2,475 research outputs found
Multiple and Precessing Collimated Outflows in the Planetary Nebula IC 4634
With its remarkable double-S shape, IC 4634 is an archetype of
point-symmetric planetary nebulae (PN). In this paper, we present a detailed
study of this PN using archival HST WFPC2 and ground-based narrow-band images
to investigate its morphology, and long-slit spectroscopic observations to
determine its kinematics and to derive its physical conditions and excitation.
The data reveal new structural components, including a distant string of knots
distributed along an arc-like feature 40"-60" from the center of the nebula, a
skin of enhanced [O III]/H-alpha ratio enveloping the inner shell and the
double-S feature, and a triple-shell structure. The spatio-kinematical study
also finds an equatorial component of the main nebula that is kinematically
independent from the bright inner S-shaped arc. We have investigated in detail
the bow shock-like features in IC 4634 and found that their morphological,
kinematical and emission properties are consistent with the interaction of a
collimated outflow with surrounding material. Indeed, the morphology and
kinematics of some of these features can be interpreted using a 3D numerical
simulation of a collimated outflow precessing at a moderate, time-dependent
velocity. Apparently, IC 4634 has experienced several episodes of
point-symmetric ejections oriented at different directions with the outer
S-shaped feature being related to an earlier point-symmetric ejection and the
outermost arc-like string of knots being the relic of an even much earlier
point-symmetric ejection. There is tantalizing evidence that the action of
these collimated outflows has also taken part in the shaping of the innermost
shell and inner S-shaped arc of IC 4634.Comment: 16 pages, 11 figures, accepted for publication in The Astrophysical
Journa
Pulsating star research and the Gaia revolution
In this article we present an overview of the ESA Gaia mission and of the
unprecedented impact that Gaia will have on the field of variable star
research. We summarise the contents and impact of the first Gaia data release
on the description of variability phenomena, with particular emphasis on
pulsating star research. The Tycho-Gaia astrometric solution, although limited
to 2.1 million stars, has been used in many studies related to pulsating stars.
Furthermore a set of 3,194 Cepheids and RR Lyrae stars with their times series
have been released. Finally we present the plans for the ongoing study of
variable phenomena with Gaia and highlight some of the possible impacts of the
second data release on variable, and specifically, pulsating stars.Comment: 12 pages, 4 figures, proceedings for the 22nd Los Alamos Stellar
Pulsation Conference Series Meeting "Wide field variability surveys: a
21st-century perspective", held in San Pedro de Atacama, Chile, Nov. 28 -
Dec. 2, 201
Objective compressive quantum process tomography
We present a compressive quantum process tomography scheme that fully characterizes any rank-deficient completely positive process with no spurious a priori information. It uses randomly chosen input states and adaptive output von Neumann measurements. Both entangled and tensor-product configurations are flexibly employable in our scheme, the latter of which are especially compatible with many-body quantum computing. Two main features of this scheme are the certification protocol that verifies whether the accumulated data uniquely characterize the quantum process and a compressive reconstruction method for the output states. We emulate multipartite scenarios with high-order transverse modes and optical fibers to demonstrate that, in terms of measurement resources, our assumption-free compressive strategy can reconstruct quantum processes almost equally efficiently using all types of input states and basis measurements
Evaluation of catalytic activity of [RuClCp(dmoPTA)(PPh3)](OSO2CF3) in the isomerization of allylic alcohols in water (dmoPTA = > 3,7-dimethyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane)
Digestibilidad y respuesta ovárica de conejas reproductoras alimentadas con dietas suplementadas con ácidos grasos poliinsaturados n-3
Aumentar el número de gazapos destetados por coneja y parto es un objetivo importante para incrementar la rentabilidad del sector cunícola industrial con efectos directos. La mejora genética de la prolificidad en las líneas de madres ha demostrado ser una estrategia eficaz para alcanzar este objetivo; sin embargo otras vías, como la influencia de diferentes fuentes de grasa en las dietas de conejas reproductoras, han sido muy poco estudiadas. Los ácidos grasos (AG) n-3 interfieren en la fisiología reproductiva porque pueden modular las enzimas involucradas en el metabolismo de las prostaglandinas y del colesterol que es el precursor de los esteroides como la progesterona (revisado en Gulliver et al., 2012). El objetivo de este trabajo es estudiar si la suplementación con AG poliinsaturados (PUFA) n-3 de las dietas de conejas durante la recría puede afectar a la tasa de ovulación y a la síntesis esteroidogénica ovárica determinada mediante las concentraciones de progesterona plasmática
Estudio inicial de la estructura genética del conejo ibicenco a aprtir de información genealógica.
