Journal articles on the topic 'Bounding exercises'

AbstractPlyometric exercises such as drop jumping and bounding offer athletes a substantiated means of enhancing athletic performance. Between the two exercises, reactive measurement using bounding (reactive bounding coefficient [RBC]) has received scant attention within the domain of training and conditioning. Therefore, this study aimed to identify the viability of utilising a speed-bounding exercise to assess horizontal reactive strength. Eleven young, male elite sprinters (age: 17.8 ± 1.3 yr; body height: 1.72 ± 0.06 m; body mass: 66.05 ± 6.10 kg; best 100 m sprint time: 10.77 ± 0.32 s) were tested for static jumps (SJ), drop jumps (DJ), 10 speed-bounding (RBC10), and 50 m sprint performance. Between-group comparisons based on sprint ability (fast [FSG] vs. slow [SSG] sprint-group) and correlation coefficients were computed subsequently. The FSG (n = 5; 50 m time: 5.82 ± 0.11 s; RBC10: 7.46 ± 0.27) performed significantly better in the RBC10 (p = 0.036) than the SSG (n = 5; 50 m time: 6.09 ± 0.13 s; RBC10: 7.09 ± 0.25). A very high correlation was attained between the RBC10 and the criterion measure, the SJ (r = 0.83). Additionally, RBC10 appeared to be correlated with 30, 50, 10-30 and 30-50 m sprint times (r = -0.52 to -0.60). This positive trend, however, was not observed for the DJ reactive strength index (trivial to moderate correlations). Good reliability was shown for the RBC10 and all sprint distances (“1.5% coefficient variation). Furthermore, all sprinters attained ground contact times of 0.12-0.18 s during the RBC10 which was indicative of fast stretch-shortening cycles during movement, suggesting that the RBC10 could be utilised to assess plyometric ability and enhance sprint performance. Overall, the RBC10 seems able to discriminate between the FSG and the SSG, indicating it has acceptable levels of validity and reliability.

AbstractJump distance per step in bounding exercises from the standing position increases with increasing number of steps. We examined the hypothesis that the joint kinetic variables of the stance leg would also increase accordingly. Eleven male athletes (sprinters and jumpers) performed bounding exercise, starting from the double-leg standing posture, and covered the longest distance possible by performing a series of seven forward alternating single-leg jumps. Kinematic and kinetic data were calculated using the data by a motion capture system and force platforms. Hip extension joint work were decreased at third step (1st: 1.07±0.22, 3rd: 0.45±0.15, 5th: 0.47±0.14 J•kg−1; partial η2: 0.86), and hip abduction joint power were increased (1st: 7.53±3.29, 3rd: 13.50±4.44, 5th: 21.37±9.93 W•kg−1; partial η2: 0.58); the knee extension joint power were increased until the third step (1st: 14.43±4.94, 3rd: 17.13±3.59, 5th: 14.28±2.86 W•kg−1; partial η2: 0.29), and ankle plantar flexion joint power increased (1st: 34.14±5.33, 3rd: 37.46±4.45, 5th: 40.11±5.66 W•kg−1; partial η2: 0.53). These results contrast with our hypothesis, and indicate that increasing the jump distance during bounding exercises is not necessarily accompanied by increases in joint kinetics of stance leg. Moreover, changes in joint kinetics vary at different joints and anatomical axes.

The objectives of this study are to study and test the effect of using the effect of the single leg and double leg bounding exercise program (BEP) on the improvement of physical agility, strength, balance, and leg muscle power. The subjects of this study were 42 students of Physical Education class 2017 STKIP PGRI Jombang.This type of research is quantitative with quasi-experimental techniques. Sampling using the Solvin formula and purposive sampling technique. The process of taking data from the initial test and the final test uses the leg dynamometer test to determine leg muscle strength, side step test for agility, force plate test for leg muscle power, and balance beam test for balance.The results of the study on the normality and homogeneous tests showed normal and homogeneous data results with a significance value above 0.05. The mean difference test was carried out using the paired test and the Manova test. The method of increasing the agility, strength, balance and leg muscle power has a significant improvement with the two experimental methods.The conclusion of this study is that the bounding exercise program can significantly increase the agility, strength, balance and leg muscle power. However, from the two exercises the increase was greater in the group using the single leg bounding type of exercise.

