226 research outputs found
Exclusive Electro-Disintegration of 3He at high Q2: II. Decay Function Formalism
Based on the theoretical framework of generalized eikonal approximation we
study the two-nucleon emission reactions in high electro-disintegration
of . Main aim is to investigate those features of the reaction which can
be unambiguously identified with the short range properties of the ground state
nuclear wave function. To evaluate the differential cross section we work in
the formalism of the decay function which characterizes the property of the
ground state wave function as well as the decay properties of final two nucleon
spectator system. Our main motivation here is to explore the accessibility of
two-- and three--nucleon short range correlations in He as well as to
isolate unambiguously single and double rescattering processes in the reaction
dynamics. Our analysis allowed us also to identify new approaches for
investigating the role of the practically unknown three-nucleon forces in the
ground state wave function of .Comment: 37 pages, 28 figure
Prevalence of Adverse Childhood Experiences in the First Decade of Life: A Study in the Portuguese Cohort, Generation XXI
Adverse childhood experiences (ACEs) are a modifiable risk factor for diseases throughout life. This study estimates the prevalence of ACEs in children, addressing associated sociodemographic characteristics and examining the relationship of ACEs with the child’s health and behaviors. We used information on 5295 participants at 10 years old, of the birth cohort Generation XXI, established in Porto, Portugal. Children answered a self-administered questionnaire on ACEs, based on the original ACEs study. Principal component analysis was used to group correlated ACEs, and a score was computed to assess their cumulative effect. Overall, 96.2% of children reported having been exposed to at least one ACE. The most prevalent ACE was a household member shouting, yelling, or screaming at the child (57.7%). Boys were more likely than girls to report “abuse”, “school problems”, and “death/severe disease”. Low parental education, income, and unemployment were associated with an increased risk of “school problems”, “death/severe disease”, and “household dysfunction”. We observed that the dimensions of ACEs could be identified at 10 years of age. A disadvantaged socioeconomic environment was associated with dimensions of ACEs. These data illustrate the natural history of dimensions of ACEs and their potential social patterning.This work was supported by the European Regional Development Fund (ERDF) through the Operational Programme Competitiveness and Internationalization and national funding from the Foundation for Science and Technology (FCT), Portuguese Ministry of Science, Technology and Higher Education under the projects “BioAdversity: How childhood social adversity shapes health: The biology of social adversity” (POCI-01-0145-FEDER-016838; PTDC/DTP-EPI/1687/2014), “HIneC: When do health inequalities start? Understanding the impact of childhood social adversity on health trajectories from birth to early adolescence” (POCI-01-0145-FEDER-029567; PTDC/SAU-PUB/29567/2017) and “STEPACHE: The pediatric roots of amplified pain: from contextual influences to risk stratification” (POCI-01-0145-FEDER-029087; PTDC/SAU-EPI/29087/2017). It is also supported by the Unidade de Investigação em Epidemiologia—Instituto de Saúde Pública da Universidade do Porto (EPIUnit) (UIDB/04750/2020) and Laboratório para a Investigação Integrativa e Translacional em Saúde Populacional (ITR) (LA/P/0064/2020), Administração Regional de Saúde Norte (Regional Department of Ministry of Health) and Fundação Calouste Gulbenkian; PhD Grant SFRH/BD/144503/2019 (to AA) funded by FCT through Fundo Social Europeu (FSE) and CEECIND/01516/2017 (to SF)
APEX: A Prime EXperiment at Jefferson Lab
APEX is an experiment at Thomas Jefferson National Accelerator Facility
(JLab) in Virginia, USA, that searches for a new gauge boson () with
sub-GeV mass and coupling to ordinary matter of . Electrons impinge upon a fixed target of high-Z material. An
is produced via a process analogous to photon bremsstrahlung,
decaying to an pair. A test run was held in July of 2010, covering
= 175 to 250 MeV and couplings g^\prime/e \; \textgreater \;
10^{-3}. A full run is approved and will cover 65 to 525
