N-body U and K matrix program

Computer program was devised to compute free-fall trajectories of satellites, allowing for injection errors and midcourse velocity perturbations. Program consists of trajectory perturbing program and N-body integrating conic program which can also be used as 2-body patch conic program

X-ray line tomography of AGN-induced motion in clusters of galaxies

The thermal broadening of emission lines of heavy ions is small enough such that Doppler shifts due to bulk motions may be detected with the next generation of X-ray observatories. This opens up the possibility to study gas velocities in the intra-cluster medium. Here we study the effect of bulk motions induced by a central active galactic nucleus (AGN) on the emission lines around the FeXXV complex. We have modelled the evolution of AGN-induced bubbles in a realistic cosmological framework and studied the resulting FeXXV line profiles. We found that in clusters with AGN feedback, motions induced by the inflation of bubbles and their buoyant rise lead to distinct features in the iron emission lines that are detectable with a spectral resolution of about 10 eV. These observations will help to determine the mechanical energy that resides in the bubbles and thereby the kinetic luminosity of the AGN.Comment: to appear in Ap

Applications of Multivariate Pattern Classification Analyses in Developmental Neuroimaging of Healthy and Clinical Populations

Analyses of functional and structural imaging data typically involve testing hypotheses at each voxel in the brain. However, it is often the case that distributed spatial patterns may be a more appropriate metric for discriminating between conditions or groups. Multivariate pattern analysis has been gaining traction in neuroimaging of adult healthy and clinical populations; studies have shown that information present in neuroimaging data can be used to decode intentions and perceptual states, as well as discriminate between healthy and diseased brains. While few studies to date have applied these methods in pediatric populations, in this review we discuss exciting potential applications for studying both healthy, and aberrant, brain development. We include an overview of methods and discussion of challenges and limitations

Impact of mentoring on socio�emotional and mental health outcomes of youth with learning disabilities and attention�deficit hyperactivity disorder

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151880/1/camh12331_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151880/2/camh12331.pd

Impact of mentoring on socio‐emotional and mental health outcomes of youth with learning disabilities and attention‐deficit hyperactivity disorder

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151880/1/camh12331_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151880/2/camh12331.pd

Aberrant Neural Function During Emotion Attribution in Female Subjects With Fragile X Syndrome

Objective: Fragile X (FraX) syndrome is caused by mutations of the FraX mental retardation-1 gene—a gene responsible for producing FraX mental retardation protein. The neurocognitive phenotype associated with FraX in female subjects includes increased risk for emotional disorders including social anxiety, depression, and attention deficit. Here, the authors investigated the neurobiological systems underlying emotion attribution in female subjects with FraX syndrome. Method: While undergoing functional magnetic resonance imaging, 10 high-functioning female subjects with FraX syndrome and 10 typically developing (TD) female subjects were presented with photographs of happy, sad, and neutral faces and instructed to determine the facial emotion. Results: No significant group differences were found for the recognition of happy faces, although the FraX group showed a trend toward a significant difference for the recognition of sad faces and significantly poorer recognition of neutral faces. Controlling for between-group differences in IQ and performance accuracy, the TD group had greater activation than the FraX group in the anterior cingulate cortex (ACC) for neutral faces compared with scrambled faces and the caudate for sad faces compared with scrambled faces (but not for sad faces compared with neutral faces). In the FraX group, FraX mental retardation protein levels positively correlated with activation in the dorsal ACC for neutral, happy, and sad faces when independently compared with scrambled faces. Significantly greater negative correlation between IQ and insula activation for neutral faces relative to scrambled faces was observed in the FraX group compared with the TD group. Significantly greater positive correlation between IQ and ACC activation for neutral faces relative to scrambled faces was observed in the TD group compared with the FraX group. Conclusions: Although emotion recognition is generally spared in FraX syndrome, the emotion circuit (i.e., ACC, caudate, insula) that modulates emotional responses to facial stimuli may be disrupted

