790 research outputs found
Addressing family planning needs among low-literate population in peri-urban areas of Delhi, India: a qualitative inquiry
Background: Since several decades, population control has remained one of the major challenges for India. Understanding family planning (FP) related knowledge and practices, especially among low-literate population groups is important for increasing the reach of FP services nearer to them, which is an essential step for population control as well as to prevent unwanted pregnancies.Methods: We conducted a cross-sectional, qualitative research study among low literate population in peri-urban areas of New Delhi, bordered with Uttar Pradesh (U.P.) state. We selected and interviewed 27 participants including married men and women in the age range 18-34 years using semi-structured interview schedules. The focus of inquiry was on fertility awareness; beliefs and practices related to menstruation, pregnancy and FP methods etc. and decision making about FP. The data were processed for thematic analysis.Results: The study revealed lack of basic scientific knowledge about fertility in this community which often resulted into unwanted pregnancies. This finding has major implications especially when the Government’s FP program is geared mainly towards sterilization and conventional spacing methods. The study further confirmed that traditional beliefs and practices like separating women during menstruation still prevail in many joint families, but less likely in the nuclear ones. There were mixed opinions about spacing methods. Husband was reported to be main decision maker in FP process in this male dominated society. Regarding sources of information on FP, women reported elder women, lady clinicians and peers whereas men reported only peers.Conclusions: This study points out various barriers for FP around which basic FP education for both men and women in this community need to be provided. The study will have implications for other parts of India which share the same socio-cultural milieu as this community
Counting subgraphs of coloring graphs
The chromatic polynomial of a graph can be viewed as
counting the number of vertices in a family of coloring graphs associated with (proper) -colorings of as a function of the
number of colors . These coloring graphs can be understood as a
reconfiguration system. We generalize the chromatic polynomial to
, counting occurrences of arbitrary induced subgraphs in
these coloring graphs, and we prove that these functions are polynomial in .
In particular, we study the chromatic pairs polynomial ,
which counts the number of edges in coloring graphs, corresponding to the
number of pairs of colorings that differ on a single vertex. We show two trees
share a chromatic pairs polynomial if and only if they have the same degree
sequence, and we conjecture that the chromatic pairs polynomial refines the
chromatic polynomial in general. We also instantiate our polynomials with other
choices of to generate new graph invariants.Comment: 25 pages, 14 figure
HAT-P-11: Discovery of a Second Planet and a Clue to Understanding Exoplanet Obliquities
HAT-P-11 is a mid-K dwarf that hosts one of the first Neptune-sized planets
found outside the solar system. The orbit of HAT-P-11b is misaligned with the
star's spin --- one of the few known cases of a misaligned planet orbiting a
star less massive than the Sun. We find an additional planet in the system
based on a decade of precision radial velocity (RV) measurements from
Keck/HIRES. HAT-P-11c is similar to Jupiter in its mass ( ) and orbital period ( year), but has a
much more eccentric orbit (). In our joint modeling of RV and
stellar activity, we found an activity-induced RV signal of 7 m s,
consistent with other active K dwarfs, but significantly smaller than the 31 m
s reflex motion due to HAT-P-11c. We investigated the dynamical coupling
between HAT-P-11b and c as a possible explanation for HAT-P-11b's misaligned
orbit, finding that planet-planet Kozai interactions cannot tilt planet b's
orbit due to general relativistic precession; however, nodal precession
operating on million year timescales is a viable mechanism to explain
HAT-P-11b's high obliquity. This leaves open the question of why HAT-P-11c may
have such a tilted orbit. At a distance of 38 pc, the HAT-P-11 system offers
rich opportunities for further exoplanet characterization through astrometry
and direct imaging.Comment: 16 pages, 11 figures, 4 tables. Accepted to A
Hubble Space Telescope Near-IR Transmission Spectroscopy of the Super-Earth HD 97658b
Recent results from the Kepler mission indicate that super-Earths (planets
with masses between 1-10 times that of the Earth) are the most common kind of
planet around nearby Sun-like stars. These planets have no direct solar system
