KINEMATIC ANALYSIS OF CYCLING DURING PREGNANCY

How much? What kind? Should I? These are questions often asked by pregnant women concerning their exercise and sport activities during pregnancy, but there is, to date, very little research in the area of biomechanics and pregnant women in sport. According to Dr. Lynne Pyrie (1987), cycling is a sport made for pregnant women. Cycling was found to strengthen the pelvic floor muscles used to propel the baby through the birth canal. However, Freyder (1989) described how with the progression of pregnancy, the center of gravity was shifted back over the pelvis to prevent falling forward causing a new, unstable posture. It is also mentioned in the literature the effects of the hormones progesterone and relaxin which cause softening of the ligaments and thus less joint stability. The purpose of this study was to compare the biomechanical changes that occurred during and following pregnancy in the sport of cycling. The subject in this study was an avid cyclist and was familiar with and trained on bicycle rollers. While cycling on a set of bicycle rollers, the subject was videotaped (60 fps) in the frontal and sagittal planes three times from two to seven months in gestation and two times during the three months after childbirth. Each performance was then digitized and analyzed using the PEAK Performance 2- dimensional movement analysis system interfaced with a Panasonic AG-7350 recorder, Sony PVM-1341 monitor, and Zenith 486 microcomputer. The horizontal and vertical linear displacements of the center of gravity and angular displacements of the right and left hips were compared. It was found that as pregnancy progressed: (a) horizontal and vertical displacements of the center of gravity increased as well as variability, (b) angular displacements of the hips increased, and (c) additional external stabilization of the performer was required. It was concluded that as pregnancy progressed, stability on the bicycle decreased gradually to the point that during the last trimester additional support was required. This research adds to the literature which supports pregnant women continuing their exercise programs that are non-weight bearing during the first two-thirds of their pregnancy but also supports the literature that cautions about the increased risk of injury due to greater instability during the latter stages

KINEMATIC COMPARATIVE ANALYSIS OF THE COORDINATION PATTERN OF THE BASKETBALL FREE THROW

Coordination patterns are an important part of everyday movement. The pattern of intersegmental movement is specific to each task we perform. Hudson (1986) broke down tasks into two basic categories: simultaneous which is used when accuracy is important to the task, and sequential which is used when velocity is the key to the task. The sequential pattern of movement is best defined by the summation of speed principle put forth by Bunn (1972) when he stated that in activities where the highest speed at the moment of release was necessary, the speed was developed when the movement of each segment started at the moment of greatest velocity of the preceding segment. The purpose of this study was to conduct a comparative biomechanical analysis of the system of coordination used in the basketball free throw. Four individuals of different abilities ranging from elite (a professional basketball player) to novice (an eleven year old boy with little basketball experience) participated in this study. The subjects were video taped (60 fps) shooting a free throw on a regulation basketball court in the sagittal plane on the right side (all subjects were right handed). Each performance was digitized and analyzed using the PEAK Performance 2-dimensional movement analysis system interfaced with a Panasonic AG-7350 recorder, Sony PVM-1341 monitor, and Zenith 486 microcomputer. The angular velocity of the shoulder, elbow, and wrist of the shooting arm and the hip, knee, and ankle of the same side were examined. It was found that all subjects exhibited simultaneous movement of all three joints of the leg. The elite performer exhibited sequential movement of the segments of the shooting arm where the novice exhibited complete simultaneous movement. From the results of the study, the free throw was defined as an intermediate task requiring both velocity and accuracy. This research may be used as a coaching tool in improving the performance of the free throw for any basketball player by studying the detailed analysis of the pattern of coordination of a professional player then comparing the player to any subject on the continuum outlined in this study

A new lower bound approach for single-machine multicriteria scheduling

The concept of maximum potential improvement has played an important role in computing lower bounds for single-machine scheduling problems with composite objective functions that are linear in the job completion times. We introduce a new method for lower bound computation; objective splitting. We show that it dominates the maximum potential improvement method in terms of speed and quality

Achieving Health Equity in Embedded Pragmatic Trials for People Living with Dementia and Their Family Caregivers

Embedded pragmatic clinical trials (ePCTs) advance research on Alzheimer's disease/Alzheimer's disease and related dementias (AD/ADRD) in real-world contexts; however, health equity issues have not yet been fully considered, assessed, or integrated into ePCT designs. Health disparity populations may not be well represented in ePCTs without special efforts to identify and successfully recruit sites of care that serve larger numbers of these populations. The National Institute on Aging (NIA) Imbedded Pragmatic Alzheimer's disease (AD) and AD-Related Dementias (AD/ADRD) Clinical Trials (IMPACT) Collaboratory's Health Equity Team will contribute to the overall mission of the collaboratory by developing and implementing strategies to address health equity in the conduct of ePCTs and ensure the collaboratory is a national resource for all Americans with dementia. As a first step toward meeting these goals, this article reviews what is currently known about the inclusion of health disparities populations of people living with dementia (PLWD) and their caregivers in ePCTs, highlights unique challenges related to health equity in the conduct of ePCTs, and suggests priority areas in the design and implementation of ePCTs to increase the awareness and avoidance of pitfalls that may perpetuate and magnify healthcare disparities

