1,297 research outputs found
Formation of fundamental structures in Bose-Einstein Condensates
The meanfield interaction in a Bose condensate provides a nonlinearity which
can allow stable structures to exist in the meanfield wavefunction. We discuss
a number of examples where condensates, modelled by the one dimensional Gross
Pitaevskii equation, can produce gray solitons and we consider in detail the
case of two identical condensates colliding in a harmonic trap. Solitons are
shown to form from dark interference fringes when the soliton structure,
constrained in a defined manner, has lower energy than the interference fringe
and an analytic expression is given for this condition.Comment: 7 pages, 3 figures, requires ioplppt.st
âWe Need to Deploy Them Very Thoughtfully and Carefullyâ: Perceptions of Analytical Treatment Interruptions in HIV Cure Research in the United States â A Qualitative Inquiry
Strategies to control HIV in the absence of antiretroviral therapy are needed to cure HIV. However, such strategies will require analytical treatment interruptions (ATIs) to determine their efficacy. We investigated how U.S. stakeholders involved in HIV cure research perceive ATIs. We conducted 36 in-depth interviews with three groups of stakeholders: 12 people living with HIV, 11 clinician-researchers, and 13 policy-makers/bioethicists. Qualitative data revealed several themes. First, there was little consensus on when ATIs would be ethically warranted. Second, the most frequent perceived hypothetical motivators for participating in research on ATIs were advancing science and contributing to society. Third, risks related to viral rebound were the most prevalent concerns related to ATIs. Stakeholders suggested ways to minimize the risks of ATIs in HIV cure research. Increased cooperation between scientists and local communities may be useful for minimizing risk. Further ethics research is necessary
Willingness to Participate in HIV Cure Research: Survey Results from 400 People Living with HIV in the United States
Introduction
Participation in early-phase HIV cure studies includes clinical risks with little to no likelihood of clinical benefit. Examining the willingness of people living with HIV to participate is important to guide study design and informed consent. Our study examined the overall willingness of people living with HIV to participate in HIV cure research in the US, focusing on perceived risks and benefits of participation.
Methods
We undertook an online survey of adults living with HIV in the US. Survey questions were developed based on previous research and a scoping review of the literature. We quantitatively assessed individualsâ perceived risks and benefits of HIV cure-related research and respondentsâ willingness to participate in different modalities of HIV cure studies.
Results
We recruited 409 study participants of whom 400 were eligible for the study and were included in the analysis (nine were not eligible due to self-declared HIV-negative status). We found >50% willingness to participate in 14 different types of HIV cure studies. Perceived clinical benefits and social benefits were important motivators, while personal clinical risks appeared to deter potential participation. Roughly two-thirds of survey respondents (68%) indicated that they were somewhat willing to stop treatment as part of HIV cure research. In the bivariate models, females, African Americans/blacks, Hispanics, individuals in the lowest income bracket, people living with HIV for longer periods of their lives, and people who were self-perceived âvery healthyâ were less willing to participate in certain types of HIV cure studies than others. Multivariate results showed the perceived benefits (adjusted odds ratios >1) and perceived risks (adjusted odds ratios <1) acted as potential motivators and deterrents to participation, respectively.
