Lieb-Robinson Bounds and the Exponential Clustering Theorem

We give a Lieb-Robinson bound for the group velocity of a large class of discrete quantum systems which can be used to prove that a non-vanishing spectral gap implies exponential clustering in the ground state of such systems.Comment: v2: corrected proof of Theorem 2. v3: slightly better bound in Theorem 2; updated proo

Use of multi-scale phase-based methods to determine optical flow in dynamic scene analysis

Estimates of optical flow in images can be made by applying a complex periodic transform to the images and tracking the movement of points of constant phase in the complex output. This approach however suffers from the problem that filters of large width give information only about broad scale image features, whilst those of small spatial extent (high resolution) cannot track fast motion, which causes a feature to move a distance that is large compared to the filter-size. A method is presented in which the flow is measured at different scales, using a series of complex filters of decreasing width. The largest filter is used to give a large scale flow estimate at each image point. Estimates at smaller scales are then carried out by using the previous result as an a priori estimate. Rather than comparing the same region in different images in order to estimate flow, the regions to be compared are displaced from one another by an amount given by the most recent previous flow estimate. This results in an estimate of flow relative to the earlier estimate. The two estimates are then added together to give a new estimate of the absolute displacement. The process is repeated at successively smaller scales. The method can therefore detect small local velocity variations superimposed on the broad scale flow, even where the magnitude of the absolute displacement is larger than the scope of the smaller filters. Without the assistance of the earlier estimates in ‘tuning\u27 the smaller filters in this manner, a smaller filter could fail to capture these velocity variations, because the absolute displacement carry the feature out of range of-the filter during successive frames. The output of the method is a series of scale-dependent flow fields corresponding to different scales, reflecting the fact that motion in the real world is a scale-dependent quantity. Application of the method to some 1 dimensional test images gives good results, with realistic flow values that could be used as an aid to segmentation. Some synthetic 2-dimentional images containing only a small number of well defined features aIso yield good-results but the method performs poorly on a random-dot stereogram and on a real-world test image pair selected from the Hamburg Taxi sequence

Propagation of Correlations in Quantum Lattice Systems

We provide a simple proof of the Lieb-Robinson bound and use it to prove the existence of the dynamics for interactions with polynomial decay. We then use our results to demonstrate that there is an upper bound on the rate at which correlations between observables with separated support can accumulate as a consequence of the dynamics.Comment: 10 page

Creating ontological definitions for use in science

Ontologies aim to represent the world in terms of uniquely defined classes and their properties which are expressed as relationships with other classes. They are becoming widely used in science to improve clarity, searching, inference and the ability to link data from different sources. Ontological definitions are descriptions that represent the essential properties of classes of entities (which include objects, object attributes and processes) that distinguish them from other classes. Classes have unique IRIs (Internationalised Resource Identifiers) that can be used for searching; they also have labels which are words of phrases that people can use to identify the class in passages of text or tables. This article provides a brief guide to help with writing good ontological definitions. The standard format of such a definition of a class, A, is: ‘a B that C’ or its semantic equivalent, where A is the class being defined, B is a parent class and C describes a set of properties of A that distinguish it from other members of B

Notes

Concealment Behavior of the Spanish Lobster, Scyllarides nodifer (Stimpson), with Observations on its Diel Activity. By L. A. Ogren Notes of the Occurrence of the Silver Anchovy, Engraulis eurystole, in the Northern Gulf of Mexico. By R. W. Hastings Studies on Decapod Crustacea from the Indian River Region of Florida VII. A Field Character for Rapid Identification of the Swimming Crabs Callinectes ornatus Ordway, 1863 and C. similis Williams, 1966 (Brachyura, Portunidae). By R.H. Gor

County-Level Hispanic Ethnic Density and Cardiovascular Disease Mortality.

