Modern Warfare: Is the Evolution of Weaponry Worth the Cost?

War is a creation of mankind that has evolved along with human civilization, leaving a bloody trail in its wake. As there are those in our world who strive to improve peacetime society, there are also those who push the limits of weaponry and revolutionize the way war is waged. In this day and age, opposing forces rarely meet on a traditional battlefield but instead inflict death and destruction from across the horizon with weapons of catastrophic capability. Consequently the costs of developing such advanced war machines are increasingly heavy. With this rapid evolution of combat and the weaponry used in it, my question is simple: Are all the advancements truly worth the cost

La impugnación de la credibilidad de testigos en el sistema penal acusatorio

Este trabajo explica en qué consiste el procedimiento de impugnación de la credibilidad de testigos en el sistema penal acusatorio colombiano consagrado en la ley 906 de 2004, analiza algunos de sus aspectos problemáticos desde la perspectiva procesal y probatoria y expone los equívocos del concepto 'impugnación' en nuestro medio y su relación con la sana crítica

Examination of Lower Limb Ambidextrous Execution of the Snap Down Technique in Folk Style Wrestling

The purpose of this study was to examine the kinematic motions of the lower extremity in the snap down technique. Specifically, the study examined the kinematic differences between execution using the dominant and non-dominant side. Angular displacement, velocity and acceleration of the hip, knee and ankle joint was examined. It was hypothesized that a significant statistical difference would be observed in multiple variables between the dominant and non-dominant limb execution. Five male collegiate wrestlers were recruited for participation in the study. Inclusion into the study was on the basis that each participant was right side dominant and displayed proper foot placement when performing the technique. Each was instructed to perform a total of ten snaps, five using each side. A standard two-dimensional kinematic analysis was conducted using data obtained at the maximal point of head impact on the mat. The results showed a significant statistical difference only at ankle joint angular acceleration (p = 0.02), though these findings were not strong enough to conclude a true difference. This indicated that lower extremity ambidexterity was achieved by the college wrestlers in the study. Further studies and future research may be warranted to examine the kinematic differences of the technique on the basis of weight class and/or experience level

Upper Limb Ambidexterity in the Wrestling Snap Down Technique

The sport of wrestling dates back as far as recorded history. Folk style is a subdivision of that ancient sport, considered the most popular form of wrestling in U.S high schools and universities. An important skill used by Folk style wrestlers is the snap down technique. However, there is a lack of scientific literature that examines the kinematic motions of the snap down technique bilaterally. Understanding athletic ambidexterity is an important factor in athletic performance and injury prevention, particularly in wrestling. Therefore, the purpose of the research study was to bilaterally examine the kinematic motions of the upper extremity in the snap down technique. A standard two-dimensional kinematic motion analysis was conducted with six male collegiate wrestlers. The results showed no significant statistical difference between right and left side in relation to elbow joint displacement (0.09, p \u3c 0.05), angular velocity (0.51, p \u3c 0.05), angular acceleration (0.99, p \u3c 0.05) and shoulder joint displacement (0.55, p \u3c 0.05), angular velocity (0.16, pp \u3c 0.05). These findings indicated that upper limb ambidexterity was achieved by all college wrestlers in the study. Further examination of the video analysis in this study, it revealed that some wrestlers performed the skill using their shoulder and elbow as “prime executors” of the technique while other wrestlers utilized their hips as the point of technique execution and used the shoulder and elbow joints as stabilizers of the opponent. Upon this discovery, future studies are warranted to investigate the kinematics of lower extremity motion in the snap down technique

Orthodontic Bracket Bond Strength Using Self-Etching Primer With or Without Pumice or Acid Etch Pretreatment

The purpose of this study was to compare the shear bond strength of orthodontic brackets to enamel in four bonding protocols: SEP without prior pumicing (None), Pre-etch and SEP without prior pumicing (Pre-etch), control: SEP with prior pumicing (Pumice), and Pre-etch and SEP with prior pumicing (Both). 80 extracted bovine incisors were randomly divided into 4 groups of 20, and brackets were bonded under the different experimental conditions. Debonding force was measured with an Instron universal testing machine. A two-way ANOVA comparing the four groups indicated that there was a significant difference in debonding force (P = 0.001). The SEP without prior pumicing group (17.69 ± 7.18 MPa) was statistically different from the SEP group with prior pumicing (25.82 ± 6.84 MPa). There was no statistical difference found among the other groups. Differences in the Adhesive Remnant Index (ARI) were analyzed by chi-square. ARI scores differed significantly (P =0.0048)

The Examination of Upper Limb Ambidexterity in Wrestling Snap Down Technique

The purpose of this study was to bilaterally examine the kinematic motions of the upper extremity in the snap down technique. Six male collegiate wrestlers were recruited and performed a total of ten snaps, five from each side. A standard two-dimensional kinematic analysis was conducted in the upper extremity. The results showed no significant difference between right and left side in the angular displacement, velocity and acceleration. These findings indicated that upper limb ambidexterity was achieved by these college wrestlers in the study. From further video analysis, the study found some wrestlers appeared to use their shoulder and elbow as prime executors of the technique while other wrestlers utilized their hips. Upon this discovery, future studies are warranted to investigate the kinematics of lower extremity motion in the snap down technique

Reactive mission and motion planning with deadlock resolution avoiding dynamic obstacles

In the near future mobile robots, such as personal robots or mobile manipulators, will share the workspace with other robots and humans. We present a method for mission and motion planning that applies to small teams of robots performing a task in an environment with moving obstacles, such as humans. Given a mission specification written in linear temporal logic, such as patrolling a set of rooms, we synthesize an automaton from which the robots can extract valid strategies. This centralized automaton is executed by the robots in the team at runtime, and in conjunction with a distributed motion planner that guarantees avoidance of moving obstacles. Our contribution is a correct-by-construction synthesis approach to multi-robot mission planning that guarantees collision avoidance with respect to moving obstacles, guarantees satisfaction of the mission specification and resolves encountered deadlocks, where a moving obstacle blocks the robot temporally. Our method provides conditions under which deadlock will be avoided by identifying environment behaviors that, when encountered at runtime, may prevent the robot team from achieving its goals. In particular, (1) it identifies deadlock conditions; (2) it is able to check whether they can be resolved; and (3) the robots implement the deadlock resolution policy locally in a distributed manner. The approach is capable of synthesizing and executing plans even with a high density of dynamic obstacles. In contrast to many existing approaches to mission and motion planning, it is scalable with the number of moving obstacles. We demonstrate the approach in physical experiments with walking humanoids moving in 2D environments and in simulation with aerial vehicles (quadrotors) navigating in 2D and 3D environments.Boeing CompanyUnited States. Office of Naval Research. Multidisciplinary University Research Initiative. SMARTS (N00014-09-1051)United States. Office of Naval Research (N00014-12-1-1000)National Science Foundation (U.S.). Expeditions in Computer Augmented Program Engineerin