Analysis of Tug of War Competition: A Narrative Complete Review

Tug-of-war (TOW) is an internationally played activity including professional and amateur athletes, defined as early as 4000 years ago (as a rope-less version) in the artwork on Egyptian tomb engravings, and is played as per the rules laid out by TWIF, which has 73 member countries and administrative headquarters in the USA. Typically, two teams of “pullers” participate and apply enormous contra directional forces on the pulling rope. Originally, two types of competition are used: knockout and points. This narrative review describes the scientific state of the art of TOW. To the best of the authors’ knowledge, no previous information has been published on this topic. Anthropometric parameters for competitors are near 83.6, lean body mass 69.4, and body fat 16. The VO2MAX is 55.8 mL/kg/min. In terms of relative strength, the dynamic leg power is 4659.8 N. Endurance TOW elicits minimal muscle damage. Injured strains and sprains comprised over half of all injuries: back (42%), shoulder–upper limb (23%) and knee (17%). Pulling movement in TOW contests can be divided into three phases, namely the “drop”, “hold” and “drive” phases. The maximal pulling force was 1041.6 ± 123.9 N. The percentage of dynamic pulling force in the static maximal pulling force was 75.5 ± 14.4% and the dynamic ranged from 106.4 to 182.5%. There are two gripping styles: indoor and outdoor. The friction characteristics between surface and shoe in TOW is important in determining a suitable shoe for indoor TOW. A waist belt might be a useful piece of equipment for TOW sport. The EMG technique in TOW entails a high degree of dorsal muscle activity during the pulling. The factor of force vanishing was the coordination among athletes. The force vanishing percentage goes from 8.82 ± 5.59 for two contenders to 19.74 ± 2.22 for eight athletes, 6.4% in the sum of two pullers. However, in the drop phase, for female elite TOW team, only the 0.5% of the pulling force was wasted. Future studies are need in order to understand better this historical sport activity.

Substrate colonization by an emulsion drop prior to spreading

In classical wetting, the spreading of an emulsion drop on a surface is preceded by the formation of a bridge connecting the drop and the surface across the sandwiched film of the suspending medium. However, this widely accepted mechanism ignores the finite solubility of the drop phase in the medium. We present experimental evidence of a new wetting mechanism, whereby the drop dissolves in the medium, and nucleates on the surface as islands that grow with time. Island growth is predicated upon a reduction in solubility near the contact line due to attractive interactions between the drop and the surface, overcoming Ostwald ripening. Ultimately, wetting is manifested as a coalescence event between the parent drop and one of the islands, which can result in significantly large critical film heights and short hydrodynamic drainage times prior to wetting. This discovery has broad relevance in areas such as froth flotation, liquid-infused surfaces, multiphase flows and microfluidics.

Analysis of Tug of War Competition. A Narrative Complete Review

Tug-of-war (TOW) is an internationally played activity including professional and amateur athletes and defined as early (4000 years ago as a rope less version) in the artwork on Egyptian tomb engravings and is played as per the rules laid out by TWIF, which has 73 member countries and administrative headquarters in the USA. Typically, two teams of “pullers” participate and apply enormous contra directional forces on the pulling rope. Originally, two types of competition are used: knockout and points. This narrative review describes the scientific state of the art about of TOW. For the best of the author’s knowledge no previous information has been published. Anthropometric parameters are near 83.6, lean body mass 69.4, and body fat 16. The VO2MAX is 55.8 ml/kg/min. Relative strength, the dynamic leg power was 4659.8 N. Endurance TOW elicits minimal muscle damage. The injured strains and sprains comprised over half of all injuries: back (42%), shoulder–upper limb (23%) and knee (17%). Pulling movement in TOW contests can be divided into three phases: namely "Drop", "Hold" and "Drive" phase. The maximal pulling forces was 1041.6 ± 123.9 N. The percentage of dynamic pulling force in static maximal pulling force was 75.5 ± 14.4% and the dynamic ranged from 106.4 to 182.5%. There are two gripping styles, indoor and outdoor. The friction characteristics between surface and shoe in TOW is important to determine a suitable shoe for indoor TOW. Waist Belt might be a useful piece of equipment for TOW sport. The EMG technique in Tow described a high activity of dorsal muscle during the pulling. The factor of force vanishing was the coordination among athletes. The force vanishing percentage goes from 8.82±5.59 for 2 contenders to 19.74±2.22 for 8 athletes, 6.4 % in the sum of 2 pullers. However, in the drop phase, for female elite TOW team, only the 0.5 % of them pulling force was wasted. Future studies are need in order to understand better this historical sport activity.

