832 research outputs found
Broccoli or Sulforaphane:Is It the Source or Dose That Matters?
There is robust epidemiological evidence for the beneficial effects of broccoli consumption on health, many of them clearly mediated by the isothiocyanate sulforaphane. Present in the plant as its precursor, glucoraphanin, sulforaphane is formed through the actions of myrosinase, a β-thioglucosidase present in either the plant tissue or the mammalian microbiome. Since first isolated from broccoli and demonstrated to have cancer chemoprotective properties in rats in the early 1990s, over 3000 publications have described its efficacy in rodent disease models, underlying mechanisms of action or, to date, over 50 clinical trials examining pharmacokinetics, pharmacodynamics and disease mitigation. This review evaluates the current state of knowledge regarding the relationships between formulation (e.g., plants, sprouts, beverages, supplements), bioavailability and efficacy, and the doses of glucoraphanin and/or sulforaphane that have been used in pre-clinical and clinical studies. We pay special attention to the challenges for better integration of animal model and clinical studies, particularly with regard to selection of dose and route of administration. More effort is required to elucidate underlying mechanisms of action and to develop and validate biomarkers of pharmacodynamic action in humans. A sobering lesson is that changes in approach will be required to implement a public health paradigm for dispensing benefit across all spectrums of the global population
Expert consensus on the contraindications and cautions of foam rolling: an international delphi study
Background: Foam rolling is a type of self-massage using tools such as foam or roller sticks. However, to date, there is no consensus on contraindications and cautions of foam rolling. A methodological approach to narrow that research gap is to obtain reliable opinions of expert groups. The aim of the study was to develop experts’ consensus on contraindications and cautions of foam rolling by means of a Delphi process. Methods: An international three-round Delphi study was conducted. Academic experts, defined as having (co-) authored at least one PubMed-listed paper on foam rolling, were invited to participate. Rounds 1 and 2 involved generation and rating of a list of possible contraindications and cautions of foam rolling. In round 3, participants indicated their agreement on contraindications and cautions for a final set of conditions. Consensus was evaluated using a priori defined criteria. Consensus on contraindications and cautions was considered as reached if more than 70% of participating experts labeled the respective item as contraindication and contraindication or caution, respectively, in round 3. Results: In the final Delphi process round, responses were received from 37 participants. Panel participants were predominantly sports scientists ( n = 21), physiotherapists ( n = 6), and medical professionals ( n = 5). Consensus on contraindications was reached for open wounds (73% agreement) and bone fractures (84%). Consensus on cautions was achieved for local tissue inflammation (97%), deep vein thrombosis (97%), osteomyelitis (94%), and myositis ossificans (92%). The highest impact/severity of an adverse event caused by contraindication/cautions was estimated for bone fractures, deep vein thrombosis, and osteomyelitis. Discussion: The mechanical forces applied through foam rolling can be considered as potential threats leading to adverse events in the context of the identified contraindications and cautions. Further evaluations by medical professionals as well as the collection of clinical data are needed to assess the risks of foam rolling and to generate guidance for different applications and professional backgrounds
Discovery of the Coldest Imaged Companion of a Sun-Like Star
We present the discovery of a brown dwarf or possible planet at a projected
separation of 1.9" = 29 AU around the star GJ 758, placing it between the
separations at which substellar companions are expected to form by core
accretion (~5 AU) or direct gravitational collapse (typically >100 AU). The
object was detected by direct imaging of its thermal glow with Subaru/HiCIAO.
At 10-40 times the mass of Jupiter and a temperature of 550-640 K, GJ 758 B
constitutes one of the few known T-type companions, and the coldest ever to be
imaged in thermal light around a Sun-like star. Its orbit is likely eccentric
and of a size comparable to Pluto's orbit, possibly as a result of
gravitational scattering or outward migration. A candidate second companion is
detected at 1.2" at one epoch.Comment: 5 pages, 3 figures, 2 tables. Accepted for publication in ApJ Letter
Imaging of a Transitional Disk Gap in Reflected Light: Indications of Planet Formation Around the Young Solar Analog LkCa 15
We present H- and Ks-band imaging data resolving the gap in the transitional
disk around LkCa 15, revealing the surrounding nebulosity. We detect sharp
elliptical contours delimiting the nebulosity on the inside as well as the
outside, consistent with the shape, size, ellipticity, and orientation of
starlight reflected from the far-side disk wall, whereas the near-side wall is
shielded from view by the disk's optically thick bulk. We note that
forward-scattering of starlight on the near-side disk surface could provide an
alternate interpretation of the nebulosity. In either case, this discovery
provides confirmation of the disk geometry that has been proposed to explain
the spectral energy distributions (SED) of such systems, comprising an
optically thick outer disk with an inner truncation radius of ~46 AU enclosing
a largely evacuated gap. Our data show an offset of the nebulosity contours
along the major axis, likely corresponding to a physical pericenter offset of
the disk gap. This reinforces the leading theory that dynamical clearing by at
least one orbiting body is the cause of the gap. Based on evolutionary models,
our high-contrast imagery imposes an upper limit of 21 Jupiter masses on
companions at separations outside of 0.1" and of 13 Jupiter masses outside of
0.2". Thus, we find that a planetary system around LkCa 15 is the most likely