This study was undertaken to compare force-time characteristics, muscle power, and electromyographic (EMG) activities of the leg muscles in maximal sprinting and in selected bounding and jumping exercises. Seven male sprinters performed maximal bounding (MB), maximal stepping (MS), maximal hopping with the right (MHR) and left (MHL) legs, and maximal sprint running (MR). These “horizontal” exercises and running were performed on a force platform. EMG activity was telemetered unilaterally from five leg muscles during each trial. The results indicated significant (p < .001) differences among the studied exercises in velocity, stride length, stride rate, flight time, and contact time. Also, significant differences were noticed in reactive forces (p < .01-.001) and power (p < .01) among the performances, whereas only insignificant differences were observed in EMG patterns. The average resultant forces during the braking and propulsion phases in MS, MHR, and MHL were greater (p < .001) than in MR and MB. Stepping and hopping are cyclic and sprint-specific and may be used as strength exercises for sprinters because of great strength demand.

Millions of high school students take Advanced Placement (AP) courses, which can provide college credit. Using nationally representative data, I identify a diverse set of higher education outcomes that are related to receipt of AP college credit. Institution fixed effects regression reduces bias associated with varying AP credit policies and student sorting across higher education. Results indicate college credits earned in high school are related to reduced time to degree, double majoring, and more advanced coursework. Bounding exercises suggest the time to degree and double major outcomes are not likely driven by bias from unobserved student characteristics. Policies used to support earning college credits while in high school appear to enhance undergraduate education and may accelerate time to degree.

This paper presents an action recognition approach based on shape and action descriptors that is aimed at the classification of physical exercises under partial occlusion. Regular physical activity in adults can be seen as a form of non-communicable diseases prevention, and may be aided by digital solutions that encourages individuals to increase their activity level. The application scenario includes workouts in front of the camera, where either the lower or upper part of the camera’s field of view is occluded. The proposed approach uses various features extracted from sequences of binary silhouettes, namely centroid trajectory, shape descriptors based on the Minimum Bounding Rectangle, action representation based on the Fourier transform and leave-one-out cross-validation for classification. Several experiments combining various parameters and shape features are performed. Despite the presence of occlusion, it was possible to obtain about 90% accuracy for several action classes, with the use of elongation values observed over time and centroid trajectory.

The wheel-legged hybrid robot (WLHR) is capable of adapting height and wheelbase configuration to traverse obstacles or rolling in confined space. Compared with legged and wheeled machines, it can be applied for more challenging mobile robotic exercises using the enhanced environment adapting performance. To make full use of the deformability and traversability of WHLR with parallel Stewart mechanism, this paper presents an optimization-driven planning framework for WHLR with parallel Stewart mechanism by abstracting the robot as a deformable bounding box. It will improve the obstacle negotiation ability of the high degree-of-freedoms robot, resulting in a shorter path through adjusting wheelbase of support polygon or trunk height instead of using a fixed configuration for wheeled robots. In the planning framework, we firstly proposed a pre-calculated signed distance field (SDF) mapping method based on point cloud data collected from a lidar sensor and a KD -tree-based point cloud fusion approach. Then, a covariant gradient optimization method is presented, which generates smooth, deformable-configuration, as well as collision-free trajectories in confined narrow spaces. Finally, with the user-defined driving velocity and position as motion inputs, obstacle-avoidancing actions including expanding or shrinking foothold polygon and lifting trunk were effectively testified in realistic conditions, demonstrating the practicability of our methodology. We analyzed the success rate of proposed framework in four different terrain scenarios through deforming configuration rather than bypassing obstacles.

The equations for fluid substitution in a sample with known porosity and the mineral’s and pore-fluid’s elastic moduli are well-documented. Discussions continue on how to conduct fluid substitution in practical situations where more than one fluid phase is present and the porosity and mineralogy are not precisely defined. We pose a different question: If we agree on a fluid substitution method, and also agree that at partial saturation the bulk modulus of the “effective” pore fluid is the harmonic average of those of the components, can we conduct fluid substitution directly on the seismic reflection amplitude? To address this question, we conducted forward modeling synthetic exercises: We systematically varied the porosity, clay content, and thickness of the reservoir and assumed that the properties of the bounding shale are fixed. Next, we used a velocity-porosity model to compute the elastic properties of the dry-rock frame and applied Gassmann’s equation to compute these properties in wet rock as well as at partial gas saturation. After that, we generated prestack synthetic seismic reflections at the top of the reservoir at full saturation and at partial saturation, and related one to the other. We found that within our assumption framework, there is an almost linear relation between the intercepts of the P-to-P reflectivity for the wet and gas reservoir. The same is true for the gradients. We have provided best-linear-fit equations that summarize these results. We applied this technique to field data and found that we can approximately predict the seismic amplitude at a gas reservoir from that measured at a wet reservoir, given that all other properties of the rock remain fixed. The solution given here should be treated as a method, meaning it should be tested and modified for various rock types and textures.

