1,178 research outputs found

    A model of the vessel traffic process

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    A model of the total vessel traffic control process that includes the functioning of the human operator (HO) is presented. The vessel traffic services (VTSs) are modeled in their possible role of monitor, conflict detector, and advisor for the total vessel traffic system. The model assumes a number of ships, with a given planned route, in a given confined area. The navigation of each ship is based on a planned route, which is updated by information about the visual scene, instruments, and the VTS. Both normal operation and collision avoidance are modeled. The model is implemented in a C program. Typical traffic situations have been simulated to showing the ability of the model to address realistic vessel traffic scenarios. The model can answer questions related to safety and efficiency, the effect of HO functioning, information necessary to perform tasks, communication between ships and VTS, the optimization of procedures, automation of the total vessel traffic process, et

    Two Different Mismatches: Integrating the Developmental and the Evolutionary-Mismatch Hypothesis

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    Evolutionary psychology aims to understand the origins of the human mind, including disease. Several theories about the origins of disease have been proposed. One concerns a developmental mismatch—a mismatch might occur at the individual level between the environment experienced during childhood and the environment the adult finds herself in, possibly resulting in disease. A second theory concerns the idea of an evolutionary mismatch—humans are adapted to ancestral conditions so they might now experience a mismatch with their modern environment, possibly resulting in disease. A third theory—differential susceptibility—outlines how genetic and epigenetic differences influence the extent to which humans are susceptible to rearing, including positive and negative experiences. Because of these differences, some individuals are more prone to develop disease than others. We review empirical studies that substantiate these theories and argue that an overarching theory that integrates these three lines into one provides a more accurate understanding of disease from an evolutionary perspective

    Effect of disorder on transport properties in a tight-binding model for lead halide perovskites

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    The hybrid organic-inorganic lead halide perovskite materials have emerged as remarkable materials for photovoltaic applications. Their strengths include good electric transport properties in spite of the disorder inherent in them. Motivated by this observation, we analyze the effects of disorder on the energy eigenstates of a tight-binding model of these materials. In particular, we analyze the spatial extension of the energy eigenstates, which is quantified by the inverse participation ratio. This parameter exhibits a tendency, and possibly a phase transition, to localization as the on-site energy disorder strength is increased. However, we argue that the disorder in the lead halide perovskites corresponds to a point in the regime of highly delocalized states. Our results also suggest that the electronic states of mixed-halide materials tend to be more localized than those of pure materials, which suggests a weaker tendency to form extended bonding states in the mixed-halide materials and is therefore not favourable for halide mixing.Comment: 24 pages (preprint), 11 figure

    Effect of different adjuvants on PCV2-associated lesions

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    Ninety, 12-14 day old pigs were randomly assigned to five groups. Group 1 (n=19) pigs were vaccinated with a Mycoplasma hyopneumoniae (M. hyopneumoniae) vaccine with an oil-in-water adjuvant (RespiSure®; Pfizer Animal Health, Inc.). Group 2 (n=17) pigs were vaccinated with a commercial M. hyopneumoniae vaccine with an aqueous adjuvant (Carbopol) (Suvaxyn® Respifend® MH; Fort Dodge Animal Health, Inc.). Group 3 (n=18) pigs were vaccinated using an oil-in-water adjuvanted vaccine containing the same amount and type of M. hyopneumoniae antigen as in group 2. Group 4 (n=18) pigs were vaccinated using an aluminum hydroxide adjuvanted vaccine containing the same amount and type of M. hyopneumoniae antigen as in group 2. Group 5 (n=18) pigs served as the controls and were sham-vaccinated with saline. Pigs were injected with 2 mL of one of the four M. hyopneumoniae vaccines at four and again at six weeks of age. PCV2 was inoculated intranasally on the day of the second vaccination at 6 weeks of age. Half of the pigs were necropsied at 21 days post inoculation (DPI). The remaining pigs were necropsied at 35 DPI. There were no differences among groups in clinical disease scores. At 21 DPI all vaccinated groups had significantly (p\u3c0.05) more severe lymphoid depletion than the saline injected group. At 35 DPI group 1 pigs had significantly (p\u3c0.05) higher amounts of PCV2 DNA in serum than pigs in groups 2, 4, and 5 as determined by quantitative real-time PCR. There was a significant (p\u3c0.05) increase in the severity of lymphoid depletion in the lymph nodes, tonsil, and spleen in groups 1 and 3 compared to groups 2, 4, and 5. Group 3 had significantly (p\u3c0.05) higher amounts of PCV2 antigen within lymph nodes, tonsil, and spleen compared to groups 2, 4 and 5. The results confirm that all adjuvants tested enhanced PCV2-induced lesions and oil-in-water products used in this study had a more severe effect

    Circuit Investigations With Open-Source Miniaturized Microscopes: Past, Present and Future

