1,171 research outputs found
Survey of Subterranean Termite (Isoptera: Rhinotermitidae) Utilization of Temperate Forests
Both native and invasive subterranean termites (Isoptera: Rhinotermitidae), including the Formosan subterranean termite, are well known pests of urban areas, but little is known about their distribution or impact in forest ecosystems of the southeastern United States. Recently harvested timber stumps were mechanically inspected for the presence of subterranean termites in multiple locations across southern Mississippi and eastern Louisiana. A systematic line plot cruise with 100 x 200m spacing and1/20thha plots was implemented, and all stumps with a diameter greater than 7.6cm were inspected. In total, 7,413 stumps were inspected for the presence of subterranean termites, and 406 of those contained native subterranean termite (Reticulitermes spp) infestations. Light traps were also placed at 8 sites to detect the presence of subterranean termite alates. While no invasive Formosan subterranean termites were found during mechanical inspection of tree stumps, alates were captured in light traps at three sites. The proportion of stumps infested with subterranean termites was negatively correlated with the number of stumps in each plot. Although 6.27% of pine stumps and 1.86% of hardwood stumps were infested, no correlation was found between subterranean termite presence and type of stump (pine or hardwood). Infestations of stumps by subterranean termites ranged from 0.94% to 14.97% depending on site
Void Statistics in Large Galaxy Redshift Surveys: Does Halo Occupation of Field Galaxies Depend on Environment?
We use measurements of the projected galaxy correlation function w_p and
galaxy void statistics to test whether the galaxy content of halos of fixed
mass is systematically different in low density environments. We present new
measurements of the void probability function (VPF) and underdensity
probability function (UPF) from Data Release Four of the Sloan Digital Sky
Survey, as well as new measurements of the VPF from the full data release of
the Two-Degree Field Galaxy Redshift Survey. We compare these measurements to
predictions calculated from models of the Halo Occupation Distribution (HOD)
that are constrained to match both w_p and the space density of galaxies. The
standard implementation of the HOD assumes that galaxy occupation depends on
halo mass only, and is independent of local environment. For luminosity-defined
samples, we find that the standard HOD prediction is a good match to the
observations, and the data exclude models in which galaxy formation efficiency
is reduced in low-density environments. More remarkably, we find that the void
statistics of red and blue galaxies (at L ~ 0.4L_*) are perfectly predicted by
standard HOD models matched to the correlation function of these samples,
ruling out "assembly bias" models in which galaxy color is correlated with
large-scale environment at fixed halo mass. We conclude that the luminosity and
color of field galaxies are determined predominantly by the mass of the halo in
which they reside and have little direct dependence on the environment in which
the host halo formed. In broader terms, our results show that the sizes and
emptiness of voids found in the distribution of L > 0.2L_* galaxies are in
excellent agreement with the predictions of a standard cosmological model with
a simple connection between galaxies and dark matter halos. (abridged)Comment: 20 emulateapj pages, 9 figures. submitted to Ap
Evaluation of Reproductive Function in Turkana Women with Enzyme Immunoassays of Urinary Hormones in the Field
The frequently reported observation that nomadic populations have lower fertility than their settled counterparts is often attributed to what are perceived as harsh, stressful conditions under which the nomads live. But the consequences of the hypothesized stresses for the reproductive biology or demography of these populations have been documented only a little. Traditionally, the Turkana of northwest Kenya are nomadic herders, but increasing numbers have settled on agricultural development schemes. We used an array of hormonal assays along with anthropometric indexes of nutritional status and interviews covering reproductive history, recent menstruation, diet, and health to compare reproductive function in nomadic and settled Turkana women. First morning urine samples were collected for three consecutive days during a series of surveys. Human choriogonadotropin (hCG; a marker for pregnancy), luteinizing hormone (LH; an indicator of ovulation), and pregnanediol glucuronide (PdG; an indicator of postovulatory luteal function) were assessed in the field with commercially available dipstick enzyme immunoassays. These assays along with the interview data allowed us to determine the reproductive status (e.g., pregnant or cycling, and if cycling, which phase of the ovarian cycle) of 166 nomadic and 194 settled Turkana women. The