Quantifying Getting High Under One’s Own Power – A Comparison of Vertical Jump Height Measurement Methods

Countermovement jump (CMJ) height is widely used as a performance test, but the methods for assessing jump height are not standardized. Some assessment methods include the use of aerial time, take-off velocity or jump and reach systems such as the Vertec commonly seen in the NFL combine. The Vertec tests an athlete’s vertical jump by having the athlete jump and reach for the highest rotating vane they can tap with their hand. However, the validity of these different methods is not well established even though the governing force-motion relationships have been known for centuries. Specifically, motion of the body’s center of mass (COM) is determined by the vertical impulse (force x Δtime) prior to take-off. At present, the agreement, or lack thereof, between the commonly used field assessment methods and the actual height the COM attains during a CMJ is not known. Here, we hypothesized that body positional changes during jump and reach tests result in jump height overestimations. PURPOSE: To compare one of the most widely utilized field methods, the Vertec to the gold standard of impulse determined jump height. METHODS: Thirty total (n=15 male, n=15 female) participants ranging in athletic ability from recreational to competitive collegiate level athletes completed three maximal effort CMJs. Jump height was determined simultaneously from the impulse collected using Bertec force plates and a Vertec system. Only the athlete’s highest jump was used in analysis. Vertec and impulse determined jump heights were compared using paired samples t-tests, with alpha level set at 0.05. RESULTS: Vertec jump heights significantly exceeded impulse determined jump heights by an average of 14 cm: 54 ± 14 vs. 40 ±11 cm (P\u3c0.001) respectively. [Vertec range: 32 to 81 cm; Impulse range: 23 to 59 cm.] CONCLUSION: The Vertec measurement system appreciably overestimates the elevation of the body’s COM during vertical jumping, here by an average of 14 cm or 5.5 inches. There was also a trend for individuals with higher jump heights to have a greater difference between the two measurements. Suggesting that reaching ability may be more of a determinant of Vertec jump height than vertical impulse. This should be of interest to sports performance professionals that use this method to analyze progress. This disparity in quantification exists because the difference between standing and reaching hand height at jump apex over-represents the vertical elevation of the COM. This phenomenon is most likely to result from the asymmetrical nature of the reaching action as athletes strike the Vertec vanes. It is also important for sport performance professionals that use the Vertec method to recognize that their athlete’s do not jump as high as they currently believe

Prospects of Traditionally important Apocynaceae plants of India in Cancer Remediation

Objectives: Apocynaceae Family plants in India had wide array of traditional uses and practised since years ago. This review aims to report selected plants of this possessing anticancer activity. Selected literature compiled from the search of electronic journals, books and encyclopedias etc. using search engines viz. Google, PubMed, Sciencedirect, GoogleScholar and SciFinder for all periods. The Dogbane family is includes atleast 150 genera and 1700 species. Around 25 genera and 50 species of the family reviewed here possess anticancer activity. The reason for this potential is due to: a) phytoconstituents b) poisonous constituents c) antimalarial activity and d) abundance of literature in traditional medicinal use.  Folk medicinal uses and reported anticancer potential suggests that the Apocynaceae plants can be formulated or developed into lead compounds or novel drugs or multidrug complex for treatment of cancer. Detailed screening of each species has to be performed in 64 pannel cell lines, mechanistic study performed clearly and effectiveness of extracts, fractions or pure isolated compounds is to be compared. Keywords:  Apocynaceae; Traditional Medicines; cancer; anticancer plants

Formulation and Evaluation of once daily sustained release matrix tablets of Aceclofenac using natural gums

In present study, an attempt has been made to evaluate the effect of natural gums on the release profile of drug from matrix system for once daily sustained release tablets formulations. Aceclofenac NSAIDs was used as a model drug to evaluate it release characteristics from different matrices. Matrix tablets of Aceclofenac were prepared by direct compression process using natural gums (xanthan gum and karaya gum) in different ratios drug: gum ratios of FX, FK and FXK (FX and FK in 1:1 ratios). The tablets were evaluated for physical characteristic like hardness, weight variation, friability, swelling index and drug content, in-vitro release of drug was performed in Phosphate buffer pH 7.4 for 24 hours. All the physical characteristic of fabricated tablet was within acceptable limits. The release of Aceclofenac from a gelatinous swollen mass, which controls the diffusion of drug molecules through the polymeric materials in to aqueous medium. The FXK matrices show  prices controlled release than FX and FK matrices because of burst effect and fast release in case of FX and FK matrices respectively and there was no chemical interaction between drug and polymers in FXK formulation as confirmed by FTIR studies. The release mechanism was explained with zero order, first order, higuchi and korsmeyer equations via swelling and non fickian diffusion mechanism. The FXK matrices leads to more  prices result than FX and FK alone by utilisation of synergistic interaction between two biopolymers and uniformity in the hydration layer in dissolution media

