2,623 research outputs found

    Drug trafficking in the Golden Triangle: The Myanmar problem and ASEAN effectiveness

    Get PDF
    This essay explores the issue of drug trafficking and production in Myanmar to understand the extent of damage this problematic situation has on the South East Asian region and to discuss what steps are being taken by institutions to stem the proliferation of narcotics such as heroin and amphetamines. Myanmar’s turbulent political history and unique geographical position have been explained to garner knowledge on why drug trafficking and production are so closely associated with the nation. The policymaking efforts of the Association of South East Asian Nations (ASEAN) to combat drug trafficking and production in the region have so far been plagued by obstructions such as internal corruption, a lack of multilateral cooperation and insufficient resources. These barriers combine to create policy that it is aligned closer to empty rhetoric than actual physical implementation. The ASEAN and China Cooperative Operations in Response to Dangerous Drugs (ACCORD) agreement has shown signs of a changing tide toward effective policymaking, due mainly to China stepping up to the plate of regional leadership. This essay recommends that in order to successfully fight drug trafficking and production, ASEAN need to establish more realistic and achievable goals with an emphasis on rehabilitation rather than punishment. Furthermore, compliance mechanisms should be put in place by ASEAN so that countries such as Myanmar, who often deviate from the status quo of drug policy, will be reprimanded for doing so in the future. Thus, creating an environment of multilateral cooperation, togetherness and consistency in relation to combatting the illegal drug trafficking and production trad

    CHANGES IN 800 METER PERSONAL RECORDS FOR COMPETITIVE FEMALE RUNNERS FROM HIGH SCHOOL TO COLLEGE

    Get PDF
    TTo advance understanding of improvements in running performance, changes in personal records (PR) from high school to college were compared. It was hypothesized that females competing in the 800m in college would improve PR times from high school to college, improvements would be different between athletic conferences, and modern statistical methods could differentiate trends in the relationship between high school and college PR. Data from female athletes competing in the 800m from three different athletic conferences (n=73) were gathered from published race results and 79.4% improved by at least 1s with no significant differences between conferences. A positive relationship exists between high school and college PRs. Knowledge of changes in running performance provides context when interpreting an individual’s improvements in running biomechanics over time

    The impact of 120 minutes of match-play on recovery and subsequent match performance:a case report in professional soccer players

    Get PDF
    The influence of a match including extra-time (ET) on subsequent 90 min match performance and recovery has not been investigated. Four professional soccer players played in three competitive matches in a 7-day period: matches one (MD1) and three (MD3) lasted 90 min and match 2 (MD2) lasted 120 min (i.e., included ET). Physical (total and high-intensity (HI) distance covered, accelerations and decelerations, and mechanical load) and technical performances (pass and dribble accuracy) were analyzed throughout match-play. Subjective measures of recovery and countermovement jump (CMJ) height were made 36–42 h post-match. Post-MD2, there were very or most likely harmful effects of ET on CMJ height (−6 ± 9%), muscle soreness (+18 ± 12%), and fatigue (+27 ± 4%) scores, and overall wellness score (−13 ± 5%) compared to post-MD1. Furthermore, there were very likely harmful effects on muscle soreness (+13 ± 14%), wellness scores (−8 ± 10%), and CMJ height (−6 ± 9%) post-MD3 vs. post-MD1. There was a possibly harmful effect of ET on HI distance covered during MD3, along with reductions in pass (−9.3%) and dribble (−12.4%) accuracy. An ET match negatively impacted recovery 36 h post-match. Furthermore, in some players, indices of performance in a 90 min match played 64 h following ET were compromised, with subsequent recovery also adversely affected

    Experimental Upper Bounds for Resonance-Enhanced Entangled Two-Photon Absorption Cross Section of Indocyanine Green