The Fossil Phase in the Life of a Galaxy Group

We investigate the origin and evolution of fossil groups in a concordance LCDM cosmological simulation. We consider haloes with masses between (1-5)\times10^{13} \hMsun and study the physical mechanisms that lead to the formation of the large gap in magnitude between the brightest and the second most bright group member, which is typical for these fossil systems. Fossil groups are found to have high dark matter concentrations, which we can relate to their early formation time. The large magnitude-gaps arise after the groups have build up half of their final mass, due to merging of massive group members. We show that the existence of fossil systems is primarily driven by the relatively early infall of massive satellites, and that we do not find a strong environmental dependence for these systems. In addition, we find tentative evidence for fossil group satellites falling in on orbits with typically lower angular momentum, which might lead to a more efficient merger onto the host. We find a population of groups at higher redshifts that go through a ``fossil phase'': a stage where they show a large magnitude-gap, which is terminated by renewed infall from their environment.Comment: 9 pages and 8 figures, submitted to MNRA

The local adsorption structure of benzene on Si(001)-(2 × 1): a photoelectron diffraction investigation

Scanned-energy mode C 1s photoelectron diffraction has been used to investigate the local adsorption geometry of benzene on Si(001) at saturation coverage and room temperature. The results show that two different local bonding geometries coexist, namely the 'standard butterfly' (SB) and 'tilted bridge' (TB) forms, with a composition of 58 ± 29% of the SB species. Detailed structural parameter values are presented for both species including Si–C bond lengths. On the basis of published measurements of the rate of conversion of the SB to the TB form on this surface, we estimate that the timescale of our experiment is sufficient for achieving equilibrium, and in this case our results indicate that the difference in the Gibbs free energy of adsorption, ΔG(TB)−ΔG(SB), is in the range −0.023 to +0.049 eV. We suggest, however, that the relative concentration of the two species may also be influenced by a combination of steric effects influencing the kinetics, and a sensitivity of the adsorption energies of the adsorbed SB and TB forms to the nature of the surrounding benzene molecules

Do alterations in pulmonary vascular tone result in changes in central blood volumes? An experimental study:An experimental study

BACKGROUND: The effects of selective pulmonary vascular tone alterations on cardiac preload have not been previously examined. Therefore, we evaluated whether changing pulmonary vascular tone either by hypoxia or the inhalation of aerosolized prostacyclin (PGI(2)) altered intrathoracic or pulmonary blood volume (ITBV, PBV, respectively), both as surrogate for left ventricular preload. Additionally, the mean systemic filling pressure analogue (Pmsa) and pressure for venous return (Pvr) were calculated as surrogate of right ventricular preload. METHODS: In a randomized controlled animal study in 6 spontaneously breathing dogs, pulmonary vascular tone was increased by controlled moderate hypoxia (FiO(2) about 0.10) and decreased by aerosolized PGI(2). Also, inhalation of PGI(2) was instituted to induce pulmonary vasodilation during normoxia and hypoxia. PBV, ITBV and circulating blood volume (Vd(circ)) were measured using transpulmonary thermo-dye dilution. Pmsa and Pvr were calculated post hoc. Either the Wilcoxon-signed rank test or Friedman ANOVA test was performed. RESULTS: During hypoxia, mean pulmonary artery pressure (PAP) increased from median [IQR] 12 [8–15] to 19 [17–25] mmHg (p < 0.05). ITBV, PBV and their ratio with Vd(circ) remained unaltered, which was also true for Pmsa, Pvr and cardiac output. PGI(2) co-inhalation during hypoxia normalized mean PAP to 13 (12–16) mmHg (p < 0.05), but left cardiac preload surrogates unaltered. PGI(2) inhalation during normoxia further decreased mean PAP to 10 (9–13) mmHg (p < 0.05) without changing any of the other investigated hemodynamic variables. CONCLUSIONS: In spontaneously breathing dogs, changes in pulmonary vascular tone altered PAP but had no effect on cardiac output, central blood volumes or their relation to circulating blood volume, nor on Pmsa and Pvr. These observations suggest that cardiac preload is preserved despite substantial alterations in right ventricular afterload