Prevalence and factors associated with depression and depression-related healthcare access in mothers of 9-month old infants in the Republic of Ireland

Aims.Untreated maternal depression during the postpartum period can have a profound impact on the short- and long-term psychological and physical well-being of children. There is, therefore, an imperative for increased understanding of the determinants of depression and depression-related healthcare access during this period.Methods.Respondents were 11 089 mothers of 9-month-old infants recruited to the Growing Up in Ireland study. Of this sample, 10 827 had complete data on all relevant variables. Respondents provided sociodemographic, socioeconomic and household information, and completed the Center for Epidemiologic Studies Depression Scale (CESD).Results.11.1% of mothers scored above the CESD threshold for depression. 10.0% of depressed mothers and 25.4% of depressed fathers had depressed partners. Among depressed mothers, 73.1% had not attended a healthcare professional for a mental health problem since the birth of the cohort infant. In the adjusted model, the likelihood of depression was highest in mothers who: had lower educational levels (odds ratio (OR) 1.26; 95% confidence intervals (CIs) 1.08, 1.46); were unemployed (OR 1.27; 95% CIs 1.10, 1.47); reported previous mental health problems (OR 6.55; 95% CIs 5.68, 7.56); reported that the cohort child was the result of an unintended pregnancy (OR 1.43; 95% CIs 1.22, 1.68), was preterm (OR 1.35; 95% CIs 1.07, 1.70), or had health/developmental problems (OR 1.20; 95% CIs 1.04, 1.39); had no partner in the household (OR 1.33; 95% CIs 1.04, 1.70) or were living with a depressed partner (OR 2.66; 95% CIs 1.97, 3.60); reported no family living nearby (OR 1.33; 95% CIs 1.16, 1.54); were in the lowest income group (OR 1.60; 95% CIs 1.21, 2.12). The primary determinant of not seeking treatment for depression was being of non-white ethnicity (OR 2.21; 95% CIs 1.18, 4.13).Conclusions.Results highlight the prevalence of maternal depression in the later postpartum period, particularly for lower socioeconomic groups, those with previous mental health problems, and those with limited social support. The large proportion of unmet need in depressed mothers, particularly among ethnic minority groups, emphasises the need for a greater awareness of postpartum mental health problems and increased efforts by healthcare professionals to ensure that mothers can access the required services.</jats:sec

Gravitational waves from galaxy encounters

We discuss the emission of gravitational radiation produced in encounters of dark matter galactic halos. To this aim we perform a number of numerical simulations of typical galaxy mergers, computing the associated gravitational radiation waveforms as well as the energy released in the processes. Our simulations yield dimensionless gravitational wave amplitudes of the order of $10^{-13}$ and gravitational wave frequencies of the order of $10^{-16}$ Hz, when the galaxies are located at a distance of 10 Mpc. These values are of the same order as those arising in the gravitational radiation originated by strong variations of the gravitational field in the early Universe, and therefore, such gravitational waves cannot be directly observed by ground-based detectors. We discuss the feasibility of an indirect detection by means of the B-mode polarization of the Cosmic Microwave Background (CMB) induced by such waves. Our results show that the gravitational waves from encounters of dark matter galactic halos leave much too small an imprint on the CMB polarization to be actually observed with ongoing and future missions.Comment: 9 pages with revtex style, 3 ps figures; to be published in Physical Review

Detection and Estimation Theory

Contains reports on theses completed and four research projects.Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E

A perturbative solution for gravitational waves in quadratic gravity

We find a gravitational wave solution to the linearized version of quadratic gravity by adding successive perturbations to the Einstein's linearized field equations. We show that only the Ricci squared quadratic invariant contributes to give a different solution of those found in Einstein's general relativity. The perturbative solution is written as a power series in the $\beta$ parameter, the coefficient of the Ricci squared term in the quadratic gravitational action. We also show that, for monochromatic waves of a given angular frequency $\omega$, the perturbative solution can be summed out to give an exact solution to linearized version of quadratic gravity, for $0<\omega<c/\mid\beta\mid^{1/2}$. This result may lead to implications to the predictions for gravitational wave backgrounds of cosmological origin.Comment: 9 pages, to appear in CQ

Investigations of the Oligocene-Miocene opening of the Ligurian Basin using amphibious refraction seismic data

