Uniform arrays of particles tend to cluster as they sediment in viscous fluids. Shape anisotropy of the particles enriches this dynamics by modifying the mode structure and the resulting instabilities of the array. A one-dimensional lattice of sedimenting spheroids in the Stokesian regime displays either an exponential or an algebraic rate of clustering depending on the initial lattice spacing (Chajwa et al. 2020 Phys. Rev. X vol. 10, pp. 041016). This is caused by an interplay between the Crowley mechanism, which promotes clumping, and a shape-induced drift mechanism, which subdues it. We theoretically and experimentally investigate the sedimentation dynamics of one-dimensional lattices of oblate spheroids or discs and show a stark difference in clustering behaviour: the Crowley mechanism results in clumps comprising several spheroids, whereas the drift mechanism results in pairs of spheroids whose asymptotic behaviour is determined by pair–hydrodynamic interactions. We find that a Stokeslet, or point-particle, approximation is insufficient to accurately describe the instability and that the corrections provided by the first reflection are necessary for obtaining some crucial dynamical features. As opposed to a sharp boundary between exponential growth and neutral eigenvalues under the Stokeslet approximation, the first-reflection correction leads to exponential growth for all initial perturbations, but far more rapid algebraic growth than exponential growth at large dimensionless lattice spacing $\tilde {d}$. For discs with aspect ratio $0.125$, corresponding to the experimental value, the instability growth rate is found to decrease with increasing lattice spacing $\tilde {d}$, approximately as $\tilde {d}^{ -4.5}$, which is faster than the $\tilde {d}^{-2}$ for spheres (Crowley 1971 J. Fluid Mech. vol. 45, pp. 151–159). It is shown that the first-reflection correction has a stabilising effect for small lattice spacing and a destabilising effect for large lattice spacing. Sedimenting pairs predominantly come together to form an inverted ‘T’, or ‘$\perp$’, which our theory accounts for through an analysis that builds on Koch & Shaqfeh (1989 J. Fluid Mech. vol. 209, pp. 521–542). This structure remains stable for a significant amount of time.

This study explores the Faraday instability as a mechanism to enhance heat transfer in two-phase systems by exciting interfacial waves through resonance. The approach is particularly applicable to reduced-gravity environments where buoyancy-driven convection is ineffective. A reduced-order model, based on a weighted residual integral boundary layer method, is used to predict interfacial dynamics and heat flux under vertical oscillations with a stabilising thermal gradient. The model employs long-wave and one-way coupling approximations to simplify the governing equations. Linear stability theory informs the oscillation parameters for subsequent nonlinear simulations, which are then qualitatively compared against experiments conducted under Earth’s gravity. Experimental results show up to a 4.5-fold enhancement in heat transfer over pure conduction. Key findings include: (i) reduced gravity lowers interfacial stability, promoting mixing and heat transfer; and (ii) oscillation-induced instability significantly improves heat transport under Earth’s gravity. Theoretical predictions qualitatively validate experimental trends in wavelength-dependent enhancement of heat transfer. Quantitative discrepancies between model and experiment are rationalised by model assumptions, such as neglecting higher-order inertial terms, idealised boundary conditions, and simplified interface dynamics. These limitations lead to underprediction of interface deflection and heat flux. Nevertheless, the study underscores the value of Faraday instability as a means to boost heat transfer in reduced gravity, with implications for thermal management in space applications.

We present a flexible, multilayer fabric strain sensor composed of a carbon fabric layer sandwiched between elastic bands. The sensor achieved a gauge factor of 3.4 and maintained its durability up to 635% strain. Its uniform graphite layer enabled reliable fabrication and easy integration into wearable formats. Performing well on commercial gloves and bands, the sensor effectively captured strain variations during body movement and enabled wireless transmission for real-time monitoring. Distinct resistance patterns were recorded for various body motions such as walking, jogging, jumping, and knee bending with a clear separation between high- and low-intensity activities. The overall design supports scalable fabrication and practical integration into wearable systems.

