375 research outputs found
Rapid-acting antidepressant drugs modulate affective bias in rats
How rapid-acting antidepressants (RAADs), such as ketamine, induce immediate and sustained improvements in mood in patients with major depressive disorder (MDD) is poorly understood. A core feature of MDD is the prevalence of cognitive processing biases associated with negative affective states, and the alleviation of negative affective biases may be an index of response to drug treatment. Here, we used an affective bias behavioral test in rats, based on an associative learning task, to investigate the effects of RAADs. To generate an affective bias, animals learned to associate two different digging substrates with a food reward in the presence or absence of an affective state manipulation. A choice between the two reward-associated digging substrates was used to quantify the affective bias generated. Acute treatment with the RAADs ketamine, scopolamine, or psilocybin selectively attenuated a negative affective bias in the affective bias test. Low, but not high, doses of ketamine and psilocybin reversed the valence of the negative affective bias 24 hours after RAAD treatment. Only treatment with psilocybin, but not ketamine or scopolamine, led to a positive affective bias that was dependent on new learning and memory formation. The relearning effects of ketamine were dependent on protein synthesis localized to the rat medial prefrontal cortex and could be modulated by cue reactivation, consistent with experience-dependent neural plasticity. These findings suggest a neuropsychological mechanism that may explain both the acute and sustained effects of RAADs, potentially linking their effects on neural plasticity with affective bias modulation in a rodent model
Marketing technology for adoption by small business
The adoption of technology for marketing is essential for the survival of small businesses and yet little is understood about owner-manager practice in this area. This paper aims to address that gap through a qualitative study of 24 owner-managed small businesses operating in the visitor economy. It found that there was a strong appetite for the adoption of technology for marketing and a clear recognition of its opportunities particularly related to how it could create a stronger market orientation and more agile marketing, adhering to the principles of effectual reasoning. However, the ability to take advantage of these opportunities was constrained by a lack of knowledge and in particular an inability to measure the return on investment. While the wider implications of the study are limited by the niche sample, a planning model for the adoption of technology for marketing is presented which can be tested through future research
Tektin 2 is required for central spindle microtubule organization and the completion of cytokinesis
During anaphase, the nonkinetochore microtubules in the spindle midzone become compacted into the central spindle, a structure which is required to both initiate and complete cytokinesis. We show that Tektin 2 (Tek2) associates with the spindle poles throughout mitosis, organizes the spindle midzone microtubules during anaphase, and assembles into the midbody matrix surrounding the compacted midzone microtubules during cytokinesis. Tek2 small interfering RNA (siRNA) disrupts central spindle organization and proper localization of MKLP1, PRC1, and Aurora B to the midzone and prevents the formation of a midbody matrix. Video microscopy revealed that loss of Tek2 results in binucleate cell formation by aberrant fusion of daughter cells after cytokinesis. Although a myosin II inhibitor, blebbistatin, prevents actin-myosin contractility, the microtubules of the central spindle are compacted. Strikingly, Tek2 siRNA abolishes this actin-myosin–independent midzone microtubule compaction. Thus, Tek2-dependent organization of the central spindle during anaphase is essential for proper midbody formation and the segregation of daughter cells after cytokinesis
Evaluation of Dynamic Cell Processes and Behavior Using Video Bioinformatics Tools
Just as body language can reveal a person’s state of well-being, dynamic changes in cell behavior and
morphology can be used to monitor processes in cultured cells. This chapter discusses how CL-Quant
software, a commercially available video bioinformatics tool, can be used to extract quantitative data on:
(1) growth/proliferation, (2) cell and colony migration, (3) reactive oxygen species (ROS) production, and
(4) neural differentiation. Protocols created using CL-Quant were used to analyze both single cells and
colonies. Time-lapse experiments in which different cell types were subjected to various chemical
exposures were done using Nikon BioStations. Proliferation rate was measured in human embryonic stem
cell colonies by quantifying colony area (pixels) and in single cells by measuring confluency (pixels).
