Quantification of drag and lift imposed by pop-up satellite archival tags and estimation of the metabolic cost to cownose rays (Rhinoptera bonasus)

The recent development of the pop-up satellite archival tag (PSAT) has allowed the collection of information on a tagged animal, such as geolocation, pressure (depth), and ambient water temperature. The success of early studies, where PSATs were used on pelagic fishes, has spurred increasing interest in the use of these tags on a large variety of species and age groups. However, some species and age groups may not be suitable candidates for carrying a PSAT because of the relatively large size of the tag and the consequent energy cost to the study animal. We examined potential energetic costs to carrying a tag for the cownose ray (Rhinoptera bonasus). Two forces act on an animal tagged with a PSAT: lift from the PSATs buoyancy and drag as the tag is moved through the water column. In a freshwater flume, a spring scale measured the total force exerted by a PSAT at flume velocities from 0.00 to 0.60 m/s. By measuring the angle of deflection of the PSAT at each velocity, we separated total force into its constituent forces — lift and drag. The power required to carry a PSAT horizontally through the water was then calculated from the drag force and velocity. Using published metabolic rates, we calculated the power for a ray of a given size to swim at a specified velocity (i.e., its swimming power). For each velocity, the power required to carry a PSAT was compared to the swimming power expressed as a percentage, %TAX (Tag Altered eXertion). A %TAX greater than 5% was felt to be energetically significant. Our analysis indicated that a ray larger than 14.8 kg can carry a PSAT without exceeding this criterion. This method of estimating swimming power can be applied to other species and would allow a researcher to decide the suitability of a given study animal for tagging with a PSAT

Quantification Of Drag And Lift Imposed By Pop-Up Satellite Archival Tags And Estimation Of The Metabolic Cost To Cownose Rays (Rhinoptera Bonasus)

The recent development of the p)p-up satellite archival tag (PSAT) has allowed the collection of information on a tagged animal, such as geolocation, pressure (depth), and ambient water temperature. The success of early studies, where PSATs were used on pelagic fishes, has spurred increasing interest in the use of these tags on a large variety of species and age groups. However, some species and age groups may not be suitable candidates for carrying a PSAT because of the relatively large size of the tag and the consequent energy cost to the study animal. We examined potential energetic costs to carrying a tag for the cownose ray (Rhinopiera bonasus). Two forces act on an animal tagged with a PSAT: lift from the PSATs buoyancy and drag as the tag is moved through the water column. In a freshwater flume, a spring scale measured the total force exerted by a PSAT at flume velocities from 0.0) to 0.60 m/s. By measuring the angle of deflection of the PSAT at each vel( city, we separated total force into its constituent forces-lift and drag. The power required to carry a PSAT horizontally through the water was then calculated from the drag force ani velocity. Using published metabolic rates, we calculated the power for a ray of a given size to swim at a specified velocity (i.e., its swimming power). For each velocity, the power required to carry a PSAT was compared to the swimming power expressed as a percentage, %TAX (Tag Altered eXertion). A %TAX greater than 5% was felt to be energetically significant. Our analysis indicated that a ray larger than 14.8 kg can carry a PSAT without exceeding this criterior. This method of estimating swimming power can be applied to other species and would allow a researcher to decide the suitability of a given study animal for tagging with a PSAT

Effective Hamiltonian for a half-filled asymmetric ionic Hubbard chain with alternating on-site interaction

We derive an effective spin Hamiltonian for the one-dimensional half-filled asymmetric ionic Hubbard model (IHM) with alternating on-site interaction in the limit of strong repulsion. It is shown that the effective Hamiltonian is that of a spin S = 1/2 anisotropic XXZ Heisenberg chain with alternating next-nearest-neighbor (NNN) and three-spin couplings in the presence of a uniform and a staggered magnetic field

TOWARDS CHARACTERIZING INCREMENTAL STRUCTURE BUILDING DURING SENTENCE COMPREHENSION

Language comprehension involves incrementally processing sequences of words and generating expectations about upcoming words based on prior context. One of the steps involved in incremental processing is incremental structure building --- i.e., determining the relationship between the words in a sentence as the sentence unfolds. To understand how comprehenders build incremental structures, it is necessary to understand what structures comprehenders build in the first place and why. This dissertation includes three projects that tackle these what and why questions by studying incremental structure building in sentences with reduced relative clauses as a case study. The first project proposes a method for characterizing what incremental structures human comprehenders build. This method involves three steps: first, implement hypotheses from generative syntax about the abstract structure of sentences in a novel computational model; second, use the model to generate quantitative behavioral predictions; and third, test these predictions using a novel web-based experimental paradigm. Applying this approach, we compared two competing theoretical hypotheses about the structure of reduced relative clauses --- Whiz-Deletion and Participial-Phrase --- and demonstrated that the Whiz-Deletion account better characterizes the incremental structures that human comprehenders build. The second project studies why the incremental structures that comprehenders construct can change depending on the environment they are in by testing the following widely debated hypothesis: comprehenders maintain probability distributions over the structures they expect to encounter and rapidly update these distributions to match the statistics of their current environment. Based on a large-scaled reading experiment, we find evidence in support of this hypothesis, but also explain why prior work might have failed to find such support. The third project proposes a method for characterizing what incremental structures Artificial Neural Networks build when processing sentences. Applying this method, we demonstrated that the incremental structures these networks build, like the structures built by human comprehenders, is better characterized by the Whiz-Deletion account than the Participial-Phrase account. Thus, by making it possible to compare the incremental structures that these networks build to the structures that humans build, this method in turn makes it possible to test hypotheses about why humans build the structures they do. I propose several directions for future work which involve applying the methods proposed in these projects to study other phenomena beyond reduced relative clauses

Can training neural language models on a curriculum with developmentally plausible data improve alignment with human reading behavior?