Background: Mesial temporal lobe epilepsy (mTLE) is a heterogenous condition with variable post-surgical outcomes. Combining high resolution magnetic resonance imaging (MRI), stereoelectroencephalography (SEEG) and histology may establish different subtypes of mTLE. Methods: Retrospective analysis of patients with mTLE with 1) SEEG Patterns 2) MRI 3) Post temporal lobectomy tissue analysis 4) Engel Classification. HippUnfold method was used to segment hippocampus on MRI. Results: Of 109 patients investigated with SEEG, 11 patients were analyzed so far. Low voltage fast activity was seen in 215 seizures, low-frequency periodic spikes in 21, sharp activity at <13 Hz in 58, rhythmic spike sharp wave activity in 86, and other types were less frequent. MRI revealed unilateral mesial temporal sclerosis (MTS) in 6 (54.55%), bilateral MTS in 2 (18.18%), and was normal in 3 (27.27%) patients. Histopathology showed ILAE grade I in 3 (37.5 %), II in 4 (50 %), IV in 1 (12.5%) patient. 63.63% had Engel Class I at 6 months. HippUnfold analysis and SEEG electrode coregistration was done in one patient and will be attempted in the rest. Conclusions: Our study highlights a strong correlation between SEEG findings and histological analysis in mTLE. A multidimensional classification will help predict long term outcomes.

We explored the dynamics of Taylor–Couette flows within square enclosures, focusing primarily on the turbulence regime and vortex behaviour at varying Reynolds numbers. Laboratory experiments were conducted using particle image velocimetry for Reynolds numbers $Re_{\varDelta }\in [0.23, 4.6]\times 10^3$ based on the minimum gap $\varDelta /d = 1/16$, $1/8$ and $1/4$, where $d$ is the cylinder diameter, or $Re\in [1.8, 9.8]\times 10^3$ based on $d/2$. At lower $Re$, the flow was dominated by well-defined Taylor and Görtler vortices, while higher $Re$ led to a turbulent state with distinct motions. Space–time radial velocity analysis revealed persistent Taylor vortices at lower $Re$, with larger gaps but increased turbulence, and irregular motions at higher $Re$, with smaller gaps. Velocity spectra reveal that the energy distribution is maintained at frequencies lower than the integral-type frequency $f_I$ across varying $\varDelta$ due to the dominance of large vortices. However, there is a monotonic increase in energy at higher frequencies beyond $f_I$. The reduced characteristic frequency $f_I\varDelta /\omega _ir_i \sim 1/10$ indicates that these motions scale linearly with angular velocity, and inversely with the gap. Proper orthogonal decomposition (POD) and spectral POD were used to distinguish between Taylor and Görtler vortices, showing the effects of gap size and the associated energy cascade. Linear stability analysis included as complementary support revealed primary instability of the Taylor vortex, which is similar to the circular enclosure, along with multiple corner modes that are unique to the geometry.

The influence of parametric forcing on a viscoelastic fluid layer, in both gravitationally stable and unstable configurations, is investigated via linear stability analysis. When such a layer is vertically oscillated beyond a threshold amplitude, large interface deflections are caused by Faraday instability. Viscosity and elasticity affect the damping rate of momentary disturbances with arbitrary wavelength, thereby altering the threshold and temporal response of this instability. In gravitationally stable configurations, calculations show that increased elasticity can either stabilize or destabilize the viscoelastic system. In weakly elastic liquids, higher elasticity increases damping, raising the threshold for Faraday instability, whereas the opposite is observed in strongly elastic liquids. While oscillatory instability occurs in Newtonian fluids for all gravity levels, we find that parametric forcing below a critical frequency will cause a monotonic instability for viscoelastic systems at microgravity. Importantly, in gravitationally unstable configurations, parametric forcing above this frequency stabilizes viscoelastic fluids, until the occurrence of a second critical frequency. This result contrasts with the case of Newtonian liquids, where under the same conditions, forcing stabilizes a system for all frequencies below a single critical frequency. Analytical expressions are obtained under the assumption of long wavelength disturbances predicting the damping rate of momentary disturbances as well as the range of parameters that lead to a monotonic response under parametric forcing.

We study several basic problems about colouring the $p$-random subgraph $G_p$ of an arbitrary graph $G$, focusing primarily on the chromatic number and colouring number of $G_p$. In particular, we show that there exist infinitely many $k$-regular graphs $G$ for which the colouring number (i.e., degeneracy) of $G_{1/2}$ is at most $k/3 + o(k)$ with high probability, thus disproving the natural prediction that such random graphs must have colouring number at least $k/2 - o(k)$.

