The effect of feedback and information on children's pedometer step counts at school

This study examined whether feedback or feedback plus physical activity information could increase the number of pedometer steps taken during 1 school week. One hundred seventy-seven students (mean age 9.124 ± 1.11 years) in three elementary schools participated. Schools were randomly assigned to control (CON), feedback (FB), or feedback plus information (FB+I) groups. Children wore pedometers during school time for 5 consecutive weekdays. The total steps of the groups were recorded at the end of each school day, with students in the FB and FB+I groups free to view their step counts. In addition, the FB+I group received information and ideas about how they could increase their daily steps. The CON group received no step-count feedback or information. Students in the FB+I group achieved significantly more steps per minute (17.17 ± 4.87) than those in the FB (13.77 ± 4.06, p = 0.003) and CON (12.41 ± 3.12, p = 0.0001) groups. Information, as well as step-count feedback, increased elementary students’ school-based physical activity (number of steps) in the short term. A longer intervention period is necessary to assess the sustained impact of this type of approach

Hawking radiation from "phase horizons" in laser filaments?

Belgiorno et al have reported on experiments aiming at the detection of (the analogue of) Hawking radiation using laser filaments [F. Belgiorno et al, Phys. Rev. Lett. 105, 203901 (2010)]. They sent intense focused Bessel pulses into a non-linear dielectric medium in order to change its refractive index via the Kerr effect and saw creation of photons orthogonal to the direction of travel of the pluses. Since the refractive index change in the pulse generated a "phase horizon" (where the phase velocity of these photons equals the pulse speed), they concluded that they observed the analogue of Hawking radiation. We study this scenario in a model with a phase horizon and a phase velocity very similar to that of their experiment and find that the effective metric does not quite correspond to a black hole. The photons created in this model are not due to the analogue of black hole evaporation but have more similarities to cosmological particle creation. Nevertheless, even this effect cannot explain the observations -- unless the pulse has significant small scale structure in both the longitudinal and transverse dimensions.Comment: 13 pages RevTeX, 2 figure

Wet-Based Glaciation on Mars

Mars is a glacial planet. It hosts water ice in large polar ice caps, and in thousands of ‘viscous flow features’ in its mid latitudes that are thought to be debris-covered water ice glaciers. These ice deposits range between a few million to ~1 billion years in age and formed during Mars’ most recent epoch, the late Amazonian. The late Amazonian was characterised by extremely cold and arid climate conditions that are not conducive to melting of ice. Consequently, late-Amazonian glaciation has been dominated by cold-based glacier thermal regimes. However, the recent discovery of an esker (a ridge of sediment deposited by meltwater flowing through a tunnel within or beneath glacial ice) associated with a viscous flow feature in the Phlegra Montes region of Mars’ northern mid latitudes provided the first indicative evidence that wet-based glaciation occurred in at least one location during the late Amazonian. In this thesis, I present the discovery of a second candidate esker associated with a viscous flow feature, in the NW Tempe Terra region of Mars’ northern mid latitudes. I argue that the remarkably similar geologic settings of the NW Tempe Terra and Phlegra Montes candidate eskers (both within tectonic rift/graben valleys) suggests that geothermal heating, possibly with an additional component of viscous strain heating within the basal ice, was a prerequisite for basal melting under cold climate conditions. I then characterise the 2D and 3D morphometries of these candidate eskers, undertake comparisons with the morphometries of ancient putative eskers on Mars and eskers on Earth, and develop conceptual models for the dynamics of esker formation in NW Tempe Terra. Finally, I present a geomorphic map of Chukhung crater, Mars, which hosts esker-like sinuous ridges associated with viscous flow features and provides a case study of the ongoing challenges for esker identification on Mars

Breaking of the overall permutation symmetry in nonlinear optical susceptibilities of one-dimensional periodic dimerized Huckel model

Based on infinite one-dimensional single-electron periodic models of trans-polyacetylene, we show analytically that the overall permutation symmetry of nonlinear optical susceptibilities is, albeit preserved in the molecular systems with only bound states, no longer generally held for the periodic systems. The overall permutation symmetry breakdown provides a fairly natural explanation to the widely observed large deviations of Kleinman symmetry for periodic systems in off-resonant regions. Physical conditions to experimentally test the overall permutation symmetry break are discussed.Comment: 7 pages, 1 figur