MeV and g^\prime/e \; \textgreater \; 2.3 \times10^{-4}.Comment: Contributed to the 8th Patras Workshop on Axions, WIMPs and WISPs,
Chicago, July 18-22, 2012. 4 pages, 4 figure
Adaptable history biases in human perceptual decisions
When making choices under conditions of perceptual uncertainty, past experience can play a vital role. However, it can also lead to biases that worsen decisions. Consistent with previous observations, we found that human choices are influenced by the success or failure of past choices even in a standard two-alternative detection task, where choice history is irrelevant. The typical bias was one that made the subject switch choices after a failure. These choice history biases led to poorer performance and were similar for observers in different countries. They were well captured by a simple logistic regression model that had been previously applied to describe psychophysical performance in mice. Such irrational biases seem at odds with the principles of reinforcement learning, which would predict exquisite adaptability to choice history. We therefore asked whether subjects could adapt their irrational biases following changes in trial order statistics. Adaptability was strong in the direction that confirmed a subject's default biases, but weaker in the opposite direction, so that existing biases could not be eradicated. We conclude that humans can adapt choice history biases, but cannot easily overcome existing biases even if irrational in the current context: adaptation is more sensitive to confirmatory than contradictory statistics
Adverse childhood experiences and bodily pain at 10 years of age: Findings from the Generation XXI cohort
Background: Youth and young adults with pain conditions report having a history of adverse childhood experiences (ACEs) more frequently than their healthy peers. The relationship between ACEs and pain before adolescence in population-based settings is not extensively researched. Objective: To examine the association between the history of ACEs and bodily pain at 10 years of age. Participants and setting: Cross-sectional analysis of 4738 participants of Generation XXI population-based birth cohort, recruited in 2005–06 in Porto, Portugal. Methods: Study includes self-reported data on ACEs exposures and bodily pain (pain presence, sites, and intensity a week prior to the interview). Adjusted odds ratios (AOR) and 95% confidence intervals (CI) were obtained from binary and multinomial logistic regression analyses to estimate the likelihood of various pain features according to the extent of exposure to ACEs (i.e., 0 ACEs, 1–3 ACEs, 4–5 ACEs, and ≥ 6 ACEs). Results: Prevalence of pain, multisite, and high-intensity pain a week prior to the interview increased with increasing exposure to ACEs. After controlling for sociodemographic characteristics, children who had experienced ≥6 ACEs were more likely to report pain [AOR 3.18 (95% CI 2.19, 4.74)], multisite pain [AOR 2.45 (95% CI 1.37, 4.40)], and high-intensity pain [AOR 4.27 (95% CI 2.56, 7.12)] compared with children with no ACEs. Conclusions: A dose-response association was observed between the cumulative number of ACEs and reports of pain in 10-year-old children, suggesting that embodiment of ACEs starts as early as childhood and that pain related to ACEs begins earlier than previously reported. © 2022 Elsevier LtdFunding text 1: This work was supported by the European Regional Development Fund (ERDF) through the Operational Programme Competitiveness and Internationalization and national funding from the Foundation for Science and Technology (FCT), Portuguese Ministry of Science, Technology and Higher Education under the projects “HIneC: When do health inequalities start? Understanding the impact of childhood social adversity on health trajectories from birth to early adolescence” ( POCI-01-0145-FEDER-029567 ; PTDC/SAU-PUB/29567/2017 ) and “STEPACHE: The pediatric roots of amplified pain: from contextual influences to risk stratification” ( POCI-01-0145-FEDER-029087 ; PTDC/SAU-EPI/29087/2017 ). It is also supported by Unidade de Investigação em Epidemiologia - Instituto de Saúde Pública da Universidade do Porto (EPIUnit) ( UIDB/04750/2020 ), Laboratório para a Investigação Integrativa e Translacional (ITR), Porto, Portugal ( LA/P/0064/2020 ), PhD Grant SFRH/BD/144503/2019 (to AA) funded