87 research outputs found
Population Dynamics Of A Diverse Rodent Assemblage In Mixed Grass-Shrub Habitat, Southeastern Colorado, 1995–2000
We followed seasonal and year-to-year population dynamics for a diverse rodent assemblage in a short-grass prairie ecosystem in southeastern Colorado (USA) for 6 yr. We captured 2,798 individual rodents (range, one to 812 individuals per species) belonging to 19 species. The two most common species, deer mice (Peromyscus maniculatus) and western harvest mice (Reithrodontomys megalotis), generally had population peaks in winter and nadirs in summer; several other murid species demonstrated autumn peaks and spring nadirs; heteromyids were infrequently captured in winter, and populations generally peaked in summer or autumn. Interannual trends indicated an interactive effect between temperature and precipitation. Conditions associated with low rodent populations or population declines were high precipitation during cold periods (autumn and winter) and low precipitation during warm periods (spring and summer). Severity of adverse effects varied by species. Heteromyids, for example, were apparently not negatively affected by the hot, dry spring and summer of 2000. Cross-correlations for the temporal series of relative population abundances between species pairs (which are affected by both seasonal and interannual population dynamics) revealed positive associations among most murids and among most heteromyids, but there were negative associations between murids and heteromyids. These results have important implications for those attempting to model population dynamics of rodent populations for purposes of predicting disease risk
Demographic Factors Associated With Prevalence Of Antibody To Sin Nombre Virus In Deer Mice In The Western United States
We used long-term data collected for up to 10 yr (1994–2004) at 23 trapping arrays (i.e., webs and grids) in Arizona, Colorado, Montana, and New Mexico to examine demographic factors known or suspected to be associated with risk of infection with Sin Nombre virus (SNV) in its natural host, the deer mouse (Peromyscus maniculatus). Gender, age (mass), wounds or scars, season, and local relative population densities were statistically associated with the period prevalence of antibody (used as a marker of infection) to SNV in host populations. Nevertheless, antibody prevalence and some of the risk factors associated with antibody prevalence, such as relative population density, gender bias, and prevalence of wounding, varied significantly among sites and even between nearby trapping arrays at a single site. This suggests that local micrositespecific differences play an important role in determining relative risk of infection by SNV in rodents and, consequently, in humans. Deer mouse relative population density varied among sites and was positively and statistically associated with infection prevalence, an association that researchers conducting shorter-term studies failed to demonstrate. Both wounding and antibody prevalence increased with mass class in both males and females; this increase was much more pronounced in males than in females and wounding was more frequent in adult males than in adult females. Prevalence of wounding was greatest among seropositive deer mice, regardless of mass class, but many deer mice without detectable wounds or scars eventually became infected. Many of these patterns, which will be useful in the development of predictive models of disease risk to humans, were only detected through the application of data collected over a long (10-yr) period and with abundant replication
Nipah Virus Infection in Dogs, Malaysia, 1999
The 1999 outbreak of Nipah virus encephalitis in humans and pigs in Peninsular Malaysia ended with the evacuation of humans and culling of pigs in the epidemic area. Serologic screening showed that, in the absence of infected pigs, dogs were not a secondary reservoir for Nipah virus
Integrated Late Eocene-Oligocene Stratigraphy of the Alabama Coastal Plain: Correlation of Hiatuses and Stratal Surfaces to Glacioeustatic Lowerings
We integrated strontium and oxygen isotopic, biostratigraphic, and magnetostratigraphic studies of two upper Eocene-Oligocene boreholes drilled near Bay Minette and St. Stephens Quarry (SSQ), Alabama. Continuous coring provided fresh, unweathered material for magnetostratigraphic studies, minimizing problems reported from nearby outcrops. Difficulties with each technique were encountered because of diagenesis, absence of marker fossils, and the presence of unconformities; however, by integrating results from isotopic stratigraphy, biostratigraphy, and magnetostratigraphy, we correlated these relatively shallow-water deposits to the geomagnetic polarity time scale (GPTS). At the SSQ borehole, the upper Eocene to lower Oligocene section is apparently complete within our stratigraphic resolution (0.2-0.5 m.y.), allowing us to estimate the ages of several stratal surfaces. Late Eocene Sr isotope age estimates are as expected at the SSQ borehole, but Oligocene ages are ~1 m.y. older than expected due to diagenesis. At the Bay Minette borehole, a latest Eocene-earliest Oligocene and a late early Oligocene hiatus were detected. We correlate these two hiatuses and stratal surfaces at SSQ with global δ^18O increases inferred to represent glacioeustatic lowerings and with evidence for hiatuses on other continental margins: (1) a distinct disconformity at the base of the Chickasawhay Limestone at both boreholes and a hiatus at Bay Minette correlates with a global δ^18O increase; we revise the age of this surface (equivalent to the TB 1.1 sequence boundary) making it ~2 m.y. older than previously reported; and (2) a surface at the top of the Shubuta Member (lowermost Oligocene) has been interpreted both as a condensed section and a disconformity; this surface at SSQ and a hiatus at Bay Minette correlate with a sharp global δ^18O increase and with hiatuses on the New Jersey and Irish margins. The timing of the hiatuses and stratal surfaces correlates with the inflection of the δ^18O increases and not with the maximum values, supporting models that indicate that unconformities form during the maximum rates of sea level fall
Pet Rodents and Fatal Lymphocytic Choriomeningitis in Transplant Patients
A unique strain of this virus was traced back to hamsters from an Ohio rodent distribution facility
Genetic Interactions with Age, Sex, Body Mass Index, and Hypertension in Relation to Atrial Fibrillation: The AFGen Consortium
It is unclear whether genetic markers interact with risk factors to influence atrial fibrillation (AF) risk. We performed genome-wide interaction analyses between genetic variants and age, sex, hypertension, and body mass index in the AFGen Consortium. Study-specific results were combined using meta-analysis (88,383 individuals of European descent, including 7,292 with AF). Variants with nominal interaction associations in the discovery analysis were tested for association in four independent studies (131,441 individuals, including 5,722 with AF). In the discovery analysis, the AF risk associated with the minor rs6817105 allele (at the PITX2 locus) was greater among subjects ≤ 65 years of age than among those > 65 years (interaction p-value = 4.0 × 10-5). The interaction p-value exceeded genome-wide significance in combined discovery and replication analyses (interaction p-value = 1.7 × 10-8). We observed one genome-wide significant interaction with body mass index and several suggestive interactions with age, sex, and body mass index in the discovery analysis. However, none was replicated in the independent sample. Our findings suggest that the pathogenesis of AF may differ according to age in individuals of European descent, but we did not observe evidence of statistically significant genetic interactions with sex, body mass index, or hypertension on AF risk
‘Orientalism is a partisan book’: applying Edward Said's insights to early modern travel writing
Since its publication in 1978, Edward Said's Orientalism has had a significant impact on postcolonial studies in a range of fields. This paper assesses his impact on the historiography of Anglophone travel writing concerning Ottoman Empire during the early modern period. Said's analysis of the relationship between representational power and colonial authority remains relevant to our understanding of early modern travel texts.
Said's epistemology raises significant issues for historians of early modern intercultural encounters. This article summarises recent debates surrounding early modern travel narratives. It contrasts doctrinaire applications of Said's theory with more recent, particularistic studies. It provides a much-needed survey of travel writing historiography that considers the continuing impact of Said's postcolonial thought on the study of early modern travel narratives relating to the Ottoman Middle East.
In so doing, it explores the lack of fit between early modern travel narratives and Said's methodology. I explore the methodological problems thrown up by conventional applications of Said's epistemology to precolonial travellers' texts. Based on a wide-ranging survey of Said's oeuvre, the article demonstrates that, more than 30 years on, Said's work remains relevant to the historiographical challenges presented by early modern English travel writing about Islam
The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and its Implications for Structure Growth
We present new measurements of cosmic microwave background (CMB) lensing over
sq. deg. of the sky. These lensing measurements are derived from the
Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB dataset, which
consists of five seasons of ACT CMB temperature and polarization observations.
