50,454 research outputs found
Category deficits and paradoxical dissociations in Alzheimer's disease and Herpes Simplex Encephalitis
No full textMost studies examining category specificity are single-case studies of patients with living or nonliving deficits. Nevertheless, no explicit or agreed criteria exist for establishing category-specific deficits in single cases regarding the type of analyses, whether to compare with healthy controls, the number of tasks, or the type of tasks. We examined two groups of patients with neurological pathology frequently accompanied by impaired semantic memory (19 patients with Alzheimer's disease and 15 with Herpes Simplex Encephalitis). Category knowledge was examined using three tasks (picture naming, naming-to-description, and feature verification). Both patient groups were compared with age- and education-matched healthy controls. The profile in each patient was examined for consistency across tasks and across different analyses; however, both proved to be inconsistent. One striking finding was the presence of paradoxical dissociations (i.e., patients who were impaired for living things on one task and nonliving things on another task). The findings have significant implications for how we determine category effects and, more generally, for the methods used to document double dissociations across individual cases in this literature
Repetitive transcranial magnetic stimulation (r-TMS) and selective serotonin reuptake inhibitor-resistance in obsessive-compulsive disorder: A meta-analysis and clinical implications
No full textIntroduction: Despite promising results from several randomized controlled trials (RCTs) and meta-analyses, the efficacy of r-TMS as a treatment for OCD remains controversial, at least in part owing to inconsistency in the trial methodologies and heterogeneity in the trial outcomes. This meta-analysis attempts to explain some of this heterogeneity by comparing the efficacy of r-TMS in patients with or without resistance to treatment with selective serotonin reuptake inhibitors (SSRI), defined using standardized criteria. Methods: We conducted a pre-registered (PROSPERO ID: 241381) systematic review and meta-analysis. English language articles reporting blinded RCTs were retrieved from searches using MEDLINE, PsycINFO, and Cochrane Library databases. Studies were subjected to subgroup analysis based on four stages of treatment resistance, defined using an adaptation of published criteria (1 = not treatment resistant, 2 = one SSRI trial failed, 3 = two SSRI trials failed, 4 = two SSRI trials failed plus one or more CBT trial failed). Meta-regression analyses investigated patient and methodological factors (age, duration of OCD, illness severity, stage of treatment-resistance, or researcher allegiance) as possible moderators of effect size. Results: Twenty-five independent comparisons (23 studies) were included. Overall, r-TMS showed a medium-sized reduction of Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) scores (Hedge's g: -0.47; 95%CI: - 0.67 to −0.27) with moderate heterogeneity (I2 = 39.8%). Assessment of publication bias using Trim and Fill analysis suggested a reduced effect size that remained significant (g: -0.29; 95%CI: −0.51 to −0.07). Subgroup analysis found that those studies including patients non-resistant to SSRI (stage 1) (g: -0.65; 95%CI: −1.05 to −0.25, k = 7) or with low SSRI-resistance (stage 2) (g:-0.47; 95%CI: −0.86 to −0.09, k = 6) produced statistically significant results with low heterogeneity, while studies including more highly resistant patients at stage 3 (g: −0.39; 95%CI: −0.90 to 0.11, k = 4) and stage 4 (g: -0.36; 95%CI: −0.75 to 0.03, k = 8) did not. Intriguingly, the only significant moderator of the effect size found by meta-regression was the severity of baseline depressive symptoms. All trials showed evidence of researcher allegiance in favour of the intervention and therefore caution is required in interpreting the reported effect sizes. Conclusion: This meta-analysis shows that r-TMS is an effective treatment for OCD, but largely for those not resistant to SSRI or failing to respond to only one SSRI trial. As a consequence, r-TMS may be best implemented earlier in the care pathway. These findings would have major implications for clinical service development, but further well-powered RCTs, which eliminate bias from researcher allegiance, are needed before definitive conclusions can be drawn
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
The Inflexible Mind: A Critical Factor in Understanding and Addressing COVID-19 Vaccine Hesitancy
No full textBackground Vaccine hesitancy has gained heightened relevance amid the COVID-19 pandemic, underscoring the urgency of understanding its determinants. This study explores the association between Covid-19 vaccine hesitancy, mental health variables and inflexible thinking. Methods A convenience sample of 252 UK adults was assessed online between June 2021 – July 2022 (when Covid-19 lockdown restrictions had finally eased). We assessed participants using the Oxford Covid Vaccine Hesitancy Scale (OCVHS), various aspects of mental health, using: the Obsessive-Compulsive Inventory-Revised (OCI-R), Compulsive Personality Assessment Scale (CPAS), Depression, Anxiety, and Stress scale (DASS-21), and finally, performance on a computerized version of the Wisconsin Card Sort Task (WCST). This study was preregistered at the Open Science Framework (https://osf.io/xd5wz). Results Multiple regression analyses showed that only cognitive inflexibility, and specifically the WCST item of perseverative errors, significantly predicted vaccine hesitancy. Conclusion Our exploratory analysis provides the first evidence that cognitive inflexibility, measured using an objective task, is an independent risk-factor for vaccine hesitancy. Public health strategies should consider the impact of an inflexible thinking style on the decision-making of those most at risk of vaccine hesitancy and adapt interventions accordingly
Power Laws in Economics and Finance
No full textA power law is the form taken by a large number of surprising empirical regularities in economics and finance. This article surveys well-documented empirical power laws concerning income and wealth, the size of cities and firms, stock market returns, trading volume, international trade, and executive pay. It reviews detail-independent theoretical motivations that make sharp predictions concerning the existence and coefficients of power laws, without requiring delicate tuning of model parameters. These theoretical mechanisms include random growth, optimization, and the economics of superstars coupled with extreme value theory. Some of the empirical regularities currently lack an appropriate explanation. This article highlights these open areas for future research.
