The need to disentangle key concepts from ecosystem-approach jargon.

The ecosystem approach--as endorsed by the Convention on Biological Diversity (CDB) in 2000-is a strategy for holistic, sustainable, and equitable natural resource management, to be implemented via the 12 Malawi Principles. These principles describe the need to manage nature in terms of dynamic ecosystems, while fully engaging with local peoples. It is an ambitious concept. Today, the term is common throughout the research and policy literature on environmental management. However, multiple meanings have been attached to the term, resulting in confusion. We reviewed references to the ecosystem approach from 1957 to 2012 and identified 3 primary uses: as an alternative to ecosystem management or ecosystem-based management; in reference to an integrated and equitable approach to resource management as per the CBD; and as a term signifying a focus on understanding and valuing ecosystem services. Although uses of this term and its variants may overlap in meaning, typically, they do not entirely reflect the ethos of the ecosystem approach as defined by the CBD. For example, there is presently an increasing emphasis on ecosystem services, but focusing on these alone does not promote decentralization of management or use of all forms of knowledge, both of which are integral to the CBD's concept. We highlight that the Malawi Principles are at risk of being forgotten. To better understand these principles, more effort to implement them is required. Such efforts should be evaluated, ideally with comparative approaches, before allowing the CBD's concept of holistic and socially engaged management to be abandoned or superseded. It is possible that attempts to implement all 12 principles together will face many challenges, but they may also offer a unique way to promote holistic and equitable governance of natural resources. Therefore, we believe that the CBD's concept of the ecosystem approach demands more attention.

Exercise training and clenbuterol reduce insulin resistance of obese Zucker rats.

This study compared the effects of aerobic exercise training and chronic administration of the selective beta 2-adrenergic agonist clenbuterol on whole body and skeletal muscle insulin resistance in obese (fa/fa) Zucker rats. Obese rats were randomly assigned to training, clenbuterol, or sedentary control groups. Lean littermates served as a second control group. After 4-5 wk of treatment, an oral glucose tolerance test was performed, followed 1 wk later by hindlimb perfusion, during which time the rates of glucose uptake and 3-O-methyl-D-glucose (3-MG) transport were assessed in the presence of a submaximal (500 microU/ml) insulin concentration. Training resulted in a significant increase in citrate synthase and cytochrome oxidase activity in the recruited muscles. Clenbuterol induced a large increase in muscle mass but provoked a significant decrease in oxidative enzyme activity and beta-adrenergic receptor density. Both treatments increased glucose tolerance and reduced the postglucose insulin response, with the improvements being more pronounced in the clenbuterol group. However, only exercise training improved insulin-stimulated hindlimb muscle glucose uptake (11.37 +/- 0.65, 8.73 +/- 0.77, and 8.27 +/- 0.41 mumol.g-1.h-1 for trained, clenbuterol, and sedentary control groups, respectively) and 3-MG transport. These results suggest that aerobic exercise training attenuated the insulin-resistant condition in the obese Zucker rat by a mechanism other than or in addition to beta 2-adrenergic receptor activation.

Muscle glucose transport, GLUT-4 content, and degree of exercise training in obese Zucker rats.

The effects of high (HI)- and low (LI)-intensity exercise training were examined on insulin-stimulated 3-O-methyl-D-glucose (3-MG) transport and concentration of insulin-regulatable glucose transporter protein (GLUT-4) in the red (fast-twitch oxidative) and white (fast-twitch glycolytic) quadriceps of the obese Zucker rat. Sedentary obese (SED) and lean (LN) Zucker rats were used as controls. 3-MG transport was determined during hindlimb perfusion in the presence of 8 mM 3-MG, 2 mM mannitol, 0.3 mM pyruvate, and 0.5 mU/ml insulin. HI and LI rats displayed greater rates of red quadriceps 3-MG transport and GLUT-4 concentrations than SED rats. No significant differences in rates of 3-MG transport or GLUT-4 concentrations were observed in the red quadriceps of HI and LI rats. There were no differences found in the rates of 3-MG transport in the white quadriceps of HI, LI, and SED rats although the difference between the HI and SED rats approached significance (P < 0.07). The GLUT-4 concentration and citrate synthase activity of HI rats were significantly greater than SED rats. The 3-MG transport rates of LN rats were twofold greater than SED rats regardless of fiber type, but a difference in GLUT-4 content between the LN and SED rats was observed only in the white quadriceps. GLUT-4 content of the obese rats was significantly correlated with citrate synthase activity (r = 0.93) and 3-MG transport (r = 0.82).(ABSTRACT TRUNCATED AT 250 WORDS)