for large measures of decision making, and are grounded in human qualities and needs including autonomy, freedom and emancipation balanced with responsibilities, obligations and duties to society. These are compared with the corresponding principles of knowledge in Western humanism which includes a strong constructivist view of reality (Makdisi, 1990). Secondly, the chapter examines the principles of good or ideal leadership and administration that humanism aims at in its preparation of officials, including those in the educational sector in both the classical Islamic tradition (Hassi, 2012) and Western approaches to humanistic administration and leadership (Czarniawska-Joerges & Guillet de Monthoux, 1994; Gagliardi & Czarniawska, 2006; Leoussi, 2000). The third section focusses on close correspondences that exist between the Islamic (Afsaruddin, 2016; al-Attas, 1980; Yasin & Jani, 2013) and Western (Aloni, 2007; Veugelers, 2011) humanist education traditions in terms of educational ideal as well as the kind of teaching practices that distinguish these traditions (Daiber, 2013; Dossett, 2014) as they apply to educational administration and leadership (Greenfield & Ribbins, 1993). The chapter concludes with a discussion of how the Islamic humanist tradition can contribute to cross-cultural and transcultural graduate teaching in international educational administration (Khan & Amann, 2013)

    Corrigendum to "European contribution to the study of ROS:A summary of the findings and prospects for the future from the COST action BM1203 (EU-ROS)" [Redox Biol. 13 (2017) 94-162]

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    The European Cooperation in Science and Technology (COST) provides an ideal framework to establish multi-disciplinary research networks. COST Action BM1203 (EU-ROS) represents a consortium of researchers from different disciplines who are dedicated to providing new insights and tools for better understanding redox biology and medicine and, in the long run, to finding new therapeutic strategies to target dysregulated redox processes in various diseases. This report highlights the major achievements of EU-ROS as well as research updates and new perspectives arising from its members. The EU-ROS consortium comprised more than 140 active members who worked together for four years on the topics briefly described below. The formation of reactive oxygen and nitrogen species (RONS) is an established hallmark of our aerobic environment and metabolism but RONS also act as messengers via redox regulation of essential cellular processes. The fact that many diseases have been found to be associated with oxidative stress established the theory of oxidative stress as a trigger of diseases that can be corrected by antioxidant therapy. However, while experimental studies support this thesis, clinical studies still generate controversial results, due to complex pathophysiology of oxidative stress in humans. For future improvement of antioxidant therapy and better understanding of redox-associated disease progression detailed knowledge on the sources and targets of RONS formation and discrimination of their detrimental or beneficial roles is required. In order to advance this important area of biology and medicine, highly synergistic approaches combining a variety of diverse and contrasting disciplines are needed
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