by FCT through Fundo Social Europeu (FSE) and FCT Investigator contract CEECIND/01516/2017 (to SF). ; Funding text 2: This work was supported by the European Regional Development Fund (ERDF) through the Operational Programme Competitiveness and Internationalization and national funding from the Foundation for Science and Technology (FCT), Portuguese Ministry of Science, Technology and Higher Education under the projects “HIneC: When do health inequalities start? Understanding the impact of childhood social adversity on health trajectories from birth to early adolescence” (POCI-01-0145-FEDER-029567; PTDC/SAU-PUB/29567/2017) and “STEPACHE: The pediatric roots of amplified pain: from contextual influences to risk stratification” (POCI-01-0145-FEDER-029087; PTDC/SAU-EPI/29087/2017). It is also supported by Unidade de Investigação em Epidemiologia - Instituto de Saúde Pública da Universidade do Porto (EPIUnit) (UIDB/04750/2020), Laboratório para a Investigação Integrativa e Translacional (ITR), Porto, Portugal (LA/P/0064/2020), PhD Grant SFRH/BD/144503/2019 (to AA) funded by FCT through Fundo Social Europeu (FSE) and FCT Investigator contract CEECIND/01516/2017 (to SF)
Initial Stage of Star Formation
Abstract In frame of the hydrodynamics wh irlwind mechanis m of b ipolar outflow formation fro m disk system the data of observations of active starburst region a dense molecular cloud of Orion KL in H 2 O maser rad iation is analyzed. It is shown that the theory as a first appro ximation exp lains the basic observant laws of active region, structure accompanying protostar formation: a disk-a b ipolar outflo w, includ ing its mechanis m ejection and self-collimation, excitation maser radiat ion
Understanding urbanicity: how interdisciplinary methods help to unravel the effects of the city on mental health
Twenty-first century urbanization poses increasing challenges for mental health. Epidemiological studies have shown that mental health problems often accumulate in urban areas, compared to rural areas, and suggested possible underlying causes associated with the social and physical urban environments. Emerging work indicates complex urban effects that depend on many individual and contextual factors at neighbourhood and country level and novel experimental work is starting to dissect potential underlying mechanisms. This review summarizes findings from epidemiology and population- based studies, neuroscience, experimental, and experience-based research and illustrates how a combined approach can move the field towards an increased understanding of the urbanicity-mental health nexus
Low-excitation blobs in the Magellanic Clouds
Aims : We study an unknown, or very poorly known, interstellar HII component
in the Magellanic Clouds. This is the first study ever devoted to this class of
objects, which we call Low-excitation blobs (LEBs).
Methods : We used low-dispersion spectroscopy carried out at ESO to obtain
emission line intensities of Ha, Hb, and [OIII] (4959+5007) for 15 objects in
the Large Magellanic Cloud and 14 objects in the Small Magellanic Cloud.
Results are displayed in excitation ([oiii]/Hb ratio) versus Hb luminosity
diagrams.
Results : We show the presence of an LEB component in the Magellanic Clouds
and study its relationship with the already known class of high-excitation
blobs (HEBs). The newly found LEBs are lower excitation counterparts of HEBs
and are powered by less massive exciting stars. Further study of LEBs is
expected to provide new pieces of information for a better understanding the
low mass end of the upper initial mass function in the Magellanic Clouds.Comment: Accepted in A&
Search for a new gauge boson in the Experiment (APEX)
We present a search at Jefferson Laboratory for new forces mediated by
sub-GeV vector bosons with weak coupling to electrons. Such a
particle can be produced in electron-nucleus fixed-target scattering and
then decay to an pair, producing a narrow resonance in the QED trident
spectrum. Using APEX test run data, we searched in the mass range 175--250 MeV,
found no evidence for an reaction, and set an upper limit of
. Our findings demonstrate that fixed-target
searches can explore a new, wide, and important range of masses and couplings
for sub-GeV forces.Comment: 5 pages, 5 figures, references adde
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