Three-Dimensional Kinematics of the Overarm Throwing Motion in Children Ages 2 to 7

Background and Purpose: Throwing is a meaningful play activity that encourages social interaction, develops the sequencing of motor skills, and signals the onset oftoddlerhood. Little published data clearly documents the three-dimensional kinematics ofthe progression of the overarm throwing motion in children. The purpose of this study is twofold: 1) To explore the biomechanical differences in the overarm throwing techniques of children between the ages of two and seven, and 2) To compare the kinematics of dominant versus non-dominant arm throws in children between the ages of two and seven. Methods: 1) Nine children, 6 males and 3 females, were classified into 3 age groups (2-3 years, 4-5 years, 6-7 years) and then videotaped while performing 6 overarm throws, 3 with each arm. 2) The Peak Motus Software was used to digitize and analyze the reflective markers on the resultant video and create data sets for each child. Five variables were analyzed: tyPe of throw, time of throw, ball velocity, maximum shoulder abduction, and elbow flexion at release. Results: 1) Older children consistently used the more mature \u27dynamic\u27 and \u27sequentially-linked\u27 throwing techniques, while the younger children were variable in their approaches. 2) The 6-7 year-olds took the longest time to throw and had the greatest time difference between arms (0.23 sec). 3) Ball velocity increased with age, with the greatest mean difference between arms (2.68 mls) occurring in the 6-7 year-olds. 4) The same group also averaged the largest amount of shoulder abduction (dominant = 60.8° Inon-dominant = 70.9°). 5) The 4-5 year-olds demonstrated the greatest amount of elbow flexion at ix release, and the largest mean difference (8.6°) between arms. Conclusion: In general, arm dominance seems to begin affecting the quality of throw between the ages of 5 and 6. Studies done with large numbers of subjects and equal sample sizes are needed to obtain statistically significant results which can be generalized to the normal population

Students' mental prototypes for functions and graphs

This research study investigates the concept of function developed by students studying English A-level mathematics. It shows that, while students may be able to use functions in their practical mathematics, their grasp of the theoretical nature of the function concept may be tenuous and inconsistent. The hypothesis is that students develop prototypes for the function concept in much the same way as they develop prototypes for concepts in everyday life. The definition of the function concept, though given in the curriculum, is not stressed and proves to be inoperative, with their understanding of the concept reliant on properties of familiar prototype examples: those having regular shaped graphs, such as x2 or sin*, those often encountered (possibly erroneously), such as a circle, those in which y is defined as an explicit formula in x, and so on. Investigations reveal significant misconceptions. For example, threequarters of a sample of students starting a university mathematics course considered that a constant function was not a function in either its graphical or algebraic forms, and threequarters thought that a circle is a function. This reveals a wide gulf between the concepts as perceived to be taught and as actually learned by the students

SLC-2000: A luminosity upgrade for the SLC

The authors discuss a possible upgrade to the Stanford Linear Collider (SLC), whose objective is to increase the SLC luminosity by at least a factor 7, to an average Z production rate of more than 35,000 per week. The centerpiece of the upgrade is the installation of a new superconducting final doublet with a field gradient of 240 T/m, which will be placed at a distance of only 70 cm from the interaction point. In addition, several bending magnet in each final focus will be lengthened and two octupole correctors are added. A complementary upgrade of damping rings and bunch compressors will allow optimum use of the modified final focus and can deliver, or exceed, the targeted luminosity. The proposed upgrade will place the SLC physics program in a very competitive position, and will also enable it to pursue its pioneering role as the first and only linear collider

Development of Readout Interconnections for the Si-W Calorimeter of SiD

The SiD collaboration is developing a Si-W sampling electromagnetic calorimeter, with anticipated application for the International Linear Collider. Assembling the modules for such a detector will involve special bonding technologies for the interconnections, especially for attaching a silicon detector wafer to a flex cable readout bus. We review the interconnect technologies involved, including oxidation removal processes, pad surface preparation, solder ball selection and placement, and bond quality assurance. Our results show that solder ball bonding is a promising technique for the Si-W ECAL, and unresolved issues are being addressed.Comment: 8 pages + title, 6 figure

