2,231 research outputs found
Spearfishing-induced behavioral changes of an unharvested species inside and outside a marine protected area.
By prohibiting fishing, marine protected areas (MPAs) provide a refuge for harvested species. Humans are often perceived as predators by prey and therefore respond fearfully to humans. Thus, fish responses to humans inside and outside of an MPA can provide insights into their perception of humans as a predatory threat. Previous studies have found differences in the distance that harvested species of fish initiate flight (flight initiation distance-FID) from humans inside and outside an MPA, but less is known about unharvested species. We focused on whether the lined bristletooth Ctenochaetus striatus, an unharvested surgeonfish, can discriminate between a snorkeler and a snorkeler with a spear gun inside and outside of a no-take MPA in Mo'orea, French Polynesia. Additionally, we incorporated starting distance (the distance between the person and prey at the start of an experimental approach), a variable that has been found to be important in assessing prey escape decisions in terrestrial species, but that has not been extensively studied in aquatic systems. Lined bristletooth FID was significantly greater in the presence of a spear gun and varied depending on if the spear gun encounter was inside or outside of the MPA. These results imply a degree of sophistication of fish antipredator behavior, generate questions as to how a nontargeted species of fish could acquire fear of humans, and demonstrate that behavioral surveys can provide insights about antipredator behavior
Industry Survey of Small Satellite Deployable Radiator Technology
The space industry is moving toward small satellites with more capability. With increased capability comes the need to dissipate additional heat. As form factors decrease in size deployable radiators provide a viable solution. A survey of 11 different technologies was conducted and performance metrics compared
Prevalence of hormone prescription and education for cis and trans women by medical trainees
PREVALENCE OF HORMONE PRESCRIPTION AND EDUCATION FOR CIS AND TRANS WOMEN BY MEDICAL TRAINEES
AUTHORS
Madison Meister, BA Candidate; Emily J Noonan, PhD, MA; Laura A. Weingartner, PhD, MS
BACKGROUND
Hormone replacement therapy is a common healthcare practice for contraception, hormone control, and menopause treatment. Transgender patients may also take hormones to affirm their gender identity, such as feminizing hormones (estrogen), for transgender women. Studying how trainees discuss hormone risks for both cis and trans women can demonstrate if disparities exist and how we may address them to overcome healthcare barriers.
METHODS
Fifty videos were analyzed of third-year medical students taking patient histories from standardized patients, including 28 cis women and 22 trans women. Students had previously completed LGBTQ clinical skills training, and patients reported taking estrogen purchased online for acne control (cis) or gender-affirming (trans) purposes. Videos were analyzed for the presence and context of hormone health risk discussion, student knowledge, and whether the student agreed to prescribe hormones.
RESULTS
Of the 90% (n=43) of students who agreed to prescribe hormones, 47% (n=20) prescribed conditionally. Conditions included: pending lab results, desire to research hormones, or checking with attending physicians. A larger proportion of trans women were prescribed hormones (95% or 21/22) compared to cisgender women (79% or 22/28). While similar proportions of students discussed hormone risks between patient groups, students discussed their knowledge or discomfort prescribing hormones more frequently with trans women (27% or n=6/22) than cis women (18% or n=5/28).
