Microlensing of circumstellar envelopes: II. emission lines from radial and azimuthal flow during fold caustic crossings

This paper examines the line profile evolution due to bulk motion in circumstellar envelopes during microlensing fold caustic crossing events. These events have recently been shown to be a sensitive probe of stellar surface brightness profiles, thus providing a means - through both photometric and spectroscopic observations - to constrain and test stellar atmosphere models. Here it is demonstrated, through the examination of simplified line profiles, that spectroscopic studies of fold caustic crossings could also prove to be a powerful diagnostic of bulk motion in circumstellar envelopes

THE EFFECTS OF FUTURES TRADING BY LARGE HEDGE FUNDS AND CTAS ON MARKET VOLATILITY

This study uses the newly available data from the CFTC to investigate the market impact of futures trading by large hedge funds and CTAs. Regression results show that there is a positive relationship between the trading volume of large hedge funds and CTAs and market volatility. However, a positive relationship between hedge fund and CTA trading volume and market volatility is consistent with either a private information or noise trader hypothesis. Three additional tests are conducted to distinguish between the private information hypothesis and the noise trader hypothesis. The first test consisted of identifying the noise component exhibited in return variances over different holding periods. The variance ratio tests provide little support for the noise trader hypothesis. The second test examined whether positive feedback trading characterized large hedge fund and CTA trading behavior. These results suggest that trading decisions by large hedge funds and CTAs, although influenced in small part by past price changes, are not driven by past price changes. The third test consists of estimating the profits and losses associated with the open interest positions of large hedge funds and CTAs. This test is based on the argument that speculative trading can only be destabilizing if speculators buy when prices are high and sell when prices are low, which in turn, implies that destabilizing speculators lose money. Across all thirteen markets, the profit for large hedge funds and CTAs is estimated to be just under $400 million. This implies that the trading decisions are likely based on valuable private information. Overall, the evidence presented in this study suggests trading by large hedge funds and CTAs is based on private fundamental information. These findings imply large hedge funds and CTAs benefit market efficiency by bringing valuable, fundamental information to the market through their trading.hedge fund, commodity trading advisor, volatility, market efficiency, futures markets, Marketing,

The ABC's of Apples, Bees, and Connections Hydrologic

Resource /Energy Economics and Policy, Q25,

Malpractice in the United Kingdom

No law exists which precisely determines the liability of a medical practitioner in respect of his patients. However, the basis of a practitioner\u27s responsibility is that he should exercise a reasonable degree of skill and care. The principle was first evoked in the case of Lanphier v. Phipos (1838) and it is obvious that in the absence of any more exact requirements, considerable latitude exists. Gradually, various decisions of the courts have limited the field of responsibility, and indicated to some extent what is meant by reasonable skill and care. With the exception of these modifications, the law has not changed materially for over a century, but at the present time, there is an undoubted increase in the frequency with which actions involving doctors and hospital authorities appear before the courts. The two most obvious factors influencing this tendency are the introduction of the National Health Service in 1948, and the Legal Aid and Advice Act of 1949

The Role Of Social Media In Crisis Management At Carnival Cruise Line

This research provides an overview of the marketing issues facing Carnival Cruise Line after several high profile incidents. Carnival Cruise Lines has suffered several mishaps which have harmed its reputation and the reputation of the cruise industry in general. Is the damage irreparable, or can careful crisis management and marketing repair the trust and confidence of Carnival’s guests and prospective cruisers? The latest disaster, an engine room fire which left the Carnival Triumph adrift in the Gulf of Mexico earlier this year prompted the Cruise Lines International Association (CLIA) to approve a “Cruise Industry Passenger Bill of Rights” ("Cruise Industry Adopts," 2013). This research offers insight into the use of social media as both a positive and negative marketing tool

Collinear Four-Wave Mixing of Two-Component Matter Waves

We demonstrate atomic four-wave mixing of two-component matter waves in a collinear geometry. Starting from a single-species Bose-Einstein condensate, seed and pump modes are prepared through microwave state transfer and state-selective Kapitza-Dirac diffraction. Four-wave mixing then populates the initially empty output modes. Simulations based on a coupled-mode expansion of the Gross-Pitaevskii equation are in very good agreement with the experimental data. We show that four-wave mixing can play an important role in studies of bosonic mixtures in optical lattices. Moreover our system should be of interest in the context of quantum atom optics.Comment: 4 pages, 4 figures; revised version, essentially as publishe

Mercury deposition in southern New Hampshire, 2006–2009

The atmospheric deposition of mercury (Hg) occurs via several mechanisms including wet, dry, and occult processes. In an effort to understand the atmospheric cycling and seasonal depositional characteristics of Hg, event-based wet deposition samples and reactive gaseous Hg (RGM) measurements were collected for approximately 3 years at Thompson Farm (TF), a near-coastal rural site in Durham, NH, part of the University of New Hampshire AIRMAP Observing Network. Total aqueous mercury exhibited seasonal patterns in Hg wet deposition at TF. The lowest Hg wet deposition was measured in the winter with an average total seasonal deposition of 1.56 μg m−2compared to the summer average of 4.71 μg m−2. Inter-annual differences in total wet deposition are generally linked with precipitation volume, with the greatest deposition occurring in the wettest year. Relationships between surface level RGM and Hg wet deposition were also investigated based on continuous RGM measurements at TF from November 2006 to September 2009. No correlations were observed between RGM mixing ratios and Hg wet deposition, however the ineffective scavenging of RGM during winter precipitation events was evidenced by the less frequent depletion of RGM below the detection level. Seasonal dry deposition of reactive gaseous Hg (RGM) was estimated using an order-of-magnitude approach. RGM mixing ratios and dry deposition estimates were greatest during the winter and spring. The seasonal ratios of Hg wet deposition to RGM dry deposition vary by up to a factor of 80