The use of neural language models to model human behavior has met with mixed success. While some work has found that the surprisal estimates from these models can be used to predict a wide range of human neural and behavioral responses, other work studying more complex syntactic phenomena has found that these surprisal estimates generate incorrect behavioral predictions. This paper explores the extent to which the misalignment between empirical and model-predicted behavior can be minimized by training models on more developmentally plausible data, such as in the BabyLM Challenge. We trained teacher language models on the BabyLM "strict-small" dataset and used sentence level surprisal estimates from these teacher models to create a curriculum. We found tentative evidence that our curriculum made it easier for models to acquire linguistic knowledge from the training data: on the subset of tasks in the BabyLM challenge suite evaluating models' grammatical knowledge of English, models first trained on the BabyLM data curriculum and then on a few randomly ordered training epochs performed slightly better than models trained on randomly ordered epochs alone. This improved linguistic knowledge acquisition did not result in better alignment with human reading behavior, however: models trained on the BabyLM dataset (with or without a curriculum) generated predictions that were as misaligned with human behavior as models trained on larger less curated datasets. This suggests that training on developmentally plausible datasets alone is likely insufficient to generate language models capable of accurately predicting human language processing.Comment: To appear in the proceedings of BabyLM shared task CoNLL 202

Modulated Rashba interaction in a quantum wire: Spin and charge dynamics

It was recently shown that a spatially modulated Rashba spin-orbit coupling in a quantum wire drives a transition from a metallic to an insulating state when the wave number of the modulation becomes commensurate with the Fermi wave length of the electrons in the wire. It was suggested that the effect may be put to practical use in a future spin transistor design. In the present article we revisit the problem and present a detailed analysis of the underlying physics. First, we explore how the build-up of charge density wave correlations in the quantum wire due to the periodic gate configuration that produces the Rashba modulation influences the transition to the insulating state. The interplay between the modulations of the charge density and that of the spin-orbit coupling turns out to be quite subtle: Depending on the relative phase between the two modulations, the joint action of the Rashba interaction and charge density wave correlations may either enhance or reduce the Rashba current blockade effect. Secondly, we inquire about the role of the Dresselhaus spin-orbit coupling that is generically present in a quantum wire embedded in semiconductor heterostructure. While the Dresselhaus coupling is found to work against the current blockade of the insulating state, the effect is small in most materials. Using an effective field theory approach, we also carry out an analysis of effects from electron- electron interactions, and show how the single-particle gap in the insulating state can be extracted from the more easily accessible collective charge and spin excitation thresholds. The smallness of the single-particle gap together with the anti-phase relation between the Rashba and chemical potential modulations pose serious difficulties for realizing a Rashba-controlled current switch in an InAs-based device. Some alternative designs are discussed.Comment: 20 pages, 6 figure

SURGICAL TREATMENT FOR MALIGNANT EPITHELIAL EYELID NEOPLASMS

The most common malignant eyelid tumors are basal cell carcinoma and squamous cell carcinoma. The study enrolled 28 patients (28 eyes) (8 men and 20 women) (mean age 74.1 ± 7.6 years). The postoperative follow-up was 23.3 ± 9.8 months. The objective of this investigation was to study the results of plastic surgery using flaps for extensive eyelid defects after removal of malignant epithelial eyelid neoplasms. The presented results of full-thickness resection of malignant epithelial eyelid neoplasms with single-stage flap reconstruction of extensive defects of the eyelid demonstrate good functional and cosmetic rehabilitation in the patients

Investigation of Changing Volt-Ampere Characteristics of AlGaInP Heterostructures with Multiple Quantum Wells under Ionizing Radiation

The results of research into degradation of volt-ampere characteristics of light emitting diodes produced on the base of AlGaInP heterostructures with multiple quantum wells are presented on the example of light emitting diodes (emission wavelengths 623 nm and 590 nm) under gamma quantum and fast neutron radiation in passive powering mode. The shifts of volt-ampere characteristics into the higher voltage range have been observed in conditions of increasing neutron fluence and radiation dose. The observed increase in the resistance of ohmic contacts is caused by the rising resistance of adjacent area, which in its turn results from the changing mobility of charge carriers. The latter varies with the growth of introduced defects under irradiation. Two different areas of current generation have been identified. A mechanism of current generation depends on injected charge carriers in the range of mid-level electron injection. Moreover, the range of high electron injection is distinguished by changing resistance of light emitting diode cores alongside with current generation conditioned by charge carrier injection