Underwater optical wireless communications : depth dependent variations in attenuation

Depth variations in the attenuation coefficient for light in the ocean were calculated using a one-parameter model based on the chlorophyll-a concentration Cc and experimentally-determined Gaussian chlorophyll-depth profiles. The depth profiles were related to surface chlorophyll levels for the range 0–4  mg/m2, representing clear, open ocean. The depth where Cc became negligible was calculated to be shallower for places of high surface chlorophyll; 111.5 m for surface chlorophyll 0.8<Cc<2.2  mg/m3 compared with 415.5 m for surface Cc<0.04  mg/m3. Below this depth is the absolute minimum attenuation for underwater ocean communication links, calculated to be 0.0092  m−1 at a wavelength of 430 nm. By combining this with satellite surface-chlorophyll data, it is possible to quantify the attenuation between any two locations in the ocean, with applications for low-noise or secure underwater communications and vertical links from the ocean surface

Missing in Action? Electronic Gaming Machines in Gambling Studies Research

In the past thirty years casinos across the world have become dominated by the rise of “electronic gaming machines” (EGMs). Expanding with tremendous speed, this technology has arguably become the dominant form of non-online gambling around the world at time of writing (DeMichele, 2017; Schwartz, 2018). EGMs are also noted as being one of the most harmful forms of gambling, with significant numbers of players betting beyond their financial limits (MacLaren et al, 2012; Stewart & Wohl, 2013), spending a disproportionate amount of time playing (Cummings, 1999; Ballon, 2005; Schüll, 2012; cf. Dickerson, 1996), becoming disconnected from the world outside of the “zone” (Schüll, 2012) of gambling play, and even becoming bankrupt or otherwise financially crippled as a result of their use (Petry, 2003; Scarf et al, 2011). Using metadata from Web of Science and Scopus databases, we analysed peer-reviewed gambling research produced in Australia, New Zealand, North America and the UK published between 1996 and 2016. Surprisingly, we found that the overwhelming of majority of articles do not specifically address EGMs as the most popular and pervasive gambling technology available. Our paper teases out some concerning implications of this finding for the interdisciplinary field of gambling studies

Sow and Litter Performance of Individual Crate and Group Hoop Barn Gestation Housing Systems: A Progress Report

The effects of swine gestation housing on sow and litter performance were evaluated at the Iowa State University Lauren Christian Swine Research and Demonstration Farm near Atlantic, IA. The gestation housing systems were 1) individual gestation crates in a mechanically ventilated, partially slatted floor, manure flush confinement building (CRATE); and 2) group pens in deep-bedded, naturally ventilated hoop structures (HOOP). The HOOP sows were fed in individual feed stalls. The sow genotypes were 1/4 Hampshire x 1/2 Yorkshire x 1/4 Landrace. Farrowing occurred every 2 weeks throughout the year

Precis of neuroconstructivism: how the brain constructs cognition

Neuroconstructivism: How the Brain Constructs Cognition proposes a unifying framework for the study of cognitive development that brings together (1) constructivism (which views development as the progressive elaboration of increasingly complex structures), (2) cognitive neuroscience (which aims to understand the neural mechanisms underlying behavior), and (3) computational modeling (which proposes formal and explicit specifications of information processing). The guiding principle of our approach is context dependence, within and (in contrast to Marr [1982]) between levels of organization. We propose that three mechanisms guide the emergence of representations: competition, cooperation, and chronotopy; which themselves allow for two central processes: proactivity and progressive specialization. We suggest that the main outcome of development is partial representations, distributed across distinct functional circuits. This framework is derived by examining development at the level of single neurons, brain systems, and whole organisms. We use the terms encellment, embrainment, and embodiment to describe the higher-level contextual influences that act at each of these levels of organization. To illustrate these mechanisms in operation we provide case studies in early visual perception, infant habituation, phonological development, and object representations in infancy. Three further case studies are concerned with interactions between levels of explanation: social development, atypical development and within that, developmental dyslexia. We conclude that cognitive development arises from a dynamic, contextual change in embodied neural structures leading to partial representations across multiple brain regions and timescales, in response to proactively specified physical and social environment

Pultrusion Die Assembly

This invention relates generally to pultrusion die assemblies, and more particularly, to a pultrusion die assembly which incorporates a plurality of functions in order to produce a continuous, thin composite fiber reinforced thermoplastic material. The invention is useful for making high performance thermoplastic composite materials in sheets which can be coiled on a spool and stored for further processing

Hotel Asset and Equity Risk Before, During, and After the Global Financial Crisis

In this paper, we use asset betas and equity betas over the period January 2000 through December 2015 to investigate the operating and financial risk of hotel industry REITs and C-Corps. We conclude that, on average over our sample period, the operating risk of C-Corps exceeds that of REITs. One interpretation of this result is that management contracts between REITs and C-Corps allocate more operating risk to C-Corps than to REITs. We also find that, on average, during our sample period, the equity betas of C-Corps exceed those of REITs. However, the difference between the average equity risk of the two sectors is much smaller than is the sectors’ difference in operating risk. Because equity betas capture both operating and financial risk, these results imply that REITs have significantly less operating risk than C-Corps and offset their lower business risk with higher financial leverage. During the global financial crisis, operating risk increases in both hotel industry subsectors, and the amount by which C-Corp asset betas exceed REIT asset betas is roughly proportionate to that observed in noncrisis periods. During the financial crisis, however, REITs experienced a greater increase in finan- cial leverage than did C-Corps, with the result being that the normal relation reverses, i.e., during the global financial crisis, REIT average equity betas significantly exceeded the average equity betas of C-Corps