Although substantial rates of oxidative phosphorylation by bacteroids of Rhizobium are required to support sustained N2 fixation in legume nodules, the enzyme nitrogenase is extremely sensitive to oxygen. This apparent paradox indicates that nodules must exercise effective control over internal oxygen concentration. Structural features including lenticel development, the thickness and arrangement of cells and air spaces in the inner and outer cortex, the presence or completeness of the common endodermis as well as the distribution of infected cells, uninfected cells and air spaces in the nodule medulla are important to gaseous ventilation of the organ. Among these, the organisation of cells and water / gas- containing extracellular voids in the inner cortex bounding the infected medulla zone are critical components to overall diffusive resistance. These elements also appear to provide the means for the oper- ation of a reversible variable diffusion barrier to control gas movement. Inhibition of nodule functioning by a widely diverse range of factors, e. g. restricted H2O or photosynthate supply, exposure to acetylene or combined N, appears to be mediated through increased diffusion resistance.

AbstractThe northeastern sector of the Rub' al-Khali desert in the eastern United Arab Emirates (UAE) is dominated by large NE–SW trending dune ridges orientated perpendicular to the currently prevailing northwesterly wind regime. In this study, extensive use has been made of artificially exposed sections through these major dune ridges that reveal internal sedimentary structures and allow an intensive, high-resolution sampling programme to be carried out. Here, we present the optical dating results for samples from 7 sections. The results indicate that dune activity and preservation occurred within the periods 7–3 ka, 16–10 ka and 22–20 ka with evidence of earlier preservation during marine oxygen isotope stages MIS 3 and 5, with net accumulation rates in the range 2.2–25 m.ka− 1. In several instances, hiatuses in the preserved record of dune accumulation coincide with stratigraphic bounding surfaces visible in the exposed section profiles with associated truncation of internal sedimentary structures. Caution must be exercised when interpreting such gaps in the recorded accumulation chronologies of these dunes since these may simply constitute phases of low preservation potential rather than phases of low aeolian activity. Other factors such as sediment supply and availability in relation to sea-level dynamics may be significant and are also considered.

Estimation of forest attributes at the stand or polygon level across the forest domain is a basic component of forest inventory programs. We tested a “k-Nearest Neighbours” (k-NN)-based method for imputing merchantable volume. Our target dataset consisted of a discrete set of forest polygons within two large forest management units, and our reference dataset was a large historical database of temporary sample plots measured over the past three decades. The linkage between the target and reference datasets was provided by polygon-level photo-interpreted forest attributes. Measurements in temporary sample plots located in all target polygons enabled us to estimate fit statistics between imputed and measured merchantable volumes. A parallel imputation exercise was also done using the current operational method used by the Province of Québec to map forest attributes over the publicly owned forest lands. Results show that the volumes estimated using the historical k-NN method show fit statistics similar to those of the operational method, with a slightly higher bias that is largely within the error term of the estimates. For both methods, the coefficient of determination between measured and imputed merchantable volume is between 0.16 and 0.19 for total volume, increases substantially when the volume is partitioned between hardwoods and softwoods, but then decreases when the volume is further distributed among species. The results underline the importance of photo-interpretation uncertainties in bounding the accuracy of volume imputation as well as the value of the k-NN procedure for imputation purposes in the context of natural forests.Key words: Forest inventory; non-parametric methods; photo-interpretation; pre-stratification; natural forests

