3,186 research outputs found

    \u3ci\u3eLeptoglossus Corculus\u3c/i\u3e and \u3ci\u3eLeptoglossus Occidentalis\u3c/i\u3e (Hemiptera: Coreidae) Attacking Red Pine, \u3ci\u3ePinus Resinosa\u3c/i\u3e, Cones in Wisconsin and Minnesota

    Get PDF
    Leptoglossus corculus and Leptoglossus occidentalis are recorded feeding on red pine cones and conelets in Wisconsin and L. occidentalis is recorded feeding on red pine conelets in Minnesota

    High resolution chronology of late Cretaceous-early Tertiary events determined from 21,000 yr orbital-climatic cycles in marine sediments

    Get PDF
    A number of South Atlantic sites cored by the Deep Sea Drilling Project (DSDP) recovered late Cretaceous and early Tertiary sediments with alternating light-dark, high-low carbonate content. The sedimentary oscillations were turned into time series by digitizing color photographs of core segments at a resolution of about 5 points/cm. Spectral analysis of these records indicates prominent periodicity at 25 to 35 cm in the Cretaceous intervals, and about 15 cm in the early Tertiary sediments. The absolute period of the cycles that is determined from paleomagnetic calibration at two sites is 20,000 to 25,000 yr, and almost certainly corresponds to the period of the earth's precessional cycle. These sequences therefore contain an internal chronometer to measure events across the K/T extinction boundary at this scale of resolution. The orbital metronome was used to address several related questions: the position of the K/T boundary within magnetic chron 29R, the fluxes of biogenic and detrital material to the deep sea immediately before and after the K/T event, the duration of the Sr anomaly, and the level of background climatic variability in the latest Cretaceous time. The carbonate/color cycles that were analyzed contain primary records of ocean carbonate productivity and chemistry, as evidenced by bioturbational mixing of adjacent beds and the weak lithification of the rhythmic sequences. It was concluded that sedimentary sequences that contain orbital cyclicity are capable of providing resolution of dramatic events in earth history with much greater precision than obtainable through radiometric methods. The data show no evidence for a gradual climatic deterioration prior to the K/T extinction event, and argue for a geologically rapid revolution at this horizon

    No free lunch theorems for quantum state measurements as resources in classical sampling and generative modelling

    Full text link
    We prove that almost all\textit{almost all} quantum states, when sampled according to the Haar measure over the unitary group, have the following property: if copies of the state are measured to provide latent random variables which are taken as an input in a classical generative model or sampling algorithm, then any alternative state whose measurements can generate the same set of target distributions will do so with the same overall cost. Here, we define the overall cost as the aggregate computational complexity of sampling from all possible distributions that can be prepared from the given input distribution. Our result holds for any length of input and output bitstring and when a uniformly random bitstring of any length is optionally provided as an additional resource. As it is easy to construct scenarios where a pair of alternative candidate states are such that classical simulation of the preparation thereof is easy in one case and hard in the other, the result can be viewed as decoupling how hard it is to obtain a latent random variable, and how useful it is as a resource in classical sampling and generative modelling.Comment: 14 page

    Quantum Monte-Carlo Integration: The Full Advantage in Minimal Circuit Depth

    Full text link
    This paper proposes a method of quantum Monte-Carlo integration that retains the full quadratic quantum advantage, without requiring any arithmetic or the quantum Fourier transform to be performed on the quantum computer. No previous proposal for quantum Monte-Carlo integration has achieved all of these at once. The heart of the proposed method is a Fourier series decomposition of the sum that approximates the expectation in Monte-Carlo integration, with each component then estimated individually using quantum amplitude estimation. The main result is presented as theoretical statement of asymptotic advantage, and numerical results are also included to illustrate the practical benefits of the proposed method. The method presented in this paper is the subject of a patent application [Quantum Computing System and Method: Patent application GB2102902.0 and SE2130060-3].Comment: Fix minor errors and add references. 17 pages, 4 figure

    Projects of Identity Creation in English Languate Textbooks Aimed at Adult Immigrants: 1900 and 2000

    Get PDF
    The purpose of this study is to investigate the temporal parallels and differences between adult immigrant education and latent identity projects intertwined with the textbooks being used in the classrooms. By analyzing a sample of textbooks from both the turn of the 20th and 21st century I attempt to find both similarities and differences between these two time periods. These two periods are similar in that they are when the largest number of immigrants arrived in America, but in many ways (global context, technology, and political environment) they are also very different. How the American educational system responded to these large influxes of `old\u27 immigrants might reflect on what the current and/or future response will be to the `new\u27 immigrants. New Americans of the past and present alike make up a large percent of the American population and much more research needs to be done to fill many of the gaps that currently exist in the literature. This textbook analysis will be focused on several projects: the depiction of work, cultural capital, hygiene; and the inclusion or exclusion of these themes in textbooks designed for immigrants. Each of these projects are a few of the numerous used to determine what constitutes a New American both past and present. These textbooks attempted to remake an immigrant identity according to the ideologies present in America at that time

    Speaking in tongues and other gifts of the Holy Spirit: A study in possession

    Get PDF
    corecore