analogue, and are currently one of the least well-understood classes of
extrasolar planets. Many super-Earths have average densities that are
consistent with a broad range of bulk compositions, including both
water-dominated worlds and rocky planets covered by a thick hydrogen and helium
atmosphere. Measurements of the transmission spectra of these planets offer the
opportunity to resolve this degeneracy by directly constraining the scale
heights and corresponding mean molecular weights of their atmospheres. We
present Hubble Space Telescope near-infrared spectroscopy of two transits of
the newly discovered transiting super-Earth HD 97658b. We use the Wide Field
Camera 3's scanning mode to measure the wavelength-dependent transit depth in
thirty individual bandpasses. Our averaged differential transmission spectrum
has a median 1 sigma uncertainty of 23 ppm in individual bins, making this the
most precise observation of an exoplanetary transmission spectrum obtained with
WFC3 to date. Our data are inconsistent with a cloud-free solar metallicity
atmosphere at the 10 sigma level. They are consistent at the 0.4 sigma level
with a flat line model, as well as effectively flat models corresponding to a
metal-rich atmosphere or a solar metallicity atmosphere with a cloud or haze
layer located at pressures of 10 mbar or higher.Comment: ApJ in press; revised version includes an updated orbital ephemeris
for the plane
Atmospheric Characterization of the Hot Jupiter Kepler-13Ab
Kepler-13Ab (= KOI-13.01) is a unique transiting hot Jupiter. It is one of
very few known short-period planets orbiting a hot A-type star, making it one
of the hottest planets currently known. The availability of Kepler data allows
us to measure the planet's occultation (secondary eclipse) and phase curve in
the optical, which we combine with occultations observed by warm Spitzer at 4.5
mic and 3.6 mic and a ground-based occultation observation in the Ks band (2.1
mic). We derive a day-side hemisphere temperature of 2,750 +- 160 K as the
effective temperature of a black body showing the same occultation depths.
Comparing the occultation depths with one-dimensional planetary atmosphere
models suggests the presence of an atmospheric temperature inversion. Our
analysis shows evidence for a relatively high geometric albedo, Ag= 0.33 +0.04
-0.06. While measured with a simplistic method, a high Ag is supported also by
the fact that the one-dimensional atmosphere models underestimate the
occultation depth in the optical. We use stellar spectra to determine the
dilution, in the four wide bands where occultation was measured, due to the
visual stellar binary companion 1.15 +- 0.05" away. The revised stellar
parameters measured using these spectra are combined with other measurements
leading to revised planetary mass and radius estimates of Mp = 4.94 - 8.09 Mjup
and Rp = 1.406 +- 0.038 Rjup. Finally, we measure a Kepler mid-occultation time
that is 34.0 +- 6.9 s earlier than expected based on the mid-transit time and
the delay due to light travel time, and discuss possible scenarios.Comment: V2: Accepted to ApJ on 2014 April 11. Spitzer photometry and model
fitting Matlab pipeline code is publicly available at:
http://gps.caltech.edu/~shporer/spitzerphot
An epidemiological study of season of birth, mental health, and neuroimaging in the UK Biobank
Environmental exposures during the perinatal period are known to have a long-term effect on adult physical and mental health. One such influential environmental exposure is the time of year of birth which affects the amount of daylight, nutrients, and viral load that an individual is exposed to within this key developmental period. Here, we investigate associations between season of birth (seasonality), four mental health traits (n = 137,588) and multi-modal neuroimaging measures (n = 33,212) within the UK Biobank. Summer births were associated with probable recurrent Major Depressive Disorder (β = 0.026, pcorr = 0.028) and greater mean cortical thickness in temporal and occipital lobes (β = 0.013 to 0.014, pcorr<0.05). Winter births were associated with greater white matter integrity globally, in the association fibers, thalamic radiations, and six individual tracts (β = -0.013 to -0.022, pcorr<0.05). Results of sensitivity analyses adjusting for birth weight were similar, with an additional association between winter birth and white matter microstructure in the forceps minor and between summer births, greater cingulate thickness and amygdala volume. Further analyses revealed associations between probable depressive phenotypes and a range of neuroimaging measures but a paucity of interactions with seasonality. Our results suggest that seasonality of birth may affect later-life brain structure and play a role in lifetime recurrent Major Depressive Disorder. Due to the small effect sizes observed, and the lack of associations with other mental health traits, further research is required to validate birth season effects in the context of different latitudes, and by co-examining genetic and epigenetic measures to reveal informative biological pathways
