Gender Determination Using Diagnostic Values of Foramen Magnum

Background: Foramen magnum is a big hole in the base of the skull. Its appearance can be useful in gender determination. So far, no study has been conducted in Iran that evaluates the value of foramen magnum in sex determination and calculates the cut-off points. This study aimed to evaluating of diagnostic value of the foramen magnum and to calculate the cut-off points for sex determination.Methods: In this cross sectional study 50 male and 50 female patients referring to the radiology department of Rasol Akram Hospital in Tehran were evaluated. The required information about the sagittal diameter, transverse diameter, and diameter of foramen magnum were assessed by brain CT scan. Chi-square and independent t test was used for the comparison of different shapes and diameters between the sexes. ROC curve was used to determine the optimal cut-off point for each indicator.Results: The best cut-off point to distinguish males from females along the anterior-posterior foramen magnum was calculated as 36.45 mm, at the transverse diameter of 30.4 mm. The proper cut-off points for the area of the foramen magnum were 877.477 mm2 and 870.29 mm2, based on the Teixeria formula and Routal formula respectively. Overall, the accuracy of these indicators was calculated as 85%.Conclusion: Based on the results of this study using CT scans images, the diameter of the foramen magnum and its area had a high accuracy in sex determination

Estimating the avoidable burden of certain modifiable risk factors in osteoporotic hip fracture using Generalized Impact Fraction (GIF) model in Iran

Backgrounds: The number of hip fractures, the most common complication of osteoporosis, has increased rapidly over the past decades. The goal of this study is to estimate the avoidable burden of certain modifiable risk factor of the condition using the Generalized Impact Fraction (GIF) model, which has been suggested and used by epidemiologists to overcome the drawbacks associated with the use of Attributable Fraction index. In addition to preventing a risk factor or the avoidable fraction of burden, this index can also calculate the change in the burden, when a risk factor is altered.Methods: International databases were searched through PubMed, CINAHLD, Embase using OVID and Google scholar. National resources were searched through IranDoc, IranMedex, SID and Journal sites. Other resources include abstract books and articles sent to the IOF congress. The following search strategy was used: (" Osteoporotic fracture" OR " Fragility Hip fracture" OR " Calcium" OR " vitamin D" OR " BMI" OR " lean body weight" OR " Physical activity" OR " exercise" OR " Smoke" ) AND (" prevalence" OR " incidence" OR " relative risk" ) and limited to " humans." Results: With regards to different scenarios already explained in modifying the studied risk factors, the greatest impact in reducing the prevalence of risk factors on osteoporotic hip fractures, was seen in low serum vitamin D levels, low physical activity and low intake of calcium and vitamin D, respectively. According to the fact that interventions for low serum vitamin D and low intake of calcium and vitamin D, are related to each other, it can be concluded that implementing interventions to change these two risk factors, in the easy, moderate and difficult scenarios, would result in approximately a 5%, 11% and 17% decrease in the burden of osteoporotic hip fractures, respectively. The addition of interventions addressing low physical activity in the easy, moderate and difficult scenarios, an 8%, 21% and 35% reduction in the burden of osteoporotic hip fractures would be reported, respectively.Conclusion: Improving serum vitamin D levels, recommending the consumption of calcium and vitamin D supplementations and advocating physical activity are the most effective interventions to reduce the risk of osteoporotic hip fractures. © 2013 Shahnazari et al; licensee BioMed Central Ltd

General methods for designing single-mode planar photonic crystal waveguides in hexagonal lattice structures

We systematically investigate and compare general methods of designing single mode photonic crystal waveguides in a two-dimensional hexagonal lattice of air holes in a dielectric material. We apply the rather general methods to dielectric-core hexagonal lattice photonic crystals since they have not been widely explored before. We show that it is possible to obtain single mode guiding in a limited portion of the photonic bandgap of hexagonal lattice structures. We also compare the potentials of different photonic crystal lattices for designing single-mode waveguides and conclude that triangular lattice structures are the best choice

