104 research outputs found
Phase Motion in the Scalar Low-Mass pi+pi- Amplitude in D+ -> pi-pi+pi+ Decay
Applying the Amplitude Difference method to Fermilab experiment E791 D+ ->
pi-pi+pi+ data, we measure the low mass pi+pi- phase motion. Our results
suggest a significant phase variation, compatible with the existence of an
isoscalar sigma(500) meson, as previously reported using an isobar model fit to
the full Dalitz-plot density.Comment: 12 pages, 8 figures Accepted for publication at PL
The structure of from charmed mesons decays
We use the QCD sum rules to evaluate the form factors associated with the
semileptonic decays of and mesons into . We consider the
meson as a quark-antiquark state with a mixture of strange and light
components. The decay rates are evaluated in terms of the mixing angle. Using
the same form factors to evaluate nonleptonic decays in the framework of the
factorization approximation we conclude that the importance of the light quarks
in is not negligible.Comment: 11 pages, 2 figures, using Revtex
Trinity: An Air-Shower Imaging Instrument to detect Ultrahigh Energy Neutrinos
Trinity is a proposed air-shower imaging system optimized for the detection
of earth-skimming ultrahigh energy tau neutrinos with energies between
GeV and GeV. Trinity will pursue three major scientific objectives.
1) It will narrow in on possible source classes responsible for the
astrophysical neutrino flux measured by IceCube. 2) It will help find the
sources of ultrahigh-energy cosmic rays (UHECR) and understand the composition
of UHECR. 3) It will test fundamental neutrino physics at the highest energies.
Trinity uses the imaging technique, which is well established and successfully
used by the very high-energy gamma-ray community (CTA, H.E.S.S., MAGIC, and
VERITAS) and the UHECR community (Telescope Array, Pierre Auger
A common brain network among state, trait, and pathological anxiety from whole-brain functional connectivity
Anxiety is one of the most common mental states of humans. Although it drives us to avoid frightening situations and to achieve our goals, it may also impose significant suffering and burden if it becomes extreme. Because we experience anxiety in a variety of forms, previous studies investigated neural substrates of anxiety in a variety of ways. These studies revealed that individuals with high state, trait, or pathological anxiety showed altered neural substrates. However, no studies have directly investigated whether the different dimensions of anxiety share a common neural substrate, despite its theoretical and practical importance. Here, we investigated a brain network of anxiety shared by different dimensions of anxiety in a unified analytical framework using functional magnetic resonance imaging (fMRI). We analyzed different datasets in a single scale, which was defined by an anxiety-related brain network derived from whole brain. We first conducted the anxiety provocation task with healthy participants who tended to feel anxiety related to obsessive-compulsive disorder (OCD) in their daily life. We found a common state anxiety brain network across participants (1585 trials obtained from 10 participants). Then, using the resting-state fMRI in combination with the participants' behavioral trait anxiety scale scores (879 participants from the Human Connectome Project), we demonstrated that trait anxiety shared the same brain network as state anxiety. Furthermore, the brain network between common to state and trait anxiety could detect patients with OCD, which is characterized by pathological anxiety-driven behaviors (174 participants from multi-site datasets). Our findings provide direct evidence that different dimensions of anxiety have a substantial biological inter-relationship. Our results also provide a biologically defined dimension of anxiety, which may promote further investigation of various human characteristics, including psychiatric disorders, from the perspective of anxiety
Brain structural covariance networks in obsessive-compulsive disorder: a graph analysis from the ENIGMA Consortium.
