University of Massachusetts Boston

About: University of Massachusetts Boston is a education organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Population & Health care. The organization has 6541 authors who have published 12918 publications receiving 411731 citations. The organization is also known as: UMass Boston.

Stress responses to polycyclic aromatic hydrocarbons in Arabidopsis include growth inhibition and hypersensitive response-like symptoms.

Abstract: Polycyclic aromatic hydrocarbons (PAHs) are of global environmental concern because they cause many health problems including cancer and inflammation of tissue in humans. Plants are important in removing PAHs from the atmosphere; yet, information on the physiology, cell and molecular biology, and biochemistry of PAH stress responses in plants is lacking. The PAH stress response was studied in Arabidopsis (Arabidopsis thaliana) exposed to the three-ring aromatic compound, phenanthrene. Morphological symptoms of PAH stress were growth reduction of the root and shoot, deformed trichomes, reduced root hairs, chlorosis, late flowering, and the appearance of white spots, which later developed into necrotic lesions. At the tissue and cellular levels, plants experienced oxidative stress. This was indicated by localized H 2 O 2 production and cell death, which were detected using 3, 3'-diaminobenzidine and trypan blue staining, respectively. Gas chromatography-mass spectrometry and fluorescence spectrometry analyses showed that phenanthrene is internalized by the plant. Gene expression of the cell wall-loosening protein expansin was repressed, whereas gene expression of the pathogenesis related protein PR1 was induced in response to PAH exposure. These findings show that (i) Arabidopsis takes up phenanthrene, suggesting possible degradation in plants, (ii) a PAH response in plants and animals may share similar stress mechanisms, since in animal cells detoxification of PAHs also results in oxidative stress, and (iii) plant specific defence mechanisms contribute to PAH stress response in Arabidopsis.

Natural Forest Management and Conservation of Biodiversity in Tropical Forests

Abstract: As a reaction to the continued dwindling of tropical forest resources, many research and develop- ment organizations have turned to the idea of natural forest management in the hope of making tropical for- est lands more profitable while maintaining biodiversity. Assertions of sustainability in logging practices have been inadequately supported, however. We begin with a review of the present knowledge of the effects of logging operations on various organisms. Post-harvest surveys of a spectrum of tropical forests indicate a range of logging effects from local extirpation to substantial increases in local densities of some species. The state of our knowledge does not permit quantitative predictions, but logging at any level appears to have sim- plifying and homogenizing effects on tropical forest diversity when examined at community or regional scales. Furthermore, the social and economic problems presented by natural forest management systems have not yet been adequately addressed. We present alternatives to the strong emphasis on "sustainable natural forest management" as a means of retaining the diversity of tropical forest communities. These alternatives include increased support for management of secondary forests, restoration of degraded lands, plantation forestry, nontimber uses for some forests, changes in accounting procedures to reflect the true value of natu- ral forests, and support for forestry agencies charged with protecting forest reserves. Manejo de Bosques Naturales y Conservacion de la Biodiversidad en Bosques Tropicales Resumen: Como una reaccion a la constante reduccion de los recursos en bosques tropicales, muchos inves- tigadores y organizaciones de desarrolo se han enfocado en la idea del manejo de bosques naturales, con la esperanza de que las tierras con bosques tropicales sean mas rentables, al mismo tiempo que se pretende mantener la biodiversidad. Sin embargo, algunas aseveraciones de sustentabilidad en practicas de tala han sido inadecuadamente soportadas. Iniciamos con una revision del conocimiento actual de los efectos de opera- ciones de tala en varios organismos. Estudios posteriores a las cosechas en un espectro de bosques tropicales indican que el rango de efectos de la tal varian desde la extriparcion local hasta el incremento sustancial en la densidad local de algunas especies. El estado actual de nuestro conocimiento no nos pemite realizar predic- ciones cuantitativas, pero la tala a cualquier nivel aparenta tener efectos de simplificacion y homogeneiza- cion en la diversidad de los bosques tropicales cuando se examina a nivel de escala regional. Mas aun, los problemas sociales y economicos en sistemas de manejo de bosques naturales no han sido abordados adecua- damente. Presentamos alternativas para el enfatizado "manejo sustentable de bosques naturales" como una medida para retener la diversidad de las comunidades de bosques tropicales. Estas alternativas incluyen un soporte mayor en el manejo de bosques secundarios, la restauracion de tierras degradadas, plantaciones forestales, usos diferentes a la tala en algunos bosques, cambios en los procediminetos de contabilidad para reflejar el valor verdadero de los bosques naturales y soporte en las agencias forestales encargadas de la pro- teccion de las reservas forestales.

Poised to prosper? A cross-system comparison of climate change effects on native and non-native species performance.

Abstract: Climate change and biological invasions are primary threats to global biodiversity that may interact in the future. To date, the hypothesis that climate change will favour non-native species has been examined exclusively through local comparisons of single or few species. Here, we take a meta-analytical approach to broadly evaluate whether non-native species are poised to respond more positively than native species to future climatic conditions. We compiled a database of studies in aquatic and terrestrial ecosystems that reported performance measures of non-native (157 species) and co-occurring native species (204 species) under different temperature, CO2 and precipitation conditions. Our analyses revealed that in terrestrial (primarily plant) systems, native and non-native species responded similarly to environmental changes. By contrast, in aquatic (primarily animal) systems, increases in temperature and CO2 largely inhibited native species. There was a general trend towards stronger responses among non-native species, including enhanced positive responses to more favourable conditions and stronger negative responses to less favourable conditions. As climate change proceeds, aquatic systems may be particularly vulnerable to invasion. Across systems, there could be a higher risk of invasion at sites becoming more climatically hospitable, whereas sites shifting towards harsher conditions may become more resistant to invasions.

Nothing Succeeds Like Succession: A Critical Review of Leader Succession Literature Since 1994

Abstract: This article reviews leader succession research from 1994 to 2004. We begin with a brief summary of Kesner and Sebora’s [Kesner, I. F., & Sebora, T. C. (1994). Executive succession: Past, present and future. Journal of Management, 20, 327–372.] review of leader succession. We then critically examine intervening progress made by scholars regarding antecedents and consequences of succession. We conclude by critiquing the state of the field from both theoretical and methodological perspectives, and offering recommendations for future research. Generally, succession continues to be an attractive venue for scholars from a wide array of disciplines. Theory and methodology continue to be of variable quality, though some progress has been noted in the past decade on both fronts. Particularly notable research has generally either examined contextual aspects of succession, thus advancing our knowledge beyond main effects research, or used succession phenomena as windows into advancing organization theory.

The Contested Politics of Corporate Governance: The Case of the Global Reporting Initiative

Abstract: The Global Reporting Initiative (GRI) has successfully become institutionalized as the preeminent global framework for voluntary corporate environmental and social reporting. Its success can be att...