Aumentar el número de gazapos destetados por coneja y parto es un objetivo importante para incrementar la rentabilidad del sector cunícola industrial con efectos directos. La
mejora genética de la prolificidad en las líneas de madres ha demostrado ser una estrategia eficaz para alcanzar este objetivo; sin embargo otras vías, como la influencia de diferentes fuentes de grasa en las dietas de conejas reproductoras, han sido muy poco estudiadas. Los ácidos grasos (AG) n-3 interfieren en la fisiología reproductiva porque pueden modular las enzimas involucradas en el metabolismo de las prostaglandinas y del colesterol que es
el precursor de los esteroides como la progesterona (revisado en Gulliver et al., 2012). El objetivo de este trabajo es estudiar si la suplementación con AG poliinsaturados (PUFA) n-3 de las dietas de conejas durante la recría puede afectar a la tasa de ovulación y a la
síntesis esteroidogénica ovárica determinada mediante las concentraciones de progesterona plasmática
The systemic lupus erythematosus IRF5 risk haplotype is associated with systemic sclerosis
Systemic sclerosis (SSc) is a fibrotic autoimmune disease in which the genetic component plays an important role. One of the strongest SSc association signals outside the human leukocyte antigen (HLA) region corresponds to interferon (IFN) regulatory factor 5 (IRF5), a major regulator of the type I IFN pathway. In this study we aimed to evaluate whether three different haplotypic blocks within this locus, which have been shown to alter the protein function influencing systemic lupus erythematosus (SLE) susceptibility, are involved in SSc susceptibility and clinical phenotypes. For that purpose, we genotyped one representative single-nucleotide polymorphism (SNP) of each block (rs10488631, rs2004640, and rs4728142) in a total of 3,361 SSc patients and 4,012 unaffected controls of Caucasian origin from Spain, Germany, The Netherlands, Italy and United Kingdom. A meta-analysis of the allele frequencies was performed to analyse the overall effect of these IRF5 genetic variants on SSc. Allelic combination and dependency tests were also carried out. The three SNPs showed strong associations with the global disease (rs4728142: P = 1.34×10<sup>−8</sup>, OR = 1.22, CI 95% = 1.14–1.30; rs2004640: P = 4.60×10<sup>−7</sup>, OR = 0.84, CI 95% = 0.78–0.90; rs10488631: P = 7.53×10<sup>−20</sup>, OR = 1.63, CI 95% = 1.47–1.81). However, the association of rs2004640 with SSc was not independent of rs4728142 (conditioned P = 0.598). The haplotype containing the risk alleles (rs4728142*A-rs2004640*T-rs10488631*C: P = 9.04×10<sup>−22</sup>, OR = 1.75, CI 95% = 1.56–1.97) better explained the observed association (likelihood P-value = 1.48×10<sup>−4</sup>), suggesting an additive effect of the three haplotypic blocks. No statistical significance was observed in the comparisons amongst SSc patients with and without the main clinical characteristics. Our data clearly indicate that the SLE risk haplotype also influences SSc predisposition, and that this association is not sub-phenotype-specific
Reproductive long-term effects, endocrine response and fatty acid profile of rabbit does fed diets supplemented with n-3 fatty acids
The
effect
of
a
diet
enriched
with
polyunsaturated
n
-3
fatty
acids
(PUFA)
on
endocrine,
reproductive,
and
productive
responses
of
rabbit
females
and
the
litters
has
been
studied.
Nulliparous
does
(
n
=
125)
were
fed
ad
libitum
from
rearing
to
second
weaning
two
diets
supplemented
with
different
fat
sources:
7.5
g/kg
lard
for
the
control
diet
(group
C;
n
=
63)
or
15
g/kg
of
a
commercial
supplement
containing
a
50%
ether
extract
and
35%
of
total
fatty
acids
(FAs)
as
PUFA
n
-3
(Group
P;
n
=
62).
Dietary
treatments
did
not
affect
apparent
digestibility
coefficients
of
nutrients,
or
reproductive
variables
of
does
including
milk
pro-
duction,
mortality
and
average
daily
gain
of
kits
over
two
lactations.
However,
on
Day
5
and
7
post-induction
of
ovulation,
progesterone
of
Group
P
tended
to
increase
to
a
greater
extent
than
in
does
of
Group
C.
Total
PUFAs,
n
-6
and
n
-3
and
eicosapentanoic
(EPA)
contents
were
greater
in
adipose
tissues
of
does
in
Group
P
than
in
Group
C.
Docosapentaenoic
acid
(DPA),
EPA,
and
docosahexaenoic
acid
(DHA)
concentrations
were
greater
in
peri-ovarian
than
in
scapular
fat
with
abdominal
fat
being
intermediate
in
concentration.
In
PUFA
sup-
plemented
does,
kit
mortality
at
the
second
parturition
tended
to
be
less
than
in
control
does.
Also,
kits
born
to
does
of
the
PUFA-supplemented
group
weighed
more
and
were
of
greater
length
than
from
does
of
control
group.
In
conclusion,
effectiveness
of
dietary
intervention
on
reproductive
and
performance
response
is
greater
in
the
second
parity,
which
suggests
an
accumulative
long-term
beneficial
effect
of
n
-3
FA
supplementation
in
reproductive
rabbit
doe
Definitions, Criteria and Global Classification of Mast Cell Disorders with Special Reference to Mast Cell Activation Syndromes: A Consensus Proposal
Activation of tissue mast cells (MCs) and their abnormal growth and accumulation in various organs are typically found in primary MC disorders also referred to as mastocytosis. However, increasing numbers of patients are now being informed that their clinical findings are due to MC activation (MCA) that is neither associated with mastocytosis nor with a defined allergic or inflammatory reaction. In other patients with MCA, MCs appear to be clonal cells, but criteria for diagnosing mastocytosis are not met. A working conference was organized in 2010 with the aim to define criteria for diagnosing MCA and related disorders, and to propose a global unifying classification of all MC disorders and pathologic MC reactions. This classification includes three types of `MCA syndromes' (MCASs), namely primary MCAS, secondary MCAS and idiopathic MCAS. MCA is now defined by robust and generally applicable criteria, including (1) typical clinical symptoms, (2) a substantial transient increase in serum total tryptase level or an increase in other MC-derived mediators, such as histamine or prostaglandin D 2, or their urinary metabolites, and (3) a response of clinical symptoms to agents that attenuate the production or activities of MC mediators. These criteria should assist in the identification and diagnosis of patients with MCAS, and in avoiding misdiagnoses or overinterpretation of clinical symptoms in daily practice. Moreover, the MCAS concept should stimulate research in order to identify and exploit new molecular mechanisms and therapeutic targets. Copyright (C) 2011 S. Karger AG, Base
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