Gaussian quantum computation with oracle-decision problems

We study a simple-harmonic-oscillator quantum computer solving oracle decision problems. We show that such computers can perform better by using nonorthogonal Gaussian wave functions rather than orthogonal top-hat wave functions as input to the information encoding process. Using the Deutsch-Jozsa problem as an example, we demonstrate that Gaussian modulation with optimized width parameter results in a lower error rate than for the top-hat encoding. We conclude that Gaussian modulation can allow for an improved trade-off between encoding, processing and measurement of the information.Comment: RevTeX4, 10 pages with 4 figure

Theory of coherent acoustic phonons in InGaN/GaN multi-quantum wells

A microscopic theory for the generation and propagation of coherent LA phonons in pseudomorphically strained wurzite (0001) InGaN/GaN multi-quantum well (MQW) p-i-n diodes is presented. The generation of coherent LA phonons is driven by photoexcitation of electron-hole pairs by an ultrafast Gaussian pump laser and is treated theoretically using the density matrix formalism. We use realistic wurzite bandstructures taking valence-band mixing and strain-induced piezo- electric fields into account. In addition, the many-body Coulomb ineraction is treated in the screened time-dependent Hartree-Fock approximation. We find that under typical experimental conditions, our microscopic theory can be simplified and mapped onto a loaded string problem which can be easily solved.Comment: 20 pages, 17 figure

Precise measurements of radio-frequency magnetic susceptibility in (anti)ferromagnetic materials

Dynamic magnetic susceptibility, $\chi$, was studied in several intermetallic materials exhibiting ferromagnetic, antiferromagnetic and metamagnetic transitions. Precise measurements by using a 14 MHz tunnel diode oscillator (TDO) allow detailed insight into the field and temperature dependence of $\chi$. In particular, local moment ferromagnets show a sharp peak in $\chi(T)$ near the Curie temperature, $T_c$. The peak amplitude decreases and shifts to higher temperatures with very small applied dc fields. Anisotropic measurements of CeVSb$_3$ show that this peak is present provided the magnetic easy axis is aligned with the excitation field. In a striking contrast, small moment, itinerant ferromagnets (i.e., ZrZn$_2$) show a broad maximum in $\chi(T)$ that responds differently to applied field. We believe that TDO measurements provide a very sensitive way to distinguish between local and itinerant moment magnetic orders. Local moment antiferromagnets do not show a peak at the N\'eel temperature, $T_N$, but only a sharp decrease of $\chi$ below $T_N$ due to the loss of spin-disorder scattering changing the penetration depth of the ac excitation field. Furthermore, we show that the TDO is capable of detecting changes in spin order as well as metamagnetic transitions. Finally, critical scaling of $\chi(T,H)$ in the vicinity of $T_C$ is discussed in CeVSb$_3$ and CeAgSb$_2$

Future Directions in Parity Violation: From Quarks to the Cosmos

I discuss the prospects for future studies of parity-violating (PV) interactions at low energies and the insights they might provide about open questions in the Standard Model as well as physics that lies beyond it. I cover four types of parity-violating observables: PV electron scattering; PV hadronic interactions; PV correlations in weak decays; and searches for the permanent electric dipole moments of quantum systems.Comment: Talk given at PAVI 06 workshop on parity-violating interactions, Milos, Greece (May, 2006); 10 page

The Van der Waals interaction of the hydrogen molecule - an exact local energy density functional

We verify that the van der Waals interaction and hence all dispersion interactions for the hydrogen molecule given by: W"= -{A/R^6}-{B/R^8}-{C/R^10}- ..., in which R is the internuclear separation, are exactly soluble. The constants A=6.4990267..., B=124.3990835 ... and C=1135.2140398... (in Hartree units) first obtained approximately by Pauling and Beach (PB) [1] using a linear variational method, can be shown to be obtainable to any desired accuracy via our exact solution. In addition we shall show that a local energy density functional can be obtained, whose variational solution rederives the exact solution for this problem. This demonstrates explicitly that a static local density functional theory exists for this system. We conclude with remarks about generalising the method to other hydrogenic systems and also to helium.Comment: 11 pages, 13 figures and 28 reference

Transverse Momentum in Semi-Inclusive Polarized Deep Inelastic Scattering and the Spin-Flavor Structure of the Proton

The non-valence spin-flavor structure of the nucleon extracted from semi-inclusive measurements of polarized deep inelastic scattering depends strongly on the transverse momentum of the detected hadrons which are used to determine the individual polarized sea distributions. This physics may explain the recent HERMES observation of a positively polarized strange sea through semi-inclusive scattering, in contrast to the negative strange sea polarization deduced from inclusive polarized deep inelastic scattering.Comment: 4 pages, revtex style, 2 figure