Bilingualism delays the onset of dementia symptoms and contributes to cognitive reserve. However, the neural basis of this mechanism remains elusive. The few studies that have investigated neural mechanisms of cognitive reserve and bilingualism have focused on Alzheimer’s disease. This study investigated the neural basis of cognitive reserve among persons with frontotemporal dementia (FTD) using regional brain volumes. Sixty-eight persons with FTD (42 bilinguals and 26 monolinguals) were included. After propensity score matching for age, sex, education, FTD subtype and clinical severity, there were 26 bilinguals and 26 monolinguals. The results showed that bilinguals had reduced thalamic volume compared to monolinguals despite having similar cognitive performance. The results indicate that bilinguals were able to tolerate more severe atrophy compared to monolinguals while maintaining comparable cognitive abilities. Our study therefore suggests that bilingualism contributes to cognitive reserve in persons with FTD.

Planar linear flows are a one-parameter family, with the parameter $\hat {\alpha }\in [-1,1]$ being a measure of the relative magnitudes of extension and vorticity; $\hat {\alpha } = -1$, $0$ and $1$ correspond to solid-body rotation, simple shear flow and planar extension, respectively. For a neutrally buoyant spherical drop in a hyperbolic planar linear flow with $\hat {\alpha }\in (0,1]$, the near-field streamlines are closed for $\lambda \gt \lambda _c = 2 \hat {\alpha } / (1 - \hat {\alpha })$, $\lambda$ being the drop-to-medium viscosity ratio; all streamlines are closed for an ambient elliptic linear flow with $\hat {\alpha }\in [-1,0)$. We use both analytical and numerical tools to show that drop deformation, as characterized by a non-zero capillary number ($Ca$), destroys the aforementioned closed-streamline topology. While inertia has previously been shown to transform closed Stokesian streamlines into open spiralling ones that run from upstream to downstream infinity, the streamline topology around a deformed drop, for small but finite $Ca$, is more complicated. Only a subset of the original closed streamlines transforms to open spiralling ones, while the remaining ones densely wind around a configuration of nested invariant tori. Our results contradict previous efforts pointing to the persistence of the closed streamline topology exterior to a deformed drop, and have important implications for transport and mixing.

Clethodim is an important herbicide for managing Texas panicum. However, its efficacy is influenced by the weed size and environmental stress during application. Therefore, field and greenhouse studies were conducted in 2023 and 2024 to evaluate clethodim efficacy on various Texas panicum sizes. Clethodim was applied at Texas panicum heights ranging from 5 cm to 60 cm. A sequential application was applied 2 wk after the initial treatment for larger weed sizes (15 to 60 cm). In separate field and greenhouse studies, nonionic surfactant (NIS), crop oil concentrate (COC), methylated seed oil (MSO), COC + ammonium sulfate (AMS), and MSO + AMS adjuvants were mixed with clethodim to determine efficacy on 10- to 15-cm and 20- to 30-cm Texas panicum. In the weed size study, sequential applications of clethodim increased Texas panicum control compared to a single application. At the 10- to 15-cm growth stage, a single application provided 90% Texas panicum control, whereas the sequential treatment improved control from 76% to 91% at the 15- to 20-cm growth stage. However, clethodim efficacy declined as Texas panicum size increased across single and sequential treatments. In the adjuvant studies, clethodim plus COC, COC + AMS, or MSO + AMS provided 91%, 93%, and 90% control at the 10- to 15-cm growth stage, respectively; however, efficacy decreased for 20- to 30-cm Texas panicum. Texas panicum efficacy was higher for clethodim plus MSO + AMS than clethodim plus MSO; however, AMS did not increase clethodim + COC efficacy. Overall, Texas panicum control with clethodim was most effective when weed height was 15 cm or less. A sequential application of clethodim was required for larger Texas panicum (>15 cm). Clethodim plus COC or MSO + AMS provided the greatest control of Texas panicum. This study demonstrated that successful Texas panicum management depends on applying clethodim at the optimum size and selecting the appropriate oil-based adjuvant especially at larger Texas panicum sizes.

