Carmel River Lagoon Enhancement Project: Water Quality and Aquatic Wildlife Monitoring, 2006-7

This is a report to the California Department of Parks and Recreation. It describes water quality and aquatic invertebrate monitoring after the construction of the Carmel River Lagoon Enhancement Project. Included are data that have been collected for two years and preliminary assessment of the enhanced ecosystem. This report marks the completion of 3-years of monitoring water quality and aquatic habitat. The report adopts the same format and certain background text from previous years’ reporting by the same research group (e.g. Larson et al., 2005). (Document contains 100 pages

The Marketing of Closed-End Fund IPOs

This study investigates a well-documented enigma in the finance literature, the aftermarket behavior of closed-end fund initial public offerings (IPOs). Many models with rational agents attribute the underpricing of industrial IPOs to information asymmetry between the IPO issues and the investing public. Since closed-end funds typically do not have pre-existing assets or proprietary rights, there is little information asymmetry about their asset valuation. Consequently, these models suggest that closed-end funds should exhibit less underpricing than industrial IPOs. However, information asymmetry theories cannot explain why closed-end funds are successfully brought to market overpriced. Specifically, closed-end funds are overpriced at issue relative to their net asset values (NAVs) due to substantial underwriting fees that average approximately 8% of total issue size. The study investigates these anomalies and describes regulatory and institutional mechanisms that contribute to the pattern of aftermarket returns. The authors perform an intraday analysis of aftermarket trades and quotes in the first 100 days of trading. They find that underwriting arrangements, identified during discussions with underwriters, help to explain not only the their primary observations, but also several unusual patterns in the transactions data. The authors show that the vast majority of volume in the first four weeks of trading is seller-initiated. Since short selling is not possible during this time period, the selling imbalance confirms the presence of flippers. However, these imbalances do not immediately translate into price declines. As the number of issues that are stabilized declines over time, the proportion of issues trading at unencumbered, market-determined prices increases. The authors also provide evidence that underwriters manage the cost of stabilizing by creating a net short position in the number of shares issued during the pre-market. Selling imbalance in the first few trading days has predictive power for the timing of subsequent price decline: the faster the short position is covered through stabilizing purchases, the sooner the price drops. Funds that exercise the over-allotment option experience longer stabilization periods. The authors document that seller-initiated trades are both larger and more profitable than buyer-initiated trades in the after market period. Small investors who buy shares in the aftermarket engage in open market transactions that they believe are at unencumbered prices. The authors believe that their findings support a marketing hypothesis for closed-end fund IPOs. To protect their reputation and improve the likelihood of a successful offer, lead underwriters promise to stabilize prices in the aftermarket, essentially granting free put options with a strike price equal to the offer price. The stabilization bid provides the opportunity for some syndicate members to sell large blocks to flippers during the pre-issue period. The number and size of sell orders in the first few days of trading show that a sizable number of these traders exercise this options and flip their shares back to the syndicate. The size of the trades suggest that they are small, retail customers. The legality of this scenario appears to be within the guidelines of current securities regulation The authors speculate that flippers are wiling to participate because of other inducements they receive through their ongoing relationships with underwriters. On the cost side, underwriters may incur significant costs from flipping and protracted stabilization. However, the cost of stabilization may well be offset by the benefits of assuring a successful initial distribution. Small investors face substantial information processing costs and may be highly susceptible to "marketing" tactics. The authors believe their findings raise questions about the adequacy of current disclosure rules for IPOs, and the propriety of securities regulation that permit short term stabilization in closed-end fund IPO aftermarkets. They also suggest that similar patterns of selling pressure, price stabilization, and asymmetric behavior between large and small trades may be found in two other securities - master limited partnerships and real estate investment trusts.

Are the class 18 myosins Myo18A and Myo18B specialist sarcomeric proteins?

Initially, the two members of class 18 myosins, Myo18A and Myo18B, appeared to exhibit highly divergent functions, complicating the assignment of class-specific functions. However, the identification of a striated muscle-specific isoform of Myo18A, Myo18Aγ, suggests that class 18 myosins may have evolved to complement the functions of conventional class 2 myosins in sarcomeres. Indeed, both genes, Myo18a and Myo18b, are predominantly expressed in the heart and somites, precursors of skeletal muscle, of developing mouse embryos. Genetic deletion of either gene in mice is embryonic lethal and is associated with the disorganization of cardiac sarcomeres. Moreover, Myo18Aγ and Myo18B localize to sarcomeric A-bands, albeit the motor (head) domains of these unconventional myosins have been both deduced and biochemically demonstrated to exhibit negligible ATPase activity, a hallmark of motor proteins. Instead, Myo18Aγ and Myo18B presumably coassemble with thick filaments and provide structural integrity and/or internal resistance through interactions with F-actin and/or other proteins. In addition, Myo18Aγ and Myo18B may play distinct roles in the assembly of myofibrils, which may arise from actin stress fibers containing the α-isoform of Myo18A, Myo18Aα. The β-isoform of Myo18A, Myo18Aβ, is similar to Myo18Aα, except that it lacks the N-terminal extension, and may serve as a negative regulator through heterodimerization with either Myo18Aα or Myo18Aγ. In this review, we contend that Myo18Aγ and Myo18B are essential for myofibril structure and function in striated muscle cells, while α- and β-isoforms of Myo18A play diverse roles in nonmuscle cells

Modality-Independent Effects of Phonological Neighborhood Structure on Initial L2 Sign Language Learning