Repetitive transcranial magnetic stimulation (r-TMS) and selective serotonin reuptake inhibitor-resistance in obsessive-compulsive disorder: A meta-analysis and clinical implications
No full textIntroduction: Despite promising results from several randomized controlled trials (RCTs) and meta-analyses, the efficacy of r-TMS as a treatment for OCD remains controversial, at least in part owing to inconsistency in the trial methodologies and heterogeneity in the trial outcomes. This meta-analysis attempts to explain some of this heterogeneity by comparing the efficacy of r-TMS in patients with or without resistance to treatment with selective serotonin reuptake inhibitors (SSRI), defined using standardized criteria.
Methods: We conducted a pre-registered (PROSPERO ID: 241381) systematic review and meta-analysis. English language articles reporting blinded RCTs were retrieved from searches using MEDLINE, PsycINFO, and Cochrane Library databases. Studies were subjected to subgroup analysis based on four stages of treatment resistance, defined using an adaptation of published criteria (1 = not treatment resistant, 2 = one SSRI trial failed, 3 = two SSRI trials failed, 4 = two SSRI trials failed plus one or more CBT trial failed). Meta-regression analyses investigated patient and methodological factors (age, duration of OCD, illness severity, stage of treatment-resistance, or researcher allegiance) as possible moderators of effect size.
Results: Twenty-five independent comparisons (23 studies) were included. Overall, r-TMS showed a medium-sized reduction of Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) scores (Hedge's g: -0.47; 95%CI: - 0.67 to -0.27) with moderate heterogeneity (I2 = 39.8%). Assessment of publication bias using Trim and Fill analysis suggested a reduced effect size that remained significant (g: -0.29; 95%CI: -0.51 to -0.07). Subgroup analysis found that those studies including patients non-resistant to SSRI (stage 1) (g: -0.65; 95%CI: -1.05 to -0.25, k = 7) or with low SSRI-resistance (stage 2) (g:-0.47; 95%CI: -0.86 to -0.09, k = 6) produced statistically significant results with low heterogeneity, while studies including more highly resistant patients at stage 3 (g: -0.39; 95%CI: -0.90 to 0.11, k = 4) and stage 4 (g: -0.36; 95%CI: -0.75 to 0.03, k = 8) did not. Intriguingly, the only significant moderator of the effect size found by meta-regression was the severity of baseline depressive symptoms. All trials showed evidence of researcher allegiance in favour of the intervention and therefore caution is required in interpreting the reported effect sizes.
Conclusion: This meta-analysis shows that r-TMS is an effective treatment for OCD, but largely for those not resistant to SSRI or failing to respond to only one SSRI trial. As a consequence, r-TMS may be best implemented earlier in the care pathway. These findings would have major implications for clinical service development, but further well-powered RCTs, which eliminate bias from researcher allegiance, are needed before definitive conclusions can be drawn
The relationship between cognitive phenotypes of compulsivity and impulsivity and clinical variables in obsessive-compulsive disorder: A systematic review and Meta-analysis
No full textBackground: This systematic review and meta-analysis explored the relationship between cognitive phenotypes of compulsivity and impulsivity and clinical variables in obsessive-compulsive disorder (OCD). Methods: We searched Pubmed, Scopus, Cochrane Library and PsychINFO databases until February 2023 for studies comparing patients with OCD and healthy controls on cognitive tests of compulsivity and impulsivity. The study followed PRISMA guidelines and was pre-registered on PROSPERO (CRD42021299017). Results: Meta-analyses of 112 studies involving 8313 participants (4289 patients with OCD and 4024 healthy controls) identified significant impairments in compulsivity (g = -0.58, [95%CI -0.68, -0.47]; k = 76) and impulsivity (g = -0.48, [95%CI -0.57, -0.38]; k = 63); no significant difference between impairments. Medication use and comorbid psychiatric disorders were not significantly related to impairments. No associations were revealed with OCD severity, depression/anxiety, or illness duration. Conclusion: Cognitive phenotypes of compulsivity and impulsivity in patients with OCD appear to be orthogonal to clinical variables, including severity of OCD symptomatology. Their clinical impact is poorly understood and may require different clinical assessment tools and interventions
Ceteris Paribus Laws
