In pursuit of ecotourism

Ecotourism is expected, by the tourism industry and academics, to grow rapidly over the next 20 years. Much has been written about ecotourism, often with missionary zeal, but there is little consensus about its definition. It is argued here that conservationists and protected area managers should adopt a definition of ecotourism which contributes to the maintenance of biodiversity and an appropriate definition is suggested.Ecotourism is not merely an alternative to mass tourism, nor is it the only alternative. The literature on nature tourism and the environmental impacts of the industry dates back to the late 1970s. Tourism is now the world's largest industry and it has an increasing impact on protected areas. Our understanding of these mechanisms, their ecological impacts and our capacity to manage tourism in protected areas lags behind the growth of tourism to protected areas.A rapid growth in nature tourism and tourism to protected areas has coincided with a shift in protected area management strategies towards integrated development. Tourism is one means available to protected area managers seeking to increase the economic value of a protected area and to offer sustainable opportunities for economic development to local people.This paper argues that potentially conflicting commercial, protected area and development interests all contribute to the emergence of ecotourism and have been doing so for many years. Ecotourism needs to be tightly defined if it is to benefit conservation. Protected area managers should consider how they can take control of nature tourism to the parks they manage and convert it into ecotourism for the benefit of conservation and the livelihoods of local people.     

In pursuit of effective toxicogenomics

Biological systems exhibit complex responses to xenobiotics varying from generic stress responses to very specific changes closely associated with the mechanism of toxicity. Until recently our view of this complexity was obscured by the simplicity of available analysis tools which allowed determination of only a few genes in any one study. Then genome sequencing and high throughput library screening projects delivered data on the genome sequence of many organisms, and clones were collected and made available to researchers in a previously unparalleled quantity. To exploit this new resource the microarray was developed from its predecessor the dot blot. Further development has expanded the number of clones contained on any one microarray to a point where the expression of many tens of thousands of genes in a biological system can be determined in a short period of time. What these data are revealing is the full complexity of the gene expression response to stimuli such as xenobiotic exposure. Toxicogenomics seeks to use the complexity of this response as a fingerprint or signature characteristic of that xenobiotic exposure. There are though two major experimental challenges that need to be dealt with for toxicogenomics to be successful. The first is technical and relates to the intrinsic difficulties associated with the accurate measurement of gene expression. For microarrays, this problem is multiplied by the number of genes on the microarray itself. To overcome this technical variability correct experimental design is critical. The second challenge concerns the biological system used. What genetic background, time point and dose of xenobiotic should be chosen? For in vitro systems should cell lines or primary cells be used? These factors, and more, could affect the gene expression profile obtained in response to the same xenobiotic exposure. Using both our data and data from public databases these issues are explored in this paper.     

In pursuit of formaldehyde: causally explanatory models and falsification

Falsification no longer is the cornerstone of philosophy of science; but it still looms widely that scientists ought to drop an explanatory hypothesis in view of negative results. We shall argue that, to the contrary, negative empirical results are unable to disqualify causally explanatory hypotheses—not because of the shielding effect of auxiliary assumptions but because of the fact that the causal irrelevance of a factor cannot empirically be established. This perspective is elaborated at a case study taken from the history of plant physiology: the formaldehyde model of photosynthesis, which for about sixty years (1870s to 1930s) dominated the field—despite the fact that in these sixty years all the attempts to conclusively demonstrate even the presence of formaldehyde in plants failed.     

Evolution in response to climate change: In pursuit of the missing evidence

Climate change is imposing intensified and novel selection pressures on organisms by altering abiotic and biotic environmental conditions on Earth, but studies demonstrating genetic adaptation to climate change mediated selection are still scarce. Evidence is accumulating to indicate that both genetic and ecological constrains may often limit populations' abilities to adapt to large scale effects of climate warming. These constraints may predispose many organisms to respond to climate change with range shifts and phenotypic plasticity, rather than through evolutionary adaptation. In general, broad conclusions about the role of evolutionary adaptation in mitigating climate change induced fitness loss in the wild are as yet difficult to make. Editor's suggested further reading in BioEssays: How will fish that evolved at constant sub‐zero temperatures cope with global warming? Notothenioids as a case study Abstract     

The Meander Site (39Lm20L) In Fort Randall Reservoir,South Dakota

Abstract

The Meander Site (39LM20l) is located on the left bank of the White River in Lyman County, South Dakota, about eight miles above the junction of the White and Missouri rivers. Test excavations at the site were conducted in 1953 by Harold A. Hus cher of the Smithsonian Institution, River BasinSurveys. Though few in number, the artifacts recovered indicate the occupation belongs to the Chouteau Aspect. Ceramic analysis suggests the site was occupied at a time somewhat prior to the occupation of the Crazy Bull Site (Frantz 1962).     

In pursuit of the whole hypha.

We know organisms first of all by their forms. Rabbit and carrot, Neurospora, and Paramecium represent particular shapes and structures, patterns in space and time. Each pattern integrates innumerable molecules into a coherent whole, reproduces itself from one generation to the next, and may persist in this manner for millions of years. In this lecture, I shall discuss efforts to render a dynamic and causal account of biological morphogenesis, using fungal hyphae as a concrete exemplar. Molecular structures and interactions are necessary but not sufficient to specify patterns on a scale three to five orders of magnitude larger. The search for alternatives leads to the importation of the concept of dynamic fields, exemplified by the proposal of Bartnicki-Garcia and Gierz that apical growth and morphogenesis report the operation of a mobile vesicle-supply center. Application of field theories to biological morphogenesis is still at an early stage, but is necessary in order to resolve the paradoxical relationship between genes and form.     

In pursuit of alpha4beta2 nicotinic receptor partial agonists for smoking cessation: carbon analogs of (-)-cytisine

The preparation and biological activity of analogs of (-)-cytisine, an alpha4beta2 nicotinic receptor partial agonist, are discussed. All-carbon-containing phenyl ring replacements of the pyridone ring system, generated via Heck cyclization protocols, exhibited weaker affinity and lower efficacy partial agonist profiles relative to (-)-cytisine. In vivo, selected compounds exhibit lower efficacy partial agonist profiles than that of (-)-cytisine.