An HST/STIS Optical Transmission Spectrum of Warm Neptune GJ 436b
GJ 436b is a prime target for understanding warm Neptune exoplanet
atmospheres and a target for multiple JWST GTO programs. Here, we report the
first space-based optical transmission spectrum of the planet using two
HST/STIS transit observations from 0.53-1.03 microns. We find no evidence for
alkali absorption features, nor evidence of a scattering slope longward of 0.53
microns. The spectrum is indicative of moderate to high metallicity (~100-1000x
solar) while moderate metallicity scenarios (~100x solar) require aerosol
opacity. The optical spectrum also rules out some highly scattering haze
models. We find an increase in transit depth around 0.8 microns in the
transmission spectra of 3 different sub-Jovian exoplanets (GJ 436b, HAT-P-26b,
and GJ 1214b). While most of the data come from STIS, data from three other
instruments may indicate this is not an instrumental effect. Only the transit
spectrum of GJ 1214b is well fit by a model with stellar plages on the
photosphere of the host star. Our photometric monitoring of the host star
reveals a stellar rotation rate of 44.1 days and an activity cycle of 7.4
years. Intriguingly, GJ 436 does not become redder as it gets dimmer, which is
expected if star spots were dominating the variability. These insights into the
nature of the GJ 436 system help refine our expectations for future
observations in the era of JWST, whose higher precision and broader wavelength
coverage will shed light on the composition and structure of GJ 436b's
atmosphere.Comment: 20 pages, 11 figures, 5 tables, Accepted to AJ. A full version of
table 1 is included as table1_mrt.tx
Who Publishes in “Predatory” Journals?
Many open access journals have a reputation for being of low quality and being dishonest with regard to peer review and publishing costs. Such journals are labeled “predatory” journals. This study examines author profiles for some of these “predatory” journals as well as for groups of more well-recognized open access journals. We collect and analyze the publication record, citation count, and geographic location of authors from the various groups of journals. Statistical analyses verify that each group of journals has a distinct author population. Those who publish in “predatory” journals are, for the most part, young and inexperienced researchers from developing countries. We believe that economic and sociocultural conditions in these developing countries have contributed to the differences found in authorship between “predatory” and “nonpredatory” journals
Oxaloacetate Enhances Neuronal Cell Bioenergetic Fluxes and Infrastructure
"This is the peer reviewed version of the following article: Wilkins, Heather M. et al. “Oxaloacetate Enhances Neuronal Cell Bioenergetic Fluxes and Infrastructure.” Journal of neurochemistry 137.1 (2016): 76–87., which has been published in final form at 10.1111/jnc.13545. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."We tested how the addition of oxaloacetate (OAA) to SH-SY5Y cells affected bioenergetic fluxes and infrastructure, and compared the effects of OAA to malate, pyruvate, and glucose deprivation. OAA displayed pro-glycolysis and pro-respiration effects. OAA pro-glycolysis effects were not a consequence of decarboxylation to pyruvate because unlike OAA, pyruvate lowered the glycolysis flux. Malate did not alter glycolysis flux and reduced mitochondrial respiration. Glucose deprivation essentially eliminated glycolysis and increased mitochondrial respiration. OAA increased, while malate decreased, the cell NAD+/NADH ratio. Cytosolic malate dehydrogenase 1 (MDH1) protein increased with OAA treatment, but not with malate or glucose deprivation. Glucose deprivation increased protein levels of ATP citrate lyase, an enzyme which produces cytosolic OAA, while OAA altered neither ATP citrate lyase mRNA nor protein levels. OAA, but not glucose deprivation, increased COX2, PGC1α, PGC1β, and PRC protein levels. OAA increased total and phosphorylated SIRT1 protein. We conclude that adding OAA to SH-SY5Y cells can support or enhance both glycolysis and respiration fluxes. These effects appear to depend, at least partly, on OAA causing a shift in the cell redox balance to a more oxidized state, that it is not a glycolysis pathway intermediate, and possibly its ability to act in an anaplerotic fashion
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