Global ATM banking: casting the net

ACH and ATM systems are examples of networks, where the benefits of one participant enhance the structure's value for the other participants. Some recent results from economic theory suggest that competitive networks are preferable in a social sense to monopoly networks.Clearinghouses (Banking) ; Automated tellers

Pattern formation during diffusion limited transformations in solids

We develop a description of diffusion limited growth in solid-solid transformations, which are strongly influenced by elastic effects. Density differences and structural transformations provoke stresses at interfaces, which affect the phase equilibrium conditions. We formulate equations for the interface kinetics similar to dendritic growth and study the growth of a stable phase from a metastable solid in both a channel geometry and in free space. We perform sharp interface calculations based on Green's function methods and phase field simulations, supplemented by analytical investigations. For pure dilatational transformations we find a single growing finger with symmetry breaking at higher driving forces, whereas for shear transformations the emergence of twin structures can be favorable. We predict the steady state shapes and propagation velocities, which can be higher than in conventional dendritic growth.Comment: submitted to Philosophical Magazin

A Gillnet Survey of Charlotte Harbor, Summer 2014

We conducted a gillnet survey from May through September 2014, at two locations in Charlotte Harbor, Florida: Long Point (LP) and Pine Island (PI). Elasmobranchs and teleosts were sampled using two different methodologies: 1) the same methodology as a previous survey conducted by Mote Marine Laboratory from 1995 to 2004 and in 2013; and 2) the methodology used in the NMFS-coordinated Gulf of Mexico Shark Pupping and Nursery (GULFSPAN) program. The goals of our study were to characterize changes in abundance and species composition of coastal sharks between the two survey periods (1995-2004 vs. 2013-2014); evaluate the potential of the fishery-independent survey to monitor trends in abundance of other fish species found in the area; compare the selectivity of the historical single panel net used by Mote with the selectivity of the multi-panel net used in GULFSPAN projects; and estimate seasonal growth patterns for juvenile blacktip sharks

Serological Changes Associated with Gill-Net Capture and Restraint in Three Species of Sharks

To investigate the biochemical effects of capture and restraint on sharks, 17 serum constituents were measured in three species (bonnethead shark Sphyrna tiburo, blacktip shark Carcharhinus limbatus, and bull shark C. leucas) after gill-net capture. The relative degree of capture effects on each animal was judged using an index of behavioral response devised for use in tag−recapture studies. Serum from each shark was assayed for glucose, creatinine, uric acid, sodium, chloride, potassium, inorganic phosphate, total and ionized calcium, total protein, albumin, globulin, alkaline phosphatase, lactate, lactate dehydrogenase, aspartate aminotransferase, and total iron. In addition, hematocrit was measured from whole blood for each shark. When correlated with the relative degree of capture effects, there were significant intraspecific changes in the concentration of potassium, lactate, inorganic phosphate, uric acid, alkaline phosphatase, aspartate aminotransferase, total and ionized calcium, and glucose. Significant interspecific differences in the concentration of sodium, chloride, potassium, total protein, albumin, globulin, lactate dehydrogenase, aspartate aminotransferase, ionized calcium, alkaline phosphatase, and glucose in minimally stressed animals also were observed. The study suggests that the deleterious effects of gill-net capture and restraint probably involve respiratory and metabolic acidosis and hypoglycemia as well as cellular damage. Species-specific and individual differences in the mortality of sharks caught in gill nets are likely related to an animal\u27s respiratory physiology and degree of struggling upon capture as well as to the extent of net entanglement around the gill area

A Physiological Analysis of Color Vision in Batoid Elasmobranchs

The potential for color vision in elasmobranchs has been studied in detail; however, a high degree of variation exists among the group. Evidence for ultraviolet (UV) vision is lacking, despite the presence of UV vision in every other vertebrate class. An integrative physiological approach was used to investigate color and ultraviolet vision in cownose rays and yellow stingrays, two batoids that inhabit different spectral environments. Both species had peaks in UV, short, medium, and long wavelength spectral regions in dark-, light-, and chromatic-adapted electroretinograms. Although no UV cones were found with microspectrophotometric analysis, both rays had multiple cone visual pigments with λmax at 470 and 551 nm in cownose rays (Rhinoptera bonasus) and 475, 533, and 562 nm in yellow stingrays (Urobatis jamaicensis). The same analysis demonstrated that both species had rod λmax at 500 and 499 nm, respectively. The lens and cornea of cownose rays maximally transmitted wavelengths greater than 350 nm and greater than 376 nm in yellow stingrays. These results support the potential for color vision in these species and future investigations should reveal the extent to which color discrimination is significant in a behavioral context