cross-sectional classifications allowed inferences of conception rates and normality of ovarian function. Follow-up surveys provided rates of pregnancy loss. Compared with the settled women, the nomadic women exhibited lower pregnancy rates and cycling nomadic women were less likely to show evidence of ovulation or luteal function. These results suggest that reproductive function of the nomadic women is diminished relative to the settled women. However, the settled women experienced a much higher rate of pregnancy loss, which may mean that their effective fecundability is in fact lower than that of the nomadic women. This study is the first to apply such a wide range of hormonal assays in the field. It demonstrates that field-based assays are feasible and robust and can play an important role in epidemiological and biodemographic studies, even in remote locations under conditions that would ordinarily be considered incompatible with on-site laboratory analysis
Microtorus: a High Finesse Microcavity with Whispering-Gallery Modes
We have demonstrated a 165 micron oblate spheroidal microcavity with free
spectral range 383.7 GHz (3.06nm), resonance bandwidth 25 MHz (Q ~ 10^7) at
1550nm, and finesse F > 10^4. The highly oblate spheroidal dielectric
microcavity combines very high Q-factor, typical of microspheres, with vastly
reduced number of excited whispering-gallery (WG) modes (by two orders of
magnitude). The very large free spectral range in the novel microcavity - few
hundred instead of few GigaHertz in typical microspheres - is desirable for
applications in spectral analysis, narrow-linewidth optical and RF oscillators,
and cavity QED.Comment: 11 pages, 3 figure
Cosmic Voids and Galaxy Bias in the Halo Occupation Framework
(Abridged) We investigate the power of void statistics to constrain galaxy
bias and the amplitude of dark matter fluctuations. We use the halo occupation
distribution (HOD) framework to describe the relation between galaxies and dark
matter. After choosing HOD parameters that reproduce the mean space density
n_gal and projected correlation function w_p measured for galaxy samples with
M_r<-19 and M_r<-21 from the Sloan Digital Sky Survey (SDSS), we predict the
void probability function (VPF) and underdensity probability function (UPF) of
these samples by populating the halos of a large, high-resolution N-body
simulation. If we make the conventional assumption that the HOD is independent
of large scale environment at fixed halo mass, then models constrained to match
n_gal and w_p predict nearly identical void statistics, independent of the
scatter between halo mass and central galaxy luminosity or uncertainties in HOD
parameters. Models with sigma_8=0.7 and sigma_8=0.9 also predict very similar
void statistics. However, the VPF and UPF are sensitive to environmental
variations of the HOD in a regime where these variations have little impact on
w_p. For example, doubling the minimum host halo mass in regions with large
scale (5 Mpc/h) density contrast delta<-0.65 has a readily detectable impact on
void probabilities of M_r<-19 galaxies, and a similar change for delta<-0.2
alters the void probabilities of M_r<-21 galaxies at a detectable level. The
VPF and UPF provide complementary information about the onset and magnitude of
density- dependence in the HOD. By detecting or ruling out HOD changes in low
density regions, void statistics can reduce systematic uncertainties in the
cosmological constraints derived from HOD modeling, and, more importantly,
reveal connections between halo formation history and galaxy properties.Comment: emulateapj, 16 pages, 13 figure
Elasticity Theory Connection Rules for Epitaxial Interfaces
Elasticity theory provides an accurate description of the long-wavelength
vibrational dynamics of homogeneous crystalline solids, and with supplemental
boundary conditions on the displacement field can also be applied to abrupt
heterojunctions and interfaces. The conventional interface boundary conditions,
or connection rules, require that the displacement field and its associated
stress field be continuous through the interface. We argue, however, that these
boundary conditions are generally incorrect for epitaxial interfaces, and we
give the general procedure for deriving the correct conditions, which depend
essentially on the detailed microscopic structure of the interface. As a simple
application of our theory we analyze in detail a one-dimensional model of an
inhomogeneous crystal, a chain of harmonic oscillators with an abrupt change in
mass and spring stiffness parameters. Our results have implications for phonon
dynamics in nanostructures such as superlattices and nanoparticles, as well as
for the thermal boundary resistance at epitaxial interfaces.Comment: 7 pages, Revte
Virtual consultations for patients with Obstructive Sleep Apnoea:systematic review and meta-analysis