Transient postseismic mantle relaxation following 2004 Sumatra earthquake: implications of seismic vulnerability in the Andaman-Nicobar region

Throughout the world, the tsunami generation potential of some large under-sea earthquakes significantly contributes to regional seismic hazard, which gives rise to significant risk in the near-shore provinces where human settlements are in sizeable population, often referred to as coastal seismic risk. In this context, we show from the pertinent GPS data that the transient stresses generated by the viscoelastic relaxation process taking place in the mantle is capable of rupturing major faults by stress transfer from the mantle through the lower crust including triggering additional rupture on the other major faults. We also infer that postseismic relaxation at relatively large depths can push some of the fault segments to reactivation causing failure sequences. As an illustration to these effects, we consider in detail the earthquake sequence comprising six events, starting from the main event of <i>M</i><sub>w</sub> = 7.5, on 10 August 2009 and tapering off to a small earthquake of <i>M</i><sub>w</sub> = 4.5 on 2 February 2011 over a period of eighteen months in the intensely seismic Andaman Islands between India and Myanmar. The persisting transient stresses, spatio-temporal seismic pattern, modeled Coulomb stress changes, and the southward migration of earthquake activity has increased the probability of moderate earthquakes recurring in the northern Andaman region, particularly closer to or somewhat south of Diglipur

First measurement of the Hubble Constant from a Dark Standard Siren using the Dark Energy Survey Galaxies and the LIGO/Virgo Binary–Black-hole Merger GW170814

International audienceWe present a multi-messenger measurement of the Hubble constant H 0 using the binary–black-hole merger GW170814 as a standard siren, combined with a photometric redshift catalog from the Dark Energy Survey (DES). The luminosity distance is obtained from the gravitational wave signal detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO)/Virgo Collaboration (LVC) on 2017 August 14, and the redshift information is provided by the DES Year 3 data. Black hole mergers such as GW170814 are expected to lack bright electromagnetic emission to uniquely identify their host galaxies and build an object-by-object Hubble diagram. However, they are suitable for a statistical measurement, provided that a galaxy catalog of adequate depth and redshift completion is available. Here we present the first Hubble parameter measurement using a black hole merger. Our analysis results in , which is consistent with both SN Ia and cosmic microwave background measurements of the Hubble constant. The quoted 68% credible region comprises 60% of the uniform prior range [20, 140] km s−1 Mpc−1, and it depends on the assumed prior range. If we take a broader prior of [10, 220] km s−1 Mpc−1, we find (57% of the prior range). Although a weak constraint on the Hubble constant from a single event is expected using the dark siren method, a multifold increase in the LVC event rate is anticipated in the coming years and combinations of many sirens will lead to improved constraints on H 0

Population of Merging Compact Binaries Inferred Using Gravitational Waves through GWTC-3