A COMPARISON OF THREE RACKET SKILLS EXECUTED SY NOVICE AND EXPERIENCED PERFORMERS

INTRODUCTIONT he purpose of this investigation was to compare an adult novice (NOV) with an experienced (EXP) adult performing a badminton deep serve, a racquetball forehand, and a racquetball drive serve. Movements were videotaped by 4cameras at 120 Hz and the 3-D data were analyzed using the PEAK5 motion measurement system. Range of motion (ROM), sequence of motion, and temporal values were assessed on the following angular movements: absolute pelvic (P) and upper torso (UT) rotation, and relative humeral (H), elbow (E), and wist (W) rotation. RESULTS For each skill and performer, the segmental sequence and ROM are presented. This information is followed by the range of lag times (LT) between segments within the sequence and the total time (TT) (backswing to contact)over which the skill occurred. Badminton Serve EXP P(37.4"),UT(69.6"), H(76.3"), W(59.7"), E(16.0°).LT(.02-.I 8s). TT(.23s).NOV UT(30.4"), P(l 3.0°), H(67.0°),W(10.2"), E(34.2").LT(.OI -.14~)T. T(.2Os).Racquetball Forehand EXP H(68.8"),P(57.g0),U T(71. I") , W(ll .go), E(12.8").LT(.02-.1 0s). TT(. II S).NOV P(34.8"), UT(69.2"), W(59.4"),E(8.7"), H(10.7").LT(.03-. 1 3s). TT(.20s).Racquetball Serve U(P P(92.4"),UT(122.0°), H(154.0°), E(75.3"),W(41.8"). LT(.00-. 10s). TT(. 1 8s).NOV P(64.3"), UT(77.g0), W(81 .OO),H(87.0°), E (0.8").LT(.OI -. 14s). TT(. 194.CONCLUSIONS1) Results for the badminton serve indicated the EXP exhibited greater ROM than the NOV for all angles except E. The NOV constrained the W to possibly allow for the greater E movement.2) In the forehand and in the racquetball serve, the NOV constrained the elbow more than the EXP which was consistent with Southard's (1 987) results; however, the great W ROM was inconsistent and appeared to be a last resort to generatevelocity.3) The EXP was more compact performing the forehand than the racquetball serve. During the serve, the lack of initial ball velocity required greater ROM to achieve the goal.4) In all 3 tasks, the EXP displayed essentially the same sequence of propulsive segmental initiation (proximal to distal). The patterns exhibited by the NOV were more simultaneous and the sequences varied for each task. REFERENCES Bird, M., Hills, L., & Hudson, J. L.(1 991 ). Intersegmental coordination: an exploration of context. In C. Tant, P.Patterson, & S. York (Eds.),Biomechanics in Sworts IX: Proceedings of the 9th International Symposium on Biomechanics in Sports (pp. 233-237).Ames, IA: Iowa State University.Southard, D. & Higgins,T,. (1 987).Changing movement patterns: effects of demonstration and practice. Research Quarterlv for Exercise and Sport, 58(1),77-80

The evolution of water control in modern farming systems: a case study of D & S Turner, Brookton, WA

