Cosmic ray muon charge ratio in the MINOS far detector

The MINOS Far Detector is a 5.4 kiloton (5.2 kt steel plus 0.2 kt scintillator plus aluminum skin) magnetized tracking calorimeter located 710 meters underground in the Soudan mine in Northern Minnesota. MINOS is the first large, deep underground detector with a magnetic field and thus capable of making measurements of the momentum and charge of cosmic ray muons. Despite encountering unexpected anomalies in distributions of the charge ratio (N{sub {mu}{sup +}}/N{sub {mu}{sup -}}) of cosmic muons, a method of canceling systematic errors is proposed and demonstrated. The result is R{sub eff} = 1.346 {+-} 0.002 (stat) {+-} 0.016 (syst) for the averaged charge ratio, and a result for a rising fit to slant depth of R(X) = 1.300 {+-} 0.008 (stat) {+-} 0.016 (syst) + (1.8 {+-} 0.3) x 10{sup -5} x X, valid over the range of slant depths from 2000 < X < 6000 MWE. This slant depth range corresponds to minimum surface muon energies between 750 GeV and 5 TeV

Herniation Pits in Human Mummies: A CT Investigation in the Capuchin Catacombs of Palermo, Sicily

Herniation pits (HPs) of the femoral neck were first described in a radiological publication in 1982 as round to oval radiolucencies in the proximal superior quadrant of the femoral neck on anteroposterior radiographs of adults. In following early clinical publications, HPs were generally recognized as an incidental finding. In contrast, in current clinical literature they are mentioned in the context of femoroacetabular impingement (FAI) of the hip joint, which is known to cause osteoarthritis (OA). The significance of HPs in chronic skeletal disorders such as OA is still unclear, but they are discussed as a possible radiological indicator for FAI in a large part of clinical studies

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Differential Resting-State Functional Connectivity of Striatal Subregions in Bipolar Depression and Hypomania

Bipolar disorder (BP) is characterized by periods of depression (BPD) and (hypo)mania (BPM), but the underlying state-related brain circuit abnormalities are not fully understood. Striatal functional activation and connectivity abnormalities have been noted in BP, but consistent findings have not been reported. To further elucidate striatal abnormalities in different BP states, this study investigated differences in resting-state functional connectivity of six striatal subregions in BPD, BPM, and healthy control (HC) subjects. Ninety medication-free subjects (30 BPD, 30 BPM, and 30 HC), closely matched for age and gender, were scanned using 3T functional magnetic resonance imaging (fMRI) acquired at resting state. Correlations of low-frequency blood oxygen level dependent signal fluctuations for six previously described striatal subregions were used to obtain connectivity maps of each subregion. Using a factorial design, main effects for differences between groups were obtained and post hoc pairwise group comparisons performed. BPD showed increased connectivity of the dorsal caudal putamen with somatosensory areas such as the insula and temporal gyrus. BPM group showed unique increased connectivity between left dorsal caudate and midbrain regions, as well as increased connectivity between ventral striatum inferior and thalamus. In addition, both BPD and BPM exhibited widespread functional connectivity abnormalities between striatal subregions and frontal cortices, limbic regions, and midbrain structures. In summary, BPD exhibited connectivity abnormalities of associative and somatosensory subregions of the putamen, while BPM exhibited connectivity abnormalities of associative and limbic caudate. Most other striatal subregion connectivity abnormalities were common to both groups and may be trait related

Distortion Correction in EPI Using an Extended PSF Method with a Reversed Phase Gradient Approach