    Full text link
    Resonant intermediate states have been proposed to increase the efficiency of entangled two-photon absorption (ETPA). Although resonance-enhanced ETPA (r-ETPA) has been demonstrated in atomic systems using bright squeezed vacuum, it has not been studied in organic molecules. We investigate for the first time r-ETPA in an organic molecular dye, indocyanine green (ICG), when excited by broadband entangled photons in near-IR. Similar to many reported virtual state mediated ETPA (v-ETPA) measurements, no r-ETPA signals are measured, with an experimental upper bound for the cross section placed at 6×10−236 \times 10^{-23} cm2^2/molecule. In addition, the classical resonance-enhanced two-photon absorption (r-TPA) cross section of ICG at 800 nm is measured for the first time to be 20(±13)20(\pm13) GM, suggesting that having a resonant intermediate state does not significantly enhance two-photon processes in ICG. The spectrotemporally resolved emission signatures of ICG excited by entangled photons are also presented to support this conclusion

    Tunable and efficient ultraviolet generation in nanophotonic lithium niobate

    Full text link
    On-chip ultraviolet sources are of great interest for building compact and scalable atomic clocks, quantum computers, and spectrometers; however, few material platforms are suitable for integrated ultraviolet light generation. Of these materials, thin-film lithium niobate is the most competitive due to its ability to be quasi-phase-matched, optical confinement, and nonlinear properties. Here, we present efficient (197 ±\pm 5 %/W/cm2^{2}) second harmonic generation of UV-A light in a periodically poled lithium niobate nanophotonic waveguide. We achieve on-chip ultraviolet powers of 30 μ\muW, demonstrating the potential for compact frequency-doubling of common near-IR laser diodes. By using a large cross section waveguide (600 nm film thickness), we achieve insensitivity to fabrication errors, and can attain first-order quasi-phase-matching with relatively long poling periods (>1.5 μ\mum). The device also demonstrates linear wavelength tunability using temperature. By varying the poling period, we have achieved the shortest reported wavelength (355 nm) generated through frequency doubling in thin-film lithium niobate. Our results open up new avenues to realize ultraviolet on-chip sources and chip-scale photonics

    Fabrication of low-cost, large-area prototype Si(Li) detectors for the GAPS experiment

    Full text link
    A Si(Li) detector fabrication procedure has been developed with the aim of satisfying the unique requirements of the GAPS (General Antiparticle Spectrometer) experiment. Si(Li) detectors are particularly well-suited to the GAPS detection scheme, in which several planes of detectors act as the target to slow and capture an incoming antiparticle into an exotic atom, as well as the spectrometer and tracker to measure the resulting decay X-rays and annihilation products. These detectors must provide the absorption depth, energy resolution, tracking efficiency, and active area necessary for this technique, all within the significant temperature, power, and cost constraints of an Antarctic long-duration balloon flight. We report here on the fabrication and performance of prototype 2"-diameter, 1-1.25 mm-thick, single-strip Si(Li) detectors that provide the necessary X-ray energy resolution of ∼\sim4 keV for a cost per unit area that is far below that of previously-acquired commercial detectors. This fabrication procedure is currently being optimized for the 4"-diameter, 2.5 mm-thick, multi-strip geometry that will be used for the GAPS flight detectors.Comment: Accepted for publication at Nuclear Instrumentation and Methods A, 12 pages, 11 figure

    Highly efficient visible and near-IR photon pair generation with thin-film lithium niobate

    Full text link
    Efficient on-chip entangled photon pair generation at telecom wavelengths is an integral aspect of emerging quantum optical technologies, particularly for quantum communication and computing. However, moving to shorter wavelengths enables the use of more accessible silicon detector technology and opens up applications in imaging and spectroscopy. Here, we present high brightness ((1.6±0.3)×109(1.6 \pm 0.3) \times 10^{9} pairs/mW/nm) visible-near-IR photon pair generation in a periodically poled lithium niobate nanophotonic waveguide. The degenerate spectrum of the photon pairs is centered at 811 nm with a bandwidth of 117 nm. The measured on-chip source efficiency of (2.3±0.5)×1011(2.3\pm 0.5) \times 10^{11} pairs/mW is on par with source efficiencies at telecom wavelengths and is also orders of magnitude higher than the efficiencies of other visible sources implemented in bulk crystal or diffused waveguide-based technologies. These results represent the shortest wavelength of photon pairs generated in a nanophotonic waveguide reported to date by nearly an octave.Comment: Main text: 10 pages, 6 figures; Supplementary material: 5 pages, 3 figures. Author initials update