Colony and single cell migration were studied by measuring total displacement (distance between the
starting and ending points) and total distance traveled by the colonies/cells. To quantify ROS production,
cells were pre-loaded with MitoSOX Red™, a mitochondrial ROS (superoxide) indicator, treated with
various chemicals, then total intensity of the red fluorescence was measured in each frame. Lastly, neural
stem cells were incubated in differentiation medium for 12 days, and time lapse images were collected
daily. Differentiation of neural stem cells was quantified using a protocol that detects young neurons. CLQuant
software can be used to evaluate biological processes in living cells, and the protocols developed in
this project can be applied to basic research and toxicological studies, or to monitor quality control in
culture facilities
Long-term efficacy and tolerability of TNFα inhibitors in the treatment of non-infectious ocular inflammation:an 8-year prospective surveillance study
BACKGROUND/AIM: To report the efficacy and tolerability of antitumour necrosis factor-alpha therapy (TNF inhibitors [TNFi]) in the management of non-infectious ocular inflammation, including uveitis and scleritis, in adult patients over an 8-year period. MATERIALS AND METHODS: This is a prospective cohort study of infliximab and adalimumab in the treatment of non-infectious ocular inflammatory disease. 43 of 85 adult patients on TNFi (34 infliximab, 9 adalimumab) for ≥1 year with non-infectious uveitis or scleritis were followed from 2006 to 2014. Clinical assessments, medication, adverse events and history of steroid rescues were collected at 6 monthly intervals. General quality of life (Short Form Health Survey (SF-36)) and visual quality of life (Vision-related quality of life Core Measure (VCM1)) were assessed annually. Outcome measures included rate of sustained remission, rate of relapse, systemic corticosteroid reduction, adverse events, and VCM1 and SF-36 scores. RESULTS: The median time on infliximab was 3.2 years (IQR 4.3) and on adalimumab was 2.4 years (IQR 1.8). Sustained remission was induced in 39 patients (91%) (0.5 per patient year) after a median of 1.2 years on a TNFi. 22 (51%) experienced one relapse, and 5 (12%) had two relapses. 23 (54%) had at least one adverse event; serious adverse events necessitating hospitalisation or cessation of medication occurred in four (9%) patients. 10 patients (23%) switched from the initiation of TNFi, at 1.7 years after starting, to another TNFi or another class of biologic therapy. CONCLUSION: TNFi treatment is associated with long-term drug-induced remission of ocular inflammation, visual stability and corticosteroid reduction. Adverse events were common and no new safety signals occurred. Relapse of inflammation occurs in half of the treated population
Rethinking the employability of international graduate migrants: reflections on the experiences of Zimbabweans with degrees from England
The last decade has seen the rise of literatures that have focused on the rapid expansion of the numbers of international students in higher education globally and the growing policy discourse around improving graduate employability. However, both, inevitably, have limitations. Together, they tend to homogenise international learners and see them narrowly as simply economic actors. More recently, however, there have been signs of important new developments in both literatures, drawing on interactive employability and capability accounts that stress both agency and structure in more satisfactory ways. We seek to further the development of an account that bridges the new wave of student mobility research and the capability-employability account. In doing so, we offer two further elements to the literature. First, we aim to bridge the gap between international higher education accounts and those of migration and diasporic studies. Second, we deliberately focus on a group that is marginal to the mainstream discourse but who are migrants that have engaged in international higher education in order to improve their labour market prospects, amongst other motivations. We do this through examining the stories of five Zimbabweans who embarked on additional higher educational studies in England after migrating to the country. Through this unique approach, we offer an important new perspective on how the debates on international higher education, employability and migration can be taken forward through closer articulation between these accounts
Joint Resummation for Higgs Production
We study the application of the joint resummation formalism to Higgs
production via gluon-gluon fusion at the LHC, defining inverse transforms by
analytic continuation. We work at next-to-leading logarithmic accuracy. We find
that at low Q_T the resummed Higgs Q_T distributions are comparable in the
joint and pure-Q_T formalisms, with relatively small influence from threshold
enhancement in this range. We find a modest (about ten percent) decrease in the
inclusive cross section, relative to pure threshold resummation.Comment: 22 pages, LaTeX, 5 figures as eps file
p16(INK4a) Prevents Centrosome Dysfunction and Genomic Instability in Primary Cells
Aneuploidy, frequently observed in premalignant lesions, disrupts gene dosage and contributes to neoplastic progression. Theodor Boveri hypothesized nearly 100 years ago that aneuploidy was due to an increase in centrosome number (multipolar mitoses) and the resultant abnormal segregation of chromosomes. We performed immunocytochemistry, quantitative immunofluorescence, karyotypic analysis, and time-lapse microscopy on primary human diploid epithelial cells and fibroblasts to better understand the mechanism involved in the production of supernumerary centrosomes (more than two microtubule nucleating bodies) to directly demonstrate that the presence of supernumerary centrosomes in genomically intact cells generates aneuploid daughter cells. We show that loss of p16(INK4a) generates supernumerary centrosomes through centriole pair splitting. Generation of supernumerary centrosomes in human diploid epithelial cells was shown to nucleate multipolar spindles and directly drive production of aneuploid daughter cells as a result of unequal segregation of the genomic material during mitosis. Finally, we demonstrate that p16(INK4a) cooperates with p21 through regulation of cyclin-dependent kinase activity to prevent centriole pair splitting. Cells with loss of p16(INK4a) activity have been found in vivo in histologically normal mammary tissue from a substantial fraction of healthy, disease-free women. Demonstration of centrosome dysfunction in cells due to loss of p16(INK4a) suggests that, under the appropriate conditions, these cells can become aneuploid. Gain or loss of genomic material (aneuploidy) may provide the necessary proproliferation and antiapoptotic mechanisms needed for the earliest stages of tumorigenesis
Signatures of the Light Down-Squark Scenario at the Upgraded Tevatron
In scenarios with relatively light down squarks, motivated, e.g., by SO(10) D
terms, jets + missing signals can be observed at the luminosity upgraded
Tevatron even if the squarks are much heavier than the gluinos and the common
gaugino mass () at lies above the LEP allowed lower bound. In
the conventional mSUGRA model with heavy squarks practically no signal is
expected in this channel. The possiblity of distinguishing between various
SUGRA motivated scenarios by exploiting the missing and jet
distributions, opposite sign dileptons + jets + missing events and clean
trilepton signals have been discussed.Comment: 14 pages, 3 ps figure
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