16,681 research outputs found
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Altered expression of glutamate signaling, growth factor, and glia genes in the locus coeruleus of patients with major depression.
Several studies have proposed that brain glutamate signaling abnormalities and glial pathology have a role in the etiology of major depressive disorder (MDD). These conclusions were primarily drawn from post-mortem studies in which forebrain brain regions were examined. The locus coeruleus (LC) is the primary source of extensive noradrenergic innervation of the forebrain and as such exerts a powerful regulatory role over cognitive and affective functions, which are dysregulated in MDD. Furthermore, altered noradrenergic neurotransmission is associated with depressive symptoms and is thought to have a role in the pathophysiology of MDD. In the present study we used laser-capture microdissection (LCM) to selectively harvest LC tissue from post-mortem brains of MDD patients, patients with bipolar disorder (BPD) and from psychiatrically normal subjects. Using microarray technology we examined global patterns of gene expression. Differential mRNA expression of select candidate genes was then interrogated using quantitative real-time PCR (qPCR) and in situ hybridization (ISH). Our findings reveal multiple signaling pathway alterations in the LC of MDD but not BPD subjects. These include glutamate signaling genes, SLC1A2, SLC1A3 and GLUL, growth factor genes FGFR3 and TrkB, and several genes exclusively expressed in astroglia. Our data extend previous findings of altered glutamate, astroglial and growth factor functions in MDD for the first time to the brainstem. These findings indicate that such alterations: (1) are unique to MDD and distinguishable from BPD, and (2) affect multiple brain regions, suggesting a whole-brain dysregulation of such functions
Ultrasonic NDE of Green-State Ceramics by Focused Through-Transmission
Reliable NDE techniques for green-state (unfired) ceramics are needed (1) to evaluate ceramic powder processing and compaction methods and (2) to screen out defective ceramic components prior to the costly densification process. Past work in the application of ultrasonic NDE to green-state ceramics has been hampered by the lack of an efficient yet safe means to obtain ultrasonic coupling, since conventional coupling fluids (water, gels, oils, etc.) have a detrimental effect on fragile green-state materials. In early work, direct contact pressure was used to obtain dry coupling between transducer and specimen [1]. This approach was later improved upon by placing an elastomer membrane between the transducer and specimen; this method provided efficient coupling at significantly lower contact pressures [2]. In the study presented here, an acoustically transparent plastic membrane was held against the ceramic specimen by atmospheric pressure [3]. The advantage of this technique is that it allows the use of ultrasonic immersion techniques as well as contact transducers
CD28- cells are increased in early rheumatoid arthritis and are linked with cytomegalovirus status
Objective: CD3+CD8+CD28− cells are higher in Rheumatoid Arthritis (RA). The aim of this study was to assess CD3+CD8+CD28− cells in patients with early RA and assess the effects of cytomegalovirus (CMV) seropositivity.
Method: In this prospective observation study, 50 RA patients were recruited from Cardiff University Hospital of Wales (UHW) rheumatology outpatient, 25 patients with early disease (disease duration 0–6 months) and 25 patients with established disease (>2 years). These were compared with 25 healthy controls. Clinical and serological markers of inflammation were noted, and peripheral blood mononuclear cells were analyzed using flow cytometry.
Results: The percentage of the CD8+CD28− T cells was increased in RA patients and was associated with disease duration. The percentage of CD8+CD28− T cells was increased in CMV positive early and established RA grouped and early RA patients in comparison to CMV negative patients (p < 0.05). There is a weak but statistically significant correlation between the percentage of CD3+CD8+CD28− cells and CRP in CMV positive RA patients (r = 0.227, p < 0.05).
Conclusion: The percentage of CD8+CD28− T cells is higher in RA patients and correlates with disease duration, highlighting a potential role early in the disease process. These cells were also higher in CMV positive early RA patients which may suggest a role of CMV in disease development
Dynamics of Quantum Vorticity in a Random Potential
I study the dynamics of a superfluid vortex in a random potential, as in the
inner crust of a neutron star. Below a critical flow velocity of the ambient
superfluid, a vortex is effectively immobilized by lattice forces even in the
limit of zero dissipation. Low-velocity, translatory motion is not dynamically
possible, a result with important implications for understanding neutron star
precession and the dynamical properties of superfluid nuclear matter.Comment: Physical Review Letters, final versio
Inclusive Scattering of Polarized Electrons on Polarized 3He Effects of Final State Interaction and the Magnetic Form Factor of the Neutron
Effects of final state interaction on asymmetries in inclusive scattering of
polarized electrons on polarized 3He are investigated using consistent 3He
bound state wave function and 3N continuum scattering states. Significant
effects are found, which influence the extraction of the magnetic neutron form
factor from A_T'. The enhancement found experimentally for A_TL' near the 3N
breakup threshold, which could not be explained in calculations carried through
in plane wave impulse approximation up to now, occurs now also in theory if the
full final state interaction is included.Comment: 29 pages, 5 figure
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Project-Based Organizing and Strategic Management: A Long-Term Research Agenda on Temporary Organizational Forms
The last several years have witnessed a growing scholarly interest in project-based organizations. This interest mirrors the diffusion of this organizational form across a wide range of industries, well beyond those where organizations have been traditionally organized by projects. To date, however, research on project based organizations has not yet offered a systematic investigation of the interactions between project-based organizing and strategic management research. An examination of the existing literature indicates that some of the answers to key strategy questions remain incomplete, at times contradictory, and at best ambiguous. This volume moves the discussion to the next level by offering a comprehensive yet integrated view of cutting edge research on project-based organizing to shed light on some of these ambiguities and clarify the relationship between project-based organizing and strategic management. To accomplish this, the volume includes the contributions of several leading scholars who have been active researchers on this subject. The articles develop and extend key strategic aspects of project-based organizing, raise many new important questions, and identify fruitful areas for future research
Highly unusual triangular crystals of theophylline: The influence of solvent on the growth rates of polar crystal faces
A noteworthy feature of the compound theophylline is that it forms crystals with a triangular habit, an extremely rare phenomenon for an organic molecule. Here, we investigate the formation of these crystals, comprised of the polymorph Form II (Pna21), and demonstrate that the triangles are obtained from solvents which are highly hydrophobic, or which have a hydrogen bond acceptor group and no hydrogen bond donor group. The formation of the triangular crystal habit is rationalized on the basis of the way such solvents interact with the inequivalent (001) and (00-1) polar crystal faces of Form II. Interactions are significantly stronger at one face than the other, inhibiting growth in one direction and limiting crystal growth to a single, triangle shaped, growth sector. This rationalization also enabled interesting surface features observed by atomic force microscopy to be interpreted. Furthermore, we report a second, previously unreported, type of triangular crystal of theophylline for which the angle at the tip of the triangle is obtuse rather than acute. These crystals are proposed, with the aid of transmission electron microscopy and crystal structure prediction, to be a new polymorphic form of theophyllin
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