The incompressible Navier–Stokes equations in spherical coordinates are solved using a pseudo-spectral method to simulate the problem of spherical Couette flow. The flow is investigated for a narrow-gap ratio with only the inner sphere rotating. We find that the flow is sensitive to the initial conditions and have used various initial conditions to obtain different branches of the bifurcation curve of the flow. We have identified three different branches dominated respectively by axisymmetric flow, travelling wave instability and equatorial instability. The axisymmetric branch shows unsteadiness at large Reynolds numbers. The travelling wave instability branch shows spiral instability and is prominent the near poles. The travelling wave instability branch further exhibits a reversal in the propagation direction of the spiral instability as the Reynolds number is increased. This branch also exhibits a multi-mode equatorial instability at larger Reynolds numbers. The equatorial instability branch exhibits twin jet streams on either side of the equator, which become unstable at larger Reynolds numbers. The flow topology on the three branches is also investigated in their phase space and found to exhibit chaotic behaviour at large Reynolds numbers on the travelling wave instability branch.

Wood apple (Limonia acidissima L., Rutaceae) is a medium to large-sized semideciduous tree native to Indian subcontinent. The Indian systems of medicine recognized this tree for its medicinal properties and nutritional fruit. The present study evaluates chemotypic diversity by using HPTLC method for identification of elite genotypes among 96 accessions of wood apple leaves collected from diverse populations across 16 states of India. Here, the multivariate analysis, including the extent of variation, broad sense heritability, genetic advance, correlation of mean value of each replicate were assessed with respect to four target bioactive molecules (quercetin, stigmasterol, psoralen and niloticin) extracted from leaves of wood apple. The results showed that the analysis of variance revealed significant variabilities for all the four biomolecules analysed. The hierarchical clustering grouped all the accessions into eight clusters. Out of which, cluster II and VI contained a maximum of 20 and 18 genotypes, respectively. Cluster VIII consisted of only three genotypes. The intra-cluster distance ranged from 0 (cluster II to VIII) to 6.83 (cluster I). The highest inter-cluster distance was found between clusters V and VII (22.52). Positive correlation was found between chemotypic traits at both the genotypic and phenotypic level. The broad sense heritability was recorded highest for quercetin (97.7%). The high genetic advance was noticed for niloticin (217.4). This study detected significant chemotypic variation among the accessions. The elite accessions identified in this study could be utilized to enhance the quality, efficacy and economic value of medicinal products.

In Peru, Andean indigeneity is often discursively gendered as female. Such a connection between indigeneity and femaleness is invoked in a range of discourses that marginalize the status of Indigenous individuals, and different forms of Indigenous heritage in the country. Yet does this imply that all variations of Indigenous femininity are evaluated and ideologized the same way? This article complicates the semiotic logics and frameworks by which Indigenous female figures have been evaluated and analyzed across different historical moments and ethnographic contexts in Peru. I use the concept of “scale” (Blommaert 2007; Gal and Irvine 2019) to highlight the conflicting and competing ideologized stances and modes of evaluation that compare Indigenous identities, female bodies, and linguistic practices in relation to each other. Through this analysis, I will show that the evaluation of Indigenous female identities is enmeshed in a matrix of competing ideologized scalar regimes, highlighting the need to think about the construction and evaluation of racial and gendered types as shifting across multiple semiotic fields and different ideologized paradigms of evaluation.

We analyse the motion of a flagellated bacterium in a two-fluid medium using slender body theory. The two-fluid model is useful for describing a body moving through a complex fluid with a microstructure whose length scale is comparable to the characteristic scale of the body. This is true for bacterial motion in biological fluids (entangled polymer solutions), where the entanglement results in a porous microstructure with typical pore diameters comparable to or larger than the flagellar bundle diameter, but smaller than the diameter of the bacterial head. Thus, the polymer and solvent satisfy different boundary conditions on the flagellar bundle and move with different velocities close to it. This gives rise to a screening length $L_B$ within which the fluids exchange momentum and the relative velocity between the two fluids decays. In this work, both the solvent and polymer of the two-fluid medium are modelled as Newtonian fluids with different viscosities $\mu _s$ and $\mu _p$ (viscosity ratio $\lambda = \mu _p/\mu _s$), thereby capturing the effects solely introduced by the microstructure of the complex fluid. From our calculations, we observe an increased drag anisotropy for a rigid, slender flagellar bundle moving through this two-fluid medium, resulting in an enhanced swimming velocity of the organism. The results are sensitive to the interaction between the bundle and the polymer, and we discuss two physical scenarios corresponding to two types of interaction. Our model provides an explanation for the experimentally observed enhancement of swimming velocity of bacteria in entangled polymer solutions and motivates further experimental investigations.