The goal of the present study was to characterize how neighborhood structure in sign language influences lexical sign acquisition in order to extend our understanding of how the lexicon influences lexical acquisition in both sign and spoken languages. A referent-matching lexical sign learning paradigm was administered to a group of 29 hearing sign language learners in order to create a sign lexicon. The lexicon was constructed based on exposures to signs that resided in either sparse or dense handshape and location neighborhoods. The results of the current study indicated that during the creation of the lexicon signs that resided in sparse neighborhoods were learned better than signs that resided in dense neighborhoods. This pattern of results is similar to what is seen in child first language acquisition of spoken language. Therefore, despite differences in child first language and adult second language acquisition, these results contribute to a growing body of literature that implicates the phonological features that structure of the lexicon is influential in initial stages of lexical acquisition for both spoken and sign languages. This is the first study that uses an innovated lexicon-construction methodology to explore interactions between phonology and the lexicon in L2 acquisition of sign language

Cortical cells are altered by factors including bone morphogenetic protein released from a placental barrier model under altered oxygenation

Episodes of hypoxia and hypoxia/reoxygenation during foetal development have been associated with increased risk of neurodevelopmental conditions presenting in later life. The mechanism for this is not understood; however, several authors have suggested that the placenta plays an important role. Previously we found both placentas from a maternal hypoxia model and pre-eclamptic placentas from patients release factors lead to a loss of dendrite complexity in rodent neurons. Here to further explore the nature and origin of these secretions we exposed a simple in vitro model of the placental barrier, consisting of a barrier of human cytotrophoblasts, to hypoxia or hypoxia/reoxygenation. We then exposed cortical cultures from embryonic rat brains to the conditioned media (CM) from below these exposed barriers and examined changes in cell morphology, number, and receptor presentation. The barriers released factors that reduced dendrite and astrocyte process lengths, decreased GABAB1 staining, and increased astrocyte number. The changes in astrocytes required the presence of neurons and were prevented by inhibition of the SMAD pathway and by neutralising Bone Morphogenetic Proteins (BMPs) 2/4. Barriers exposed to hypoxia/reoxygenation also released factors that reduced dendrite lengths but increased GABAB1 staining. Both oxygen changes caused barriers to release factors that decreased GluN1, GABAAα1 staining and increased GluN3a staining. We find that hypoxia in particular will elicit the release of factors that increase astrocyte number and decrease process length as well as causing changes in the intensity of glutamate and GABA receptor staining. There is some evidence that BMPs are released and contribute to these changes

Computational Fluid Dynamic Simulations for Determination of Ventricular Workload in Aortic Arch Obstructions

Objective The cardiac workload associated with various types of aortic obstruction was determined using computational fluid dynamic simulations. Methods Computed tomography image data were collected from 4 patients with 4 distinct types of aortic arch obstructions and 4 controls. The categorization of arch hypoplasia corresponded to the “A, B, C” nomenclature of arch interruption; a type “D” was added to represent diffuse arch hypoplasia. Measurements of the vessel diameter were compared against the normal measurements to determine the degree of narrowing. Three-dimensional models were created for each patient, and additional models were created for type A and B hypoplasia to represent 25%, 50%, and 75% diameter narrowing. The boundary conditions for the computational simulations were chosen to achieve realistic flow and pressures in the control cases. The simulations were then repeated after changing the boundary conditions to represent a range of cardiac and vascular adaptations. The resulting cardiac workload was compared with the control cases. Results Of the 4 patients investigated, 1 had aortic coarctation and 3 had aortic hypoplasia. The cardiac workload of the patients with 25% narrowing type A and B hypoplasia was not appreciably different from that of the control. When comparing the different arch obstructions, 75% type A, 50% type B, and 50% type D hypoplasia required a greater workload increase than 75% coarctation. Conclusions The present study has determined the hemodynamic significance of aortic arch obstruction using computational simulations to calculate the cardiac workload. These results suggest that all types of hypoplasia pose more of a workload challenge than coarctation with an equivalent degree of narrowing

Simple, Defensible Sample Sizes Based on Cost Efficiency -- With Discussion and Rejoinder

The conventional approach of choosing sample size to provide 80% or greater power ignores the cost implications of different sample size choices. Costs, however, are often impossible for investigators and funders to ignore in actual practice. Here, we propose and justify a new approach for choosing sample size based on cost efficiency, the ratio of a study’s projected scientific and/or practical value to its total cost. By showing that a study’s projected value exhibits diminishing marginal returns as a function of increasing sample size for a wide variety of definitions of study value, we are able to develop two simple choices that can be defended as more cost efficient than any larger sample size. The first is to choose the sample size that minimizes the average cost per subject. The second is to choose sample size to minimize total cost divided by the square root of sample size. This latter method is theoretically more justifiable for innovative studies, but also performs reasonably well and has some justification in other cases. For example, if projected study value is assumed to be proportional to power at a specific alternative and total cost is a linear function of sample size, then this approach is guaranteed either to produce more than 90% power or to be more cost efficient than any sample size that does. These methods are easy to implement, based on reliable inputs, and well justified, so they should be regarded as acceptable alternatives to current conventional approaches

Bostonia: The Boston University Alumni Magazine. Volume 11

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Sad or happy? The effects of emotions on stated preferences for environmental goods

A substantial literature in behavioural science and psychology shows that emotions affect human choices and values. This paper investigates whether such emotional impacts are also present in stated choice experiments for environmental goods. If this were so, it would introduce an additional element of context dependence to the welfare measures derived from such methods, and would be at odds with the rational choice model underlying welfare economics. A laboratory experiment using three different emotion treatments was combined with a stated preference choice experiment concerned with changes in coastal water quality and fish populations in New Zealand. No statistically significant effects of changes in emotional state on estimated preference parameters, willingness to pay or the randomness of choices were found. The paper concludes by questioning, why such a contrast exists with empirical findings in behavioural science

Bostonia: The Boston University Alumni Magazine. Volume 12

Founded in 1900, Bostonia magazine is Boston University’s main alumni publication