Efficient adaptive integration of functions with sharp gradients and cusps in n-dimensional parallelepipeds

In this paper, we study the efficient numerical integration of functions with sharp gradients and cusps. An adaptive integration algorithm is presented that systematically improves the accuracy of the integration of a set of functions. The algorithm is based on a divide and conquer strategy and is independent of the location of the sharp gradient or cusp. The error analysis reveals that for a $C^0$ function (derivative-discontinuity at a point), a rate of convergence of $n+1$ is obtained in $R^n$. Two applications of the adaptive integration scheme are studied. First, we use the adaptive quadratures for the integration of the regularized Heaviside function---a strongly localized function that is used for modeling sharp gradients. Then, the adaptive quadratures are employed in the enriched finite element solution of the all-electron Coulomb problem in crystalline diamond. The source term and enrichment functions of this problem have sharp gradients and cusps at the nuclei. We show that the optimal rate of convergence is obtained with only a marginal increase in the number of integration points with respect to the pure finite element solution with the same number of elements. The adaptive integration scheme is simple, robust, and directly applicable to any generalized finite element method employing enrichments with sharp local variations or cusps in $n$-dimensional parallelepiped elements.Comment: 22 page

Quantum Dynamics in a Time-dependent Hard-Wall Spherical Trap

Exact solution of the Schr\"{o}dinger equation is given for a particle inside a hard sphere whose wall is moving with a constant velocity. Numerical computations are presented for both contracting and expanding spheres. The propagator is constructed and compared with the propagator of a particle in an infinite square well with one wall in uniform motion.Comment: 6 pages, 4 figures, Accepted by Europhys. Let

Coherent control of birefringence and optical activity

Control of polarization of light with light is demonstrated in thin slabs of linear material promising ultrafast all-optical data processing at arbitrarily low intensities. In proof-of-principle experiments we access any polarization azimuth and any ellipticity

Generalized Duffy transformation for integrating vertex singularities

For an integrand with a 1/r vertex singularity, the Duffy transformation from a triangle (pyramid) to a square (cube) provides an accurate and efficient technique to evaluate the integral. In this paper, we generalize the Duffy transformation to power singularities of the form p(x)/r α , where p is a trivariate polynomial and α > 0 is the strength of the singularity. We use the map (u, v, w) → (x, y, z) : x = u β , y = x v, z = x w, and judiciously choose β to accurately estimate the integral. For α = 1, the Duffy transformation (β = 1) is optimal, whereas if α ≠ 1, we show that there are other values of β that prove to be substantially better. Numerical tests in two and three dimensions are presented that reveal the improved accuracy of the new transformation. Higher-order partition of unity finite element solutions for the Laplace equation with a derivative singularity at a re-entrant corner are presented to demonstrate the benefits of using the generalized Duffy transformation

A Knowledge Management Perspective of Generative Artificial Intelligence

In this editorial, revisiting Alavi and Leidner (2001) as a conceptual lens, we consider the organizational implications of generative artificial intelligence (GenAI) from a knowledge management (KM) perspective. We examine how GenAI impacts the processes of knowledge creation, storage, transfer, and application, highlighting both the opportunities and challenges this technology presents. In knowledge creation, GenAI enhances information processing and cognitive functions, fostering individual and organizational learning. However, it also introduces risks like AI bias and reduced human socialization, potentially marginalizing junior knowledge workers. For knowledge storage and retrieval, GenAI’s ability to quickly access vast knowledge bases significantly changes employee interactions with KM systems. This raises questions about balancing human-derived tacit knowledge with AI-generated explicit knowledge. The paper also explores GenAI’s role in knowledge transfer, particularly in training and cultivating a learning culture. Challenges include an overreliance on AI and risks in disseminating sensitive information. In terms of knowledge application, GenAI is seen as a tool to boost productivity and innovation, but issues like knowledge misapplication, intellectual property, and ethical considerations are critical. Conclusively, the paper argues for a balanced approach to integrating GenAI into KM processes. It advocates for harmonizing GenAI’s capabilities with human insights to effectively manage knowledge in contemporary organizations, ensuring both technological advances and ethical responsibility

Antinociceptive effect of the endemic species Glaucium vitellinum boiss and buhse

