Reviews

Rob Phillips, The Developer's Handbook to Interactive Multimedia, London: Kogan Page, 1997. ISBN: 0–7494–2121–5.241 pages. £22.50

Separation of river network–scale nitrogen removal among the main channel and two transient storage compartments

Transient storage (TS) zones are important areas of dissolved inorganic nitrogen (DIN) processing in rivers. We assessed sensitivities regarding the relative impact that the main channel (MC), surface TS (STS), and hyporheic TS (HTS) have on network denitrification using a model applied to the Ipswich River in Massachusetts, United States. STS and HTS connectivity and size were parameterized using the results of in situ solute tracer studies in first‐ through fifth‐order reaches. DIN removal was simulated in all compartments for every river grid cell using reactivity derived from Lotic Intersite Nitrogen Experiment (LINX2) studies, hydraulic characteristics, and simulated discharge. Model results suggest that although MC‐to‐STS connectivity is greater than MC‐to‐HTS connectivity at the reach scale, at basin scales, there is a high probability of water entering the HTS at some point along its flow path through the river network. Assuming our best empirical estimates of hydraulic parameters and reactivity, the MC, HTS, and STS removed approximately 38%, 21%, and 14% of total DIN inputs during a typical base flow period, respectively. There is considerable uncertainty in many of the parameters, particularly the estimates of reaction rates in the different compartments. Using sensitivity analyses, we found that the size of TS is more important for DIN removal processes than its connectivity with the MC when reactivity is low to moderate, whereas TS connectivity is more important when reaction rates are rapid. Our work suggests a network perspective is needed to understand how connectivity, residence times, and reactivity interact to influence DIN processing in hierarchical river systems

A theory of the chain melting phase transition of aqueous phospholipid dispersions

A model for the chain melting phase transition in dilute aqueous phospholipid bilayer dispersions is presented. This model includes interactions between head groups, between hydrocarbon chains, and within the chains. The head groups are modeled as hard disks which are constrained to lie on a two-dimensional surface separating the aqueous and hydrocarbon regions. The chain statistics problem is treated in an approximate manner using an approach motivated by scaled particle theory to describe the inter-chain steric repulsions in a mathematically tractable way. In this approach the whole system interacts with any given chain through an average lateral pressure which is proportional to the hard disk pressure. Following Nagle, we assume that the steric repulsions between chains and between head groups and the trans-gauche rotation energies are the dominant interactions in determining the transition and we describe the effect of the other interactions with a mean field approximation. Using the known transition temperature of a series of 1,2-diacyl phosphatidyl cholines to adjust two parameters in the theory, the model gives enthalpy and area changes that are in quite reasonable agreement with experiment. Moreover, the curvature observed in the plot of the transition temperature against acyl chain length is reproduced

Submesoscale dispersion in the vicinity of the Deepwater Horizon spill

Reliable forecasts for the dispersion of oceanic contamination are important for coastal ecosystems, society and the economy as evidenced by the Deepwater Horizon oil spill in the Gulf of Mexico in 2010 and the Fukushima nuclear plant incident in the Pacific Ocean in 2011. Accurate prediction of pollutant pathways and concentrations at the ocean surface requires understanding ocean dynamics over a broad range of spatial scales. Fundamental questions concerning the structure of the velocity field at the submesoscales (100 meters to tens of kilometers, hours to days) remain unresolved due to a lack of synoptic measurements at these scales. \textcolor{black} {Using high-frequency position data provided by the near-simultaneous release of hundreds of accurately tracked surface drifters, we study the structure of submesoscale surface velocity fluctuations in the Northern Gulf Mexico. Observed two-point statistics confirm the accuracy of classic turbulence scaling laws at 200m$-$50km scales and clearly indicate that dispersion at the submesoscales is \textit{local}, driven predominantly by energetic submesoscale fluctuations.} The results demonstrate the feasibility and utility of deploying large clusters of drifting instruments to provide synoptic observations of spatial variability of the ocean surface velocity field. Our findings allow quantification of the submesoscale-driven dispersion missing in current operational circulation models and satellite altimeter-derived velocity fields.Comment: 9 pages, 6 figure

Chinese Soldiers as Prisoners in Korea: Ideological Enigma

The handling and dispositions of enemy prisoners of war, as a national responsibility, established itself on the front-burner of America’s attention span, as a crucial sidebar to the war in Iraq. Controversy has, rightly or wrongly, also characterized American views of the military prison facility at Guantanamo Navy Base in Cuba as a detention center. The widely-publicized events at the U.S.-run Abu Ghraib prison in Baghdad focused worldwide attention on how we appeared to be carrying out the responsibility which evolves upon a country with prisoners in its custody

Mobilizing Extension for Youth Suicide Prevention Using the Signs of Suicide (SOS) Program

From 2000 to 2004 (the latest year for available data), the number of 11-19 year olds taking their own lives across the U.S was equivalent to five suicides each and every day. While youth suicide prevention has not been a traditional purview of Extension, Extension has a unique and powerful opportunity to help prevent youth suicides by working with schools to implement an evidenced-based program called the Signs of Suicide (SOS) program. While school counselors, nurses, and/or social workers present the actual SOS program to students, Extension specialists and agents can help schools facilitate SOS program planning and implementation

The crime drop and the security hypothesis

Major crime drops were experienced in the United States and most other industrialised countries for a decade from the early to mid-1990s. Yet there is little agreement over explanation or lessons for policy. Here it is proposed that change in the quantity and quality of security was a key driver of the crime drop. From evidence relating to vehicle theft in two countries it is concluded that electronic immobilisers and central locking were particularly effective. It is suggested that reduced car theft may have induced drops in other crime including violence. From this platform a broader security hypothesis, linked to routine activity and opportunity theory, is outlined

The Drug Testing Project in International Sports: Dilemmas in an Expanding Regulatory Regime

Over the past two decades testing for performance enhancing drugs has become central to the legitimacy of international sport. A constant battle exists between athletes and coaches seeking to enhance performance at almost any cost and sporting authorities that deem the use of performance enhancing drugs illegal. As more methods of enhancement are discovered, the list of banned substances continues to grow, making enforcement more complex. Recently various sporting bodies, realizing that competition testing is ineffective in detecting the most commonly used drugs, have begun monitoring elite athletes year round and testing them around the world on short notice. For the sports drug testing project to succeed, it will have to achieve a level of international cooperation and institution-building far beyond that which has so far been accomplished. This Article addresses some of the obstacles to an expanding international regulatory regime

Emerson Electric -- Application and Results of an Electric Energy Audit

The objective of the study was to examine the electrical usage of an Emerson division located in the Northeast, provide a method of managing the usage and make recommendations for conservation. Both past and present usage were examined in an attempt to determine if potential savings might be realized by a reduction in energy and peak demand. Discussion will include an electrical energy tracking mechanism, ratios and indicators, use of rate consultants, state sales tax exemption clauses, and sample calculations of cost improvements on demand charges