1,982 research outputs found
Coupled quintessence and vacuum decay
We discuss observational consequences of a class of cosmological models
characterized by the dilution of pressureless matter attenuated with respect to
the usual scaling due to the decay of vacuum energy. We carry out a
joint statistical analysis of observational data from the new \emph{gold}
sample of 182 SNe Ia, recent estimates of the CMB shift parameter, and BAO
measurements from the SDSS to show that such models favor the decay of vacuum
only into the dark matter sector, and that the separately conserved baryons
cannot be neglected. In order to explore ways to more fundamentally motivated
models, we also derive a coupled scalar field version for this general class of
vacuum decay scenarios.Comment: 6 pages, 3 figures, LaTe
Methodological assessment of HCC literature
Despite the fact that the hepatocellular carcinoma (HCC) represents a major health problem, very few interventions are available for this disease, and only sorafenib is approved for the treatment of advanced disease. Of note, only very few interventions have been thoroughly evaluated over time for HCC patients compared with several hundreds in other, equally highly lethal, tumours. Additionally, clinical trials in HCC have often been questioned for poor design and methodological issues. As a consequence, a gap between what is measured in clinical trials and what clinicians have to face in daily practice often occurs. As a result of this scenario, even the most recent guidelines for treatment of HCC patients use low strength evidence to make recommendations. In this review, we will discuss some of the potential methodological issues hindering a rational development of new treatments for HCC patient
Predictors of hotel clients’ satisfaction in the Cape Verde Islands
Tourism has been fundamental for countries’ economic development, and Africa is the
destination with the biggest tourism growth potential. Using 1414 travelers’ online reviews collected
from TripAdvisor, the present work aims to understand which variables predict the satisfaction of
Cape Verde’s hotel clients. Satisfaction was analyzed using sentiment analysis and ANOVA to predict
the effect of the gathered variables on clients’ satisfaction. Results indicate that 90% of the clients
revealed positive satisfaction and that nationality, date of stay, and previous traveler experiences
affect satisfaction. Contrarily to our predictions, there is no statistically significant evidence that
gender influences satisfaction. The findings of this study will help hotel marketing managers to align
their strategies accordingly and meet their clients’ expectations.info:eu-repo/semantics/publishedVersio
a systematic review and meta-analysis
OKThere is significant evidence linking a 'reward deficiency syndrome' (RDS), comprising decreased availability of striatal dopamine D2-like receptors (DD2lR) and addiction-like behaviors underlying substance use disorders and obesity. Regarding obesity, a systematic review of the literature with a meta-analysis of such data is lacking. Following a systematic review of the literature, we performed random-effects meta-analyses to determine group differences in case-control studies comparing DD2lR between individuals with obesity and non-obese controls and prospective studies of pre- to post-bariatric surgery DD2lR changes. Cohen's d was used to measure effect size. Additionally, we explored factors potentially associated with group differences in DD2lR availability, such as obesity severity, using univariate meta-regression. In a meta-analysis including positron emission tomography (PET) and single-photon emission computed tomography (SPECT) studies, striatal DD2lR availability did not significantly differ between obesity and controls. However, in studies comprising patients with class III obesity or higher, group differences were significant, favoring lower DD2lR availability in the obesity group. This effect of obesity severity was corroborated by meta-regressions showing inverse associations between the body mass index (BMI) of the obesity group and DD2lR availability. Post-bariatric changes in DD2lR availability were not found, although a limited number of studies were included in this meta-analysis. These results support lower DD2lR in higher classes of obesity which is a more targeted population to explore unanswered questions regarding the RDS.publishersversionpublishe
Mechanistic insights into the electrochemical reduction of CO2 to CO on Ni(salphen) complexes
LA/P/0056/2020.
The NMR spectrometers are part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project No 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC).
FCT is acknowledged for PTDCQUI-QIN0252_2021 (PNM).
The CARISMA COST action CM1205 is acknowledged. MJC thanks N. A. G. Bandeira for technical assistance. The CATSUS doctoral programme is also acknowledged.