Background: Glaucium vitellinum is an endemic species and is extensively exploited as an anti-inflammatory agent in Iranian traditional medicine. Objectives: This study was designed to evaluate the antinociceptive activities of G. vitellinum methanol extract in male mice. Materials and Methods: The formalin and hot-plate methods were used for pain evaluation in mice. Glaucium vitellinum extract (50, 100, 200 and 400 mg/kg body weight IP), saline and morphine (2 mg/kg, IP) were administered 15 minutes prior to the formalin test. The nociceptive responses were divided to two phases; phase I (0 - 15 minutes) and phase II (15 - 60 minutes) were compared to the control and morphine. In the hot-plate test, G. vitellinum extract (80, 160, 200 and 250 mg/kg IP), saline and morphine (5 mg/kg, IP) were administered and, behavioral responses were immediately tested, 15, 30, 45 and 60 minutes after the injection. Comparisons between the groups were carried out using the analysis of variance (ANOVA), and post hoc Tukey's test. Results: All doses of G. vitellinum extract induced anti-nociception activity during the first and second phases of the formalin test. The extract showed a significant (P < 0.05) dose-related inhibition during the first phase compared to the control group. In the second phase of the formalin test, the extract showed analgesic activity comparable to the effect of morphine. In pre-treatment with non-selective opioid receptor antagonist, naloxone could reverse the anti-nociceptive effect of the extract in the formalin test. In the hot-plate method, with the highest dose of 250 mg/kg, the anti-nociceptive activity of the studied extract was comparable to the standard drug, morphine. Conclusions: This study revealed that G. vitellinum extract possessed a significant anti-nociceptive activity in formalin pain models and hot-plate test in mice and might have a potent role against pain. © 2016, School of Pharmacy, Ahvaz Jundishapur University of Medical Sciences

A survey of patient safety culture: A tool for improving patient safety in healthcare providers service organizations

Background and aims: Patient safety is one of the main factors in quality of services provided by a health system. Patient safety culture plays a key role in improvement of patient safety, reduction of medical errors, and prevention of adverse events in health care organizations. Thereby, the present study is aimed to survey patient safety culture in hospitals of Neyshabur University of Medical Sciences. Methods: This research was a cross sectional study that conducted on all qualified staff of hospitals affiliated with Neyshabur University of Medical Sciences in 2013. Hospital Survey of Patient Safety Culture (HSOPSC) questionnaire was used to assess patient safety culture. The collected data were analyzed in SPSS (16), using Chi-Square test and logistic regression model. Results: Total score average of patient safety culture was 25.50±9.52. The results showed that among the twelve dimensions the highest and lowest scores were obtained by the supervisor/ manager expectations & actions promoting patient safety (score rate 45) and the reporting frequency of adverse events (score rate 15) respectively According to logistic regression model there was also significant relationship between the patient safety culture and direct contact with the patient, employment duration in hospital, and current unit (p<0.05). Conclusion: Total average of patient safety culture and scores of all twelve dimensions were lower than the acceptable criteria. Patient safety culture in the studied hospitals urgently needs enhancement and improvement. So, creating policies to institutionalize and enhance patient safety culture among the staffs are recommended

Low back pain:Moving toward mechanism-based management

Low back pain is a complex, multifactorial, and heterogeneous condition, but this does not make it an exception in medicine. Management of low back pain based on a mechanistic approach and developing more effective multidisciplinary treatment is possible and would finally implement the biopsychosocial model of care

The effect of serum vitamin D normalization in preventing recurrences of benign paroxysmal positional vertigo: A case-control study

Background: Benign paroxysmal positional vertigo (BPPV) is a condition with recurrent attacks in a significant proportion of patients. The present case- control study was conducted to assess the influence of serum vitamin D normalization on recurrent attacks of vitamin D deficient patients. Methods: Diagnosis of BPPV was made based on history and clinical examination and exclusion of other conditions. Serum 25-hydroxy vitamin D (25-OHD) was measured using ELISA method and a levels of < 20 ng/ml was considered a deficiency of vitamin D. Inclusion criteria were as follows: history of recurrent attacks and serum 25-OHD < 20.ng/ml. While the patients with history of trauma, surgery and chronic systemic diseases were excluded. The patients were classified into two groups: treatment and control, intermittently. Both groups received Epley rehabilitation therapy one session per week for 4 weeks but the treatment group received an additional supplement of 50.000 IU of vitamin D (cholecalciferol) weekly for two months to achieve serum 25-OHD � 30 ng/ml and the study patients were followed-up for 6 months. Results: Twenty-seven patients were allocated to each group. At baseline, serum 25-OHD was similar (10.7�2.3 vs 11.41�1.9, P=0.23). At month 2, serum 25-OHD in the treatment group increased significantly to � 30 ng/ml, whereas serum 25-OHD in the control group remained unchanged (34.2�3.3 vs 10.6 10.6�2.2 ng/ml, P=0.001). During the follow-up period, attacks of BPPV in the treatment group decreased significantly compared with the control group (14.8 vs 96.3 OR= 0.18, P=0.001). Conclusion: The findings of this study indicate that the normalization of serum vitamin D significantly reduces BPPV recurrences