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    The ability to simultaneously image the spatiotemporal activity signatures from many neurons during unrestrained vertebrate behaviors has become possible through the development of miniaturized fluorescence microscopes, or miniscopes, sufficiently light to be carried by small animals such as bats, birds and rodents. Miniscopes have permitted the study of circuits underlying song vocalization, action sequencing, head-direction tuning, spatial memory encoding and sleep to name a few. The foundation for these microscopes has been laid over the last two decades through academic research with some of this work resulting in commercialization. More recently, open-source initiatives have led to an even broader adoption of miniscopes in the neuroscience community. Open-source designs allow for rapid modification and extension of their function, which has resulted in a new generation of miniscopes that now permit wire-free or wireless recording, concurrent electrophysiology and imaging, two-color fluorescence detection, simultaneous optical actuation and read-out as well as wide-field and volumetric light-field imaging. These novel miniscopes will further expand the toolset of those seeking affordable methods to probe neural circuit function during naturalistic behaviors. Here, we will discuss the early development, present use and future potential of miniscopes

    The effect of population variation on the accuracy of sex estimates derived from basal occipital discriminant functions

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    Multiple discriminant functions that estimate sex from the dimensions of the basal occipital have been published. However, as there is limited exploration of basal dimension variation between groups, the accuracy of these functions when applied to archaeological material is unknown. This study compares basal dimensions between four known sex-at-death post-medieval European samples and explores how metric differences impact on the accuracy of sex assessment discriminant functions. Published data from St Bride’s, London (n = 146) and the Georges Olivier collection, Paris (n = 68) were compared with new data from the eighteenth to nineteenth century Dutch Middenbeemster sample (n = 74) and the early twentieth century Rainer sample, Romania (n = 282) using independent t tests. The Middenbeemster and Rainer data were substituted into six published discriminant functions derived from the St Bride’s and the Georges Olivier samples, and the results were compared to their known sex. Multiple statistically significant differences were found between the four groups. Of the six discriminant functions tested, five failed to reach the published accuracy and fell below chance. In addition, even where the samples were statistically comparable in means, trends for difference also impacted the accuracy of discriminant functions. Enough variation in basal occipital dimensions existed in the European groups to decrease the accuracy of sex estimation discriminant functions to unusable. Possible inter-observer error, varying genetic, socioeconomic, and geographical factors are likely causes of dimension variation. This research further highlights the dangers of using sex estimation discriminant functions on samples that differ to the original derivative population and demonstrates the need for more rigorous testing

    An explorative philosophical study of envisaging the electrical energy infrastructure of the future

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    The electrical energy infrastructure is one of the key life-sustaining technologies of contemporary Western society. This infrastructure is extremely complex due to its size, its multifarious technologies, and its interweaving with societal structures. Smart grids are important in future infrastructure, yet extant literature does not adequately address this complexity. This paper argues that different elements of the philosophy of Dooyeweerd offer a key to understanding this intricate complexity more fundamentally. Key concepts are the ideas of normative practices, enkapsis (intertwinement) of practices, individuality structures, and ideals and basic beliefs. By developing these ideas in the context of smart grid engineering, our research contributes to philosophy of technology, philosophy of design, and philosophy of sustainability. It offers an ontological analysis of these infrastructures, pointing a direction to the development of workable infrastructures and supporting the transition to a sustainable society

    Surface and bulk transitions in three-dimensional O(n) models

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    Using Monte Carlo methods and finite-size scaling, we investigate surface criticality in the O(n)(n) models on the simple-cubic lattice with n=1n=1, 2, and 3, i.e. the Ising, XY, and Heisenberg models. For the critical couplings we find Kc(n=2)=0.4541655(10)K_{\rm c}(n=2)=0.454 1655 (10) and Kc(n=3)=0.693002(2)K_{\rm c}(n=3)= 0.693 002 (2). We simulate the three models with open surfaces and determine the surface magnetic exponents at the ordinary transition to be yh1(o)=0.7374(15)y_{h1}^{\rm (o)}=0.7374 (15), 0.781(2)0.781 (2), and 0.813(2)0.813 (2) for n=1n=1, 2, and 3, respectively. Then we vary the surface coupling K1K_1 and locate the so-called special transition at κc(n=1)=0.50214(8)\kappa_{\rm c} (n=1)=0.50214 (8) and κc(n=2)=0.6222(3)\kappa_{\rm c} (n=2)=0.6222 (3), where κ=K1/K−1\kappa=K_1/K-1. The corresponding surface thermal and magnetic exponents are yt1(s)=0.715(1)y_{t1}^{\rm (s)} =0.715 (1) and yh1(s)=1.636(1)y_{h1}^{\rm (s)} =1.636 (1) for the Ising model, and yt1(s)=0.608(4)y_{t1}^{\rm (s)} =0.608 (4) andyh1(s)=1.675(1)y_{h1}^{\rm (s)} =1.675 (1) for the XY model. Finite-size corrections with an exponent close to -1/2 occur for both models. Also for the Heisenberg model we find substantial evidence for the existence of a special surface transition.Comment: TeX paper and 10 eps figure
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