406 research outputs found
Tumor bed delineation for external beam accelerated partial breast irradiation: A systematic review
AbstractIn recent years, accelerated partial breast irradiation (APBI) has been considered an alternative to whole breast irradiation for patients undergoing breast-conserving therapy. APBI delivers higher doses of radiation in fewer fractions to the post-lumpectomy tumor bed with a 1–2cm margin, targeting the area at the highest risk of local recurrence while sparing normal breast tissue. However, there are inherent challenges in defining accurate target volumes for APBI. Studies have shown that significant interobserver variation exists among radiation oncologists defining the lumpectomy cavity, which raises the question of how to improve the accuracy and consistency in the delineation of tumor bed volumes. The combination of standardized guidelines and surgical clips significantly improves an observer’s ability in delineation, and it is the standard in multiple ongoing external-beam APBI trials. However, questions about the accuracy of the clips to mark the lumpectomy cavity remain, as clips only define a few points at the margin of the cavity. This paper reviews the techniques that have been developed so far to improve target delineation in APBI delivered by conformal external beam radiation therapy, including the use of standardized guidelines, surgical clips or fiducial markers, pre-operative computed tomography imaging, and additional imaging modalities, including magnetic resonance imaging, ultrasound imaging, and positron emission tomography/computed tomography. Alternatives to post-operative APBI, future directions, and clinical recommendations were also discussed
Mutant screen reveals the Piccolo's control over depression and brain-gonad crosstalk
Successful sexual reproduction involves a highly complex, genetically encoded interplay between animal physiology and behavior. Here we developed a screen to identify genes essential for rat reproduction based on an unbiased methodology involving mutagenesis via the Sleeping Beauty transposon. As expected, our screen identified genes where reproductive failure was connected to gametogenesis (Btrc, Pan3, Spaca6, Ube2k) and embryogenesis (Alk3, Exoc6b, Slc1a3, Tmx4, Zmynd8). In addition, our screen identified Atg13 (longevity) Dlg1 and Pclo (neuronal disorders), previously not associated with reproduction. Dominant Pclo traits caused epileptiform activity and affected genes supporting GABAergic synaptic transmission (Gabra6, Gabrg3), and animals exhibited a compromised crosstalk between the brain and gonads via disturbed GnRH signaling. Recessive Pclo traits disrupted conspecific recognition required for courtship/mating and were mapped to allelic markers for major depressive disorder (Grm5, Htr2a, Sorcs3, Negr1, Drd2). Thus, Pclo-deficiency in rats link neural networks controlling sexual motivation to Pclo variants that have been associated with human neurological disorders
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"Older Adults with ASD: The Consequences of Aging." Insights from a series of special interest group meetings held at the International Society for Autism Research 2016-2017
A special interest group (SIG) entitled "Older Adults with ASD: The Consequences of Aging" was held at the International Society for Autism Research (INSAR) annual meetings in 2016 and 2017. The SIG and subsequent meetings brought together, for the first time, international delegates who were members of the autistic community, researchers, practitioners and service providers. Based on aging autism research that is already underway in UK, Europe, Australia and North America, discussions focussed on conceptualising the parameters of aging when referring to autism, and the measures that are appropriate to use with older adults when considering diagnostic assessment, cognitive factors and quality of life in older age. Thus, the aim of this SIG was to progress the research agenda on current and future directions for autism research in the context of aging. A global issue on how to define 'aging' when referring to ASD was at the forefront of discussions. The ‘aging’ concept can in principle refer to all developmental transitions. However, in this paper we focus on the cognitive and physical changes that take place from mid-life onwards. Accordingly, it was agreed that aging and ASD research should focus on adults over the age of 50 years, given the high rates of co-occurring physical and mental health concerns and increased risk of premature death in some individuals. Moreover, very little is known about the cognitive change, care needs and outcomes of autistic adults beyond this age. Discussions on the topics of diagnostic and cognitive assessments, and of quality of life and well-being were explored through shared knowledge about which measures are currently being used and which background questions should be asked to obtain comprehensive and informative developmental and medical histories. Accordingly, a survey was completed by SIG delegates who were representatives of international research groups across four continents, and who are currently conducting studies with older autistic adults. Considerable overlap was identified across different research groups in measures of both autism and quality of life, which pointed to combining data and shared learnings as the logical next step. Regarding the background questions that were asked, the different research groups covered similar topics but the groups differed in the way these questions were formulated when working with autistic adults across a range of cognitive abilities. It became clear that continued input from individuals on the autism spectrum is important to ensure that questionnaires used in ongoing and future are accessible and understandable for people across the whole autistic spectrum, including those with limited verbal abilities
Does the engineering culture in UK higher education advance women’s careers?
