One topic of increasing interest to conservationists is to assess the human value of ecosystems, from the provision of food and water to recreation, carbon storage and supporting biodiversity, to better understand their importance. But biodiversity and other ecosystem services are increasingly threatened by human activities. The hope among conservation biologists and policy makers is that futur...

A four generation supersymmetric model is proposed, in which the Tevatron “top-quark” events are reinterpreted as the production of t′ which decays dominantly to bW. In this model, mt ≃ mW , and t → t̃χ̃01, with t̃ → cχ̃01. This decay chain, which rarely produces a hard isolated lepton, would have been missed in all previous top quark searches. A narrow region of the model parameter space exists wh...

I have alwayswanted to be adoctor.Manyaspects ofmedicine enthralled me: research, diagnosis, and the possibility of improving a patient’s quality of life, in particular.Walking the corridors of a hospital felt exhilarating. At 15 I had a volunteer position at the local hospital. Although my assignments were answering phones, directing visitors, and, my favorite, delivering goods topatients, I f...

by human activity is easily understood, though difficult to halt: the spectacular decline in once-common species that ranged over vast areas of diverse habitats proved initially a much more difficult problem to understand. An example of this is the extraordinary reduction in numbers of three Asian vultures — the Oriental white-backed (Gyps bengalensis), long-billed (Gyps indicus) and slender-bi...

Among vertebrates, the cellular and molecular mechanisms of neural induction appear largely divergent [1], thus providing little indication of the ancestral chordate mode. Ascidians, which belong to a sub-phylum of the chordates (Urochordata) long separated from the lineage leading to the vertebrates, may provide insight to these questions [2,3]. We have investigated neural specification in asc...

extremely optimistic about the future. There are two general categories for my enthusiasm: the tangible benefits that will be brought by financially invigorated research programs, and perhaps the more important intangible benefits to morale, image and outlook that will be brought by replacing political ideologues with responsible scientists. Even if I myself never see a single dollar in increas...

As I write these words, thick snow blankets my lawn and my Potentilla is badly frosted, but you know, we gardeners are never gloomy for long. We know, as we toast our muffins and stir our cocoa, that now is the time to plan next Summer's garden. Of course, with so many gardening programmes on the television nowadays, its quite easy to produce a colourful display. Almost too easy, for the boring...