Direct numerical simulations of the turbulence of a Herschel–Bulkley (HB) fluid in a rough channel are performed at a shear Reynolds number $Re_{\tau } \approx 300$ and a Bingham number ${Bn} \approx 0.9$. For the type of rough surface used in this study, the results indicate that Townsend's wall similarity hypothesis also holds for HB fluids. However, there are notable differences compared with the effect of roughness on Newtonian fluids. More specifically, the effect of roughness appears to be slightly stronger for HB fluids, in the sense that the bulk Reynolds number, based on the viscosity at the wall, is reduced further due to the increase in viscosity in the troughs of the roughness surface induced by the low shear. At the same time, for the simulated rough surface, the contribution of form drag to the total pressure drop is reduced from 1/4 to about 1/5 due to the persistence of viscous shear in the boundary layer, reducing its shielding effect. As for the friction factor, due to the nonlinearity of the HB constitutive relation, its use with the wall shear rate from the mean wall shear stress underpredicts the minimum viscosity at the wall by up to 18 %. This inevitably leads to uncertainties in the prediction of the friction factor. Finally, it is observed that the rough surface is unable to break the peculiar near-wall flow structure of HB fluids, which consists of long persistent low-speed streaks occupying the entire domain. This means that the small-scale energy is significantly reduced for HB fluids, even in rough channels, with the energy more concentrated in the lower wavenumber range, implying an increase in the slope of the power spectrum to $-7/2$ in the inertial range, as shown by Mitishita et al. (J. Non-Newtonian Fluid Mech., vol. 293, 2021, 104570).

Blast waves have been produced in solid target by irradiation with short-pulse high-intensity lasers. The mechanism of production relies on energy deposition from the hot electrons produced by laser–matter interaction, producing a steep temperature gradient inside the target. Hot electrons also produce preheating of the material ahead of the blast wave and expansion of the target rear side, which results in a complex blast wave propagation dynamic. Several diagnostics have been used to characterize the hot electron source, the induced preheating and the velocity of the blast wave. Results are compared to numerical simulations. These show how blast wave pressure is initially very large (more than 100 Mbar), but it decreases very rapidly during propagation.

OBJECTIVES/GOALS: Inexpensive, accurate home monitoring is the standard-of-care in many diseases like hypertension or diabetes; however, it has yet to be widely used in neurodegenerative diseases. We used wearable activity monitors and computer-vision evaluated assessments to estimate Parkinson’s disease (PD)-related disease burden. METHODS/STUDY POPULATION: We recruited 22 people from the University of Iowa Movement Disorders Clinic. Each person completed a standardized set of 3 fine motor tasks using their hands. We recorded a video of this activity, which was evaluated using MediaPipe - an open-source pose classification program from Alphabet - as well as had an nurse-practitioner evaluate the performance on a validated scale (UPDRS). Participants wore a Fitbit Inspire 3 activity tracker at home for the next two weeks. We quantified disease burden using the Parkinson’s Disease Questionnaire 39 - a validated 39-item survey about the intensity of PD-related impairment. Using data from the videos and activity trackers, we estimated 1) the standardized UPDRS assessment of motor impairment and 2) the total PDQ-39 score. RESULTS/ANTICIPATED RESULTS: We found observationally recorded fastest sustained (at least 5 minutes) walking speed was a strong predictor of PDQ-39, explaining over one third of the variability in the measure. Range of motion in the videos was a significant predictor of UPDRS scores; however, was only weakly related to the overall PDQ-39 score. Further processing of the signals from the video, including wavelets and frequency domain analysis, may provide better predictive capabilities. PDQ-39 subscores (e.g., cognition, social support, mobility) will be the subject of further analysis. DISCUSSION/SIGNIFICANCE: Home monitoring has become the standard in other fields because of the better generalizability of home measurements. Improving the detection and evaluation of PD using home monitoring will lead to more timely and accurately changes in medication and less need for clinic visits - especially off levodopa.