Droplet Digital PCR Phasing (DROP-PHASE): A Novel Method for Straightforward Detection of BCR-ABL1 Compound Mutations in Tyrosine Kinase Inhibitors Resistant Chronic Myeloid Leukemia (CML) and Acute Lymphoblastic Leukemia (ALL)

Chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL) are, respectively, a myeloproliferative and a lymphoproliferative neoplasm that can be characterized by the chimeric fusion oncogene BCR-ABL1. Tyrosine Kinase Inhibitors (TKI) are the standard therapy for patients with CML/ALL. However, mutations of the BCR-ABL1 kinase domain constitute a major cause of treatment failure in CML and ALL receiving TKI therapy. While 2nd and 3rd generation TKI have proven their efficacy against mutated BCR-ABL1-mediated clonal expansion, the presence of compound mutations can produce high level of resistance to these TKIs. Even the last addition to the TKI armamentarium, ponatinib, remains ineffective against some BCR-ABL1 compound mutations (Zabriskie, M.S., et al., BCR-ABL1 Compound Mutations Combining Key Kinase Domain Positions Confer Clinical Resistance to Ponatinib in Ph Chromosome-Positive Leukemia. Cancer Cell, 2014. 26(3):p.428-442). Therefore, the distinction between compound (different mutations present on 1 unique malignant clone) and polyclonal mutations (different mutations present on 2 or more different clones) is of great clinical importance in order to select the most suitable treatment and to estimate outcomes. The objective of this study is to determine in a straightforward way whether BCR-ABL1 mutations discovered by Next Generation Sequencing are compound mutations or polyclonal mutations. A simple proof-of-concept experiment was first performed by using 3 synthetic oligonucleotides (gBlocks, IDT) mimicking the presence of compound mutations versus polyclonal mutations in resistant leukemia cells. The first oligo harbored the M237I mutation, the second oligo mutations E255K, E279K, V299L, T315I, F359V, A380S, H396R, S417Y, F459K and F486S and the third one contained all the mutations. Dual-color probes assays have been set up to target specifically 2 different mutations. Mixtures of 2 oligonucleotides harboring 1 mutation each versus 1 oligonucleotide harboring 2 mutations have been compared by performing duplex droplet digital PCR (ddPCR) reactions on the Bio-Rad ddPCR QX200 System. Linkage detection is based on the observation that the presence of 2 targets on the same DNA molecule increases the number of double-positive droplets relative to the number expected due to chance. Automatic linkage evaluation was made by the QuantaSoft Software and mathematical calculations refer to (Regan, J.F., et al., A rapid molecular approach for chromosomal phasing. PLoS One, 2015. 10(3): p. e0118270). The first experiment successfully validated the detection of mutations residing on two different oligonucleotides (polyclonal mutations) versus mutations on the same molecule (compound mutations). When performing serial dilutions of 2 oligonucleotides containing different mutations, a sensitivity of 10%:90% was achieved with a good linearity (r2=0.97). Mixing experiment also showed that ddPCR phasing could distinguish between a mixture of compound and polyclonal mutations versus and the sole presence of polyclonal mutations at the same sensitivity and linearity levels. Moreover, no influence of the genomic distance between mutations (from position 255 to position 562) was observed. The strategy was further applied to 20 clinical samples from CML/ALL patients characterized by multiple resistance mutations. Drop-phase is a rapid (< 4 hours), scalable (100 samples), technically easy to perform and cost-effective method. This strategy will help to identify compound mutations in patients with TKI-resistant CML/ALL and allow to modulate the patient's drug strategy and to prevent progression and therapeutic failure. Disclosures Vannuffel: Incyte: Consultancy. Soverini:Incyte: Consultancy.