This work is dedicated to the code verification of MPACT, which is developed under the Consortium for Advanced Simulation of Light Water Reactors by the University of Michigan and Oak Ridge National Laboratory, where the numerical solution is compared to the reference solution of a benchmark problem with a known analytical solution. In this work, Benchmark Problem 3.4 in Barry Ganapol’s benchmark book was chosen as an MOC code verification test problem. Problem 3.4 is a bare cylinder of infinite height, which is an excellent benchmark problem for 2D MOC. To ensure that this benchmark problem exercised the same code as typically used by MPACT, the bare rod configuration was surrounded by a bounding box filled with a non-scattering material. To avoid implementing a critical rod search in the MPACT code, the MPACT analysis was performed using cross sections that yielded the given c, the average number of secondary neutrons per collision, and a rod radius that was the corresponding critical rod radius. MPACT agreed with all cases to within a few pcm. The convergence behavior was studied. The results show a 2nd order radial convergence, consistent with flat-source approximation. The convergence curves with respect to ray spacing and polar angle quadrature set order were also obtained. The other quantity of interest tabulated for Problem 3.4 was the radial distribution of the scalar flux. Two configurations were analyzed, and the resultant radial flux profiles agreed very well with the tabulated results. The verification of the production neutronics code MPACT has been augmented by the addition of the analytical solutions for an infinite cylinder from the Ganapol benchmark book. These test cases can be included in the regression suite for MPACT.

Introduction: the article considers the high-alert regime and the associated restrictive measures related to the freedom of movement and introduced in connection with the threat of the spread of COVID-19. Aim: with the help of theoretical and legal analysis, we investigate the nature of the high-alert regime and the set of anti-epidemic measures implemented to prevent the spread of the COVID-19 pandemic; we also analyze the constitutionality and validity of restrictions on the right of an individual to freedom of movement and the proportionality of the restrictive measures imposed (quarantine, complete lockdown) in relation to the elderly, a particularly vulnerable population group. Methods: dialectical method, theoretical methods of formal and dialectical logic, comparative legal method, system-structural method, method of interpretation of legal norms, and others. Results: the research allows us to say that the set of terms related to the high-alert regime is not clearly defined from the legal perspective; moreover, there is no legally bounding limit to its operation (the period of its being in effect) and a mechanism for its direct implementation. We argue that the restriction of the freedom of movement for persons aged 65 and older is disproportionate in the context of their health protection interests. The article defines the following guarantees of restricting the exercise of the individual’s right to freedom of movement: the legality and validity of temporary administrative and legal measures, the balance between private interests (preserving the protection of the legal status) and public interests (preventing the spread of the infection), specifics of the epidemiological situation, a set of timely measures aimed at providing particularly vulnerable categories of citizens with everything vital. Conclusions: we propose to interpret the restriction of the exercise of an individual’s rights under a high-alert regime as a legally justified state intervention (through the adoption of proportionate restrictive measures) in the sphere of an individual’s private autonomy in order to protect national security, public order, human life and health. We consider it necessary that legislation should specify the provisions defining the range of circumstances when a high-alert regime is to be introduced, the limits, boundaries and scope of additional powers of special actors, and the scope of possible discretion; the means to ensure this administrative and legal regime; the list of rights and freedoms subject to restriction when it is established, as well as the mechanism for their protection. Keywords: Citizens’ rights and freedoms; freedom of movement; COVID-19 pandemic; high alert regime; restrictive measures; proportionality; elderly citizens (persons aged 65 and older)

Purpose: Plyometric exercises are incorporated in anterior cruciate ligament injures of the knee (ACL) injury prevention programs that have effectively decreased risk factors for anterior cruciate ligament injures of the knee injuries, but the impact on the rate of isometric torque development of the musculature of the knee is unclear. The purpose of this study was to determine the effects of a 6-week plyometric program pulled from a commonly utilized anterior cruciate ligament injures of the knee injury prevention program on rate of isometric torque development (RTD) in healthy active females. Methods: College-aged participants were randomly split into two different groups (16-plyometric training and 15-control). Plyometric exercises included 180° jumps, bounding for distance, bounding in place, broad jump-stick, cone jumps, hop - hop stick, jump into bounding, jump - jump - jump vertical jump, mattress jumps, scissors jump, single-legged jumps for distance, squat jumps, step-jump up-down-vertical jump, tuck jumps, and wall jumps. Participants in the training group performed the exercises three times a week on alternating days, for 30-minute sessions. All participants performed a vertical jump measurement and completed maximum voluntary isometric contractions (MVICs) of ankle plantar flexion, knee extension, and knee flexion rate of torque development. Results: There was a main effect of session for plantar flexion rate of torque development time windows and vertical jump. The analysis revealed no significant differences for group by session interactions for any other rate of torque development measurement or the vertical jump. Conclusions: Plyometric exercises utilized from an anterior cruciate ligament injures of the knee injury prevention program did not change lower body isometric torque development or vertical jump height of active females. Since the plyometric training did not improve vertical jump, the training may not have been performed vigorous enough for the participants to cause a neuromuscular adaptation. Based on findings, 6-weeks of plyometric training from an isolated ACL injury prevention program should not be used to increase the vertical jump of healthy, active females.

