A Checklist of Parasites of \u3ci\u3ePeromyscus maniculatus\u3c/i\u3e in North America

This document represents a summary of parasites, in the broadest sense of the term, reported from Peromyscus maniculatus from throughout its range in North America. The document provides data from work ranging from paleontological findings to relatively current reports of parasites and parasitism from P. maniculatus and covers viruses, bacteria sensu lato, protists, helminths, and ectoparasites

\u3ci\u3eSteganoderma\u3c/i\u3e Stafford, 1904 (Digenea: Zoogonidae: Lepidophyllinae) from Two Species of Rockfishes from Deep Waters off Oregon Including a New Species and an Updated Key to Species of This Genus

Steganoderma eamiqtrema n. sp. and a single unidentified specimen of Steganoderma Stafford, 1904 (Zoogonidae: Lepidophyllinae) obtained from the intestine of the greenstriped rockfish, Sebastes elongatus Ayres, 1859, and the flag rockfish, Sebastes rubrivinctus (Jordan and Gilbert, 1880) (Scorpaeniformes: Sebastidae), collected from 190–200 m depths off Oregon, USA, are described. The new species is distinguished from its seven other congeners by a diagnostic combination of morphological features including an elongate oval to spindle-shaped body, a clavate to comma-shaped cirrus pouch located in the forebody and hindbody, a bipartite seminal vesicle, a bifurcal or just post-bifurcal genital pore, a larger ventral than oral sucker, and a smooth testes and ovary with a relatively small distance between them. We present an updated key to the eight species now in Steganoderma and provide a list of parasites known from Se. elongatus and Se. rubrivinctus. The discovery of S. eamiqtrema in Se. elongatus represents the second species of zoogonid known from this host, and the finding of Steganoderma sp. in Se. rubrivinctus represents the first report of a digenean from this host species. A detailed discussion also is given of the type species, S. formosum Stafford, 1904, and questions are raised as to whether this species has a worldwide distribution and infects such a wide variety of fish hosts. We present evidence including variation we observed in redescriptions of the type species, query the implausible idea that there could be gene flow between conspecific helminths geographically separated in the North Atlantic and North Pacific Oceans over such a vast geological period, and offer the possibility that some prior reports of S. formosum may, indeed, be S. eamiqtrema; all of which suggests S. formosum sensu lato may be part of a species complex and not the same worldwide species. Steganoderma is represented in the deep sea by S. eamiqtrema, S. formosum, and Steganoderma sp., and limited speculation is given as to the host specificity of this genus and life history strategies of the new species in deeper waters. Finally, molecular studies of species of Steganoderma are sorely needed (i.e., there is no DNA sequence data currently available in GenBank for any species of this genus), and we suspect that with further molecular, morphological, and life history work, this genus will be taxonomically divided up

Parasites: The Inside Scoop

Parasites are organisms that live inside or on another species, called the host. Parasites depend on their hosts for food and a place to live. They may harm the host in small or large ways. Parasitism is the most common mode of life on Earth. Humans, other animals, and all plants have parasites, usually two or more kinds. Even parasites can have parasites. There are millions of species of parasites, and scientists discover new ones every day. Parasite specimens are stored in museums all around the world. One of the world’s largest collections is in the H. W. Manter Laboratory of Parasitology at the University of Nebraska State Museum.https://digitalcommons.unl.edu/zeabook/1106/thumbnail.jp

A Method for Measuring the Attachment Strength of the Cestode \u3ci\u3eHymenolepis diminuta\u3c/i\u3e to the Rat Intestine

A unique adaptation of many internal parasites of mammals is their ability to stay in the intestine for extended periods of time and resist the normal peristaltic movements and forces that push and expel material. To better understand parasite adhesion behavior and replicate their attachment method in medical devices, an experiment was designed and performed using the rat tapeworm, Hymenolepis diminuta. The experiment employed a tensile test machine and a digital scale and was designed to calculate the attachment strength of the scolex to the mucosa through the change of the value of the digital scale during the tensile test. The attachment force of H. diminuta is 0.021 ± 0.011 g. This method could be applied in studies of parasite biomechanics and the results may help medical device researchers to better mimic the unique functional morphology of this species of parasite

Numerical investigation of the late-time Kerr tails

The late-time behavior of a scalar field on fixed Kerr background is examined in a numerical framework incorporating the techniques of conformal compactification and hyperbolic initial value formulation. The applied code is 1+(1+2) as it is based on the use of the spectral method in the angular directions while in the time-radial section fourth order finite differencing, along with the method of lines, is applied. The evolution of various types of stationary and non-stationary pure multipole initial states are investigated. The asymptotic decay rates are determined not only in the domain of outer communication but along the event horizon and at future null infinity as well. The decay rates are found to be different for stationary and non-stationary initial data, and they also depend on the fall off properties of the initial data toward future null infinity. The energy and angular momentum transfers are found to show significantly different behavior in the initial phase of the time evolution. The quasinormal ringing phase and the tail phase are also investigated. In the tail phase, the decay exponents for the energy and angular momentum losses at future null infinity are found to be smaller than at the horizon which is in accordance with the behavior of the field itself and it means that at late times the energy and angular momentum falling into the black hole become negligible in comparison with the energy and angular momentum radiated toward future null infinity. The energy and angular momentum balances are used as additional verifications of the reliability of our numerical method.Comment: 33 pages, 12 figure

