KamLAND Bounds on Solar Antineutrinos and neutrino transition magnetic moments

We investigate the possibility of detecting solar electron antineutrinos with the KamLAND experiment. These electron antineutrinos are predicted by spin-flavor oscillations at a significant rate even if this mechanism is not the leading solution to the SNP. KamLAND is sensitive to antineutrinos originated from solar ${}^8$B neutrinos. From KamLAND negative results after 145 days of data taking, we obtain model independent limits on the total flux of solar electron antineutrinos $\Phi({}^8 B)< 1.1-3.5\times 10^4 cm^{-2}\ s^{-1}$, more than one order of magnitude smaller than existing limits, and on their appearance probability$P<0.15%$(95antineutrino production by spin-flavor precession, this upper bound implies an upper limit on the product of the intrinsic neutrino magnetic moment and the value of the solar magnetic field$\mu B< 2.3\times 10^{-21}$MeV 95LMA$(\Delta m^2, \tan^2\theta)$values). Limits on neutrino transition moments are also obtained. For realistic values of other astrophysical solar parameters these upper limits would imply that the neutrino magnetic moment is constrained to be, in the most conservative case,$\mu\lsim 3.9\times 10^{-12} \mu_B$(95CL) for a relatively small field$B= 50$kG. For higher values of the magnetic field we obtain:$\mu\lsim 9.0\times 10^{-13} \mu_B$for field$B= 200$kG and$\mu\lsim 2.0\times 10^{-13} \mu_B$for field$B= 1000$ kG at the same statistical significance.Comment: 13 pages, 2 figure

LOFAR sparse image reconstruction

International audienceContext. The LOw Frequency ARray (LOFAR) radio telescope is a giant digital phased array interferometer with multiple antennas distributed in Europe. It provides discrete sets of Fourier components of the sky brightness. Recovering the original brightness distribution with aperture synthesis forms an inverse problem that can be solved by various deconvolution and minimization methods. Aims. Recent papers have established a clear link between the discrete nature of radio interferometry measurement and the " compressed sensing " (CS) theory, which supports sparse reconstruction methods to form an image from the measured visibilities. Empowered by proximal theory, CS offers a sound framework for efficient global minimization and sparse data representation using fast algorithms. Combined with instrumental direction-dependent effects (DDE) in the scope of a real instrument, we developed and validated a new method based on this framework. Methods. We implemented a sparse reconstruction method in the standard LOFAR imaging tool and compared the photometric and resolution performance of this new imager with that of CLEAN-based methods (CLEAN and MS-CLEAN) with simulated and real LOFAR data. Results. We show that i) sparse reconstruction performs as well as CLEAN in recovering the flux of point sources; ii) performs much better on extended objects (the root mean square error is reduced by a factor of up to 10); and iii) provides a solution with an effective angular resolution 2−3 times better than the CLEAN images. Conclusions. Sparse recovery gives a correct photometry on high dynamic and wide-field images and improved realistic structures of extended sources (of simulated and real LOFAR datasets). This sparse reconstruction method is compatible with modern interferometric imagers that handle DDE corrections (A-and W-projections) required for current and future instruments such as LOFAR and SKA

Walking, Gross Motor Development, and Brain Functional Connectivity in Infants and Toddlers

Infant gross motor development is vital to adaptive function and predictive of both cognitive outcomes and neurodevelopmental disorders. However, little is known about neural systems underlying the emergence of walking and general gross motor abilities. Using resting state fcMRI, we identified functional brain networks associated with walking and gross motor scores in a mixed cross-sectional and longitudinal cohort of infants at high and low risk for autism spectrum disorder, who represent a dimensionally distributed range of motor function. At age 12 months, functional connectivity of motor and default mode networks was correlated with walking, whereas dorsal attention and posterior cingulo-opercular networks were implicated at age 24 months. Analyses of general gross motor function also revealed involvement of motor and default mode networks at 12 and 24 months, with dorsal attention, cingulo-opercular, frontoparietal, and subcortical networks additionally implicated at 24 months. These findings suggest that changes in network-level brain-behavior relationships underlie the emergence and consolidation of walking and gross motor abilities in the toddler period. This initial description of network substrates of early gross motor development may inform hypotheses regarding neural systems contributing to typical and atypical motor outcomes, as well as neurodevelopmental disorders associated with motor dysfunction