    Red supergiants as potential Type IIn supernova progenitors: Spatially resolved 4.6 micron CO emission around VY CMa and Betelgeuse

    Full text link
    We present high-resolution 4.6micron CO spectra of the circumstellar environments of two RSGs that are potential SN progenitors: Betelgeuse and VY CMa. Around Betelgeuse, 12CO emission within 3arcsec follows a mildly clumpy but otherwise spherical shell, smaller than its 55arcsec shell in KI lambda7699. In stark contrast, 4.6micron CO emission around VY CMa is coincident with bright KI in its clumpy asymmetric reflection nebula, within 5arcsec of the star. Our CO data reveal redshifted features not seen in KI spectra of VY CMa, indicating a more isotropic distribution of gas punctuated by randomly distributed asymmetric clumps. The relative CO and KI distribution in Betelgeuse arises from ionization effects within a steady wind, whereas in VY CMa, KI is emitted from skins of CO cloudlets resulting from episodic mass ejections 500--1000 yr ago. In both cases, CO and KI trace potential pre-SN circumstellar matter: we conclude that an extreme RSG like VY CMa might produce a Type IIn event like SN1988Z if it were to explode in its current state, but Betelgeuse will not. VY CMa demonstrates that LBVs are not necessarily the only progenitors of SNe IIn, but it underscores the requirement that SNe IIn suffer enhanced episodic mass loss shortly before exploding.Comment: 16 pages, AJ accepte

    Lower Limb Muscle Activation in Young Adults Walking in Water and on Land

    Get PDF
    Previous research has shown that exercise interventions requiring increased activation of the tibialis anterior (TA), the primary ankle dorsiflexor, can improve walking performance in individuals with foot drop. Correspondingly, heightened drag forces experienced during walking performed in water may augment TA activation during the swing phase of gait, potentially leading to improved walking gait on land. Therefore, this study aimed to compare surface electromyographic (sEMG) activation in the TA and medial gastrocnemius (GM) during gait performed in water versus on land. Thirty-eight healthy, recreationally active young adults, comprising 18 females and 20 males, participated in the study. Each participant completed 2 min walking trials under five conditions: land 2.5 mph, land 3.5 mph, water 2.5 mph, water 3.5 mph, and water 3.5 mph with added jet resistance. Stride kinematics were collected using 2-dimensional underwater motion capture. TA and GM, muscle activation magnitudes, were quantified using sEMG root-mean-square (RMS) amplitudes for both the swing and stance phases of walking. Additionally, TA and GM co-activation (Co-A) indices were estimated. Two-way within-subjects repeated measures analyses of variance were used to evaluate the main effects of and interactions between the environment and walking speed. Additionally, paired sample t-tests were conducted as a secondary analysis to investigate differences between walking in water at 3.5 mph with and without added jet resistance. Main effects and interactions were observed across various stride kinematics and sEMG measures. Notably, TA sEMG RMS during the swing phase of walking gait performed at 2.5 mph was 15% greater in water than on land (p \u3c 0.001). This effect increased when walking gait was performed at 3.5 mph (94%; p \u3c 0.001) and when jet resistance was added to the 3.5 mph condition (52%; p \u3c 0.001). Furthermore, TA Co-A was increased during the stance phase of gait in water compared to on land (p \u3c 0.001), while GM Co-A was reduced during the swing phase (p \u3c 0.001). The findings of this study offer compelling evidence supporting the efficacy of aquatic treadmill walking as a potential treatment for individuals suffering from foot drop. However, further research is needed to evaluate whether a causal relationship exists between heightened TA activation observed during aquatic treadmill walking and improvements in voluntary dorsiflexion during gait
    • …
    corecore