The Ligurian Basin is located north-west of Corsica at the transition from the western Alpine orogen to the Apennine system. The Back-arc basin was generated by the southeast trench retreat of the Apennines-Calabrian-Maghrebides subduction zone. The opening took place from late Oligocene to Miocene. While the extension led to extreme continental thinning and un-roofing of mantle material little is known about the style of back-arc rifting. To shed light on the present day crustal and lithospheric architecture of the Ligurian Basin, active seismic data have been recorded on short period ocean bottom seismometers in the framework of SPP2017 4D-MB, the German component of AlpArray. Two refraction seismic profiles were shot across and along the centre of the Ligurian Basin. P01 was shot in an E-W direction from the Gulf of Lion to Corsica. The profile extends onshore Corsica to image the necking zone of continental thinning. P02 is a transect along the basin in NE-SW direction extending a previous shot seismic profile reaching to the Italian cost near Genua. The majority of the ocean bottom seismometer data show sedimentary and crustal phases of good quality and weaker in amplitude mantle phases to offsets up to 70 km. The arrivals of seismic phases were picked and inverted in a travel time tomography. The results for p01 show a crust-mantle boundary in the central basin at ~12 km depth below sea surface. The crust-mantle boundary deepens from ~12 km to ~18 km within 25 - 30 km towards Corsica. The results do not map an axial valley as expected for oceanic spreading. However, an extremely thinned continental crust indicates a long-lasting rifting process that possibly did not initiate oceanic spreading before the opening of the Ligurian Basin stopped. This is in good agreement with recent kinematic modelling performed in the second phase of the SPP2017 4D-MB. The modelling results of p01 indicate that continental crust can be stretched over several million years when the opening rate is low, i.e. <2 mm/year, and syn-rift sedimentation rate is high. Subduction initiation could occur in ultra-thinned continental crust as basin inversion has been observed at the northern Ligurian margin as a result of the African-European convergence. Additionally, the observations from the Ligurian Basin might be transferred to the evolution of the Piemont-Liguro Ocean. So far oceanic crust was assumed as initial conditions for the subduction of the Piemont-Liguro Ocean. An ultra-thin continental crust as initial condition would explain the observed thin subducted Piemont-Liguro plate which seemed to be thinner than 6-7 km oceanic crust. Further, a dry continental crust could explain why no back-arc volcanism was observed. The along-basin profile p02 shows a deepening crust-mantle boundary from 11 to 13 km. Based on the retrieved velocity model, gravity modelling and further results from surrounding studies we conclude that the continental crust is thinning from the northeast to the southwest which is related to the increase of extension away from the rotation pole of the anticlockwise rotation of the Corsica-Sardinia block. It remains unclear if at the southern end of the profile the mantle is overlain directly by sediments or by extremely thinned continental crust of up to 2.5 km thickness. The results however document, that seafloor spreading and the formation of mantle-derived oceanic crust was not initiated during the extension of the Ligurian Basin

Thermal history of the plasma and high-frequency gravitons

Possible deviations from a radiation-dominated evolution, occurring prior the synthesis of light nuclei, impacted on the spectral energy density of high-frequency gravitons. For a systematic scrutiny of this situation, the $\Lambda$CDM paradigm must be complemented by (at least two) physical parameters describing, respectively, a threshold frequency and a slope. The supplementary frequency scale sets the lower border of a high-frequency domain where the spectral energy grows with a slope which depends, predominantly, upon the total sound speed of the plasma right after inflation. While the infra-red region of the graviton energy spectrum is nearly scale-invariant, the expected signals for typical frequencies larger than 0.01 nHz are hereby analyzed in a model-independent framework by requiring that the total sound speed of the post-inflationary plasma be smaller than the speed of light. Current (e.g. low-frequency) upper limits on the tensor power spectra (determined from the combined analysis of the three large-scale data sets) are shown to be compatible with a detectable signal in the frequency range of wide-band interferometers. In the present context, the scrutiny of the early evolution of the sound speed of the plasma can then be mapped onto a reliable strategy of parameter extraction including not only the well established cosmological observables but also the forthcoming data from wide band interferometers.Comment: 47 pages, 31 included figures, to appear in Classical and Quantum Gravit

Optimal Location of Two Laser-interferometric Detectors for Gravitational Wave Backgrounds at 100 MHz