We report on the population properties of compact binary mergers inferred from gravitational-wave observations of these systems during the first three LIGO-Virgo observing runs. The Gravitational-Wave Transient Catalog 3 (GWTC-3) contains signals consistent with three classes of binary mergers: binary black hole, binary neutron star, and neutron star-black hole mergers. We infer the binary neutron star merger rate to be between 10 and 1700 Gpc-3 yr-1 and the neutron star-black hole merger rate to be between 7.8 and 140 Gpc-3 yr-1, assuming a constant rate density in the comoving frame and taking the union of 90% credible intervals for methods used in this work. We infer the binary black hole merger rate, allowing for evolution with redshift, to be between 17.9 and 44 Gpc-3 yr-1 at a fiducial redshift (z=0.2). The rate of binary black hole mergers is observed to increase with redshift at a rate proportional to (1+z)κ with κ=2.9-1.8+1.7 for z≲1. Using both binary neutron star and neutron star-black hole binaries, we obtain a broad, relatively flat neutron star mass distribution extending from 1.2-0.2+0.1 to 2.0-0.3+0.3M⊙. We confidently determine that the merger rate as a function of mass sharply declines after the expected maximum neutron star mass, but cannot yet confirm or rule out the existence of a lower mass gap between neutron stars and black holes. We also find the binary black hole mass distribution has localized over- and underdensities relative to a power-law distribution, with peaks emerging at chirp masses of 8.3-0.5+0.3 and 27.9-1.8+1.9M⊙. While we continue to find that the mass distribution of a binary's more massive component strongly decreases as a function of primary mass, we observe no evidence of a strongly suppressed merger rate above approximately 60M⊙, which would indicate the presence of a upper mass gap. Observed black hole spins are small, with half of spin magnitudes below χi≈0.25. While the majority of spins are preferentially aligned with the orbital angular momentum, we infer evidence of antialigned spins among the binary population. We observe an increase in spin magnitude for systems with more unequal-mass ratio. We also observe evidence of misalignment of spins relative to the orbital angular momentum

All-sky search for long-duration gravitational-wave bursts in the third Advanced LIGO and Advanced Virgo run

After the detection of gravitational waves from compact binary coalescences, the search for transient gravitational-wave signals with less well-defined waveforms for which matched filtering is not well suited is one of the frontiers for gravitational-wave astronomy. Broadly classified into “short” ≲1  s and “long” ≳1  s duration signals, these signals are expected from a variety of astrophysical processes, including non-axisymmetric deformations in magnetars or eccentric binary black hole coalescences. In this work, we present a search for long-duration gravitational-wave transients from Advanced LIGO and Advanced Virgo’s third observing run from April 2019 to March 2020. For this search, we use minimal assumptions for the sky location, event time, waveform morphology, and duration of the source. The search covers the range of 2–500 s in duration and a frequency band of 24–2048 Hz. We find no significant triggers within this parameter space; we report sensitivity limits on the signal strength of gravitational waves characterized by the root-sum-square amplitude hrss as a function of waveform morphology. These hrss limits improve upon the results from the second observing run by an average factor of 1.8

The population of merging compact binaries inferred using gravitational waves through GWTC-3

We report on the population properties of 76 compact binary mergers detected with gravitational waves below a false alarm rate of 1 per year through GWTC-3. The catalog contains three classes of binary mergers: BBH, BNS, and NSBH mergers. We infer the BNS merger rate to be between 10 $\rm{Gpc^{-3} yr^{-1}}$ and 1700 $\rm{Gpc^{-3} yr^{-1}}$ and the NSBH merger rate to be between 7.8 $\rm{Gpc^{-3}\, yr^{-1}}$ and 140 $\rm{Gpc^{-3} yr^{-1}}$ , assuming a constant rate density versus comoving volume and taking the union of 90% credible intervals for methods used in this work. Accounting for the BBH merger rate to evolve with redshift, we find the BBH merger rate to be between 17.9 $\rm{Gpc^{-3}\, yr^{-1}}$ and 44 $\rm{Gpc^{-3}\, yr^{-1}}$ at a fiducial redshift (z=0.2). We obtain a broad neutron star mass distribution extending from $1.2^{+0.1}_{-0.2} M_\odot$ to $2.0^{+0.3}_{-0.3} M_\odot$. We can confidently identify a rapid decrease in merger rate versus component mass between neutron star-like masses and black-hole-like masses, but there is no evidence that the merger rate increases again before 10 $M_\odot$. We also find the BBH mass distribution has localized over- and under-densities relative to a power law distribution. While we continue to find the mass distribution of a binary's more massive component strongly decreases as a function of primary mass, we observe no evidence of a strongly suppressed merger rate above $\sim 60 M_\odot$. The rate of BBH mergers is observed to increase with redshift at a rate proportional to $(1+z)^{\kappa}$ with $\kappa = 2.9^{+1.7}_{-1.8}$ for $z\lesssim 1$. Observed black hole spins are small, with half of spin magnitudes below $\chi_i \simeq 0.25$. We observe evidence of negative aligned spins in the population, and an increase in spin magnitude for systems with more unequal mass ratio