Abstract Background Chronic obstructive pulmonary disease (COPD) is a disorder linked with a multitude of extra pulmonary manifestations (also known as treatable traits), including low bone mineral density (BMD). To date, no specific guidelines exist for the management of BMD in this population. Impact loading exercise has been identified as an intervention that improves or maintains BMD in other populations. However, the feasibility of and tolerance to impact loading exercise has not been tested in people with COPD. The aim of the proposed study will be to investigate the feasibility and tolerance of adding impact loading exercise to a standard pulmonary rehabilitation programme (PRP) in people with COPD and report its effects on bone health, balance and falls risk. Methods This is a protocol for a pilot feasibility and tolerance randomised controlled trial (RCT). Fifty-eight people with COPD will be randomly allocated, on a 1:1 ratio, to either the experimental or control group. Initially, participants in both groups will complete a standard 8-week (twice-weekly) PRP followed by a 32-week period of maintenance exercises. Over the initial 8-week period, participants allocated to the experimental group will also undertake targeted lower limb resistance exercises and commence a programme of impact loading exercises (e.g. bounding and drop jumps). On completion of the initial 8-week PRP, in addition to the standard maintenance exercises, participants in the experimental group will continue with home-based impact loading exercises, four times a week, for the extra 32 weeks. The primary outcome of this study is feasibility of and tolerance to impact loading exercises. Feasibility will be measured using data collected pertaining to recruitment, withdrawal and completion. Adherence to the exercises will be collected using exercise logs. Tolerance to the exercises will be determined using outcomes to assess pain, recording any adverse effects such as a fall and feedback from the participants in semi-structured interviews on completing of the trial. The effects of the 40-week experimental intervention on bone health, balance and falls risk will be reported. Discussion This pilot RCT will test the feasibility and tolerance of an intervention that has never been trialed in people with COPD. It will also provide initial information regarding the size of the effect this intervention has on outcomes such as BMD, balance and falls risk. These data will be critical when designing a definitive RCT to advance this area of research. Trial registration Australian and New Zealand Clinical Trials Registry (ANZCTR): 12620001085965 (20/10/2020)

Abstract In recent decades, the number of evaluated interventions to improve access to school has multiplied, but few studies report long-term impacts. This paper reports the impact of an educational intervention that provided school uniforms to children in poor communities in Kenya. The program used a lottery to determine who would receive a school uniform. Receiving a uniform reduced school absenteeism by 37 percent for the average student (7 percentage points) and by 55 percent for children who initially had no uniform (15 percentage points). Eight years after the program began, there is no evidence of sustained impact of the program on highest grade completed or primary school completion rates. A bounding exercise suggests no substantive positive, long-term impacts. These results contribute to a small literature on the long-run impacts of educational interventions and demonstrate the risk of initial impacts depreciating over time.

The direct extension of the Hashin-Shtrikman methodology to nonlinear composite problems generally produces at most one new bound - either an upper bound or a lower bound - and in some cases produces no new bound at all. This paper is devoted to the construction of bounds, of generalized Hashin-Shtrikman type, for any nonlinear composite whose behaviour can be characterized in terms of a convex potential function. The construction relies on the use of a nonlinear comparison medium’ and trial fields with the property of ‘bounded mean oscillation’. This permits the exercise of control over the size of the penalty incurred from the use of a nonlinear, as opposed to linear, comparison medium. In cases where a linear comparison medium is adequate, the already established bounds of Hashin-Shtrikman type are reproduced. The exposition is presented in the context of bounding the properties of a nonlinear dielectric, for which a single bound was obtained previously by one of the authors. The approach, however, is applicable more generally.