Brain structural covariance networks reflect covariation in morphology of different brain areas and are thought to reflect common trajectories in brain development and maturation. Large-scale investigation of structural covariance networks in obsessive-compulsive disorder (OCD) may provide clues to the pathophysiology of this neurodevelopmental disorder. Using T1-weighted MRI scans acquired from 1616 individuals with OCD and 1463 healthy controls across 37 datasets participating in the ENIGMA-OCD Working Group, we calculated intra-individual brain structural covariance networks (using the bilaterally-averaged values of 33 cortical surface areas, 33 cortical thickness values, and six subcortical volumes), in which edge weights were proportional to the similarity between two brain morphological features in terms of deviation from healthy controls (i.e. z-score transformed). Global networks were characterized using measures of network segregation (clustering and modularity), network integration (global efficiency), and their balance (small-worldness), and their community membership was assessed. Hub profiling of regional networks was undertaken using measures of betweenness, closeness, and eigenvector centrality. Individually calculated network measures were integrated across the 37 datasets using a meta-analytical approach. These network measures were summated across the network density range of K = 0.10-0.25 per participant, and were integrated across the 37 datasets using a meta-analytical approach. Compared with healthy controls, at a global level, the structural covariance networks of OCD showed lower clustering (P < 0.0001), lower modularity (P < 0.0001), and lower small-worldness (P = 0.017). Detection of community membership emphasized lower network segregation in OCD compared to healthy controls. At the regional level, there were lower (rank-transformed) centrality values in OCD for volume of caudate nucleus and thalamus, and surface area of paracentral cortex, indicative of altered distribution of brain hubs. Centrality of cingulate and orbito-frontal as well as other brain areas was associated with OCD illness duration, suggesting greater involvement of these brain areas with illness chronicity. In summary, the findings of this study, the largest brain structural covariance study of OCD to date, point to a less segregated organization of structural covariance networks in OCD, and reorganization of brain hubs. The segregation findings suggest a possible signature of altered brain morphometry in OCD, while the hub findings point to OCD-related alterations in trajectories of brain development and maturation, particularly in cingulate and orbitofrontal regions
Distinct subcortical volume alterations in pediatric and adult OCD: a worldwide meta- and mega-analysis
Objective: structural brain imaging studies in obsessive compulsive disorder (OCD) have produced inconsistent findings. This may be partially due to limited statistical power from relatively small samples and clinical heterogeneity related to variation in illness profile and developmental stage. To address these limitations, the authors conducted meta and mega-analyses of data from OCD sites worldwide. Method: T-1 images from 1,830 OCD patients and 1,759 control subjects were analyzed, using coordinated and standardized processing, to identify subcortical brain volumes that differ between OCD patients and healthy subjects. The authors performed a meta analysis on the mean of the left and right hemisphere measures of each subcortical structure, and they performed a mega-analysis by pooling these volumetric measurements from each site. The authors additionally examined potential modulating effects of clinical characteristics on morphological differences in OCD patients. Results: the meta-analysis indicated that adult patients had significantly smaller hippocampal volumes (Cohen's d=-0.13; % difference=-2.80) and larger pallidum volumes (d=0.16; % difference=3.16) compared with adult controls. Both effects were stronger in medicated patients compared with controls (d=-0.29, % difference=-4.18, and d=0.29, % difference=4.38, respectively). Unmedicated pediatric patients had significantly larger thalamic volumes (d=0.38, % difference=3.08) compared with pediatric controls. None of these findings were mediated by sample characteristics, such as mean age or scanning field strength. The mega-analysis yielded similar results. Conclusions: the results indicate different patterns of sub cortical abnormalities in pediatric and adult OCD patients. The patlidum and hippocampus seem to be of importance in adult OCD, whereas the thalamus seems to be key in pediatric OCD. These findings highlight the potential importance of neurodevelopmental alterations in OCD and suggest that further research on neuroplasticity in OCD may be useful
From colorectal cancer pattern to the characterization of individuals at risk: Picture for genetic research in Latin America
Colorectal cancer (CRC) is one of the most common cancers in Latin America and the Caribbean, with the highest rates reported for Uruguay, Brazil and Argentina. We provide a global snapshot of the CRC patterns, how screening is performed, and compared/contrasted to the genetic profile of Lynch syndrome (LS) in the region. From the literature, we find that only nine (20%) of the Latin America and the Caribbean countries have developed guidelines for early detection of CRC, and also with a low adherence. We describe a genetic profile of LS, including a total of 2,685 suspected families, where confirmed LS ranged from 8% in Uruguay and Argentina to 60% in Peru. Among confirmed LS, path_MLH1 variants were most commonly identified in Peru (82%), Mexico (80%), Chile (60%), and path_MSH2/EPCAM variants were most frequently identified in Colombia (80%) and Argentina (47%). Path_MSH6 and path_PMS2 variants were less common, but they showed important presence in Brazil (15%) and Chile (10%), respectively. Important differences exist at identifying LS families in Latin American countries, where the spectrum of path_MLH1 and path_MSH2 variants are those most frequently identified. Our findings have an impact on the evaluation of the patients and their relatives at risk for LS, derived from the gene affected. Although the awareness of hereditary cancer and genetic testing has improved in the last decade, it is remains deficient, with 39%–80% of the families not being identified for LS among those who actually met both the clinical criteria for LS and showed MMR deficiency.Fil: Vaccaro, Carlos Alberto. