Biodiversity of the Deep-Sea Continental Margin Bordering the Gulf of Maine (NW Atlantic): Relationships among Sub-Regions and to Shelf Systems

Background: In contrast to the well-studied continental shelf region of the Gulf of Maine, fundamental questions regarding the diversity, distribution, and abundance of species living in deep-sea habitats along the adjacent continental margin remain unanswered. Lack of such knowledge precludes a greater understanding of the Gulf of Maine ecosystem and limits development of alternatives for conservation and management. Methodology/Principal Findings: We use data from the published literature, unpublished studies, museum records and online sources, to: (1) assess the current state of knowledge of species diversity in the deep-sea habitats adjacent to the Gulf of Maine (39–43uN, 63–71uW, 150–3000 m depth); (2) compare patterns of taxonomic diversity and distribution of megafaunal and macrofaunal species among six distinct sub-regions and to the continental shelf; and (3) estimate the amount of unknown diversity in the region. Known diversity for the deep-sea region is 1,671 species; most are narrowly distributed and known to occur within only one sub-region. The number of species varies by sub-region and is directly related to sampling effort occurring within each. Fishes, corals, decapod crustaceans, molluscs, and echinoderms are relatively well known, while most other taxonomic groups are poorly known. Taxonomic diversity decreases with increasing distance from the continental shelf and with changes in benthic topography. Low similarity in faunal composition suggests the deep-sea region harbours faunal communities distinct from those of the continental shelf. Non-parametric estimators of species richness suggest a minimum of 50% of the deep-sea species inventory remains to be discovered. Conclusions/Significance: The current state of knowledge of biodiversity in this deep-sea region is rudimentary. Our ability to answer questions is hampered by a lack of sufficient data for many taxonomic groups, which is constrained by sampling biases, life-history characteristics of target species, and the lack of trained taxonomists

Seachange : subtitle an environmental history of the Pacific halibut fishery 1878-1960

Seachange is a study of shifting emphases in Pacific halibut conservation policy, and a story about the changing relationship between people and nature. North American fishery conservation policy cut its teeth on the Pacific halibut fishery. It has been cooperatively managed by Canada and the United States since 1923, and has been at the center of what may prove to be two of the most important debates over fishery policy in the last century. What follows, however, is less a study of specific policies than it is a study of shifting emphases in North American fishery management. Although people have been fishing halibut for hundreds of years, the idea that their activities need to be managed is relatively new. But the idea of "management" begs two further questions: managed how and to what end? These are the questions to which Seachange seeks answers.Arts, Faculty ofGeography, Department ofGraduat

Drosophila Pickpocket Channel Function in Courtship Behavior and Water Detection

The gustatory system is primarily involved in feeding, allowing animals to distinguish nutrients from toxins. In the fruit fly Drosophila melanogaster, neurons of the gustatory system also function during egg-laying and courtship behavior, and are broadly involved in contact-mediated chemical recognition. Gustatory input in Drosophila occurs at structures called taste bristles, which are located on the proboscis, legs, wing margins, and ovipositor. Four chemosensory neurons are housed at the base of each bristle, three of which faithfully respond to specific modalities: sugars, bitters, or water. However, the function of the fourth chemosensory neuron, and the molecular mechanism responsible for its activation, remained elusive. Further, the physical properties of molecules responsible for sensory neuron detection is poorly understood.Microarray analyses identified two genes encoding epithelial sodium channels (deg/ENaCs), PPK23 and PPK29, which show co-expression in the fourth taste neuron and are not expressed in any other tissues. These genes were exciting candidates for defining sensory neuron specificity, as a related channel, PPK28, confers water sensitivity to taste neurons. Initial expression studies revealed that these genes were co-expressed with the transcription factor fruitless, a critical molecule in the organization or sexual dimorphism in the fly. We hypothesized that PPK23 and/or PPK29 may function in pheromone detection and contribute to aspects of courtship behavior. The second chapter of this thesis demonstrates that these genes are imperative for mate discrimination during courtship, and the cells that express them serve as one of the earliest filters for the neural circuitry that leads to courtship enhancement or courtship inhibition. Finally, cells that express these genes respond directly to pheromone application in a male or female specific manner, suggesting the balance between attraction and repulsion at the sensory level may contribute to the overall decision of the organism.How do pickpocket subunits contribute to mate discrimination behavior? The third chapter of this thesis is an exploration into subunit expression specificity. Calcium imaging studies suggest a heterogeneity in PPK23 cells. In order to separate attractive and repulsive circuits at the sensory level, we ascertained the behavioral genetic interactions between multiple subunits. We found that the population of cells expressing the subunit PPK25 responds exclusively to female pheromone molecules and is also critical for female receptivity. This provides direct genetic access to this component of the courtship circuit.The function of pickpocket ion channels in signal transduction has yet to be demonstrated. PPK28 detects low osmolarity and has been shown to function when misexpressed in neurons as well as in heterologous systems. However whether it is a direct transducer of osmolarity or perhaps an amplifier of another protein is not known. In the fourth chapter, we delve into the mechanism of gating of pickpocket channels using PPK28 as a model. Our data suggest it is a direct transducer of mechanical force on the membrane and provides an exciting example to study other Deg/ENaC proteins in the role of mechanosensation

Detours and frolics on the Internet: Employer liability and management control of cybertorts

Most employers are aware of their legal right to monitor employees' computer activities, and they are increasingly doing so. Yet, few of those who do monitor are aware that exercising this right may impose a legal duty to monitor prudently in order to protect third parties and to report criminal activity to the appropriate authorities. This paper briefly examines employers' legal right to monitor their employees' computer activities. Our subsequent analysis of the ruling in Doe v. XYC Corp. [Doe v XYC Corp., 382 N.J. Super. 122, 887 A.2d 1156 (2005)]. illustrates that those businesses that do assert their rights to monitor may assume a duty to report child pornography to the authorities, as well as a duty of reasonable care when reacting to their employees engaging in so-called cybertorts. We discuss how this ruling may extend the doctrines of 'detours' and 'frolics' into cyberspace. We also discuss the potential for employers' liability for other cybercrimes and cybertorts committed by their employees. We conclude by examining the contours of computer monitoring policies that effectively serve employers' risk management objectives without unduly invading employees' privacy, and the likely consequences of failing to achieve such a balance.Electronic monitoring Information technology Risk management Public policy Organizational justice

Evaluation of spray deposition in potatoes using various spray delivery systems

The tomato-potato psyllid incurs high control costs through intensive spraying and other treatments. A field study was conducted in March 2012 in Pukekohe, New Zealand, to evaluate the pesticide deposition potential of five different spray delivery systems. The treatments included a conventional boom, a canopy submerged drop sprayer combination, a pneumatic electrostatic spraying system, an air-assisted rotary atomizer, and a high-volume air-assist boom. Each system was calibrated for appropriate spray volume rates between 167 and 400 litres/ha. Rhodamine WT fluorescent dye used as a tracer was sampled on folded Kromekote® sampling cards oriented flat and horizontally above, central to, and below the canopy. Spray coverage rates were quantified at designated heights adjacent to leaves to assess deposition throughout the potato canopy. All treatments that consisted of one or more novel technologies consistently gave higher coverage to the underside of the potato leaves than with the conventional boom