Background Hispanics are the fastest growing ethnic group in the United States, and little is known about how Hispanic ethnic population density impacts cardiovascular disease ( CVD ) mortality. Methods and Results We examined county-level deaths for Hispanics and non-Hispanic whites from 2003 to 2012 using data from the National Center for Health Statistics' Multiple Cause of Death mortality files. Counties with more than 20 Hispanic deaths (n=715) were included in the analyses. CVD deaths were identified using International Classification of Diseases, Tenth Revision (ICD-10), I00 to I78, and population estimates were calculated using linear interpolation from 2000 and 2010 census data. Multivariate linear regression was used to examine the association of Hispanic ethnic density with Hispanic and non-Hispanic white age-adjusted CVD mortality rates. County-level age-adjusted CVD mortality rates were adjusted for county-level demographic, socioeconomic, and healthcare factors. There were a total of 4 769 040 deaths among Hispanics (n=382 416) and non-Hispanic whites (n=4 386 624). Overall, cardiovascular age-adjusted mortality rates were higher among non-Hispanic whites compared with Hispanics (244.8 versus 189.0 per 100 000). Hispanic density ranged from 1% to 96% in each county. Counties in the highest compared with lowest category of Hispanic density had 60% higher Hispanic mortality (215.3 versus 134.2 per 100 000 population). In linear regression models, after adjusting for county-level demographic, socioeconomic, and healthcare factors, increasing Hispanic ethnic density remained strongly associated with mortality for Hispanics but not for non-Hispanic whites. Conclusions CVD mortality is higher in counties with higher Hispanic ethnic density. County-level characteristics do not fully explain the higher CVD mortality among Hispanics in ethnically concentrated counties

Food Habits of Juvenile American Alligators in the Upper Lake Pontchartrain Estuary

Food habits of juvenile (0.49-1.21 m total length) American alligators (Alligator mississippiensis) from an area in southeastern Louisiana were investigated. One-hundred and one stomach samples were obtained by stomach-pumping. Crustaceans (crayfish; blue crabs, Callinectes sapidus; grass shrimp, Palaemonetes sp.), insects (hemipterans, coleopterans), and small fish (least killifish, Heterandria formosa; mosquitofish, Gambusia affinis) constituted the majority of prey items taken. Fish consumption was significantly more frequent during April and May than during June through September (P\u3c0.025). This differential use of prey species may be due to seasonally fluctuating water levels in the study area. Comparisons of juvenile alligator food habits revealed dietary differences between Louisiana and Florida (P\u3c0.001), possibly due to the different prey available at the two areas. Prey utilization was not significantly different between larger alligators (0.9-1.2 m total length) and smaller alligators (0.3·0.9 m total length) (P\u3e0.25)

The Fish Fauna of Lake Maurepas, an Oligohaline Part of the Lake Pontchartrain Estuary

Lake Maurepas is a slightly saline body of water located at the upper end of the Lake Pontchartrain estuary. Of 67 fish species collected during 1983-84, 33 species (49%) are primarily freshwater, 6 (9%) are primarily marine, and 28 (42%) are estuarine or diadromous, commonly occurring in both freshwater and marine habitats. Major freshwater species (e.g. lctalurus furcatus, I. punctatus, and Aplodinotus grunniens) were present throughout the year, whereas most marine and estuarine species were seasonally present (e.g. Anchoa mitchilli, Brevoortia patronus, and Micropogonias undulatus), or were present during periods of higher (up to 2.5 o/oo) salinity (e.g. Cynoscion arenarius, Leiostomus xanthurus, and Pogonias cromis). Literature records indicate that larger percentages of marine species are present during years when salinities are higher (up to 8 o/oo)

The date of the call of the Prophet Jeremiah : texts and issues

This dissertation entitled, "The Date of the Call of the Prophet Jeremiah: Texts and Issues," attempts to demonstrate that the most plausible date for the beginning of the prophetic career of Jeremiah is that provided in the tradition itself, i.e. the thirteenth year of Josiah (627). In supporting this, two main topics are addressed. First, the alternative dates which have been forwarded in modern scholarship are examined, and shown to be based upon untenable ideas. Secondly, the various objections which have been proffered against the 627 date are analysed, and the case is made that these objections are invalid. Finally, an attempt is made to explain the message and activity of the prophet within the historical milieu of Judah in the years 627-622. The current study develops this thesis in seven chapters. The first chapter discusses the historical context of the years 640-609, and Josiah's reforms. In chapter two it is argued that the prose sermons should be attributed to Jeremiah, and represent a style of the seventh century. Chapter three demonstrates the implausibility of the alternative dating proposals, while in chapter four it is proposed that the threatened invader of the foe from the north oracles was not originally identified by Jeremiah. The issue of Isaiah and the reforms of Hezekiah as a comparable example is handled in chapter five. Chapter six addresses Jeremiah's attitude toward the cultic reforms of Josiah and the appearance of Deuteronomy in 622, and it is shown that the prophet did speak out in support of the newly published law book. Finally in chapter seven, Jeremiah's relative withdrawal from public activity during the period 622-609 is demonstrated, and the prophet's message is explained in light of the setting of the years 627-622