687 research outputs found
Dopamine restores reward prediction errors in old age
Get PDFSenescence affects the ability to utilize information about the likelihood of rewards for optimal decision-making. Using functional magnetic resonance imaging in humans, we found that healthy older adults had an abnormal signature of expected value, resulting in an incomplete reward prediction error (RPE) signal in the nucleus accumbens, a brain region that receives rich input projections from substantia nigra/ventral tegmental area (SN/VTA) dopaminergic neurons. Structural connectivity between SN/VTA and striatum, measured by diffusion tensor imaging, was tightly coupled to inter-individual differences in the expression of this expected reward value signal. The dopamine precursor levodopa (L-DOPA) increased the task-based learning rate and task performance in some older adults to the level of young adults. This drug effect was linked to restoration of a canonical neural RPE. Our results identify a neurochemical signature underlying abnormal reward processing in older adults and indicate that this can be modulated by L-DOPA
Dynamical mean-field theory of realistic spin glasses beyond independent-mode approximation. II. Effect of reaction field
No full textThe author extends the previous calculation on a dynamical mean-field theory of realistic spin glasses (Chowdhury and Mookerjee) so as to incorporate the effect of the reaction field. The 'ordering temperature' of a mode is shown to depend not only on the corresponding eigenvalue of the random matrix J but also on the structure of the whole spectrum
Biomechanical signals and the C-type natriuretic peptide counteract catabolic activities induced by IL-1? in chondrocyte/agarose constructs
Get PDFIntroduction: The present study examined the effect of C-type natriuretic peptide (CNP) on the anabolic and catabolic activities in chondrocyte/agarose constructs subjected to dynamic compression. Methods: Constructs were cultured under free-swelling conditions or subjected to dynamic compression with low (0.1 to 100 pM) or high concentrations (1 to 1,000 nM) of CNP, interleukin-1? (IL-1?), and/or KT-5823 (inhibits cyclic GMP-dependent protein kinase II (PKGII)). Anabolic and catabolic activities were assessed as follows: nitric oxide (NO) and prostaglandin E2 (PGE2) release, and [3H]-thymidine and 35SO4 incorporation were quantified by using biochemical assays. Gene expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), aggrecan, and collagen type II were assessed with real-time quantitative PCR (qPCR). Two-way ANOVA and the post hoc Bonferroni-corrected t tests were used to examine data. Results: CNP reduced NO and PGE2 release and partially restored [3H]-thymidine and 35SO4 incorporation in constructs cultured with IL-1?. The response was dependent on the concentration of CNP, such that 100 pM increased [3H]-thymidine incorporation (P < 0.001). This is in contrast to 35SO4 incorporation, which was enhanced with 100 or 1000 nM CNP in the presence and absence of IL-1? (P < 0.001). Stimulation by both dynamic compression and CNP and/or the PKGII inhibitor further reduced NO and PGE2 release and restored [3H]-thymidine and 35SO4 incorporation. In the presence and absence of IL-1?, the magnitude of stimulation for [3H]-thymidine and 35SO4 incorporation by dynamic compression was dependent on the concentration of CNP and the response was inhibited with the PKGII inhibitor. In addition, stimulation by CNP and/or dynamic compression reduced IL-1?-induced iNOS and COX-2 expression and restored aggrecan and collagen type II expression. The catabolic response was not further influenced with the PKGII inhibitor in IL-1?-treated constructs. Conclusions: Treatment with CNP and dynamic compression increased anabolic activities and blocked catabolic effects induced by IL-1?. The anabolic response was PKGII mediated and raises important questions about the molecular mechanisms of CNP with mechanical signals in cartilage. Therapeutic agents like CNP could be administered in conjunction with controlled exercise therapy to slow the OA disease progression and to repair damaged cartilage. The findings from this research provide the potential for developing novel agents to slow the pathophysiologic mechanisms and to treat OA in the young and old. <br/
Efficacy of lignocaine with clonidine and adrenaline in minor oral surgical procedure
No full textUse of vasoconstrictors in local anaesthesia is well known. The study was done on 30 patients who underwent removal of bilateral impacted third molars. The aim of the study was to compare the efficacy of lignocaine with clonidine and lignocaine with adrenaline in respect to onset, duration of anaesthesia, and postoperative analgesia along with hemodynamic stability (systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate in intraoral nerve block. The patients were randomly selected of both sexes (male and female) between the age group of 18-40 years. Patients received 2 mL of 2% lignocaine with adrenaline (12.5 μg/mL) on one side and 2 mL of 2% lignocaine with clonidine (15 μg/mL) on the other side at two different appointments. 2 millilitres of drug was administered in both the test group and the control group. Statistically there was significant decrease in intraoperative and postoperative systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate in the lignocaine with clonidine group. The efficacy of clonidine based on visual analog scale was similar to adrenaline. No significant operative complications were observed
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
Get PDFIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
Next Generation Business Handbook: New Strategies from Tomorrow’s Thought Leaders
No full textDonald Gibson is a contributing author, Returning Human to HR Management.”, pp. 887-902.