Recently, observational searches for gravitational wave background (GWB) have been developed and given constraints on the energy density of GWB in a broad range of frequencies. These constraints have already resulted in the rejection of some theoretical models of relatively large GWB spectra. However, at 100 MHz, there is no strict upper limit from direct observation, though an indirect limit exists due to He4 abundance due to big-bang nucleosynthesis. In our previous paper, we investigated the detector designs that can effectively respond to GW at high frequencies, where the wavelength of GW is comparable to the size of a detector, and found that the configuration, a so-called synchronous-recycling interferometer is best at these sensitivity. In this paper, we investigated the optimal location of two synchronous-recycling interferometers and derived their cross-correlation sensitivity to GWB. We found that the sensitivity is nearly optimized and hardly changed if two coaligned detectors are located within a range 0.2 m, and that the sensitivity achievable in an experiment is far below compared with the constraint previously obtained in experiments.Comment: 17 pages, 6 figure

Acceleration disturbances and requirements for ASTROD I

ASTRODynamical Space Test of Relativity using Optical Devices I (ASTROD I) mainly aims at testing relativistic gravity and measuring the solar-system parameters with high precision, by carrying out laser ranging between a spacecraft in a solar orbit and ground stations. In order to achieve these goals, the magnitude of the total acceleration disturbance of the proof mass has to be less than 10&#8722;13 m s&#8722;2 Hz&#8722;1/2 at 0.1 m Hz. In this paper, we give a preliminary overview of the sources and magnitude of acceleration disturbances that could arise in the ASTROD I proof mass. Based on the estimates of the acceleration disturbances and by assuming a simple controlloop model, we infer requirements for ASTROD I. Our estimates show that most of the requirements for ASTROD I can be relaxed in comparison with Laser Interferometer Space Antenna (LISA).Comment: 19 pages, two figures, accepted for publication by Class. Quantum Grav. (at press

The relation between school leadership from a distributed perspective and teachers' organizational commitment: examining the source of the leadership function

Purpose: In this study the relationship between school leadership and teachers’ organizational commitment is examined by taking into account a distributed leadership perspective. The relation between teachers’ organizational commitment and contextual variables of teachers’ perceptions of the quality and the source of the supportive and supervisory leadership function, participative decision making, and cooperation within the leadership team are examined. Research Design: A survey was set up involving 1,522 teachers from 46 large secondary schools in Flanders (Belgium). Because the data in the present study have an inherent hierarchical structure, that is, teachers are nested into schools, hierarchical linear modeling techniques are applied. Findings: The analyses reveal that 9% of the variance in teachers’ organizational commitment is attributable to differences between schools. Teachers’ organizational commitment is mainly related to quality of the supportive leadership, cooperation within the leadership team, and participative decision making. Who performed the supportive leadership function plays only a marginally significant positive role. The quality of the supervisory leadership function and the role of the leadership team members in this function were not significantly related to teachers’ organizational commitment. Conclusions: The implications of the findings are that to promote teachers’ organizational commitment teachers should feel supported by their leadership team and that this leadership team should be characterized by group cohesion, role clarity, and goal orientedness. Recommendations for further research are provided

Spectral Optical Monitoring of the Narrow Line Seyfert 1 galaxy Ark 564

We present the results of a long-term (1999--2010) spectral optical monitoring campaign of the active galactic nucleus (AGN) Ark 564, which shows a strong Fe II line emission in the optical. This AGN is a narrow line Seyfert 1 (NLS1) galaxies, a group of AGNs with specific spectral characteristics. We analyze the light curves of the permitted Ha, Hb, optical Fe II line fluxes, and the continuum flux in order to search for a time lag between them. Additionally, in order to estimate the contribution of iron lines from different multiplets, we fit the Hb and Fe II lines with a sum of Gaussian components. We found that during the monitoring period the spectral variation (F_max/F_min) of Ark 564 was between 1.5 for Ha to 1.8 for the Fe II lines. The correlation between the Fe II and Hb flux variations is of higher significance than that of Ha and Hb (whose correlation is almost absent). The permitted-line profiles are Lorentzian-like, and did not change shape during the monitoring period. We investigated, in detail, the optical Fe II emission and found different degrees of correlation between the Fe II emission arising from different spectral multiplets and the continuum flux. The relatively weak and different degrees of correlations between permitted lines and continuum fluxes indicate a rather complex source of ionization of the broad line emission region.Comment: Accepted for publication in ApJ