Searching for stochastic gravitational waves using data from the two colocated LIGO Hanford detectors

Searches for a stochastic gravitational-wave background (SGWB) using terrestrial detectors typically involve cross-correlating data from pairs of detectors. The sensitivity of such cross-correlation analyses depends, among other things, on the separation between the two detectors: the smaller the separation, the better the sensitivity. Hence, a colocated detector pair is more sensitive to a gravitational-wave background than a noncolocated detector pair. However, colocated detectors are also expected to suffer from correlated noise from instrumental and environmental effects that could contaminate the measurement of the background. Hence, methods to identify and mitigate the effects of correlated noise are necessary to achieve the potential increase in sensitivity of colocated detectors. Here we report on the first SGWB analysis using the two LIGO Hanford detectors and address the complications arising from correlated environmental noise. We apply correlated noise identification and mitigation techniques to data taken by the two LIGO Hanford detectors, H1 and H2, during LIGO's fifth science run. At low frequencies, 40-460 Hz, we are unable to sufficiently mitigate the correlated noise to a level where we may confidently measure or bound the stochastic gravitational-wave signal. However, at high frequencies, 460-1000 Hz, these techniques are sufficient to set a 95% confidence level upper limit on the gravitational-wave energy density of Ω (f )-4(f /900 Hz )3 , which improves on the previous upper limit by a factor of ˜180 . In doing so, we demonstrate techniques that will be useful for future searches using advanced detectors, where correlated noise (e.g., from global magnetic fields) may affect even widely separated detectors

Characterization of the LIGO detectors during their sixth science run

In 2009-2010, the Laser Interferometer Gravitational-wave Observatory (LIGO) operated together with international partners Virgo and GEO600 as a network to search for gravitational waves of astrophysical origin. The sensitivity of these detectors was limited by a combination of noise sources inherent to the instrumental design and its environment, often localized in time or frequency, that couple into the gravitational-wave readout. Here we review the performance of the LIGO instruments during this epoch, the work done to characterize the detectors and their data, and the effect that transient and continuous noise artefacts have on the sensitivity of LIGO to a variety of astrophysical sources

A proof of the Geroch-Horowitz-Penrose formulation of the strong cosmic censor conjecture motivated by computability theory

In this paper we present a proof of a mathematical version of the strong cosmic censor conjecture attributed to Geroch-Horowitz and Penrose but formulated explicitly by Wald. The proof is based on the existence of future-inextendible causal curves in causal pasts of events on the future Cauchy horizon in a non-globally hyperbolic space-time. By examining explicit non-globally hyperbolic space-times we find that in case of several physically relevant solutions these future-inextendible curves have in fact infinite length. This way we recognize a close relationship between asymptotically flat or anti-de Sitter, physically relevant extendible space-times and the so-called Malament-Hogarth space-times which play a central role in recent investigations in the theory of "gravitational computers". This motivates us to exhibit a more sharp, more geometric formulation of the strong cosmic censor conjecture, namely "all physically relevant, asymptotically flat or anti-de Sitter but non-globally hyperbolic space-times are Malament-Hogarth ones". Our observations may indicate a natural but hidden connection between the strong cosmic censorship scenario and the Church-Turing thesis revealing an unexpected conceptual depth beneath both conjectures.Comment: 16pp, LaTeX, no figures. Final published versio

Improved upper limits on the stochastic gravitational-wave background from 2009-2010 LIGO and Virgo data

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of ΩGW(f)=Ωα(f/fref)α, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of α=0, we constrain the energy density of the stochastic background to be ΩGW(f)\u3c5.6×10-6. For the 600-1000 Hz band, ΩGW(f)\u3c0.14(f/900Hz)3, a factor of 2.5 lower than the best previously reported upper limits. We find ΩGW(f)\u3c1.8×10-4 using a spectral index of zero for 170-600 Hz and ΩGW(f)\u3c1.0(f/1300Hz)3 for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves

First all-sky search for continuous gravitational waves from unknown sources in binary systems

We present the first results of an all-sky search for continuous gravitational waves from unknown spinning neutron stars in binary systems using LIGO and Virgo data. Using a specially developed analysis program, the TwoSpect algorithm, the search was carried out on data from the sixth LIGO science run and the second and third Virgo science runs. The search covers a range of frequencies from 20 Hz to 520 Hz, a range of orbital periods from 2 to ∼2,254h and a frequency- and period-dependent range of frequency modulation depths from 0.277 to 100 mHz. This corresponds to a range of projected semimajor axes of the orbit from ∼0.6×10-3ls to ∼6,500ls assuming the orbit of the binary is circular. While no plausible candidate gravitational wave events survive the pipeline, upper limits are set on the analyzed data. The most sensitive 95% confidence upper limit obtained on gravitational wave strain is 2.3×10-24 at 217 Hz, assuming the source waves are circularly polarized. Although this search has been optimized for circular binary orbits, the upper limits obtained remain valid for orbital eccentricities as large as 0.9. In addition, upper limits are placed on continuous gravitational wave emission from the low-mass x-ray binary Scorpius X-1 between 20 Hz and 57.25 Hz