Characterization of the critical values of branching random walks on weighted graphs through infinite-type branching processes

We study the branching random walk on weighted graphs; site-breeding and edge-breeding branching random walks on graphs are seen as particular cases. We describe the strong critical value in terms of a geometrical parameter of the graph. We characterize the weak critical value and relate it to another geometrical parameter. We prove that, at the strong critical value, the process dies out locally almost surely; while, at the weak critical value, global survival and global extinction are both possible.Comment: 14 pages, corrected some typos and minor mistake

Survival, extinction and approximation of discrete-time branching random walks

We consider a general discrete-time branching random walk on a countable set X. We relate local, strong local and global survival with suitable inequalities involving the first-moment matrix M of the process. In particular we prove that, while the local behavior is characterized by M, the global behavior cannot be completely described in terms of properties involving M alone. Moreover we show that locally surviving branching random walks can be approximated by sequences of spatially confined and stochastically dominated branching random walks which eventually survive locally if the (possibly finite) state space is large enough. An analogous result can be achieved by approximating a branching random walk by a sequence of multitype contact processes and allowing a sufficiently large number of particles per site. We compare these results with the ones obtained in the continuous-time case and we give some examples and counterexamples.Comment: 32 pages, a few misprints have been correcte

First insights into the vertical habitat use of the whitespotted eagle ray Aetobatus narinari revealed by pop‐up satellite archival tags

The whitespotted eagle ray Aetobatus narinari is a tropical to warm‐temperate benthopelagic batoid that ranges widely throughout the western Atlantic Ocean. Despite conservation concerns for the species, its vertical habitat use and diving behaviour remain unknown. Patterns and drivers in the depth distribution of A. narinari were investigated at two separate locations, the western North Atlantic (Islands of Bermuda) and the eastern Gulf of Mexico (Sarasota, Florida, U.S.A.). Between 2010 and 2014, seven pop‐up satellite archival tags were attached to A. narinari using three methods: a through‐tail suture, an external tail‐band and through‐wing attachment. Retention time ranged from 0 to 180 days, with tags attached via the through‐tail method retained longest. Tagged rays spent the majority of time (82.85 ± 12.17% S.D.) within the upper 10 m of the water column and, with one exception, no rays travelled deeper than ~26 m. One Bermuda ray recorded a maximum depth of 50.5 m, suggesting that these animals make excursions off the fore‐reef slope of the Bermuda Platform. Individuals occupied deeper depths (7.42 ± 3.99 m S.D.) during the day versus night (4.90 ± 2.89 m S.D.), which may be explained by foraging and/or predator avoidance. Each individual experienced a significant difference in depth and temperature distributions over the diel cycle. There was evidence that mean hourly depth was best described by location and individual variation using a generalized additive mixed model approach. This is the first study to compare depth distributions of A. narinari from different locations and describe the thermal habitat for this species. Our study highlights the importance of region in describing A. narinari depth use, which may be relevant when developing management plans, whilst demonstrating that diel patterns appear to hold across individuals

Boundary line analysis of the effect of water-filled pore space on nitrous oxide emission from cores of arable soil

The boundary line has been proposed as a model of the effects of a variable on a biological response, when this variable might limit the response in only some of a set of observations. It is proposed that the upper boundary (in some circumstances the lower boundary) represents the response function of interest. Boundary-line analysis is a method for estimating this response function from data. The approach has been used to model the emission of N2O from soil in response to various soil properties. However, the methods that have been used to identify the boundary are based on somewhat ad hoc partitions of the data. A statistical model that we have presented previously has not been applied to this problem in soil science, and we do so here to represent how the water-filled pore space (WFPS) of the soil affects the rate of N2O emission. We derive a boundary-line response that can be shown to be a better model for the data than an unbounded alternative by statistical criteria. Furthermore, the fitted boundary-response model is consistent with past empirical observations and modelling studies with respect to both the WFPS at which the potential emission rate is largest and the measurement error for the emission rates themselves. We show how the fitted model might be used to interpret data on soil volumetric water content with respect to seasonal changes in potential emissions, and to compare potential emissions between soil series that have contrasting physical properties