Publisher Copyright:
© 2023 The Royal Society of Chemistry.Cyclic voltammetry and bulk electrolysis showed that [Ni(ii)(salphen)] [1], [Ni(ii)(tBu-salphen)] [2], and a binuclear Ni(ii) compound combining salphen and tBu-salphen [3] react with CO2 to yield a metal-carbonyl species that is stable under an oxygen free atmosphere. Upon exposure to air, a stoichiometric amount of CO is released (detected by gas chromatography) and protonation regenerates the initial complex. To shed light on the mechanism of CO2 reduction and O2-dependent CO release by [1], UV-vis, EPR and SEC-IR spectroscopy studies complemented with DFT calculations were performed. It is proposed that the mono reduced [Ni(i)(salphen)]−, 2[1]−, formed a CO2 complex, 2[1(CO2)]−, which was then further reduced to 3[1(CO2)]2−. After addition of two protons, the coordinated CO2 was reduced to CO and released, regenerating 1[1]. Alternatively, 2[1(CO2)]− is protonated and then reduced to the same intermediate as before, continuing the same way. In the second cycle, the CO released competed with CO2 and coordinated to 2[1]− much more strongly, thereby deactivating the system. The new 2[1(CO)]− was reduced to 3[1(CO)]2− which was identified by comparison of experimental spectroscopic (UV-vis, EPR, SEC-IR) data with DFT calculated parameters.publishersversionpublishe
How the interplay between neuroscience and phenomenology changed our understanding of obsessive-compulsive disorder
The understanding of obsessive-compulsive disorder (OCD) has evolved with the knowledge of behavior, the brain, and their relationship. Modern views of OCD as a neuropsychiatric disorder originated from early lesion studies, with more recent models incorporating detailed neuropsychological findings, such as perseveration in set-shifting tasks, and findings of altered brain structure and function, namely of orbitofrontal corticostriatal circuits and their limbic connections. Interestingly, as neurobiological models of OCD evolved from cortical and cognitive to sub-cortical and behavioral, the focus of OCD phenomenology also moved from thought control and contents to new concepts rooted in animal models of action control. Most recently, the proposed analogy between habitual action control and compulsive behavior has led to the hypothesis that individuals suffering from OCD may be predisposed to rely excessively on habitual rather than on goal-directed behavioral strategies. Alternatively, compulsions have been proposed to result either from hyper-valuation of certain actions and/or their outcomes, or from excessive uncertainty in the monitoring of action performance, both leading to perseveration in prepotent actions such as washing or checking. In short, the last decades have witnessed a formidable renovation in the pathophysiology, phenomenology, and even semantics, of OCD. Nevertheless, such progress is challenged by several caveats, not least psychopathological oversimplification and overgeneralization of animal to human extrapolations. Here we present an historical overview of the understanding of OCD, highlighting converging studies and trends in neuroscience, psychiatry and neuropsychology, and how they influenced current perspectives on the nosology and phenomenology of this disorder.publishersversionpublishe
Large-scale analysis of the SDSS-III DR8 photometric luminous galaxies angular correlation function
We analyse the large-scale angular correlation function (ACF) of the CMASS
luminous galaxies (LGs), a photometric-redshift catalogue based on the Data
Release 8 (DR8) of the Sloan Digital Sky Survey-III. This catalogue contains
over LGs in the range , which was split
into four redshift shells of constant width. First, we estimate the constraints
on the redshift-space distortion (RSD) parameters and ,
where is the galaxy bias, the growth rate and is the
normalization of the perturbations, finding that they vary appreciably among
different redshift shells, in agreement with previous results using DR7 data.
When assuming constant RSD parameters over the survey redshift range, we obtain
, which agrees at the level with Baryon
Oscillation Spectroscopic Survey DR9 spectroscopic results. Next, we performed
two cosmological analyses, where relevant parameters not fitted were kept fixed
at their fiducial values. In the first analysis, we extracted the baryon
acoustic oscillation peak position for the four redshift shells, and combined
with the sound horizon scale from 7-year \textit{Wilkinson Microwave Anisotropy
Probe} to produce the constraints and
. In the second analysis, we used the ACF full shape
information to constrain cosmology using real data for the first time, finding
and .
These results are in good agreement with findings, showing that the ACF
can be efficiently applied to constrain cosmology in future photometric galaxy
surveys.Comment: MNRAS accepted. Minor corrections to match publish versio
Cross-Cultural Adaptation and Psychometric Evaluation of the Perceived Ability to Cope With Trauma Scale in Portuguese Patients With Breast Cancer
Funding: RL was supported by the 2018 Scientific Employment Stimulus from Fundação para a Ciência e Tecnologia, Portugal (CEECIND/04157/2018). DF, BS, and AO-M were supported by the BOUNCE project (grant agreement no. 777167), and AO-M was supported by the FAITH project (grant agreement no. 875358), both funded by the European Union’s Horizon 2020 Research and Innovation Programme.Background: The impact of a cancer diagnosis may be traumatic, depending on the psychological resources used by patients. Appropriate coping strategies are related to better adaptation to the disease, with coping flexibility, corresponding to the ability to replace ineffective coping strategies, demonstrated to be highly related with self-efficacy to handle trauma. The Perceived Ability to Cope with Trauma (PACT) scale is a self-rated questionnaire that assesses the perceived ability to cope with potentially traumatic events, providing a measure of coping flexibility. The current study aimed at examining the psychometric properties of the PACT Scale in Portuguese patients with breast cancer. Methods: The study included 172 patients recently diagnosed with early breast cancer. Participants completed a Portuguese version of the PACT scale, and instruments of self-efficacy for coping with cancer (Cancer Behavior Inventory-Brief Version-CBI-B), of quality of life (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core-30-QLQ-C30), and of psychological distress (Hospital Anxiety and Depression Scale-HADS) that were used as convergent and divergent measures, thus assessing construct validity. A confirmatory factor analysis (CFA) was performed to test the factor structure of the Portuguese version of PACT scale and reliabilities were examined. Results: Results from the CFA confirmed the two-factor structure, consistent with the original Forward and Trauma focus subscales. The two subscales demonstrated high internal consistencies. Convergent and divergent validities were confirmed: the PACT scale was related to high self-efficacy to cope with cancer (CBI-B), to high perceived quality of life (QLQ-C30), and to low psychological distress (HADS). Discussion: Overall, the current results support and replicate the psychometric properties of the PACT scale. The scale was found to be a valid and reliable self-reported measure to assess Portuguese breast cancer patients regarding beliefs about their capabilities in managing the potentially traumatic sequelae of cancer. The PACT is a simple and brief measure of coping flexibility to trauma, with potential relevance for application in clinical and research settings.publishersversionpublishe
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