Darrell and Suzanne Turner’s WISALTS journey began after Darrell’s father David became a firm believer of the WISALTS method. Their family’s first introduction to Harry Whittington’s work was in early 1970’s when Harry established a bank from one of their waterholes to the Aldersyde-Kweda road. They witnessed the bank running water and to this day it still does. It was in the mid 1980’s that the first test of major renovations began, Tom Mills (WISALTS Quairading) came and surveyed an 8 kilometre bank. This bank was constructed as a double push dozer bank which had a good result initially, this confirmed to Darrell and his father that they were on the right track. However, over time the clay broke down and the bank began to leak in the sandy areas, which created other problems. To counter this problem, WISALTS decided to test whether lining the sand seams with a plastic barrier would stop the leak. The majority of work began in the mid 1990’s with the installation of banks and plastic in the deeper sand areas. This method proved more effective than the traditional double push method, however, there were still some issues with water moving around the edges of plastic. By the late 1990’s after a WISALTS discussion with Harry and Laurie Adamson (WISALTS Quairading) it was decided that plastic should be used in all the banks as it gave a more effective and durable seal. At this time Darrell began working with Noel Powell, purchasing a shared excavator to make this labour-intensive job more efficient. From 1998 to 2005 Darrell and Noel worked together to install many kilometres of plastic lined banks on their farms and properties throughout the district. Recently Darrell has begun filling in the banks and leaving the plastic lining. This has allowed machinery to operate over the plastic barriers and the paddocks could be worked as normal without the obstacle of the banks. The results from installing Interceptor Barriers (plastic lined trench with-out a surface bank) gave a significant reduction in waterlogged areas and a more even distribution of water over the landscape. It stopped the water accumulating in seepage areas (sand plain seeps) and retained the water higher in the landscape for the crop to use. The recent filling in of banks has also eliminated weed problems caused by the banks. The plastic lined method has also helped to stem water flow from neighbour’s properties (see case study 1). This has allowed areas to remain productive and prevent or slow the spread of salinity. Darrell’s rational for installing Interceptor Barriers are driven by increases in productivity with environmental benefits as a bonus. The vision for the future is a continuation of installing plastic barriers starting at the top of the hill and a program to fill in the old banks to take advantage of GPS technologies and weed control. With knife points, stubble retention and 100% cropping there is no longer a need to manage surface water flow. This publication is part of the WISALTS (Whittington Interceptor Sustainable Agriculture Land Treatment Society Incorporated) Collection

Optical (VRI) Photometry in the Field of the Galaxy Cluster AC 118 at z=0.31

We present new photometric V-, R- and I-band data for the rich galaxy cluster AC 118 at z=0.31. The new photometry covers an area of 8.6x8.6 arcmin$^2$, corresponding to 2.9$\times$2.9 Mpc$^2$ (H$_0=50$ km s$^{-1}$ Mpc$^{-1}$, q$_0=0.5$ and $\Lambda = 0$). The data have been collected for a project aimed at studying galaxy evolution through the color-magnitude relation and the fundamental plane. We provide a catalogue including all the sources (N = 1206) detected in the cluster field. The galaxy sample is complete to V=22.8 mag (N_gal=574), R=22.3 mag (N_gal=649) and I=20.8 mag (N_gal=419). We give aperture magnitudes within a fixed aperture of 4.4 arcsec and Kron magnitudes. We also give photometric redshifts for 459 sources for which additional U- and K-band photometry is available. We derive and discuss the V- and R-band luminosity functions. The catalogue, which is distributed in electronic form, is intended as a tool for studies in galaxy evolution.Comment: 15 pages, 6 figures, A&A in pres

Long term minimum tillage investigations, Stubble management, Deep ripping

Direct drilling Long term minimum tillage investigations (1) Continuous cropping – 77A16, 77A18, 77MT15, 77WH17, 77WH13, 78M25. (2) Rotational cropping – 77A43, 77E52, 77M35, 77M56, 77MT51, 77WH8. Stubble management – 79M7, 79WH6, 82M34, 84M1, 82LG4, 82LG46 (82KD1). Deep ripping - 82M35 in Minimum Tillage Rotation section also contains a deep ripping treatment. 77WH17, 80A44, 80NO46, 81M45, 81NO3, 81NO4, 82GE37, 82GE38, 82M30, 82M46, 82M60, 82ME38, 82N32, 82WH49, 84E24, (84C42, 84C43, 84C44, 84C45, 84C46) Eradu Sandplain – ECRS, 84E23, 84E24, 84JE43, 84JE44, 84LG37, 84M38, 84NO58, 84WH2, 84WH3, 84WH39. Additional deep ripping research is included in summaries by W. Bowden, D. Tennant, J. Hamblin, J. Wilson

A comparison of human and computer marking of short free-text student responses

The computer marking of short-answer free-text responses of around a sentence in length has been found to be at least as good as that of six human markers. The marking accuracy of three separate computerised systems has been compared, one system (Intelligent Assessment Technologies FreeText Author) is based on computational linguistics whilst two (Regular Expressions and OpenMark) are based on the algorithmic manipulation of keywords. In all three cases, the development of high-quality response matching has been achieved by the use of real student responses to developmental versions of the questions and FreeText Author and OpenMark have been found to produce marking of broadly similar accuracy. Reasons for lack of accuracy in human marking and in each of the computer systems are discussed