No full textLaws of nature take center stage in philosophy of science. Laws are usually believed to stand in a tight conceptual relation to many important key concepts such as causation, explanation, confirmation, determinism, counterfactuals etc. Traditionally, philosophers of science have focused on physical laws, which were taken to be at least true, universal statements that support counterfactual claims. But, although this claim about laws might be true with respect to physics, laws in the special sciences (such as biology, psychology, economics etc.) appear to have—maybe not surprisingly—different features than the laws of physics. Special science laws—for instance, the economic law “Under the condition of perfect competition, an increase of demand of a commodity leads to an increase of price, given that the quantity of the supplied commodity remains constant” and, in biology, Mendel's Laws—are usually taken to “have exceptions”, to be “non-universal” or “to be ceteris paribus laws”. How and whether the laws of physics and the laws of the special sciences differ is one of the crucial questions motivating the debate on ceteris paribus laws. Another major, controversial question concerns the determination of the precise meaning of “ceteris paribus”. Philosophers have attempted to explicate the meaning of ceteris paribus clauses in different ways. The question of meaning is connected to the problem of empirical content, i.e., the question whether ceteris paribus laws have non-trivial and empirically testable content. Since many philosophers have argued that ceteris paribus laws lack empirically testable content, this problem constitutes a major challenge to a theory of ceteris paribus laws
Emergence of power laws with different power-law exponents from reversal quasi-symmetry and Gibrat’s law
No full textTo explore the emergence of power laws in social and economic phenomena, the authors discuss the mechanism whereby reversal quasi-symmetry and Gibrat’s law lead to power laws with different powerlaw exponents. Reversal quasi-symmetry is invariance under the exchange of variables in the joint PDF (probability density function). Gibrat’s law means that the conditional PDF of the exchange rate of variables does not depend on the initial value. By employing empirical worldwide data for firm size, from categories such as plant assets K, the number of employees L, and sales Y in the same year, reversal quasi-symmetry, Gibrat’s laws, and power-law distributions were observed. We note that relations between power-law exponents and the parameter of reversal quasi-symmetry in the same year were first confirmed. Reversal quasi-symmetry not only of two variables but also of three variables was considered. The authors claim the following. There is a plane in 3-dimensional space (log K, log L, log Y ) with respect to which the joint PDF PJ (K,L, Y ) is invariant under the exchange of variables. The plane accurately fits empirical data (K,L, Y ) that follow power-law distributions. This plane is known as the Cobb-Douglas production function, Y = AKαLβ which is frequently hypothesized in economics.
Depolarization and decreased surface expression of K+ channels contribute to NSAID-inhibition of intestinal restitution
No full textNon-steroidal anti-inflammatory drugs (NSAIDs) contribute to gastrointestinal ulcer formation by inhibiting epithelial cell migration and mucosal restitution; however, the drug-affected signaling pathways are poorly defined. We investigated whether NSAID inhibition of intestinal epithelial migration is associated with depletion of intracellular polyamines, depolarization of membrane potential (Em) and altered surface expression of K+ channels. Epithelial cell migration in response to the wounding of confluent IEC-6 and IEC-Cdx2 monolayers was reduced by indomethacin (100μM), phenylbutazone (100μM) and NS-398 (100μM) but not by SC-560 (1μM). NSAID-inhibition of intestinal cell migration was not associated with depletion of intracellular polyamines. Treatment of IEC-6 and IEC-Cdx2 cells with indomethacin, phenylbutazone and NS-398 induced significant depolarization of Em, whereas treatment with SC-560 had no effect on Em. The Em of IEC-Cdx2 cells was: −38.5±1.8mV under control conditions; −35.9±1.6mV after treatment with SC-560; −18.8±1.2mV after treatment with indomethacin; and −23.7±1.4mV after treatment with NS-398. Whereas SC-560 had no significant effects on the total cellular expression of Kv1.4 channel protein, indomethacin and NS-398 decreased not only the total cellular expression of Kv1.4, but also the cell surface expression of both Kv1.4 and Kv1.6 channel subunits in IEC-Cdx2. Both Kv1.4 and Kv1.6 channel proteins were immunoprecipitated by Kv1.4 antibody from IEC-Cdx2 lysates, indicating that these subunits co-assemble to form heteromeric Kv channels. These results suggest that NSAID inhibition of epithelial cell migration is independent of polyamine-depletion, and is associated with depolarization of Em and decreased surface expression of heteromeric Kv1 channels.ID: S0006295207001931; M3: Article; Accession Number: S0006295207001931; Author: L.C. Freeman (b); Author: D.F. Narvaez (a); Author: A. McCoy (a); Author: F.B. von Stein (c); Author: S. Young (b); Author: K. Silver (a); Author: S. Ganta (b); Author: D. Koch (b); Author: R. Hunter (b); Author: R.F. Gilmour (c); Author: J.D. Lillich (a, ⁎); Affiliation: Department of Clinical Sciences, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Anatomy and Physiology, Kansas State University, Manhattan, KS 66506, United States; Affiliation: Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, United States; Keyword: Non-steroidal anti-inflammatory drugs; Keyword: Intestinal epithelial cells; Keyword: Membrane potential; Keyword: Potassium channels; Number of Pages: 12; Language: English;Source type: Electronic(1)http://search.ebscohost.com/login.aspx?direct=true&db=edselp&AN=S0006295207001931&site=eds-live&scope=sit
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