Current research suggests that increases in the number of women studying engineering and related courses have not been matched by a similar increase in women engineering professionals. This suggests that although women are attracted to engineering, their experiences in higher education (HE) discourage them from pursuing their chosen career path. The paper explores whether the masculine culture of the engineering sector permeates the culture and curriculum in engineering HE, and if it does, what impact this has on women engineering students. This is achieved through semi-structured, qualitative interviews with a range of female engineering students from both the pre and post 1992 university sectors. Findings indicate that while women are not deterred from pursuing their chosen engineering career, the culture and structure of the engineering education system has been designed for a male audience. This suggests that engineering HE does not benefit most female students to the same extent as male students. It is recommended
that HE engineering must review its structure, culture, practices and curriculum if it is to retain female engineering graduates and to attract more women into the sector. This paper fulfils an identified gap in research on women in engineering and will be of interest to university engineering departments and faculties and the Engineering Council, as well as to those in the fields of social policy, education and equal opportunities
Single Spin Asymmetry in Polarized Proton-Proton Elastic Scattering at GeV
We report a high precision measurement of the transverse single spin
asymmetry at the center of mass energy GeV in elastic
proton-proton scattering by the STAR experiment at RHIC. The was measured
in the four-momentum transfer squared range \GeVcSq, the region of a significant interference between the
electromagnetic and hadronic scattering amplitudes. The measured values of
and its -dependence are consistent with a vanishing hadronic spin-flip
amplitude, thus providing strong constraints on the ratio of the single
spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated
by the Pomeron amplitude at this , we conclude that this measurement
addresses the question about the presence of a hadronic spin flip due to the
Pomeron exchange in polarized proton-proton elastic scattering.Comment: 12 pages, 6 figure
Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV
We report a measurement of the longitudinal double-spin asymmetry A_LL and
the differential cross section for inclusive Pi0 production at midrapidity in
polarized proton collisions at sqrt(s) = 200 GeV. The cross section was
measured over a transverse momentum range of 1 < p_T < 17 GeV/c and found to be
in good agreement with a next-to-leading order perturbative QCD calculation.
The longitudinal double-spin asymmetry was measured in the range of 3.7 < p_T <
11 GeV/c and excludes a maximal positive gluon polarization in the proton. The
mean transverse momentum fraction of Pi0's in their parent jets was found to be
around 0.7 for electromagnetically triggered events.Comment: 6 pages, 3 figures, submitted to Phys. Rev. D (RC
Measurement of the parity-violating longitudinal single-spin asymmetry for boson production in polarized proton-proton collisions at GeV
We report the first measurement of the parity violating single-spin
asymmetries for midrapidity decay positrons and electrons from and
boson production in longitudinally polarized proton-proton collisions
at GeV by the STAR experiment at RHIC. The measured asymmetries,
and , are consistent with theory
predictions, which are large and of opposite sign. These predictions are based
on polarized quark and antiquark distribution functions constrained by
polarized DIS measurements.Comment: 6 pages, 4 figures, submitted to Physics Review Letter
High non-photonic electron production in + collisions at = 200 GeV
We present the measurement of non-photonic electron production at high
transverse momentum ( 2.5 GeV/) in + collisions at
= 200 GeV using data recorded during 2005 and 2008 by the STAR
experiment at the Relativistic Heavy Ion Collider (RHIC). The measured
cross-sections from the two runs are consistent with each other despite a large
difference in photonic background levels due to different detector
configurations. We compare the measured non-photonic electron cross-sections
with previously published RHIC data and pQCD calculations. Using the relative
contributions of B and D mesons to non-photonic electrons, we determine the
integrated cross sections of electrons () at 3 GeV/10 GeV/ from bottom and charm meson decays to be = 4.0({\rm
stat.})({\rm syst.}) nb and =
6.2({\rm stat.})({\rm syst.}) nb, respectively.Comment: 17 pages, 17 figure
Evolution of the differential transverse momentum correlation function with centrality in Au+Au collisions at GeV
We present first measurements of the evolution of the differential transverse
momentum correlation function, {\it C}, with collision centrality in Au+Au
interactions at GeV. {\it C} exhibits a strong dependence
on collision centrality that is qualitatively similar to that of number
correlations previously reported. We use the observed longitudinal broadening
of the near-side peak of {\it C} with increasing centrality to estimate the
ratio of the shear viscosity to entropy density, , of the matter formed
in central Au+Au interactions. We obtain an upper limit estimate of
that suggests that the produced medium has a small viscosity per unit entropy.Comment: 7 pages, 4 figures, STAR paper published in Phys. Lett.
Measurement of the Bottom contribution to non-photonic electron production in collisions at =200 GeV
The contribution of meson decays to non-photonic electrons, which are
mainly produced by the semi-leptonic decays of heavy flavor mesons, in
collisions at 200 GeV has been measured using azimuthal
correlations between non-photonic electrons and hadrons. The extracted
decay contribution is approximately 50% at a transverse momentum of GeV/. These measurements constrain the nuclear modification factor for
electrons from and meson decays. The result indicates that meson
production in heavy ion collisions is also suppressed at high .Comment: 6 pages, 4 figures, accepted by PR
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