explanation for the disk architecture.Comment: 5 pages, 4 figures, accepted for publication in ApJ Letters. Minor
change to Figure
New Techniques for High-Contrast Imaging with ADI: the ACORNS-ADI SEEDS Data Reduction Pipeline
We describe Algorithms for Calibration, Optimized Registration, and Nulling
the Star in Angular Differential Imaging (ACORNS-ADI), a new, parallelized
software package to reduce high-contrast imaging data, and its application to
data from the SEEDS survey. We implement several new algorithms, including a
method to register saturated images, a trimmed mean for combining an image
sequence that reduces noise by up to ~20%, and a robust and computationally
fast method to compute the sensitivity of a high-contrast observation
everywhere on the field-of-view without introducing artificial sources. We also
include a description of image processing steps to remove electronic artifacts
specific to Hawaii2-RG detectors like the one used for SEEDS, and a detailed
analysis of the Locally Optimized Combination of Images (LOCI) algorithm
commonly used to reduce high-contrast imaging data. ACORNS-ADI is written in
python. It is efficient and open-source, and includes several optional features
which may improve performance on data from other instruments. ACORNS-ADI
requires minimal modification to reduce data from instruments other than
HiCIAO. It is freely available for download at
www.github.com/t-brandt/acorns-adi under a BSD license.Comment: 15 pages, 9 figures, accepted to ApJ. Replaced with accepted version;
mostly minor changes. Software update
Subaru Imaging of Asymmetric Features in a Transitional Disk in Upper Scorpius
We report high-resolution (0.07 arcsec) near-infrared polarized intensity
images of the circumstellar disk around the star 2MASS J16042165-2130284
obtained with HiCIAO mounted on the Subaru 8.2 m telescope. We present our
-band data, which clearly exhibits a resolved, face-on disk with a large
inner hole for the first time at infrared wavelengths. We detect the
centrosymmetric polarization pattern in the circumstellar material as has been
observed in other disks. Elliptical fitting gives the semimajor axis, semiminor
axis, and position angle (P.A.) of the disk as 63 AU, 62 AU, and -14
, respectively. The disk is asymmetric, with one dip located at P.A.s
of . Our observed disk size agrees well with a previous study
of dust and CO emission at submillimeter wavelength with Submillimeter Array.
Hence, the near-infrared light is interpreted as scattered light reflected from
the inner edge of the disk. Our observations also detect an elongated arc (50
AU) extending over the disk inner hole. It emanates at the inner edge of the
western side of the disk, extending inward first, then curving to the
northeast. We discuss the possibility that the inner hole, the dip, and the arc
that we have observed may be related to the existence of unseen bodies within
the disk.Comment: 21 pages, 3 figures, published 2012 November 7 by ApJL, typo
correcte
Orbital characterization of GJ1108A system, and comparison of dynamical mass with model-derived mass for resolved binaries
We report an orbital characterization of GJ1108Aab that is a low-mass binary
system in pre-main-sequence phase. Via the combination of astrometry using
adaptive optics and radial velocity measurements, an eccentric orbital solution
of =0.63 is obtained, which might be induced by the Kozai-Lidov mechanism
with a widely separated GJ1108B system. Combined with several observed
properties, we confirm the system is indeed young. Columba is the most probable
moving group, to which the GJ1108A system belongs, although its membership to
the group has not been established. If the age of Columba is assumed for
GJ1108A, the dynamical masses of both GJ1108Aa and GJ1108Ab ( and ) are more massive than what an
evolutionary model predicts based on the age and luminosities. We consider the
discrepancy in mass comparison can attribute to an age uncertainty; the system
is likely older than stars in Columba, and effects that are not implemented in
classical models such as accretion history and magnetic activity are not
preferred to explain the mass discrepancy. We also discuss the performance of
the evolutionary model by compiling similar low-mass objects in evolutionary
state based on the literature. Consequently, it is suggested that the current
model on average reproduces the mass of resolved low-mass binaries without any
significant offsets.Comment: Accepted in Ap
Direct Imaging of a Cold Jovian Exoplanet in Orbit around the Sun-like Star GJ 504
Several exoplanets have recently been imaged at wide separations of >10 AU
from their parent stars. These span a limited range of ages (<50 Myr) and
atmospheric properties, with temperatures of 800--1800 K and very red colors (J
- H > 0.5 mag), implying thick cloud covers. Furthermore, substantial model
uncertainties exist at these young ages due to the unknown initial conditions
at formation, which can lead to an order of magnitude of uncertainty in the
modeled planet mass. Here, we report the direct imaging discovery of a Jovian
exoplanet around the Sun-like star GJ 504, detected as part of the SEEDS
survey. The system is older than all other known directly-imaged planets; as a
result, its estimated mass remains in the planetary regime independent of
uncertainties related to choices of initial conditions in the exoplanet
modeling. Using the most common exoplanet cooling model, and given the system
age of 160 [+350, -60] Myr, GJ 504 b has an estimated mass of 4 [+4.5, -1.0]
Jupiter masses, among the lowest of directly imaged planets. Its projected
separation of 43.5 AU exceeds the typical outer boundary of ~30 AU predicted
for the core accretion mechanism. GJ 504 b is also significantly cooler (510
[+30, -20] K) and has a bluer color (J-H = -0.23 mag) than previously imaged
exoplanets, suggesting a largely cloud-free atmosphere accessible to
spectroscopic characterization. Thus, it has the potential of providing novel
insights into the origins of giant planets, as well as their atmospheric
properties.Comment: 20 pages, 12 figures, Accepted for publication in ApJ. Minor updates
from the version
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