2,241 research outputs found

    Alien Registration- Smith, Ethel N. (Fort Fairfield, Aroostook County)

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    https://digitalmaine.com/alien_docs/36491/thumbnail.jp

    Készülőben az új Európai Moha Vörös Könyv = The new Red Data Book of European Bryophytes in preparation

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    The new Red Data Book of European Bryophytes is the most important recent project of the European Committee for Conservation of Bryophytes, and the basis of bryophyte conservation in most European countries. The first edition, published in 1995, is now in urgent need of updating. Since its publication, our knowledge of the bryophytes of Europe has been considerably improved, especially concerning taxonomy and distribution. The work has started: a comprehensive table, listing the occurrence and Red List status of each species, in each European country, has been prepared. A short list of candidate species for IUCN threat assessment was established by eliminating species known with certainty to be of least concern. Of 2140 bryophyte species known to occur in Europe, 241 liverworts and 721 mosses were selected for further consideration. Among them, 28 liverworts and 98 mosses occur in Hungary. Examples of some species occurring in Hungary are presented below to show which criteria are used to select species for the European candidate list. With 12 fi gures

    Difficulties in Testing for Covarion-Like Properties of Sequences under the Confounding Influence of Changing Proportions of Variable Sites

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    The covarion (COV)-like properties of sequences are poorly described and their impact on phylogenetic analyses poorly understood. We demonstrate using simulations that, under an evolutionary model where the proportion of variable sites changes in nonadjacent lineages, log likelihood values for rates across site (RAS) and COV models become similar, making models difficult to distinguish. Further, although COV and RAS models provide a great improvement in likelihood scores over a homogeneous model with these simulated data, reconstruction accuracy of tree building is low, suggesting caution when it is suspected that proportions of variable sites differ in different evolutionary lineages. We study the performance of a recently developed contingency test that detects the presence of COV-type evolution modified for protein data. We report that if proportions of variable sites (pvar) change in a lineage-specific manner such that their distributions in different lineages become sufficiently nonoverlapping, then the contingency test can incorrectly suggest a homogeneous model. Also of concern is the possibility of different proportions of variable sites between the groups being studied. In a study of chloroplast proteins, interpretation of the test is found to be susceptible to different partitioning of taxon groups, making the test very subjective in its implementation. Extreme intergroup differences in the extent of divergence and difference in proportions of variable sites could be contributing to this effect

    Maximum black-hole spin from quasi-circular binary mergers

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    Black holes of mass M must have a spin angular momentum S below the Kerr limit chi = S/M^2 < 1, but whether astrophysical black holes can attain this limiting spin depends on their accretion history. Gas accretion from a thin disk limits the black-hole spin to chi_gas < 0.9980 +- 0.0002, as electromagnetic radiation from this disk with retrograde angular momentum is preferentially absorbed by the black hole. Extrapolation of numerical-relativity simulations of equal-mass binary black-hole mergers to maximum initial spins suggests these mergers yield a maximum spin chi_eq < 0.95. Here we show that for smaller mass ratios q = m/M << 1, the superradiant extraction of angular momentum from the larger black hole imposes a fundamental limit chi_lim < 0.9979 +- 0.0001 on the final black-hole spin even in the test-particle limit q -> 0 of binary black-hole mergers. The nearly equal values of chi_gas and chi_lim imply that measurement of supermassive black-hole spins cannot distinguish a black hole built by gas accretion from one assembled by the gravitational inspiral of a disk of compact stellar remnants. We also show how superradiant scattering alters the mass and spin predicted by models derived from extrapolating test-particle mergers to finite mass ratios.Comment: final version accepted in PRD, new Fig.4 and discussio

    Measurement of a Sign-Changing Two-Gap Superconducting Phase in Electron-Doped Ba(Fe_{1-x}Co_x)_2As_2 Single Crystals using Scanning Tunneling Spectroscopy

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    Scanning tunneling spectroscopic studies of Ba(Fe1xCox)2As2Ba(Fe_{1-x}Co_x)_2As_2 (x = 0.06, 0.12) single crystals reveal direct evidence for predominantly two-gap superconductivity. These gaps decrease with increasing temperature and vanish above the superconducting transition TcT_c. The two-gap nature and the slightly doping- and energy-dependent quasiparticle scattering interferences near the wave-vectors (±π,0)(\pm \pi, 0) and (0,±π)(0, \pm \pi) are consistent with sign-changing ss-wave superconductivity. The excess zero-bias conductance and the large gap-to-TcT_c ratios suggest dominant unitary impurity scattering.Comment: 4 pages, 4 figures. Paper accepted for publication in Physical Review Letters. Contact author: Nai-Chang Yeh ([email protected]

