27,018 research outputs found
The drag of a body moving transversely in a confined stratified fluid
The slow motion of a body through a stratified fluid bounded laterally by insulating walls is studied for both large and small Peclet number. The Taylor column and its associated boundary and shear layers are very different from the analogous problem in a rotating fluid. In particular, the large Peclet number problem is non-linear and exhibits mixing of statically unstable fluid layers, and hence the drag is order one; whereas the small Peclet number flow is everywhere stable, and the drag is of the order of the Peclet number
In silico characterisation and chromosomal localisation of human RRH (peropsin) – implications for opsin evolution
Reproductive and developmental effects of phthalate diesters in females.
Phthalate diesters, widely used in flexible plastics and consumer products, have become prevalent contaminants in the environment. Human exposure is ubiquitous and higher phthalate metabolite concentrations documented in patients using medications with phthalate-containing slow release capsules raises concerns for potential health effects. Furthermore, animal studies suggest that phthalate exposure can modulate circulating hormone concentrations and thus may be able to adversely affect reproductive physiology and the development of estrogen sensitive target tissues. Therefore, we conducted a systematic review of the epidemiological and experimental animal literature examining the relationship between phthalate exposure and adverse female reproductive health outcomes. The epidemiological literature is sparse for most outcomes studied and plagued by small sample size, methodological weaknesses, and thus fails to support a conclusion of an adverse effect of phthalate exposure. Despite a paucity of experimental animal studies for several phthalates, we conclude that there is sufficient evidence to suggest that phthalates are reproductive toxicants. However, we note that the concentrations needed to induce adverse health effects are high compared to the concentrations measured in contemporary human biomonitoring studies. We propose that the current patchwork of studies, potential for additive effects and evidence of adverse effects of phthalate exposure in subsequent generations and at lower concentrations than in the parental generation support the need for further study
Water resource records of the Econfina Creek Basin area, Florida
The Econfina Creek basin area in northwestern Florida, which includes Bay
County, southeastern Washiigton County, and parts of Calhoun, Gulf, and
Jackson counties is shown in figure 1. The basin has an abundant supply of
ground water and surface water of good quality. This determination is based on
a three-year investigation of the water resources of the basin by the U. S.
Geological Survey in cooperation with the Division of Geology, Florida Board of
Conservation, during the period from October 1961 through June 1964. The
purpose of this report is to assemble the basic data collected during this
investigation for those persons interested in water development or management
in this basin.
(Document has 131 pages.
Mode switching in the nearby Mira-like variable R Doradus
We discuss visual observations spanning nearly 70 years of the nearby
semiregular variable R Doradus. Using wavelet analysis, we show that the star
switches back and forth between two pulsation modes having periods of 332 days
and about 175 days, the latter with much smaller amplitude. Comparison with
model calculations suggests that the two modes are the first and third radial
overtone, with the physical diameter of the star making fundamental mode
pulsation unlikely. The mode changes occur on a timescale of about 1000 d,
which is too rapid be related to a change in the overall thermal structure of
the star and may instead be related to weak chaos.
The Hipparcos distance to R Dor is 62.4 +/- 2.8 pc which, taken with its
dominant 332-day period, places it exactly on the period-luminosity relation of
Miras in the Large Magellanic Cloud. Our results imply first overtone pulsation
for all Miras which fall on the P-L relation. We argue that semiregular
variables with long periods may largely be a subset of Miras and should be
included in studies of Mira behaviour. The semiregulars may contain the
immediate evolutionary Mira progenitors, or stars may alternate between periods
of semiregular and Mira behaviour.Comment: 12 pages, latex with figures, accepted by MNRA
Does abortion reduce self-esteem and life satisfaction?
PurposeThis study aims to assess the effects of obtaining an abortion versus being denied an abortion on self-esteem and life satisfaction.MethodsWe present the first 2.5 years of a 5-year longitudinal telephone-interview study that follows 956 women who sought an abortion from 30 facilities across the USA. We examine the self-esteem and life satisfaction trajectories of women who sought and received abortions just under the facility's gestational age limit, of women who sought and received abortions in their first trimester of pregnancy, and of women who sought abortions just beyond the facility gestational limit and were denied an abortion. We use adjusted mixed effects linear regression analyses to assess whether the trajectories of women who sought and obtained an abortion differ from those who were denied one.ResultsWomen denied an abortion initially reported lower self-esteem and life satisfaction than women who sought and obtained an abortion. For all study groups, except those who obtained first trimester abortions, self-esteem and life satisfaction improved over time. The initially lower levels of self-esteem and life satisfaction among women denied an abortion improved more rapidly reaching similar levels as those obtaining abortions at 6 months to one year after abortion seeking. For women obtaining first trimester abortions, initially higher levels of life satisfaction remained steady over time.ConclusionsThere is no evidence that abortion harms women's self-esteem or life satisfaction in the short term
Ground Beetles From a Remnant Oak-Maple-Beech Forest and Its Surroundings in Northeastern Ohio (Coleoptera: Carabidae)
We report 66 ground beetle species in 14 tribes from a natural preserve in northeastern Ohio (Stark County). Six species are new state records. Data from pitfall trap transects across adjoining habitats suggest narrow habitat preferences in some species and broad tolerances in others.
Trends toward flightlessness in forest species and macroptery in the fauna of disturbed agricultural sites are apparent
Prompt energization of relativistic and highly relativistic electrons during a substorm interval: Van Allen Probes observations
Abstract On 17 March 2013, a large magnetic storm significantly depleted the multi-MeV radiation belt. We present multi-instrument observations from the Van Allen Probes spacecraft Radiation Belt Storm Probe A and Radiation Belt Storm Probe B at ~6 Re in the midnight sector magnetosphere and from ground-based ionospheric sensors during a substorm dipolarization followed by rapid reenergization of multi-MeV electrons. A 50% increase in magnetic field magnitude occurred simultaneously with dramatic increases in 100 keV electron fluxes and a 100 times increase in VLF wave intensity. The 100 keV electrons and intense VLF waves provide a seed population and energy source for subsequent radiation belt enhancements. Highly relativistic (\u3e2 MeV) electron fluxes increased immediately at L* ~ 4.5 and 4.5 MeV flux increased \u3e90 times at L* = 4 over 5 h. Although plasmasphere expansion brings the enhanced radiation belt multi-MeV fluxes inside the plasmasphere several hours postsubstorm, we localize their prompt reenergization during the event to regions outside the plasmasphere. Key Points Substorm dynamics are important for highly relativistic electron energization Cold plasma preconditioning is significant for rapid relativistic energization Relativistic / highly relativistic electron energization can occur in \u3c 5 hrs
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