Conclusion
Our study is the first attempt to quantify potential motivators and deterrents of participation in HIV cure research in the US using perceived risks and benefits. The results offer guidance to HIV cure researchers and developers of interventions about the beneficial and detrimental characteristics of HIV cure strategies that are most meaningful to people living with HIV. The study also highlights new potential lines of inquiry for further social science and ethics research
Pion-Muon Asymmetry Revisited
Long ago an unexpected and unexplainable phenomena was observed. The
distribution of muons from positive pion decay at rest was anisotropic with an
excess in the backward direction relative to the direction of the proton beam
from which the pions were created. Although this effect was observed by several
different groups with pions produced by different means, the result was not
accepted by the physics community, because it is in direct conflict with a
large set of other experiments indicating that the pion is a pseudoscalar
particle. It is possible to satisfy both sets of experiments if helicity-zero
vector particles exist and the pion is such a particle. Helicity-zero vector
particles have direction but no net spin. For the neutral pion to be a vector
particle requires an additional modification to conventional theory as
discussed herein. An experiment is proposed which can prove that the asymmetry
in the distribution of muons from pion decay is a genuine physical effect
because the asymmetry can be modified in a controllable manner. A positive
result will also prove that the pion is NOT a pseudoscalar particle.Comment: 9 pages, 3 figure
The Mass Assembly History of Field Galaxies: Detection of an Evolving Mass Limit for Star Forming Galaxies
We characterize the mass-dependent evolution in a large sample of more than
8,000 galaxies using spectroscopic redshifts drawn from the DEEP2 Galaxy
Redshift Survey in the range 0.4 < z < 1.4 and stellar masses calculated from
K-band photometry obtained at Palomar Observatory. Using restframe (U-B) color
and [OII] equivalent widths, we distinguish star-forming from passive
populations in order to explore the nature of "downsizing''--a pattern in which
the sites of active star formation shift from high mass galaxies at early times
to lower mass systems at later epochs. Over the redshift range probed, we
identify a mass limit, M_Q, above which star formation appears to be quenched.
The physical mechanisms responsible for downsizing can thus be empirically
quantified by charting the evolution in this threshold mass. We find that M_Q
decreases with time by a factor of ~3 across the redshift range sampled
according with a redshift dependence of (1+z)^3.5. To further constrain
possible quenching mechanisms, we investigate how this downsizing signal
depends on local galaxy environment. For the majority of galaxies in regions
near the median density, there is no significant correlation between downsizing
and environment. However, a trend is observed in the comparison between more
extreme environments that are more than 3 times overdense or underdense
relative to the median. Here, we find that downsizing is accelerated in
overdense regions which host higher numbers of massive, early-type galaxies and
fewer late-types as compared to the underdense regions. Our results
significantly constrain recent suggestions for the origin of downsizing and
indicate that the process for quenching star formation must, primarily, be
internally driven. (Abridged)Comment: Accepted to ApJ, revised version addressing referee's comments, 23
pages, 13 figure
A systematic review of biomarkers for disease progression in Parkinson's disease
Peer reviewedPublisher PD
BMQ
BMQ: Boston Medical Quarterly was published from 1950-1966 by the Boston University School of Medicine and the Massachusetts Memorial Hospitals
Impact of the Cancer Prevention and Control Research Network: Accelerating the Translation of Research Into Practice
The Cancer Prevention and Control Research Network (CPCRN) is a thematic network dedicated to accelerating the adoption of evidence-based cancer prevention and control practices in communities by advancing dissemination and implementation science. Funded by the Centers for Disease Control and Prevention and National Cancer Institute, CPCRN has operated at two levels: Each participating Network Center conducts research projects with primarily local partners as well as multicenter collaborative research projects with state and national partners. Through multicenter collaboration, thematic networks leverage the expertise, resources, and partnerships of participating centers to conduct research projects collectively that might not be feasible individually. Although multicenter collaboration often is advocated, it is challenging to promote and assess. Using bibliometric network analysis and other graphical methods, this paper describes CPCRNâs multicenter publication progression from 2004 to 2014. Searching PubMed, Scopus, and Web of Science in 2014 identified 249 peer-reviewed CPCRN publications involving two or more centers out of 6,534 total. The research and public health impact of these multicenter collaborative projects initiated by CPCRN during that 10-year period were then examined. CPCRN established numerous workgroups around topics such as: 2-1-1, training and technical assistance, colorectal cancer control, federally qualified health centers, cancer survivorship, and human papillomavirus. The paper discusses the challenges that arise in promoting multicenter collaboration and the strategies that CPCRN uses to address those challenges. The lessons learned should broadly interest those seeking to promote multisite collaboration to address public health problems, such as cancer prevention and control
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