Trees and shrubs as sources of fodder in Australia

Experience with browse plants in Australia is briefly reviewed in terms of their forage value to animals, their economic value to the landholder and their ecological contribution to landscape stability. Of the cultivated species only two have achieved any degree of commercial acceptance (Leucaena leucocephala and Chamaecytisus palmensis). Both of these are of sufficiently high forage value to be used as the sole source of feed during seasonal periods of nutritional shortage. Both are also leguminous shrubs that establish readily from seed. It is suggested that a limitation in their present use is the reliance on stands of single species which leaves these grazing systems vulnerable to disease and insects. Grazing systems so far developed for high production and persistence of cultivated species involve short periods of intense grazing followed by long periods of recovery. Similar management may be necessary in the arid and semi-arid rangelands where palatable browse species are in decline

Current and Future Drug Targets in Weight Management

Obesity will continue to be one of the leading causes of chronic disease unless the ongoing rise in the prevalence of this condition is reversed. Accumulating morbidity figures and a shortage of effective drugs have generated substantial research activity with several molecular targets being investigated. However, pharmacological modulation of body weight is extremely complex, since it is essentially a battle against one of the strongest human instincts and highly efficient mechanisms of energy uptake and storage. This review provides an overview of the different molecular strategies intended to lower body weight or adipose tissue mass. Weight-loss drugs in development include molecules intended to reduce the absorption of lipids from the GI tract, various ways to limit food intake, and compounds that increase energy expenditure or reduce adipose tissue size. A number of new preparations, including combinations of the existing drugs topiramate plus phentermine, bupropion plus naltrexone, and the selective 5-HT2C agonist lorcaserin have recently been filed for approval. Behind these leading candidates are several other potentially promising compounds and combinations currently undergoing phase II and III testing. Some interesting targets further on the horizon are also discussed

Developing a model of plant hormone interactions

Plant growth and development is influenced by mutual interactions among plant hormones. The five classical plant hormones are auxins, cytokinins, gibberellins, abscisic acid and ethylene. They are small diffusible molecules that easily penetrate between cells. In addition, newer classes of plant hormones have been identified such as brassinosteroids, jasmonic acid, salicylic acid and various small proteins or peptides. These hormones also play important roles in the regulation of plant growth and development. This review begins with a brief summary of the current findings on plant hormones. Based on this knowledge, a conceptual model about interactions among plant hormones is built so as to link and develop an understanding of the diverse functions of different plant hormones as a whole in plants

Enhanced Histaminergic Neurotransmission and Sleep-Wake Alterations, a Study in Histamine H3-Receptor Knock-Out Mice

International audienceLong-term abolition of a brain arousal system impairs wakefulness (W), but little is known about the consequences of long-term enhancement. The brain histaminergic arousal system is under the negative control of H3-autoreceptors whose deletion results in permanent enhancement of histamine (HA) turnover. In order to determine the consequences of enhancement of the histaminergic system, we compared the cortical EEG and sleep-wake states of H3-receptor knockout (H3R-/-) and wild-type mouse littermates. We found that H3R-/-mice had rich phenotypes. On the one hand, they showed clear signs of enhanced HA neurotransmission and vigilance, i.e., a higher EEG θ power during spontaneous W and a greater extent of W or sleep restriction during behavioral tasks, including environmental change, locomotion, and motivation tests. On the other hand, during the baseline dark period, they displayed deficient W and signs of sleep deterioration, such as pronounced sleep fragmentation and reduced cortical slow activity during slow wave sleep (SWS), most likely due to a desensitization of postsynaptic histaminergic receptors as a result of constant HA release. Ciproxifan (H3-receptor inverse agonist) enhanced W in wild-type mice, but not in H3R-/-mice, indicating a functional deletion of H3-receptors, whereas triprolidine (postsynaptic H1-receptor antagonist) or α-fluoromethylhistidine (HA-synthesis inhibitor) caused a greater SWS increase in H3R-/- than in wild-type mice, consistent with enhanced HA neurotransmission. These sleep-wake characteristics and the obesity phenotypes previously reported in this animal model suggest that chronic enhancement of histaminergic neurotransmission eventually compromises the arousal system, leading to sleep-wake, behavioral, and metabolic disorders similar to those caused by voluntary sleep restriction in humans