Human C-peptide Dose Dependently Prevents Early Neuropathy in the BB/Wor-rat

In order to explore the neuroprotective and crossspecies activities of.C-peptide on type 1 diabetic neuropathy, spontaneously diabetic BB/W-rats were given increasing doses of human recombinant Cpeptide (hrC-peptide). Diabetic rats received 10, 100, 500, or 1000 μg of hrC-peptide/kg body weight/ day from onset of diabetes. After 2 months of hrC-peptide administration, 100 μg and greater doses completely prevented the nerve conduction defect, which was associated with a significant but incomplete prevention of neural Na+/K+-ATPase activity in diabetic rats with 500 μg or greater C-peptide replacement. Increasing doses of hrC-peptide showed increasing prevention of early structural abnormalities such as paranodal swelling and axonal degeneration and an increasing frequency of regenerating sural nerve fibers. We conclude that hrC-peptide exerts a dose dependent protection on type 1 diabetic neuropathy in rats and that this effect is probably mediated by the partially conserved sequence of the active C-terminal pentapeptid

Testing the Higgs Mechanism in the Lepton Sector with multi-TeV e+e- Collisions

Multi-TeV e+e- collisions provide with a large enough sample of Higgs bosons to enable measurements of its suppressed decays. Results of a detailed study of the determination of the muon Yukawa coupling at 3 TeV, based on full detector simulation and event reconstruction, are presented. The muon Yukawa coupling can be determined with a relative accuracy of 0.04 to 0.08 for Higgs bosons masses from 120 GeV to 150 GeV, with an integrated luminosity of 5 inverse-ab. The result is not affected by overlapping two-photon background.Comment: 6 pages, 2 figures, submitted to J Phys G.: Nucl. Phy

Mobility of thorium ions in liquid xenon

We present a measurement of the $^{226}$Th ion mobility in LXe at 163.0 K and 0.9 bar. The result obtained, 0.240$\pm$0.011 (stat) $\pm$0.011 (syst) cm$^{2}$/(kV-s), is compared with a popular model of ion transport.Comment: 6.5 pages,

Lycoris -- a large-area, high resolution beam telescope

A high-resolution beam telescope is one of the most important and demanding infrastructure components at any test beam facility. Its main purpose is to provide reference particle tracks from the incoming test beam particles to the test beam users, which allows measurement of the performance of the device-under-test (DUT). \LYCORIS, a six-plane compact beam telescope with an active area of $\sim$10$\times$\SI{10}{\square\centi\metre} (extensible to 10$\times$\SI{20}{\square\centi\metre}) was installed at the \DIITBF in 2019, to provide a precise momentum measurement in a \SI{1}{\tesla} solenoid magnet or to provide tracking over a large area. The overall design of \LYCORIS will be described as well as the performance of the chosen silicon sensor. The \SI{25}{\micro\metre} pitch micro-strip sensor used for \LYCORIS was originally designed for the \SID detector concept for the International Linear Collider. It adopts a second metallization layer to route signals from strips to the bump-bonded \KPIX ASIC and uses a wire-bonded flex cable for the connection to the DAQ and the power supply system. This arrangement eliminates the need for a dedicated hybrid PCB. Its performance was tested for the first time in this project. The system has been evaluated at the \DIITBF in several test-beam campaigns and has demonstrated an average single-point resolution of \SI{7.07}{\micro\meter}.Comment: 43 pages, 37 figure

THGEM-based detectors for sampling elements in DHCAL: laboratory and beam evaluation

We report on the results of an extensive R&D program aimed at the evaluation of Thick-Gas Electron Multipliers (THGEM) as potential active elements for Digital Hadron Calorimetry (DHCAL). Results are presented on efficiency, pad multiplicity and discharge probability of a 10x10 cm2 prototype detector with 1 cm2 readout pads. The detector is comprised of single- or double-THGEM multipliers coupled to the pad electrode either directly or via a resistive anode. Investigations employing standard discrete electronics and the KPiX readout system have been carried out both under laboratory conditions and with muons and pions at the CERN RD51 test beam. For detectors having a charge-induction gap, it has been shown that even a ~6 mm thick single-THGEM detector reached detection efficiencies above 95%, with pad-hit multiplicity of 1.1-1.2 per event; discharge probabilities were of the order of 1e-6 - 1e-5 sparks/trigger, depending on the detector structure and gain. Preliminary beam tests with a WELL hole-structure, closed by a resistive anode, yielded discharge probabilities of <2e-6 for an efficiency of ~95%. Methods are presented to reduce charge-spread and pad multiplicity with resistive anodes. The new method showed good prospects for further evaluation of very thin THGEM-based detectors as potential active elements for DHCAL, with competitive performances, simplicity and robustness. Further developments are in course.Comment: 15 pages, 11 figures, MPGD2011 conference proceedin