This time last year we proposed the theme of the 'loop' issue to the M/C collective because it sounded deeply cool, satisfying our poststructuralist posturings about reflexivity and representation, while also tapping into everyday cultural objects and practices. We expected that the 'loop' issue would generate some interesting and varied responses, and it did. We received submissions about music, visual art, language, child development, pop-cultural artefacts, mathematics and culture in general. These explorations of disparate fields seemed, however, to be tied together by a common thread: the concept of "generation" itself. Each article in the 'loop' issue describes a loop that does not simply repeat an original operation, but that through iteration creates new possibilities and new meanings. More recently, when we began the process of putting the 'loop' issue together we found ourselves faced with a problem we had not envisaged: how might we structure the issue to reflect our guiding metaphor? How might we make articles about loops read like a loop? For all its decentredness, the web is ultimately still a linear medium, and one that constructs fairly rigorous and striated hierarchies. Even M/C, which has tried to set itself apart from traditional printed academic journals, is still structurally reminiscent of them. We toyed with the idea of hyperlinking articles or changing the table of contents from a descending list to a circular one. Apart from the inconceivably difficult task of convincing our web-designers to change the table of contents template for a one-off issue, such strategies would not necessarily have the desired effect. Readers could choose not to make use of our designed loop—hypertext would still work against us because readers might jump around in any order they desired. Moreover, the very necessity for the issue to have a "feature article" would straighten out any loop we might construct. An editorially enforced structure, it seemed, was not the answer. So we turned to our contributions. Strangely enough (or perhaps not strangely at all), we found that, read together, they could be perceived as generating their own internal spiralling system of interconnected loops. We as editors have therefore sought to place the contributions in an order that brings out this cyclical reading. The issue's feature article is Laurie Johnson's "Agency, Beyond Strange Cultural Loops"; a highly accessible, gently amusing, and deeply thought-out meditation on the production and analysis of culture. Johnson works his way from the simple concept of infinite loops in computer programs, though the strange loops described by Douglas Hofstader and drawn by M.C Escher in his work Drawing Hands, to what he calls "strange cultural loops", in which the reception of original signs is shaped by what has been seen before. He contends that such loops constitute culture, because the very notion of cultural re-production is impossible without considering agency. Infinite loops are infinite only if we decide them to be, just as culture is recognisable if and how we choose it to be. What makes culture easily graspable in everyday life, yet so difficult to analyse, is that reception is as productive of culture as creation. The first of our two special visual art features is Vince Dziekan's "The Synthetic Image", which is at once an exhibition of 13 digital artists and an exploration of the curatorial process. "The Synthetic Image" is an astounding interactive exhibition/installation which the user is invited to explore via a kind of looped nodal map. Indeed, "The Synthetic Image" immerses the user in three kinds of loops. First, art and critique are drawn together into interlinking loops. Second, a centrifugal hypertextual structure is used to both create and display a narrative space. Third, the metaphor of the loop is used to discuss the synthetic nature of digital art that explores the relationship between the real and the virtual. M/C is extremely proud to present this exhibition in conjunction with the Department of Multimedia and Digital Arts at Monash University, Melbourne. Simone Murray explores cultural production through corporate loops in "Harry Potter, Inc.: Content Recycling for Corporate Strategy". Murray investigates not the first-wave success of the books but the second-wave take up of Harry Potter as a franchisable cultural product with substantial multi-demographic appeal. This is a detailed examination of how America Online-Time Warner (AOL-TW) has linked its corporate strategy to the characteristics of the Harry Potter brand. More than a simple sequential marketing operation, AOL-TW recycles content of the books, film, and soundtracks, in three ways: reusing digital content to sell its own products, licencing significant portions of content to secondary manufacturers, and, finally, using Harry Potter content to stimulate interest in non-Harry Potter AOL-TW products. Content recycling exemplifies current corporate drives toward synergy. In "Mastering the 'Visual Groove': Animated Electric Light Bulb Signs, Locations, and Loops", Margaret Weigel reminds that looping media are not new phenomena, dating from the Victorian era and coming to particular prominence in the looping electric light bulb signs of the late 1800s and early 1900s. Our reactions to electric signs were, she argues, strangely similar to those of many new media: moral panic and debate, leading to acceptance and even fondness. Weigel describes many of these