We determine the amplitude of the CMB lensing power spectrum at
precision ( significance) using a novel pipeline that minimizes
sensitivity to foregrounds and to noise properties. To ensure our results are
robust, we analyze an extensive set of null tests, consistency tests, and
systematic error estimates and employ a blinded analysis framework. The
baseline spectrum is well fit by a lensing amplitude of
relative to the Planck 2018 CMB power spectra
best-fit CDM model and relative to
the best-fit model. From our lensing power
spectrum measurement, we derive constraints on the parameter combination
of
from ACT DR6 CMB lensing alone and
when combining ACT DR6 and Planck NPIPE
CMB lensing power spectra. These results are in excellent agreement with
CDM model constraints from Planck or
CMB power spectrum measurements. Our lensing measurements from redshifts
-- are thus fully consistent with CDM structure growth
predictions based on CMB anisotropies probing primarily . We find no
evidence for a suppression of the amplitude of cosmic structure at low
redshiftsComment: 45+21 pages, 50 figures. Prepared for submission to ApJ. Also see
companion papers Madhavacheril et al and MacCrann et a
The Atacama Cosmology Telescope: High-resolution component-separated maps across one-third of the sky
Observations of the millimeter sky contain valuable information on a number
of signals, including the blackbody cosmic microwave background (CMB), Galactic
emissions, and the Compton- distortion due to the thermal Sunyaev-Zel'dovich
(tSZ) effect. Extracting new insight into cosmological and astrophysical
questions often requires combining multi-wavelength observations to spectrally
isolate one component. In this work, we present a new arcminute-resolution
Compton- map, which traces out the line-of-sight-integrated electron
pressure, as well as maps of the CMB in intensity and E-mode polarization,
across a third of the sky (around 13,000 sq.~deg.). We produce these through a
joint analysis of data from the Atacama Cosmology Telescope (ACT) Data Release
4 and 6 at frequencies of roughly 93, 148, and 225 GHz, together with data from
the \textit{Planck} satellite at frequencies between 30 GHz and 545 GHz. We
present detailed verification of an internal linear combination pipeline
implemented in a needlet frame that allows us to efficiently suppress Galactic
contamination and account for spatial variations in the ACT instrument noise.
These maps provide a significant advance, in noise levels and resolution, over
the existing \textit{Planck} component-separated maps and will enable a host of
science goals including studies of cluster and galaxy astrophysics, inferences
of the cosmic velocity field, primordial non-Gaussianity searches, and
gravitational lensing reconstruction of the CMB.Comment: The Compton-y map and associated products will be made publicly
available upon publication of the paper. The CMB T and E mode maps will be
made available when the DR6 maps are made publi
The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters
We present cosmological constraints from a gravitational lensing mass map
covering 9400 sq. deg. reconstructed from CMB measurements made by the Atacama
Cosmology Telescope (ACT) from 2017 to 2021. In combination with BAO
measurements (from SDSS and 6dF), we obtain the amplitude of matter
fluctuations at 1.8% precision,
and the Hubble
constant at
1.6% precision. A joint constraint with CMB lensing measured by the Planck
satellite yields even more precise values: ,
and . These measurements agree
well with CDM-model extrapolations from the CMB anisotropies measured
by Planck. To compare these constraints to those from the KiDS, DES, and HSC
galaxy surveys, we revisit those data sets with a uniform set of assumptions,
and find from all three surveys are lower than that from ACT+Planck
lensing by varying levels ranging from 1.7-2.1. These results motivate
further measurements and comparison, not just between the CMB anisotropies and
galaxy lensing, but also between CMB lensing probing on
mostly-linear scales and galaxy lensing at on smaller scales. We
combine our CMB lensing measurements with CMB anisotropies to constrain
extensions of CDM, limiting the sum of the neutrino masses to eV (95% c.l.), for example. Our results provide independent
confirmation that the universe is spatially flat, conforms with general
relativity, and is described remarkably well by the CDM model, while
paving a promising path for neutrino physics with gravitational lensing from
upcoming ground-based CMB surveys.Comment: 30 pages, 16 figures, prepared for submission to ApJ. Cosmological
likelihood data is here:
https://lambda.gsfc.nasa.gov/product/act/actadv_prod_table.html ; likelihood
software is here: https://github.com/ACTCollaboration/act_dr6_lenslike . Also
see companion papers Qu et al and MacCrann et al. Mass maps will be released
when papers are publishe
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