The Egyptian Cardiothoracic Surgeon (ECTS - E-Journal)
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Density functional theory studies of MTSL nitroxide side chain conformations attached to an activation loop
No full textA quantum mechanical (QM) method rooted on density functional theory (DFT) has been employed to determine conformations of the methane-thiosulfonate spin label (MTSL) attached to a fragment extracted from the activation loop of Aurora-A kinase. The features of the calculated energy surface revealed low energy barriers between isoenergetic minima, and the system could be described in a population of 76 rotamers that can be also considered for other systems since it was found that the χ3, χ4 and χ5 do not depend on the previous two dihedral angles. Conformational states obtained were seen to be comparable to those obtained in the α-helix systems studied previously, indicating that the protein backbone does not affect the torsional profiles significantly and suggesting the possibility to use determined conformations for other protein systems for further modelling studies
Differential Group Delay of the Frequency Following Response Measured Vertically and Horizontally
No full textThe frequency following response (FFR) arises from the sustained neural activity of a population of neurons that are phase locked to periodic acoustic stimuli. Determining the source of the FFR noninvasively may be useful for understanding the function of phase locking in the auditory pathway to the temporal envelope and fine structure of sounds. The current study compared the FFR recorded with a horizontally aligned (mastoid-to-mastoid) electrode montage and a vertically aligned (forehead-to-neck) electrode montage. Unlike previous studies, envelope and fine structure latencies were derived simultaneously from the same narrowband stimuli to minimize differences in cochlear delay. Stimuli were five amplitude-modulated tones centered at 576 Hz, each with a different modulation rate, resulting in different side-band frequencies across stimulus conditions. Changes in response phase across modulation frequency and side-band frequency (group delay) were used to determine the latency of the FFR reflecting phase locking to the envelope and temporal fine structure, respectively. For the FFR reflecting phase locking to the temporal fine structure, the horizontal montage had a shorter group delay than the vertical montage, suggesting an earlier generation source within the auditory pathway. For the FFR reflecting phase locking to the envelope, group delay was longer than that for the fine structure FFR, and no significant difference in group delay was found between montages. However, it is possible that multiple sources of FFR (including the cochlear microphonic) were recorded by each montage, complicating interpretations of the group delay
Multibeam bathymetric survey of the Ipala Submarine Canyon, Jalisco, Mexico (20°N):The southern boundary of the Banderas Forearc Block?
No full textThe Middle America Trench bends sharply northward at 20°N. This, along with the close proximity of the Rivera-North America Euler pole to the northern end of this trench, sharply increases the obliquity of subduction at 20°N. By analogy with other subduction zones with similar sharply changing obliquity, significant trench parallel extension is expected to exist in the forearc region near the bend. To evaluate this possibility, multibeam bathymetric, seafloor backscatter and sub-bottom seismic reflection data were collected in this area during the MORTIC08 campaign of the B.O. El Puma. These data image in detail a large submarine canyon (the Ipala Canyon) extending from the coast at 20°05'N to the Middle America Trench at 19°50'N. This canyon is 114 km long and is fed by sediments originating from two, possibly three, small rivers: the Ipala, Tecolotlán and Maria Garza. This canyon deeply incises (up to 600 m) the entire continental slope and at least the outer part of the shelf. Within the canyon, we observe meanders and narrow channels produced by turbidity flows indicating that the canyon is active. In the marginal areas of the canyon slumps, rills, and uplifts suggest that mass movements and fluid flow have had a major impact on the seafloor morphology. The seafloor bathymetry, backscatter images and sub-bottom reflection profiles evidence the tectonic processes occurring in this area. Of particular interest, the canyon is deflected by almost 90° at three locations, the deflections all having a similar azimuth of between 125° and 130°. Given the prominence and geometry of this canyon, along with its tectonic setting, we propose that the presence of the canyon is related to extension produced by the sharp change in the plate convergence. If so, the canyon may lie along the southeast boundary of a major forearc block (the Banderas Forearc Block).</p
IL-4-producing ILC2s are required for the differentiation of TH2 cells following Heligmosomoides polygyrus infection.
No full textImmunity to many human and murine gastrointestinal helminth parasites requires interleukin-4 (IL-4)-directed type 2 helper (TH2) differentiation of CD4(+) T cells to elicit type-2 immunity. Despite a good understanding of the inflammatory cascade elicited following helminth infection, the initial source of IL-4 is unclear. Previous studies using the rat helminth parasite Nippostronglyus brasiliensis, identified an important role for basophil-derived IL-4 for TH2 differentiation. However, basophils are redundant for TH2 differentiation following infection with the natural helminth parasite of mice Heligmosomoides polygyrus, indicating that other sources of IL-4 are required. In this study using H. polygyrus, which is controlled by IL-4-dependent immunity, we identified that group-2 innate lymphoid cells (ILC2s) produced significant amounts of IL-4 and IL-2 following H. polygyrus infection. Leukotriene D4 was sufficient to stimulate IL-4 secretion by ILC2s, and the supernatant from activated ILC2s could potently drive TH2 differentiation in vitro in an IL-4-dependent manner. Furthermore, specific deletion of IL-4 from ILC2s compromised TH2 differentiation in vivo. Overall, this study highlights a previously unrecognized and important role for ILC2-derived IL-4 for TH2 differentiation in a natural TH2-dependent model of human helminthiasis.Mucosal Immunology advance online publication 17 February 2016. doi:10.1038/mi.2016.4
Towards political participation and capacity: elections, voting and representation in early modern Scotland
No full textBuilding democratic capacity within an accountable governance model presents a challenge in many states, and Western efforts to impose forms of parliamentary government often fails because of the broader democratic deficit within the political cultures of those states. Historians can offer some insight into the evolution of that capacity by examining societies in the past where forms of election, voting and representation were present, and where those practices led ultimately to the formation of political cultures in which democratic forms of government has deep roots.This paper examines the electoral and voting practices along with different forms of elected representatives in Scotland between the mid-sixteenth and the mid-eighteenth centuries.Types of practice are identified in relation to parliament, the law courts, church courts and burgh councils.The paper establishes a powerful indigenous tradition distinct from that of England that contributed to the wider evolution of governance in Great Britain and the British colonial possessions in North America. The discussion underlines the importance of deep-rooted and long-established electoral, voting and representative ideas in forming political cultures with high participation and resilient capacity