DISCUSSION
We expected students to prescribe combined estrogen-progestin oral contraception to cis women. These data show students more readily prescribed estrogen for gender-affirming purposes, suggesting that LGBTQ clinical skills interventions may help prepare students to provide gender-affirming care
Kepler-1656b: a Dense Sub-Saturn With an Extreme Eccentricity
Kepler-1656b is a 5 planet with an orbital period of 32 days initially
detected by the prime Kepler mission. We obtained precision radial velocities
of Kepler-1656 with Keck/HIRES in order to confirm the planet and to
characterize its mass and orbital eccentricity. With a mass of ,
Kepler-1656b is more massive than most planets of comparable size. Its high
mass implies that a significant fraction, roughly 80%, of the planet's total
mass is in high density material such as rock/iron, with the remaining mass in
a low density H/He envelope. The planet also has a high eccentricity of , the largest measured eccentricity for any planet less than 100
. The planet's high density and high eccentricity may be the result of one
or more scattering and merger events during or after the dispersal of the
protoplanetary disk.Comment: 10 pages, 6 figures, published in The Astronomical Journa
Optical Technologies for UV Remote Sensing Instruments
Over the last decade significant advances in technology have made possible development of instruments with substantially improved efficiency in the UV spectral region. In the area of optical coatings and materials, the importance of recent developments in chemical vapor deposited (CVD) silicon carbide (SiC) mirrors, SiC films, and multilayer coatings in the context of ultraviolet instrumentation design are discussed. For example, the development of chemically vapor deposited (CVD) silicon carbide (SiC) mirrors, with high ultraviolet (UV) reflectance and low scatter surfaces, provides the opportunity to extend higher spectral/spatial resolution capability into the 50-nm region. Optical coatings for normal incidence diffraction gratings are particularly important for the evolution of efficient extreme ultraviolet (EUV) spectrographs. SiC films are important for optimizing the spectrograph performance in the 90 nm spectral region. The performance evaluation of the flight optical components for the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) instrument, a spectroscopic instrument to fly aboard the Solar and Heliospheric Observatory (SOHO) mission, designed to study dynamic processes, temperatures, and densities in the plasma of the upper atmosphere of the Sun in the wavelength range from 50 nm to 160 nm, is discussed. The optical components were evaluated for imaging and scatter in the UV. The performance evaluation of SOHO/CDS (Coronal Diagnostic Spectrometer) flight gratings tested for spectral resolution and scatter in the DGEF is reviewed and preliminary results on resolution and scatter testing of Space Telescope Imaging Spectrograph (STIS) technology development diffraction gratings are presented
Vortex phase diagram in trapped Bose-Einstein condensation
The vortex phase diagram in the external rotation frequency versus
temperature is calculated for dilute Bose-Einstein condensed gases. It is
determined within the Bogoliubov-Popov theory for a finite temperature where
the condensate and non-condensate fractions are treated in an equal footing.
The temperature dependences of various thermodynamic instability lines for the
vortex nucleation are computed to construct the phase diagram. Experiments are
proposed to resolve a recent controversy on the vortex creation problem
associated with the quantized vortex observation in Rb atom gases.Comment: 11 pages, 8 figure
Creation of a monopole in a spinor condensate
We propose a method to create a monopole structure in a spin-1 spinor
condensate by applying the basic methods used to create vortices and solitons
experimentally in single-component condensates. We show, however, that by using
a two-component structure for a monopole, we can simplify our proposed
experimental approach and apply it also to ferromagnetic spinor condensates. We
also discuss the observation and dynamics of such a monopole structure, and
note that the dynamics of the two-component monopole differs from the dynamics
of the three-component monopole.Comment: The focus of the paper is shifted towards creation and observation of
monopole
Multiply quantized vortices in trapped Bose-Einstein condensates
Vortex configurations in rotating Bose-Einstein condensed gases trapped in
power-law and anharmonic potentials are studied. When the confining potential
is steeper than harmonic in the plane perpendicular to the axis of rotation,
vortices with quantum numbers larger than one are energetically favorable if
the interaction is weak enough. Features of the wave function for small and
intermediate rotation frequencies are investigated numerically.Comment: 9 pages, 6 figures. Revised and extended article following referee
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New Lower Kazanian (Upper Permian) terebratulids (Brachiopoda) from the Northeastern Russian Platform: Family Dielasmatidae Schuchert, 1913
The study of Lower Kazanian terebratulids from the eastern Russian Platform displayed a well-pronounced homeomorphy. The examination of the inner shell morphology revealed a wide diversity of brachiopod species and genera. The new genera Gruntelasma, with the type species G. bajtuganensis sp. nov., and Grigorjevaelasma, with the type species G. rossica sp. nov., are described and assigned to the family Dielasmatidae. © 2004 by MAIKA "Nauka/Interperiodica" (Russia)
Dynamical instability of a condensate induced by a rotating thermal gas
We study surface modes of the condensate in the presence of a rotating
thermal cloud in an axisymmetric trap. By considering collisions that transfer
atoms between the condensate and noncondensate, we find that modes which rotate
in the same sense as the thermal cloud damp less strongly than counter-rotating
modes. We show that above a critical angular rotation frequency, equivalent to
the Landau stability criterion, the co-rotating mode becomes dynamically
unstable, leading to the possibility of vortex nucleation. This kind of
mechanism is proposed as a natural explanation for the formation of vortices
observed recently in the experiment of Haljan \emph{et al} {[}P. C. Haljan
\emph{et al.}, cond-mat/0106362{]}. We also generalize our stability analysis
to treat the case where the stationary state of the condensate already
possesses a single vortex.Comment: 4 pages, no figure
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