whimsical modernist spectacles, particularly those of Broadway (the "Great White Way") in the early 1900s, and then describes their reception by tourists and locals. While tourists were drawn to the nightly spectacles, locals mastered and integrated the cyclical marketing systems into their daily lives. Greg Hainge's "Platonic Relations: The Problem of the Loop in Contemporary Electronic Music" proposes a way in which looping in electronic music may avoid the banal "Platonic" mode of repetition maligned by Deleuze in Difference and Repetition. In electronic music, Hainge argues, this passive approach to the loop conceives of the sampled element as "constitut[ing] an originary identity," the repetition of which constructs "an absolute internal resemblance". Moreover, Platonic looping itself forms a kind of technologically-determinist feedback loop within which the electronic artist finds him- or herself caught. By analysing the way in which electronic artist Kaffe Matthews breaks free of the Platonic mode, Hainge identifies a more "improvisational and dynamic aesthetic" of looping. In "Making Data Flow: On the Implications of Code Loops", Adrian Mackenzie explores and typologises loops in computer code. He argues that computer code has become an object of intense interest in cultural life, perhaps because computer code is at least as generative of meaning as content is supposed to be. Loops are an integral part of the coding process, and are also an interesting way to investigate the generation of meaning through information flows. Mackenzie finds the distinguishing feature of code loops to be their bounding conditions. Different bounding conditions, of course, generate different information flows. Given this, flows can be adapted to different cultural purposes by writers, artists, and hackers interested in exploring different spatio-temporal manifolds. Andrew T. Jacobs, in "Appropriating a Slur: Semantic Looping in the African-American Usage of 'Nigga'", unravels the fascinating rhetorical process by which the highly charged epithet 'nigger' has been reclaimed as 'nigga' by African-Americans. Drawing on rhetorical analysis and African-American sociology, Jacobs argues that co-opting the slur has involved three looping mechanisms—agnominatio, semantic inversion, and chiastic slayingthemselves combined into a looping process which he calls "semantic looping". He concludes that the use of "nigga" is a resistance strategy that functions through both recalling and refuting racism. In "Loops and Fakes and Illusions", Keith Russell investigates the role loops play in the childhood development of social understanding. Not only do loops figure in development, but, as Russell's reading of D.W. Winnicott demonstrates, childhood development itself is a sustaining loop. Following John Dewey, Russell contends that perplexity is the source of intellectual development, and that children exercise their perplexity by puzzling over illusions based around loops. Russell explores how these illusions and fakes demonstrate the tensions and dynamics of social reality, concluding that playing with loops is a lifelong process. Cameron Brown's "Rep-tiles with Woven Horns" is the second of our special visual art features. The title of Brown's article is also the title of the image gracing the cover of this issue. The image itself is particularly suited to the "loop" issue because it is a fractal created by recursion. Brown's article describes the geometry and mathematics behind the image, providing a step-by step demonstration of its creation. We think that even non-mathematicians will follow the logic of the steps involved, and gain a deeper appreciation of both the power and elegance of recursion. As we must, we conclude the 'loop' issue much as we began it, exploring the links between agency and the generative power of the loop. Like Laurie Johnson, Luis O. Arata's "Creation by looping Interactions" questions the creative process involved in M.C. Escher's Drawing Hands, but imagines it as an animated process with two different outcomes. While one outcome is a closed loop—akin to the Platonic looping described by Hainge—generating only itself, the other is an open loop. Open loops, Arata contends, are a form of interaction, a powerful reflexive dialogue of participatory creation. He shows that cutting-edge science is finding the reflexive creativity of open loops to be increasingly important both to practice and theory, concluding that innovation is all the richer for it. Thus, one might say that Johnson and Arata each takes the role of one of the hands in the artwork they both analyse: Escher's Drawing Hands. Within that larger loop, smaller loops are described, and so, like Nietzsche, we find ourselves "insatiably calling out da capo" (56). References Nietzsche, Friedrich. Beyond Good and Evil. Trans. R.J. Hollingdale. Harmondsworth: Penguin, 1973. Citation reference for this article MLA Style Mitchell, Peta and Rintel, E. Sean. "Editorial" M/C: A Journal of Media and Culture 5.4 (2002). [your date of access] < http://www.media-culture.org.au/mc/0208/editorial.php>. Chicago Style Mitchell, Peta and Rintel, E. Sean, "Editorial" M/C: A Journal of Media and Culture 5, no. 4 (2002), < http://www.media-culture.org.au/mc/0208/editorial.php> ([your date of access]). APA Style Mitchell, Peta and Rintel, E. Sean. (2002) Editorial. M/C: A Journal of Media and Culture 5(4). < http://www.media-culture.org.au/mc/0208/editorial.php> ([your date of access]).