In echo-planar imaging (EPI), such as commonly used for functional MRI (fMRI) and diffusion-tensor imaging (DTI), compressed distortion is a more difficult challenge than local stretching as spatial information can be lost in strongly compressed areas. In addition, the effects are more severe at ultra-high field (UHF) such as 7T due to increased field inhomogeneity. To resolve this problem, two EPIs with opposite phase-encoding (PE) polarity were acquired and combined after distortion correction. For distortion correction, a point spread function (PSF) mapping method was chosen due to its high correction accuracy and extended to perform distortion correction of both EPIs with opposite PE polarity thus reducing the PSF reference scan time. Because the amount of spatial information differs between the opposite PE datasets, the method was further extended to incorporate a weighted combination of the two distortion-corrected images to maximize the spatial information content of a final corrected image. The correction accuracy of the proposed method was evaluated in distortion-corrected data using both forward and reverse phase-encoded PSF reference data and compared with the reversed gradient approaches suggested previously. Further we demonstrate that the extended PSF method with an improved weighted combination can recover local distortions and spatial information loss and be applied successfully not only to spin-echo EPI, but also to gradient-echo EPIs acquired with both PE directions to perform geometrically accurate image reconstruction

Resting State Brain Network Disturbances Related to Hypomania and Depression in Medication-Free Bipolar Disorder

Research on resting functional brain networks in bipolar disorder (BP) has been unable to differentiate between disturbances related to mania or depression, which is necessary to understand the mechanisms leading to each state. Past research has also been unable to elucidate the impact of BP-related network disturbances on the organizational properties of the brain (eg, communication efficiency). Thus, the present work sought to isolate network disturbances related to BP, fractionate these into components associated with manic and depressive symptoms, and characterize the impact of disturbances on network function. Graph theory was used to analyze resting functional magnetic resonance imaging data from 60 medication-free patients meeting the criteria for BP and either a current hypomanic (n=30) or depressed (n=30) episode and 30 closely age/sex-matched healthy controls. Correction for multiple comparisons was carried out. Compared with controls, BP patients evidenced hyperconnectivity in a network involving right amygdala. Fractionation revealed that (hypo)manic symptoms were associated with hyperconnectivity in an overlapping network and disruptions in the brain's ‘small-world' network organization. Depressive symptoms predicted hyperconnectivity in a network involving orbitofrontal cortex along with a less resilient global network organization. Findings provide deeper insight into the differential pathophysiological processes associated with hypomania and depression, along with the particular impact these differential processes have on network function

The EPI-PSF kernel based weighting maps and the ratio map in GE- (I) and SE-EPIs (II): two weighting maps, <i>W</i>_<i>f</i>(<i>s</i>) (a) and <i>W</i>_<i>r</i>(<i>s</i>) (b), are calculated respectively from the forward and reverse EPI-PSF kernel using Eq. 6 and the ratio (c) is shown in logarithmic scale using the equation log_e(<i>W</i>_<i>f</i>(<i>s</i>)/<i>W</i>_<i>r</i>(<i>s</i>)).

<p>The EPI-PSF kernel based weighting maps and the ratio map in GE- (I) and SE-EPIs (II): two weighting maps, <i>W</i>_<i>f</i>(<i>s</i>) (a) and <i>W</i>_<i>r</i>(<i>s</i>) (b), are calculated respectively from the forward and reverse EPI-PSF kernel using <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116320#pone.0116320.e006" target="_blank">Eq. 6</a> and the ratio (c) is shown in logarithmic scale using the equation log_e(<i>W</i>_<i>f</i>(<i>s</i>)/<i>W</i>_<i>r</i>(<i>s</i>)).</p

A diagram of extension of the PSF data from a single (for example, forward) PSF reference data: (a) measured forward 3D PSF data set, distortion-free (top) and distorted (right) reference images calculated respectively by Eqs. 2 and 3, (front) 2D PSF image in <i>y-s</i> plane at selected fixed <i>x</i>; (b) an expansion image from a small portion of the 2D PSF image in (a); (c) procedure of inversion of the 2D PSF image along the <i>y</i>-direction in the <i>s</i>-coordinates with respect to the diagonal line; (d) mirrored 2D PSF image; (e) an extended PSF data corresponding to the reverse PSF data.

<p>Finally, two EPI-PSF kernels for distortion correction (DiCo) in the both EPIs are calculated from the forward and extended PSF data.</p