Minimum Target Sets in Non-Progressive Threshold Models: When Timing Matters

Let $G$ be a graph, which represents a social network, and suppose each node $v$ has a threshold value $\tau(v)$. Consider an initial configuration, where each node is either positive or negative. In each discrete time step, a node $v$ becomes/remains positive if at least $\tau(v)$ of its neighbors are positive and negative otherwise. A node set $\mathcal{S}$ is a Target Set (TS) whenever the following holds: if $\mathcal{S}$ is fully positive initially, all nodes in the graph become positive eventually. We focus on a generalization of TS, called Timed TS (TTS), where it is permitted to assign a positive state to a node at any step of the process, rather than just at the beginning. We provide graph structures for which the minimum TTS is significantly smaller than the minimum TS, indicating that timing is an essential aspect of successful target selection strategies. Furthermore, we prove tight bounds on the minimum size of a TTS in terms of the number of nodes and maximum degree when the thresholds are assigned based on the majority rule. We show that the problem of determining the minimum size of a TTS is NP-hard and provide an Integer Linear Programming formulation and a greedy algorithm. We evaluate the performance of our algorithm by conducting experiments on various synthetic and real-world networks. We also present a linear-time exact algorithm for trees.Comment: Accepted in ECAI-23 (26th European Conference on Artificial Intelligence

September the 11th 2001 and Security Dilemma

Security and insecurity are complex concepts that states have problem in defining them in different conditions. Complexity of the concepts comes out of security dilemma which states face when they seek to recognize enemy and scale of threat that the enemy may cause. Events of September the 11th formed a new condition in which United States faced the security dilemma that had not risen from a specific country but the enemy that was not recognizable and did not behave like states. United States attempted to solve the mentioned security dilemma by defining enemy, its threats and the new condition after events of September the 11th. This article, in order to explain the security dilemma of the United States after events of the September the 11th, is written in two parts; the first part is to explain security dilemma and the approaches that have been given to solve it and the second part tends to explain the security dilemma that United States faced after terrorist attacks of September the 11th 2001. Keywords: Security dilemma; Terrorism; United States; September the 11thRésumé: La sécurité et l'insécurité sont des concepts complexes et les Etats ont des difficultés à les définir dans des conditions différentes. La complexité des concepts vient du dilemme de sécurité auquel les Etats font face quand ils cherchent à reconnaître l'ennemi et l'ampleur de la menace que l'ennemi peut causer. Les événements du 11 septembre a formé une nouvelle condition, dans laquelle les États-Unis ont fait face à un dilemme de sécurité qui ne venait pas d'un pays spécifique, mais d'un ennemi non reconnaissable qui ne se comportait pas comme des États. Les États-Unis ont tenté de résoudre ce dilemme de sécurité par la définition de l'ennemi, de ses menaces et de la nouvelle condition après les événements du 11 septembre. Cet article, afin d'expliquer le dilemme de la sécurité des États-Unis après les événements du 11 septembre, est composé en deux parties: la première partie est d'expliquer le dilemme de sécurité et les approches qui ont été utilisées pour le résoudre et la deuxième partie tend à expliquer le dilemme de sécurité auquel les États-Unis font face après les attentats terroristes du 11 septembre 2001.Mots-clés: dilemme de sécurité; terrorisme; États-Unis; 11 septembr

Casimir force in the presence of a magnetodielectric medium

In this article we investigate the Casimir effect in the presence of a medium by quantizing the Electromagnetic (EM) field in the presence of a magnetodielectric medium by using the path integral formalism. For a given medium with definite electric and magnetic susceptibilities, explicit expressions for the Casimir force are obtained which are in agree with the original Casimir force between two conducting parallel plates immersed in the quantum electromagnetic vacuum.Comment: 8 pages, 1 figur

Multimodal Damping of a Nonlinear Structure with a Passive Piezoelectric Network

International audienceThis work proposes the implementation of a multimodal and fully passive piezoelectric tuned vibration absorber that mitigates several resonances of a nonlinear structure. By extending a principle of similarity, an analogous electrical network is designed in order to reproduce the dynamics of the mechanical structure. Several electrical resonances are simultaneously tuned to the mechanical resonances, thus providing the equivalent of a multimodal vibration absorber from electromechanical coupling through an array of piezoelectric patches. Furthermore, the use of a nonlinear capacitor in the analogous network generates an autonomous adjustment of the electrical resonance frequencies when the structure reaches the nonlinear domain. The interest of this method is proved experimentally by mitigating vibration over a wide frequency range that covers the first three modes of a beam with cubic nonlinearity