Skewed sex ratio in an estuarine lobster (Homarus americanus) population

A total of 19,485 lobsters were caught sites in the estuarine and coastal waters of New Hampshire from 1989 to 1992, and their size and sex were determined. The sex ratio of lobsters caught farthest from the coast, in Great Bay, was heavily skewed in favor in males. Sex ratios in other estuarine and river sites were also skewed toward males, and there was a tendency for the number of males per female to decline as one moved down the estuary toward the coast, where the sex ratio was nearly 1:1. The single offshore site was dominated by females, with about 0.6 males for each female. There were also seasonal trends in the sex ratios in the upper estuarine sties, where the number of males per female tended to decline from summer through autumn. In general, differences in the sex ratios between sites were those of primarily adult lobsters larger than 80 mm carapace length (CL). At all sites, the sex ratio of lobsters smaller than this size was close to 1:1, whereas in the upper estuary the mean sex ratio of lobsters greater than 80 mm CL was more than 14:1. These data, in conjunction with seasonal variations of sex ratios, suggest that differential movements of adult male and female lobsters is the primary cause of skewed sex ratios in the Great Bay Estuary

A Lagrangian relaxation approach to the edge-weighted clique problem

The $b$-clique polytope $CP^n_b$ is the convex hull of the node and edge incidence vectors of all subcliques of size at most $b$ of a complete graph on $n$ nodes. Including the Boolean quadric polytope $QP^n$ as a special case and being closely related to the quadratic knapsack polytope, it has received considerable attention in the literature. In particular, the max-cut problem is equivalent with optimizing a linear function over $QP^n_n$. The problem of optimizing linear functions over $CP^n_b$ has so far been approached via heuristic combinatorial algorithms and cutting-plane methods. We study the structure of $CP^n_b$ in further detail and present a new computational approach to the linear optimization problem based on Lucena's suggestion of integrating cutting planes into a Lagrangian relaxation of an integer programming problem. In particular, we show that the separation problem for tree inequalities becomes polynomial in our Lagrangian framework. Finally, computational results are presented. \u

Lobster movements in response to a hurricane

There are several anecdotal reports of the American lobster Homarus americanus moving to deeper water, or suffering increased mortality, in response to storm events. It has also been reported that changes in salinity and temperature, similar to those resulting from storm events, can elicit avoidance behaviors. In 1991, during an ongoing lobster study, Hurricane Bob caused a substantial drop in salinity in the Great Bay Estuary, New Hamphire, USA. This freshet, and possibly related environmental perturbations, was associated with increased movement of lobsters down the estuary toward the coast and a rise in catch in areas closer to the coast. Thus, our data support the hypothesis that storms can induce movements of lobsters and subsequent transient shifts in the demographics of the lobster population

Resource Sharing Success Stories in Tasmania

The councils of Kentish, Latrobe, Waratah-Wynyard, and Circular Head in Tasmania engaged the Australian Centre of Excellence for Local Government and the University of Technology Sydney Centre for Local Government (UTS:CLG) to review their resource sharing arrangements. The review considered governance and decision-making arrangements, the current State Government reform agenda, strategic capacity of the councils and a financial analysis of savings from resource sharing arrangements

Review of Resource Sharing Arrangements Between Kentish and Latrobe Councils

Kentish and Latrobe Councils have been undertaking various forms of resource sharing since 1992 in order to improve levels of service and preserve and maintain local representation. The councils are keen to continue to grow, enhance and refine the resource sharing arrangements and engaged the Australian Centre of Excellence for Local Government (ACELG) at the University of Technology Sydney to review the resource sharing arrangements between the two councils

Workforce planning guidelines for local government in Tasmania

Workforce planning in Tasmania as a whole, and in the local government sector in particular, is essential to meet the needs of communities and deliver a growing, prosperous Tasmania. As the level of government best placed to meet community needs, councils are in a unique position to identify the skills, knowledge and expertise needed to effectively tailor services, generate economic and employment opportunities and support the overall prosperity of their local and regional communities. Planning a future workforce to deliver vital services needs to be clearly linked to local, regional and state-wide priorities. Councils have a key role to plan for their own workforces as part of strategic planning but also play an important role in partnering with a range of local, regional and state level organisations to identify and support conditions for economic growth. Workforce planning brings important benefits to councils and their communities and these guidelines are intended to help local government plan at a local, sub-regional and regional level to support the future growth of a vibrant Tasmanian economy

Lobster movements in response to a hurricane

There are several anecdotal reports of the American lobster Homarus americanus moving to deeper water, or suffering increased mortality, in response to storm events. It has also been reported that changes in salinity and temperature, similar to those resulting from storm events, can elicit avoidance behaviors. In 1991, during an ongoing lobster study, Hurricane Bob caused a substantial drop in salinity in the Great Bay Estuary, New Hamphire, USA. This freshet, and possibly related environmental perturbations, was associated with increased movement of lobsters down the estuary toward the coast and a rise in catch in areas closer to the coast. Thus, our data support the hypothesis that storms can induce movements of lobsters and subsequent transient shifts in the demographics of the lobster population

Nature, nurture and early brain development (2000)

"Information from Human Environmental Sciences Extension.""Child development."New 1/00/5M

Components, production processes, and recommendations for future research in organic light emitting diodes

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 29).Organic Light Emitting Diodes (OLEDs) are small, optoelectronic devices that can be used in the production of energy-efficient, high definition displays in cell phones, computers, and televisions. These devices have great potential to replace light emitting diodes (LEDs) completely because they are more environmentally friendly to produce, they are more efficient, and they can create displays much thinner than current LED displays. Moreover, OLEDs allow for the creation of brighter, flexible screens. While these devices have great potential, it has not been realized yet due to cost and difficulty in optimizing production processes. Many companies have been attempting to produce affordable OLED displays for years, but have not been successful due to lack of optimization of production processes. Work should continue to be done in economic optimization of the processes and also optimization of energy efficiency of the devices.by Lindsay Hunting.S.B

Comparative Growth and Survival of Juvenile Atlantic Cod (Gadus morhua)Cultured in Copper and Nylon Net Pens

Bio-fouling on net pens has been a major concern for the marine aquaculture industry. As cage systems increase in size, so does the surface area for the attachment of colonial organisms that create drag on the net, reduce water flow important to fish health, and increase operational expenses due to net cleaning. To solve this problem, the International Copper Association (ICA) has been developing copper alloy netting for sea cages. Copper netting has unique properties that minimize bio-fouling, reduce the risk of fish escapement, prevent predators from entering the net pen, and is recyclable. To test the alloy netting, an experiment was conducted to compare juvenile cod cultured in traditional nylon nets with cod grown in Seawire copper netting ([email protected]). Six, 0.78 m3 cages were each stocked with 200 Atlantic cod (Gadus morhua) averaging 29 ± 2.2 g and grown for 4 months in coastal waters of New Hampshire, USA. Results of the study indicated no significant differences in cod growth, survival, feed conversion ratio (FCR), specific growth rate (SGR), or Fulton’s condition factor (K) between the fish grown in the copper alloy and nylon nets. A chemical analysis was conducted on the cod and indicated no differences in copper levels in muscle, liver and gill tissues taken from the net treatments. Nylon nets with antifouling paint accumulated significantly more bio-fouling than the copper nets. Materials that were in direct contact with the copper netting (plastic cable ties) fouled heavily with hydroids indicating minimal leaching to the environment. This study describes some of the beneficial attributes of copper netting, however future studies need to be conducted over a longer period of time, on a larger scale, and in a more energetic environment to definitively test the utility of this new product