Predicting chemical effects on birds: a critical literature review.

The effects of chemicals on birds has created a great deal of public concern and scientific debate. A wealth of information on species distribution, breeding numbers and population changes has provided a good basis for identifying environmental problems after the event. However, the difficulty lies in using such information for predicting possible chemical impacts in the future. Standard laboratory toxicity testing is carried out as a routine requirement for both national and international regulatory authorities, and the prediction of effects is still centred around these tests. .Development work has concentrated on test regimes and field validation, but little attention has been focused on the interpretation of the data in the light of the other factors which influence the survival and reproduction of wild birds. Standard and non standard tests, field trials, monitoring and risk assessment methods and approaches are reviewed. It is concluded that laboratory testing has an important place in the prediction of the effects of chemicals on wild bird populations. However, such tests must be seen merely as a means of screening chemicals for potential effects rather than realistic models of events in the natural world. Test design needs to be varied, .and risk assessment flexible, with significant scope for expert judgement. Risk assessment of chemicals should be fate-led to minimize the unnecessary use of laboratory animals by identifying the distribution and availability of chemicals in the environment before testing for effects. Preliminary risk assessment conclusions should be validated in the field. Multidisciplinary studies involving testing, field trials, monitoring and risk assessment should ideally be carried out; disciplines such as toxicology, environmental chemistry, ecology, population dynamics, ethology, physiology and land use geography all have a part to play

Profile of the scuba diving vacationer to the island of Bonaire

The island of Bonaire, part of the Netherland Antilles in the Caribbean, is percieved to be experiencing a decline in their tourism arrivals of scuba diving vacationers from the United States. Tourism is an important export for the economic stability of Bonaire, with the scuba vacationing market accounting for up to 53% of total arrivals to the island (Tourism Corporation Bonaire). Economic impacts are filtering down to the working class, affecting the socio-economic climate of the island. Bonaire has enjoyed being one of the premier scuba diving destinations on the Caribbean for many years. Its clear waters, tropical climate, abundant marine life, ease of shore access, and calm seas on the leeward side of the island lend it to being a scuba diver\u27s paradise. The Tourism Corporation Bonaire (herein called \u27 TCB\u27) has shifted its focus of target markets to that of upscale, European clientele. In the recent economic recession in the United States, combined with the war in the Gulf, many islands, hotels and attractions have shifted their strategies in this manner. The reason for the high-end market is due to the amount of discretionary income and time the market segment has. Market share is becoming increasingly harder to obtain and sustain due to increased competition of this target market. The Council of Underwater Resort Operators (herein called \u27CURO\u27) are interested in finding out who their clientele are, and where they are coming from. The assessment of where Bonaire is in respect to product life cycle is also an important issue to be considered in this study. This may show the need for improvement of percieved image, as well as possibly infrastructure and/or superstructures

Ten-Dimensional Supergravity Constraints from the Pure Spinor Formalism for the Superstring

It has recently been shown that the ten-dimensional superstring can be quantized using the BRST operator $Q=\oint\lambda^\alpha d_\alpha$ where $\lambda^\alpha$ is a pure spinor satisfying $\lambda \gamma^m \lambda=0$ and $d_\alpha$ is the fermionic supersymmetric derivative. In this paper, the pure spinor version of superstring theory is formulated in a curved supergravity background and it is shown that nilpotency and holomorphicity of the pure spinor BRST operator imply the on-shell superspace constraints of the supergravity background. This is shown to lowest order in $\alpha'$ for the heterotic and Type II superstrings, thus providing a compact pure spinor version of the ten-dimensional superspace constraints for N=1, Type IIA and Type IIB supergravities. Since quantization is straightforward using the pure spinor version of the superstring, it is expected that these methods can also be used to compute higher-order $\alpha'$ corrections to the ten-dimensional superspace constraints.Comment: 30 pages late

Kappa-symmetric SL(2,R) covariant D-brane actions

A superspace formulation of IIB supergravity which includes the field strengths of the duals of the usual physical one, three and five-form field strengths as well as the eleven-form field strength is given. The superembedding formalism is used to construct kappa-symmetric SL(2,R) covariant D-brane actions in an arbitrary supergravity background.Comment: 20 pages. Minor clarification in text. References adde

Anomaly-Free Tensor-Yang-Mills System and Its Dual Formulation

We consider the (1,0) supersymmetric Yang-Mills multiplet coupled to a self-dual tensor multiplet in six dimensions. It is shown that the counterterm required to cancel the one-loop gauge anomaly modifies the classical equations of motion previously obtained by Bergshoeff, Sezgin and Sokatchev (BSS). We discuss the supermultiplet structure of the anomalies exhibited in the resulting equations of motion. The anomaly corrected field equations agree with the global limit, recently obtained by Duff, Liu, Lu and Pope, of a matter coupled supergravity theory in six dimensions. We also obtain the dual formulation of the BSS model in which the tensor multiplet is free while the field equations of the Yang-Mills multiplet contain the fields of the tensor multiplet at the classical level