Background: The COVID-19 pandemic has accelerated the adoption of virtual care strategies for the management of patients with Obstructive Sleep Apnoea/Hypopnoea Syndrome. Research question: What is the effectiveness of virtual consultations compared to in-person consultations for the management of Continuous Positive Airway Pressure therapy in adult patients with Obstructive Sleep Apnoea/Hypopnoea Syndrome? Methods: A systematic review and meta-analysis (PROSPERO; CRD42022297532) based on six electronic databases plus manually selected journals was conducted in January 2022. Two researchers independently selected, quality appraised, and extracted data. The co-primary outcomes were patient-reported sleepiness, assessed by the Epworth Sleepiness Scale, and reported cost-effectiveness. Findings: 12 studies (n=1823 adults) were included in the review. Seven studies (n=1089) were included in the meta-analysis which showed no difference in the magnitude of improvement in patient-reported sleepiness scores between virtual and in-person consultations (MD [95%CI], -0.39 [-1.38 to 0.60]; p=0.4), though Epworth Sleepiness Scale scores improved in both groups. Virtual care strategies modestly increased Continuous Positive Airway Pressure therapy adherence and were found to be less costly than in-person care strategies in the three Spanish trials that reported cost-effectiveness. Conclusion: The findings of this review suggest that virtual care delivered by telephone or video consultations is as effective as in-person consultations for improving subjective sleepiness in patients with Obstructive Sleep Apnoea/Hypopnoea Syndrome treated with Continuous Positive Airway Pressure. This clinical management strategy may also improve Continuous Positive Airway Pressure adherence without increasing the costs, supporting its potential as a follow-up management strategy, where patients prefer this approach
Facial coloration tracks changes in women’s estradiol
Red facial coloration is an important social cue in many primate species, including humans. In such species, the vasodilatory effects ofestradiolmay cause red facial coloration to change systematically during females’ ovarian cycle. Although increased red facial coloration during estrus has been observed in female mandrills (Mandrillus sphinx) and rhesus macaques (Macaca mulatta), evidence linking primate facial color changes directly to changes in measured estradiol is lacking. Addressing this issue, we used alongitudinal designto demonstrate that red facial coloration tracks within-subject changes in women's estradiol, but not within-subject changes in women'sprogesteroneor estradiol-to-progesterone ratio. Moreover, the relationship between estradiol and facial redness was observed in two independent samples of women (N=50 andN=65). Our results suggest that changes in facial coloration may provide cues of women's fertility and present the first evidence for a direct link between estradiol and female facial redness in a primate species
Soylent: A Word Processor with a Crowd Inside
This paper introduces architectural and interaction patterns for integrating crowdsourced human contributions directly into user interfaces. We focus on writing and editing, com-plex endeavors that span many levels of conceptual and pragmatic activity. Authoring tools offer help with prag-matics, but for higher-level help, writers commonly turn to other people. We thus present Soylent, a word processing interface that enables writers to call on Mechanical Turk workers to shorten, proofread, and otherwise edit parts of their documents on demand. To improve worker quality, we introduce the Find-Fix-Verify crowd programming pat-tern, which splits tasks into a series of generation and re-view stages. Evaluation studies demonstrate the feasibility of crowdsourced editing and investigate questions of relia-bility, cost, wait time, and work time for edits.National Science Foundation (U.S.) (Grant No. IIS-0712793
Ehrlichia ewingii Infection in White-Tailed Deer (Odocoileus virginianus)
Two closely related zoonotic ehrlichiae, Ehrlichia chaffeensis and E. ewingii, are transmitted by Amblyomma americanum, the lone star tick. Because white-tailed deer (Odocoileus virginianus) are critical hosts for all mobile stages of A. americanum and are important vertebrate reservoirs of E. chaffeensis, we investigated whether deer may be infected with E. ewingii, a cause of granulocytotropic ehrlichiosis in humans and dogs. To test for E. ewingii infection, we used polymerase chain reaction and inoculation of fawns with whole blood from wild deer. Of 110 deer tested from 20 locations in 8 U.S. states, 6 (5.5%) were positive for E. ewingii. In addition, natural E. ewingii infection was confirmed through infection of captive fawns. These findings expand the geographic distribution of E. ewingii, along with risk for human infection, to include areas of Kentucky, Georgia, and South Carolina. These data suggest that white-tailed deer may be an important reservoir for E. ewingii
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