Efeitos da aplicação de prostaglandinas intervaladas de 10 dias sobre características reprodutivas de cabras leiteiras nulíparas cíclicas

Relataram-se os efeitos da aplicação de prostaglandina sobre características reprodutivas de cabras leiteiras nulíparas cíclicas. Cabras Alpinas (n=9) e Saanen (n=9) receberam duas doses de 22,5mg PGF2a com 10 dias de intervalo. A progesterona plasmática (ng/mL) foi determinada a partir de amostras de sangue coletadas nos dias 0 (primeira dose), 5, 10 (segunda dose), 15, 20, 25 e 30. Após início do segundo estro, as fêmeas foram monitoradas por ultrassonografia transretal a cada quatro horas até oito horas após a ovulação. A gestação foi verificada por ultrassonografia transretal nos dias 20, 25, 30, 35 e 90 após a segunda dose. As características estudadas foram semelhantes entre as raças (P>0,05). Animais em estro e o intervalo parto-estro de, respectivamente, 78,9% e 50,6±17,2h e 88,9% e 50,0±14,8h após a primeira e segunda administrações de prostaglandina, não diferiram (P>0,05). Todas as cabras ovularam e registraram-se valores do intervalo parto-ovulação após a segunda aplicação de prostaglandina de 64,5±19,5h e após início do estro de 18,0±9,1h, a taxa de ovulação de 1,3±0,5 e diâmetro do folículo ovulatório de 8,1±1,1mm. Perda embrionária ocorreu antes de 30 dias de gestação. O estro pode ser eficientemente sincronizado em cabras leiteiras núliparas com duas doses de prostaglandina intervaladas de 10 dias. _________________________________________________________________________________________ ABSTRACT: This study reported the effects of prostaglandin (PGF2a) administration 10 days apart on reproductive parameters of cyclic artificial inseminated (AI) nulliparous Alpine (n=9) and Saanen (n=9) goats. Animals received two doses of 22.5mg PGF2a 10 days apart. After 1st and 2nd PGF2a administrations, estrus was monitored at 12 h intervals, with a buck teaser. Plasma progesterone concentration (ng/mL) was determined from blood sampled on day 0 (1st PGF2a) and the following 5, 10 (2nd PGF2a), 15, 20, 25 and 30 days. After the onset of the second estrus, females were transrectally (5 MHz probe) scanned at 4 hour intervals until at least 8h after ovulation. Pregnancy was checked through transrectal ultrasound on days 20, 25, 30, 35 and 90 after insemination. All parameters studied did not differ between breeds (P>0.05). Estrous response and interval to estrus, respectively, after 1st (78.9% and 50.6±17.2h) and 2nd PGF2a (88.9% and 50.0±14.8h) administration did not differ (P>0.05). Overall animals ovulating (100.0%), interval to ovulation after 2nd PGF2a (64.5±19.5h) and after estrous onset (18.0±9.1h), ovulation rate (1.3±0.5), diameter of ovulatory follicle (8.1±1.1mm) were recorded. Embryo loss occurred before day 30 of pregnancy. Estrus can be efficiently synchronized in nulliparous Alpine and Saanen goats with two doses of prostaglandin 10 days apart

A Prospective Evaluation of Infant Cerebellar-Cerebral Functional Connectivity in Relation to Behavioral Development in Autism Spectrum Disorder