    Motor Learning Deficits in Parkinson\u27s Disease (PD) and Their Effect on Training Response in Gait and Balance: A Narrative Review

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    Parkinson\u27s disease (PD) is a neurological disorder traditionally associated with degeneration of the dopaminergic neurons within the substantia nigra, which results in bradykinesia, rigidity, tremor, and postural instability and gait disability (PIGD). The disorder has also been implicated in degradation of motor learning. While individuals with PD are able to learn, certain aspects of learning, especially automatic responses to feedback, are faulty, resulting in a reliance on feedforward systems of movement learning and control. Because of this, patients with PD may require more training to achieve and retain motor learning and may require additional sensory information or motor guidance in order to facilitate this learning. Furthermore, they may be unable to maintain these gains in environments and situations in which conscious effort is divided (such as dual-tasking). These shortcomings in motor learning could play a large part in degenerative gait and balance symptoms often seen in the disease, as patients are unable to adapt to gradual sensory and motor degradation. Research has shown that physical and exercise therapy can help patients with PD to adapt new feedforward strategies to partially counteract these symptoms. In particular, balance, treadmill, resistance, and repeated perturbation training therapies have been shown to improve motor patterns in PD. However, much research is still needed to determine which of these therapies best alleviates which symptoms of PIGD, the needed dose and intensity of these therapies, and long-term retention effects. The benefits of such technologies as augmented feedback, motorized perturbations, virtual reality, and weight-bearing assistance are also of interest. This narrative review will evaluate the effect of PD on motor learning and the effect of motor learning deficits on response to physical therapy and training programs, focusing specifically on features related to PIGD. Potential methods to strengthen therapeutic effects will be discussed

    Investigating a Caddo Mound Site in the Ouachita River Valley

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    Archeologists from the Natural Resources Conservation Service and Arkansas Archeological Survey employed multiple techniques to investigate a newly recorded mound site (3DA673) in the Ouachita River valley in southern Arkansas. Topographic mapping documented a large two-stage mound. Geophysical surveying around the mound revealed anomalies in the gradiometry and resistance data, and soil coring detailed floodplain soils. A test unit was excavated in a large circular anomaly that corresponded to a low topographic rise north of the main mound. While very few artifacts were found, a burned zone and a post mold feature suggest the anomaly was a burned structure covered with fill, and show the potential for buried cultural deposits at the site. Based on the 2010–2011 investigations, 3DA673 and the neighboring site 3DA403 represent the archeological residues of a Middle to Late Caddo period community (ca. A.D. 1400s)

    Liver function as an engineering system

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    Process Systems Engineering has tackled a wide range of problems including manufacturing, the environment, and advanced materials design. Here we discuss how tools can be deployed to tackle medical problems which involve complex chemical transformations and spatial phenomena looking in particular at the liver system, the body's chemical factory. We show how an existing model has been developed to model distributed behavior necessary to predict the behavior of drugs for treating liver disease. The model has been used to predict the effects of suppression of de novo lipogenesis, stimulation of β-oxidation and a combination of the two. A reduced model has also been used to explore the prediction of behavior of hormones in the blood stream controlling glucose levels to ensure that levels are kept within safe bounds using interval methods. The predictions are made resulting from uncertainty in two key parameters with oscillating input resulting from regular feeding

    Motor Subtypes of Parkinson\u27s Disease can be Identified by Frequency Component of Postural Stability

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    Parkinson\u27s disease (PD) can be divided into two subtypes based on clinical features€”namely tremor dominant (TD) and postural instability and gait difficulty (PIGD). This categorization is important at the early stage of PD, since identifying the subtypes can help to predict the clinical progression of the disease. Accordingly, correctly diagnosing subtypes is critical in initiating appropriate early interventions and tracking the progression of the disease. However, as the disease progresses, it becomes increasingly difficult to further distinguish those attributes that are relevant to the subtypes. In this study, we investigated whether a method using the standing center of pressure (COP) time series data can separate two subtypes of PD by looking at the frequency component of COP (i.e., COP position and speed). Thirty-six participants diagnosed with PD were evaluated, with their bare feet on the force platform, and were instructed to stand upright with their arms by their sides for 20 s (with their eyes open and closed), which is consistent with the traditional COP measures. Fast Fourier transform (FFT) and wavelet transform (WT) were performed to distinguish between the motor subtypes using the COP measures. The TD group exhibited larger amplitudes at the frequency range of 3-7 Hz when compared to the PIGD group. Both the FFT and WT methods were able to differentiate the subtypes. COP time series information can be used to differentiate between the two motor subtypes of PD, using the frequency component of postural stability
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