Spatial reasoning to determine stream network from LANDSAT imagery

In LANDSAT imagery, spectral and spatial information can be used to detect the drainage network as well as the relative elevation model in mountainous terrain. To do this, mixed information of material reflectance in the original LANDSAT imagery must be separated. From the material reflectance information, big visible rivers can be detected. From the topographic modulation information, ridges and valleys can be detected and assigned relative elevations. A complete elevation model can be generated by interpolating values for nonridge and non-valley pixels. The small streams not detectable from material reflectance information can be located in the valleys with flow direction known from the elevation model. Finally, the flow directions of big visible rivers can be inferred by solving a consistent labeling problem based on a set of spatial reasoning constraints

Parasitism, Adult Emergence, Sex Ratio, and Size of \u3ci\u3eAphidius Colemani\u3c/i\u3e (Hymenoptera: Aphidiidae) on Several Aphid Species

Aphidius colemani Viereck parasitizes several economically important aphid pests of small grain crops including the greenbug, Schizaphis graminum and the Russian wheat aphid, Diuraphis noxia. The ability of A. colemani to switch from S. graminum to several species of aphids common to agricultural and associated non-agricultural ecosystems in the Great Plains, and the effects of host-change on several biological parameters that influence population growth rate were determined. Female A. colemani parasitized and developed to adulthood in nine of 14 aphid species to which they were exposed in the laboratory. All small grain feeding aphids except Sipha flava were parasi­tized. Two sunflower feeding species (Aphis nerii and A. helianthi) and two crucifer feeding species (Lipaphis erysimi and Brevicoryne brassicae) were parasitized, as was the cotton aphid. Aphis gossypii. The average percentage of aphids parasitized differed significantly among host aphid species. as did the percentage of parasitoids surviving from the mummy to the adult stage and the time required for immature development. The sex ratio of adults that enclosed from the various hosts did not differ significantly among species. Dry weights of adult parasitoids differed significantly among host species. Adults from S. graminum weighed most (0.054 mg) while those emerging from A. helianthi weighed least (0.020 mg). Results are discussed in terms of strategies for classical biological control of aphid pests of cereals

TASK DECOMPOSITION AND THE HIGH PERFORMANCE JUNIOR TENNIS SERVE

To develop consistency in the toss placement and racket trajectory, coaches often decompose the serve and practise it in separate parts. This study compared the kinematics of the ball toss as part of the discrete serve skill and when the skill was decomposed. A 22 camera VICON MX motion analysis system, operating at 250 Hz, captured racket and ball kinematics of 5 elite junior players hitting flat first serves (FS) directed to the ‘T’ of the deuce service box and a ball toss (BT) drill where players were instructed to perform the decomposed skill as in the FS. Paired t-tests were used to assess within-group differences. Vertical displacement of ball zenith increased significantly (~20cm) during BT. Consistency in select racket and ball kinematics characterised the FS, while this appeared to decrease in BT

SEAT SPECIFIC TECHNIQUE IN PAIR OARED ROWING

Biomechanical analyses were conducted on ten established pair combinations to determine if evidence existed to support the theory of seat specific rowing technique. No statistically significant differences were found between stern and bow seat rowers in the variables analysed, but sufficient evidence existed to warrant further investigation into this issue. When two rowers who demonstrated the appropriate seat specific technique were combined, the improvement in average boat velocity was 8 standard deviations greater than the control group mean. It was concluded that the improved boat velocity produced by this crew was at least partially due to the combination of rowers who exhibited the appropriate seat specific technique

‘BEND IT LIKE BECKHAM’: BALL ROTATION IN THE CURVED FOOTBALL KICK

The objectives of this study were to quantify the 3D angular velocity and spin axes of a curved versus straight kick for goal in football. A 12 camera 250 Hz 3D Vicon motion analysis system recorded 4 semi-professional soccer players, as they performed 5 straight (S) and 10 curved (C) kicks. While the velocity of the ball was similar for both kicks (~20 m.s-1), spin rate was significantly different (S=22.6 rad.s-1; C=36.4 rad.s-1). While the level of spin for the straight kick was surprising, the elevation angle of its spin axis was significantly lower in the straight compared with curved kicks (S=30.4°; C=62.6°

Selection of an instrument to evaluate the organizational environment of nurses working in intensive care: an integrative review