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder diagnosed based on social impairment, restricted interests, and repetitive behaviors. Contemporary theories posit that cerebellar pathology contributes causally to ASD by disrupting error-based learning (EBL) during infancy. The present study represents the first test of this theory in a prospective infant sample, with potential implications for ASD detection. Methods: Data from the Infant Brain Imaging Study (n = 94, 68 male) were used to examine 6-month cerebellar functional connectivity magnetic resonance imaging in relation to later (12/24-month) ASD-associated behaviors and outcomes. Hypothesis-driven univariate analyses and machine learning–based predictive tests examined cerebellar–frontoparietal network (FPN; subserves error signaling in support of EBL) and cerebellar–default mode network (DMN; broadly implicated in ASD) connections. Cerebellar-FPN functional connectivity was used as a proxy for EBL, and cerebellar-DMN functional connectivity provided a comparative foil. Data-driven functional connectivity magnetic resonance imaging enrichment examined brain-wide behavioral associations, with post hoc tests of cerebellar connections. Results: Cerebellar-FPN and cerebellar-DMN connections did not demonstrate associations with ASD. Functional connectivity magnetic resonance imaging enrichment identified 6-month correlates of later ASD-associated behaviors in networks of a priori interest (FPN, DMN), as well as in cingulo-opercular (also implicated in error signaling) and medial visual networks. Post hoc tests did not suggest a role for cerebellar connections. Conclusions: We failed to identify cerebellar functional connectivity–based contributions to ASD. However, we observed prospective correlates of ASD-associated behaviors in networks that support EBL. Future studies may replicate and extend network-level positive results, and tests of the cerebellum may investigate brain-behavior associations at different developmental stages and/or using different neuroimaging modalities

Event-wise ⟨p\u3csub\u3et\u3c/sub\u3e⟩ fluctuations in Au-Au collisions at √s\u3csub\u3eNN\u3c/sub\u3e = 130 GeV

We present the first large-acceptance measurement of event-wise mean transverse momentum ⟨pt⟩ fluctuations for Au-Au collisions at nucleon-nucleon center-of-momentum collision energy √sNN = 130 GeV. The observed nonstatistical ⟨pt⟩ fluctuations substantially exceed in magnitude fluctuations expected from the finite number of particles produced in a typical collision. The r.m.s. fractional width excess of the event-wise ⟨pt⟩ distribution is 13.7±0.1(stat) ±1.3(syst)% relative to a statistical reference, for the 15% most-central collisions and for charged hadrons within pseudorapidity range |η|c. The width excess varies smoothly but nonmonotonically with collision centrality and does not display rapid changes with centrality which might indicate the presence of critical fluctuations. The reported ⟨pt⟩ fluctuation excess is qualitatively larger than those observed at lower energies and differs markedly from theoretical expectations. Contributions to ⟨pt⟩ fluctuations from semihard parton scattering in the initial state and dissipation in the bulk colored medium are discussed

Event-wise ⟨p\u3csub\u3et\u3c/sub\u3e⟩ fluctuations in Au-Au collisions at √s\u3csub\u3eNN\u3c/sub\u3e = 130 GeV

We present the first large-acceptance measurement of event-wise mean transverse momentum ⟨pt⟩ fluctuations for Au-Au collisions at nucleon-nucleon center-of-momentum collision energy √sNN = 130 GeV. The observed nonstatistical ⟨pt⟩ fluctuations substantially exceed in magnitude fluctuations expected from the finite number of particles produced in a typical collision. The r.m.s. fractional width excess of the event-wise ⟨pt⟩ distribution is 13.7±0.1(stat) ±1.3(syst)% relative to a statistical reference, for the 15% most-central collisions and for charged hadrons within pseudorapidity range |η|c. The width excess varies smoothly but nonmonotonically with collision centrality and does not display rapid changes with centrality which might indicate the presence of critical fluctuations. The reported ⟨pt⟩ fluctuation excess is qualitatively larger than those observed at lower energies and differs markedly from theoretical expectations. Contributions to ⟨pt⟩ fluctuations from semihard parton scattering in the initial state and dissipation in the bulk colored medium are discussed