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: López Kostner, Francisco. No especifíca;Fil: Adriana, Della Valle. Hospital Fuerzas Armadas; UruguayFil: Inez Palmero, Edenir. Hospital de cáncer de Barretos, FACISB; BrasilFil: Rossi, Benedito Mauro. Hospital Sirio Libanes; BrasilFil: Antelo, Marina. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; Argentina. Universidad Nacional de Lanús; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Solano, Angela Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Carraro, Dirce Maria. No especifíca;Fil: Forones, Nora Manoukian. Universidade Federal de Sao Paulo; BrasilFil: Bohorquez, Mabel. Universidad del Tolima; ColombiaFil: Lino Silva, Leonardo S.. Instituto Nacional de Cancerologia; MéxicoFil: Buleje, Jose. Universidad de San Martín de Porres; PerúFil: Spirandelli, Florencia. No especifíca;Fil: Abe Sandes, Kiyoko. Universidade Federal da Bahia; BrasilFil: Nascimento, Ivana. No especifíca;Fil: Sullcahuaman, Yasser. Universidad Peruana de Ciencias Aplicadas; Perú. Instituto de Investigación Genomica; PerúFil: Sarroca, Carlos. Hospital Fuerzas Armadas; UruguayFil: Gonzalez, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional e Ingeniería Biomédica - Hospital Italiano. Instituto de Medicina Traslacional e Ingeniería Biomédica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e Ingeniería Biomédica; ArgentinaFil: Herrando, Alberto Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional e Ingeniería Biomédica - Hospital Italiano. Instituto de Medicina Traslacional e Ingeniería Biomédica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e Ingeniería Biomédica; ArgentinaFil: Alvarez, Karin. No especifíca;Fil: Neffa, Florencia. Hospital Fuerzas Armadas; UruguayFil: Galvão, Henrique Camposreis. Barretos Cancer Hospital; BrasilFil: Esperon, Patricia. Hospital Fuerzas Armadas; UruguayFil: Golubicki, Mariano. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Cisterna, Daniel. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Cardoso, Florencia C.. Centro de Educación Medica E Invest.clinicas; ArgentinaFil: Tardin Torrezan, Giovana. No especifíca;Fil: Aguiar Junior, Samuel. No especifíca;Fil: Aparecida Marques Pimenta, Célia. Universidade Federal de Sao Paulo; BrasilFil: Nirvana da Cruz Formiga, María. No especifíca;Fil: Santos, Erika. Hospital Sirio Libanes; BrasilFil: Sá, Caroline U.. Hospital Sirio Libanes; BrasilFil: Oliveira, Edite P.. Hospital Sirio Libanes; BrasilFil: Fujita, Ricardo. Universidad de San Martín de Porres; PerúFil: Spirandelli, Enrique. No especifíca;Fil: Jimenez, Geiner. No especifíca;Fil: Santa Cruz Guindalini, Rodrigo. Universidade de Sao Paulo; BrasilFil: Gondim Meira Velame de Azevedo, Renata. No especifíca;Fil: Souza Mario Bueno, Larissa. Universidade Federal da Bahia; BrasilFil: dos Santos Nogueira, Sonia Tereza. No especifíca;Fil: Piñero, Tamara Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional e Ingeniería Biomédica - Hospital Italiano. Instituto de Medicina Traslacional e Ingeniería Biomédica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e Ingeniería Biomédica; Argentin
Cerebrospinal Fluid Space Alterations in Melancholic Depression
Melancholic depression is a biologically homogeneous clinical entity in which structural brain alterations have been described. Interestingly, reports of structural alterations in melancholia include volume increases in Cerebro-Spinal Fluid (CSF) spaces. However, there are no previous reports of CSF volume alterations using automated whole-brain voxel-wise approaches, as tissue classification algorithms have been traditionally regarded as less reliable for CSF segmentation. Here we aimed to assess CSF volumetric alterations in melancholic depression and their clinical correlates by means of a novel segmentation algorithm (‘new segment’, as implemented in the software Statistical Parametric Mapping-SPM8), incorporating specific features that may improve CSF segmentation. A three-dimensional Magnetic Resonance Image (MRI) was obtained from seventy patients with melancholic depression and forty healthy control subjects. Although imaging data were pre-processed with the ‘new segment’ algorithm, in order to obtain a comparison with previous segmentation approaches, tissue segmentation was also performed with the ‘unified segmentation’ approach. Melancholic patients showed a CSF volume increase in the region of the left Sylvian fissure, and a CSF volume decrease in the subarachnoid spaces surrounding medial and lateral parietal cortices. Furthermore, CSF increases in the left Sylvian fissure were negatively correlated with the reduction percentage of depressive symptoms at discharge. None of these results were replicated with the ‘unified segmentation’ approach. By contrast, between-group differences in the left Sylvian fissure were replicated with a non-automated quantification of the CSF content of this region. Left Sylvian fissure alterations reported here are in agreement with previous findings from non-automated CSF assessments, and also with other reports of gray and white matter insular alterations in depressive samples using automated approaches. The reliable characterization of CSF alterations may help in the comprehensive characterization of brain structural abnormalities in psychiatric samples and in the development of etiopathogenic hypotheses relating to the disorders
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