Objective: To determine an appropriate survey instrument to evaluate the impact of organizational structures on the work environment of intensive care nurses. Background: Internationally the demand for intensive care is increasing. Solely increasing bed capacity is not sustainable. Large capacity multi-specialty Intensive Care Units are emerging as the preferred organizational model with benefits resulting from optimizing operational synergies and economies of scale. The impact of this organizational transition on intensive care nurses is not well understood. An appropriate survey instrument for intensive care nurses is required. Design: Integrative literature review. Data Sources: CINAHL, PubMed, EMBASE and OVID Nursing databases searched for studies published between 2005 and 2013. Review methods: An integrative review and quality assessment of the studies was undertaken to select nurse outcome measures associated with organizational structures across a range of acute and critical care settings. Congruence between nurse outcome measures and nurse survey instruments tested in the literature was assessed to select instruments for further psychometric evaluation. Results: Thirty-one cross sectional quantitative studies, from fourteen countries, were reviewed. Twenty one nurse outcome measures associated with organizational factors were identified and a total of twenty five survey instruments used in the studies reviewed. Assessment of congruence and psychometric properties determined that a combination of two instruments is required to comprehensively assess the organizational environment of nurses working in intensive care units. Conclusion: The environment of nurses working in intensive care is effectively evaluated with an instrument that combines subscales from the Practice Environment Scale-Nurse Work Index and Maslach’s Burnout Inventory

The Preventing Australian Football Injuries with Exercise (PAFIX) Study: a group randomised controlled trial

Background: Knee injuries are a major injury concern for Australian Football players and participants of many other sports worldwide. There is increasing evidence from laboratory and biomechanically focused studies about the likely benefit of targeted exercise programmes to prevent knee injuries. However, there have been few international studies that have evaluated the effectiveness of such programmes in the real-world context of community sport that have combined epidemiological, behavioural and biomechanical approaches. Objective: To implement a fully piloted and tested exercise training intervention to reduce the number of football-related knee injuries. In so doing, to evaluate the intervention's effectiveness in the real-world context of community football and to determine if the underlying neural and biomechanical training adaptations are associated with decreased risk of injury. Setting: Adult players from community-level Australian Football clubs in two Australian states over the 2007-08 playing seasons. Methods: A group-clustered randomised controlled trial with teams of players randomly allocated to either a coach-delivered targeted exercise programme or usual behaviour (control). Epidemiological component: field- based injury surveillance and monitoring of training/game exposures. Behavioural component: evaluation of player and coach attitudes, knowledge, behaviours and com- pliance, both before and after the intervention is implemented. Biomechanical component: biomechanical, game mobility and neuromuscular parameters assessed to determine the fundamental effect of training on these factors and injury risk. Outcome measures: The rate and severity of injury in the intervention group compared with the control group. Changes, if any, in behavioural components. Process evaluation: coach delivery factors and likely sustainability

Graphical description of the action of Clifford operators on stabilizer states

We introduce a graphical representation of stabilizer states and translate the action of Clifford operators on stabilizer states into graph operations on the corresponding stabilizer-state graphs. Our stabilizer graphs are constructed of solid and hollow nodes, with (undirected) edges between nodes and with loops and signs attached to individual nodes. We find that local Clifford transformations are completely described in terms of local complementation on nodes and along edges, loop complementation, and change of node type or sign. Additionally, we show that a small set of equivalence rules generates all graphs corresponding to a given stabilizer state; we do this by constructing an efficient procedure for testing the equality of any two stabilizer graphs.Comment: 14 pages, 8 figures. Version 2 contains significant changes. Submitted to PR

A COMPARISON OF UNDERWATER GLIDING AND KICKING TECHNIQUES

Net forces created when towing swimmers through water were examined for gliding and undelwater kicking. Sixteen experienced male swimmers of similar body shape were towed through water via a motorised winch and pulley system. A load cell measured net force (propulsive force - drag force) at velocities of 1.6, 1.9, 2.2, 2.5 and 3.1 ms-', respectively. At each velocity swimmers performed a prone streamline glide; lateral streamline glide; prone freestyle kick; prone dolphin kick; and lateral dolphin kick. A 2- way repeated measures ANOVA revealed significant differences between the gliding and kicking conditions at different velocities. Results suggest that there is an optimal velocity at which to begin undelwater kicking in order to prevent energy loss from excessive active drag