2,412 research outputs found
Living deep-water Lophelia and Madrepora corals in Maltese waters (Strait of Sicily, Mediterranean Sea)
The occurrence of living deep-water corals, Lophelia pertusa and Madrepora oculata, from stations 21-42 km
off the southern and south-western coast of Malta is reported. Fragments of living colonies of both species, as well as some
large pieces of Lophelia frameworks were recovered from depths of 390-617 m together with the solitary coral
Desmophyllum dianthus (= cristagalli). The accompanying biota included the barnacle Pachylasma giganteum, the
gastropod Coralliophila richardi, the bivalves Asperarca nodulosa and Spondylus gussonii, and the polychaete Eunice
norvegicus, all of which are frequently associated with deep-water corals. The occurrence of the Lophelia-Madrepora-
Desmophyllum triad, the large pieces of coral frameworks consisting predominantly of live, healthy polyps, and the
associated biota, suggest that coral patches may be present in at least some of the investigated localities, rather than just
fragmented remains or isolated colonies.peer-reviewe
Hydraulics Boot Camp
With a continuing need for additional hydraulic analysis for projects, we will walk through some of the common requirements for projects, discuss common errors, and highlight how to improve hydraulic submittals
The Impact of Embeddedness, Leadership, and Succession on Technology Initiative Perceptions of Success (TIPS) in American International Schools
The purpose of this study is to learn how embeddedness, leadership style, and succession in an American international school setting affects perceptions of success related to technology initiative implementation. This study will use both case study and survey data methods. The goal of the study is to identify aspects that play a role in faculty perceptions in order to better plan out new initiatives. The results can help leaders to increase the likelihood that their future initiatives are perceived as successful
Portfolio Rebalancing: A Test of the Markowitz-Van Dijk Heuristic
Institutional investors usually employ mean-variance analysis to determine optimal
portfolio weights. Almost immediately upon implementation, however, the portfolio’s
weights become sub-optimal as changes in asset prices cause the portfolio to drift away
from the optimal targets. In an idealized world without transaction costs investors would
rebalance continually to the optimal weights. In the presence of transaction costs
investors must balance the cost of sub-optimality with the cost of restoring the optimal
weights. We apply a quadratic heuristic to address the asset weight drift problem, and we
compare it to a dynamic programming solution as well as to standard industry heuristics.
Our tests reveal that the quadratic heuristic provides solutions that are remarkably close
to the dynamic programming solutions for those cases in which dynamic programming is
feasible and far superior to solutions based on standard industry heuristics. In the case of
five assets, in fact, it performs better than dynamic programming due to approximations
required to implement the dynamic programming algorithm. Moreover, unlike the
dynamic programming solution, the quadratic heuristic is scalable to as many as several
hundreds assets
Carbohydrate-derived iminium salt organocatalysts for the asymmetric epoxidation of alkenes
A new family of carbohydrate-based dihydroisoquinolinium salts has been prepared and tested for potential as asymmetric catalysts for the epoxidation of unfunctionalized alkene substrates, providing up to 57% ee in the product epoxides
Mapping the CMB III: combined analysis of QMAP flights
We present results from the QMAP balloon experiment, which maps the Cosmic
Microwave Background (CMB) and probes its angular power spectrum on degree
scales. In two separate flights, data were taken in six channels at two
frequency bands between 26 to 46 GHz. We describe our method for mapmaking
(removal of 1/f-noise and scan-synchronous offsets) and power spectrum
estimation, as well as the results of a joint analysis of the data from both
flights. This produces a 527 square degree map of the CMB around the North
Celestial Pole, allowing a wide variety of systematic cross-checks. The
frequency dependence of the fluctuations is consistent with CMB and
inconsistent with Galactic foreground emission. The anisotropy is measured in
three multipole bands from l~40 to l~200, and the angular power spectrum shows
a distinct rise which is consistent with the Saskatoon results.Comment: 4 pages, with 3 figures included. Submitted to ApJL. Window functions
are available at http://pupgg.princeton.edu/~cmb/welcome.html and color
figures and links at http://www.sns.ias.edu/~angelica/skymap.html#qma
Modern Migration in Ghana and Mali: A Comparison of Urban Migration Patterns
West Africa has a long tradition of human migration. Since the era of European colonization and during the twentieth century much of this migration has been rural to urban. This paper analyzes statistical data, observations, and interviews to compare the impacts of this migration on the cities of Bamako, Mali and Accra, Ghana. This analysis supports the conclusions that rural to urban migration in Ghana has resulted in the creation of an urban subsistence existence and an increased number of people participating in the informal sector of the economy. It further shows that when compared with Ghana, internal migration patterns and factors in Mali have resulted in much less growth in the urban population and informal sector of the economy. It appears that the people of Mali continue to prefer to engage in subsistence agriculture rather than to shift to a subsistence urban existence
Design and analysis issues of integrated control systems for high-speed civil transports
A study was conducted to identify, rank, and define development plans for the critical guidance and control design and analysis issues as related to economically viable and environmentally acceptable high-speed civil transport. The issues were identified in a multistep process. First, pertinent literature on supersonic cruise aircraft was reviewed, and experts were consulted to establish the fundamental characteristics and problems inherent to supersonic cruise aircraft. Next, the advanced technologies and strategies being pursued for the high-speed civil transport were considered to determine any additional unique control problems the transport may have. Finally, existing technologies and methods were examined to determine their capabilities for the design and analysis of high-speed civil transport control systems and to identify the shortcomings and issues. Three priority levels - mandatory, highly beneficial, and desirable - were established. Within each of these levels, the issues were further ranked. Technology development plans for each issue were defined. Each plan contains a task breakdown and schedule
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