Book description: Next Generation Business Handbook offers strategies for the next generation of business success from the best business schools around the world. Presents fresh ideas from the young, up-and-coming business thinkers and experts from the world\u27s best business schools. Coverage of topics like career imprinting and operating in a virtual workspace that are receiving increased attention in organizations. Organized around Chowdhury\u27s next generation business model. - Publisher description.https://digitalcommons.fairfield.edu/business-books/1018/thumbnail.jp
A critique of vanishing voice in noncooperative spaces: the perspective of an aspirant black female intellectual activist
Get PDFWe adopt and extend the concept of ‘noncooperative space’ to analyze how (aspirant) black women intellectual activists attempt to sustain their efforts within settings that publicly endorse racial equality, while, in practice, the contexts remain deeply racist. Noncooperative spaces reflect institutional, organizational, and social environments portrayed by powerful white agents as conducive to anti-racism work and promoting racial equality but, indeed, constrain individuals who challenge racism. Our work, which is grounded in intersectionality, draws on an autoethnographic account of racially motivated domestic violence suffered by our lead author. Our analysis suggests that (aspirant) black women intellectual activists must develop courage to sustain their ‘voice’ within noncooperative spaces. However, the three interlinked dimensions of noncooperative spaces—namely, deceiving design, hegemonic actors’ indifference to racism, and (some assimilated gatekeepers’) false equivalence—may gradually erode a black female scholar’s courage. This forces her ‘voice’ to vanish temporarily, or even permanently. Courage is thus fragile and depletable. Yet, courage can be regenerated, resulting in regaining voice. Consequently, we propose courageous collective action by white allies and black and brown individuals who voluntarily and officially cooperate within and across various spaces to achieve racial equality
Bibliometric cartography of information retrieval research by using co-word analysis
No full textThe aim of this study is to map the intellectual structure of the field of Information Retrieval (IR) during the period of 1987-1997. Co-word analysis was employed to reveal patterns and trends in the IR field by measuring the association strengths of terms representative of relevant publications or other texts produced in IR field. Data were collected from Science Citation Index (SCI) and Social Science Citation Index (SSCI) for the period of 1987-1997. In addition to the keywords added by the SCI and SSCI databases, other important keywords were extracted from titles and abstracts manually. These keywords were further standardized using vocabulary control tools. In order to trace the dynamic changes of the IR field, the whole 11-year period was further separated into two consecutive periods: 1987-1991 and 1992-1997. The results show that the IR field has some established research themes and it also changes rapidly to embrace new themes
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Human Rights Discourse in the Post-9/11 Age
No full textThis book offers a materialist critique of mainstream human rights discourse in the period following 9/11, examining literary works, critical histories, international declarations, government statutes, NGO manifestos, and a documentary film. The author points out some of the contradictions that emerge in contemporary rights language when material relations are not sufficiently perceived or acknowledged, and he directs attention to the role of some rights talk in maintaining and managing the accelerated global project of capital accumulation. Even as rights discourse points to injustices-for example, injustices related to labor, gender, the citizen's relationship to the state, or the movement of refugees-it can simultaneously maintain systems of oppression. By constructing subjects who are aligned to the interests of capital, by emphasizing individual "empowerment," and/or by containing social disenchantment, it reinforces the process of wealth accumulation, supports neoliberal ideologies, and diminishes the possibility of real transformation through collective struggle. Kanishka Chowdhury is Professor of English and Director of the Program in American Culture and Difference at the University of St. Thomas, MN, USA. His first book, The New India: Citizenship, Subjectivity, and Economic Liberalization, was published by Palgrave Macmillan in 2011
Correction to: Double end-on azido derivative of a tridentate (NNO) Schiff base dimeric copper(II) complex: synthesis, X-ray structure, magnetic property and catalytic effectiveness (Journal of Coordination Chemistry, (2020), 73, 20-22, (3062-3078), 10.1080/00958972.2020.1836360)
No full textWhen the article was published online, the author name Dariusz Bieńko had not been included in the article. Now, this had been added and republished online
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