Convective mass transfer from a submerged drop in a thin falling film

We investigate the fluid mechanics of removing a passive tracer contained in small, thin, viscous drops attached to a flat inclined substrate using thin gravity-driven film flows. We focus on the case where the drop cannot be detached either partially or completely from the surface by the mechanical forces exerted by the cleaning fluid on the drop surface. Instead, a convective mass transfer establishes across the drop–film interface and the dilute passive tracer dispersed in the drop diffuses into the film flow, which then transports them away. The Péclet number for the passive tracer in the film phase is very high, whereas the Péclet number in the drop phase varies from $\mathit{Pe}_{d}\approx 10^{-2}$ to $1$. The characteristic transport time in the drop is much larger than in the film. We model the mass transfer of the passive tracer from the bulk of the drop phase into the film phase using an empirical model based on an analogy with Newton’s law of cooling. This simple empirical model is supported by a theoretical model solving the quasi-steady two-dimensional advection–diffusion equation in the film, coupled with a time-dependent one-dimensional diffusion equation in the drop. We find excellent agreement between our experimental data and the two models, which predict an exponential decrease in time of the tracer concentration in the drop. The results are valid for all drop and film Péclet numbers studied. The overall transport characteristic time is related to the drop diffusion time scale, as diffusion within the drop is the limiting process. This result remains valid even for $\mathit{Pe}_{d}\approx 1$. Finally, our theoretical model predicts the well-known relationship between the Sherwood number and the Reynolds number in the case of a well-mixed drop $\mathit{Sh}\propto \mathit{Re}_{L}^{1/3}=({\it\gamma}L^{2}/{\it\nu}_{f})^{1/3}$, based on the drop length $L$, film shear rate ${\it\gamma}$ and film kinematic viscosity ${\it\nu}_{f}$. We show that this relationship is mathematically equivalent to a more physically intuitive relationship $\mathit{Sh}\propto \mathit{Re}_{{\it\delta}}$, based on the diffusive boundary-layer thickness ${\it\delta}$. The model also predicts a correction in the case of a non-uniform drop concentration. The correction depends on $Re_{{\it\delta}}$, the film Schmidt number, the drop aspect ratio and the diffusivity ratio between the two phases. This prediction is in remarkable agreement with experimental data at low drop Péclet number. It continues to agree as $\mathit{Pe}_{d}$ approaches $1$, although the influence of the Reynolds number increases such that $\mathit{Sh}\propto \mathit{Re}_{{\it\delta}}$.

Emulsion flow through a packed bed with multiple drop breakup

Pressure-driven squeezing of a concentrated emulsion of deformable drops through a randomly packed granular material is studied by rigorous three-dimensional multidrop–multiparticle simulations at low Reynolds numbers. The drops are comparable in size with granular particles, so the drop phase and the carrier fluid have different permeabilities, and the emulsion cannot be treated as single phase. Squeezing requires significant drop deformation and can meet much resistance, depending on the capillary number $\boldsymbol{Ca}$. The granular material is modelled as a random loose packing (RLP) of many highly-frictional rigid monodisperse spheres in a periodic cell in mechanical equilibrium. Flow simulations for many drops squeezing through the network of solid spheres are performed by an extension of the multipole-accelerated boundary-integral (BI) algorithm of Zinchenko & Davis (J. Comput. Phys., vol. 227, 2008, pp. 7841–7888). A major improvement is robust mesh control on drop surfaces combined with a novel fragmentation algorithm, now allowing for long-time simulations with intricate drop shapes and multiple breakups. A major challenge is that up to $O(1{0}^{5} )$ time steps are required in a simulation for time averaging, and $O(1{0}^{4} )$ boundary elements per surface to sufficiently resolve lubrication and breakups. Such simulations are feasible due to multipole acceleration, with two orders-of-magnitude gain over the standard BI coding. For initial drop-to-particle size ratio 0.51–0.52, emulsion concentration 41–42 % in the available space, and matching viscosities, time- and ensemble-averaged permeabilities of the drop phase and the continuous phase are studied versus $\boldsymbol{Ca}$ for systems of different size (up to 36 particles and 100 drops in a periodic cell). An avalanche of drop breakups observed at sufficiently large $\boldsymbol{Ca}$ does not preclude the permeabilities from reaching a statistical steady state in a feasible simulation time. The critical, system-size-independent $\boldsymbol{Ca}$, when the drop-phase flow effectively stops due to blockage in the pores by capillary forces, is estimated from simulations. For a sample RLP configuration, deep distinctions are found between the flow of concentrated emulsions and single-drop motion.