Miracle-dz/UniFAR-FTUs huggingface dataset:
Effect of tabs on the shear layer dynamics of a jet in cross-flow

Abstract Direct numerical simulations (DNS) of a jet in cross-flow (JICF) with a triangular tab at two positions are performed at jet-to-cross-flow velocity ratios of $R = 2$ and $4$ with a jet Reynolds number of 2000 based on the jet's bulk velocity and exit diameter. The DNS and dynamic mode decomposition show the sensitivity of the tab's effect on the jet upstream shear layer (USL) structure and cross-section to $R$, echoing the experimental discoveries of Harris et al. (J. Fluid Mech., vol. 918, 2021). Furthermore, DNS reveals that the presence of a tab placed on the upstream side of the nozzle significantly modifies the USL through production of streamwise vortices that curl around the spanwise vortex tubes originating from the primary instability of the USL. This provides an explanation for the improvement in mixing that has been associated with an upstream tab. The streamwise vortex structure shows remarkable similarities to the ‘strain-oriented vortex tubes’ observed for disturbed plane shear layers by Lasheras & Choi (J. Fluid Mech., vol. 189, 1988, pp. 53–86). For both $R$ cases, the USL instability is delayed, the jet penetration is reduced, and the jet cross-section is flattened, although the tab has a less pronounced effect on the USL structure at higher velocity ratios, where the formation of the streamwise vortices is delayed. In contrast, a tab placed 45$^\circ$ from the upstream position produces significantly different effects compared with the upstream tab. At $R = 4$, the jet cross-section is significantly skewed away from the tab and a tertiary vortex is formed, as observed in past studies of round JICFs at relatively high $R$ and low Reynolds numbers. The ability of the tab to produce a controllable steady-state tertiary vortex has implications for a variety of applications. The 45$^\circ$ tab produces asymmetric effects in the wake of the jet at $R = 2$, but the effect on the jet cross-section is much smaller, highlighting the sensitivity of jets at high $R$ to asymmetric perturbations.
‘It’s been quite a poor show’ – exploring whether practitioners working for Improving Access to Psychological Therapies (IAPT) services are culturally competent to deal with the needs of Black, Asian and Minority Ethnic (BAME) communities

Abstract Cultural competency is a core clinical skill. Yet, psychological therapists may be inadequately trained to deal with the needs of service users from Black, Asian and Minority Ethnic (BAME) backgrounds. This can lead to dissatisfaction with mental health services, disengagement from therapy, and poorer treatment outcomes when compared to the White British population. The aim of this study was to explore whether practitioners working for Improving Access to Psychological Therapies (IAPT) services are culturally competent to deal with the needs of diverse communities. Semi-structured interviews were carried out with a range of practitioners, from early career psychological wellbeing practitioners (PWPs) to senior cognitive behavioural therapists (n=16). Reflexive thematic analysis (RTA) was used to analyse the data, guided by a six-phase process to produce a robust pattern-based analysis. Overall, three themes were generated: (1) encountering cultural dissonance within therapy; (2) challenges in making cultural adaptations to therapy; and (3) identifying cultural competency needs. Out of sixteen participants, only nine therapists received one-day formal training throughout their therapeutic career, whilst seven reported receiving no cultural competence training at all. Overall, it appears that there is an urgent need and desire for therapists to be offered cultural competency training so that they can better serve BAME communities. Clinical implications and future recommendations are made. Key learning aims (1) To briefly introduce cross-cultural theoretical models that may assist mental health professionals to think critically about Western notions of therapy and whether they are suited to the needs of ethnic minority communities. (2) To consider challenges IAPT practitioners encounter during therapy and identify examples of good practice. (3) To explore to what extent IAPT practitioners feel culturally competent to deal with the needs of BAME communities. (4) To encourage IAPT services and decision makers (e.g. training bodies and commissioners) to enhance cultural competence training so that practitioners can better serve ethnic minority communities.
Illuminating the evolution of bioluminescence in sharks

The evolutionary context in which shark bioluminescence originated is poorly understood, despite it being critical to uncovering influential factors in the evolutionary history and diversity of living chondrichthyans as well as the mechanisms of deep‐water colonization by vertebrates. This study provides the first joint reconstruction of the habitats, lifestyles, and occurrence of bioluminescence in the evolution of squalomorph sharks using ancestral state estimation analysis to resolve the timing of deep‐sea colonization, the evolutionary origin of bioluminescence and the ancestral ecologies of this group. The results suggest that most squalomorphs originated in neritic environments from where they colonized deep waters on several independent occasions during the Late Jurassic and Early Cretaceous, predating most of the previous estimates of the timing of this event. The colonization of the deep sea took place via the benthic zone, in contrast to the view that an intermediate mesopelagic stage occurred during this ecological transition. Finally, the analyses accounting for uncertainty of the presence of bioluminescence strongly support that this trait evolved only once among sharks in a bathydemersal ancestor. This study reveals that shark bioluminescence evolved in a complex scenario that combines elements of several previous proposals, and enriches our perspective on the sequence of events that characterized the vertebrate conquest of the deep sea.
A Seinhorst Model Determined the Host-Parasite Relationships of Meloidogyne javanica Infecting Fenugreek cv. UM202

Abstract Root-knot nematodes (RKNs) have been shown to be challenging and persistent pests of economic crops worldwide. Among RKNs, Meloidogyne javanica is particularly important, as it rapidly spreads and has a diverse host range. Measuring its damaging threshold level will help us to develop management strategies for adequate plant protection against nematodes. In our study, we observed the relationship between a linear series of 12 initial population densities (Pi) of M. javanica, i.e., 0, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, and 128 second-staged juveniles (J2s) g-1 soil, and fenugreek cv. UM202 growth parameters were investigated using a Seinhorst model. A Seinhorst model was fitted to shoot length and dry weight data for fenugreek plants. A positive correlation was found between J2s inoculum levels and percent reductions in growth parameters. The 1.3 J2s of M. javanica g-1 soil were found to damage threshold levels with respect to shoot length and shoot dry weight of fenugreek plants. The minimum relative values (m) for shoot length and shoot dry weight were 0.15 and 0.17, respectively, at Pi =128 J2s g-1 soil. The maximum nematode reproduction rate (Pf /Pi) was 31.6 at an initial population density (Pi) of 2 J2s g-1 soil.
Fuzzy cognitive map reconstruction - dynamics vs. History

This study is concerned with a fundamental issue of time series representation for modeling and prediction with Fuzzy Cognitive Maps. We introduce two distinct time series representation schemes for Fuzzy Cognitive Map design. First method is based on time series amplitude, amplitude change, and change of amplitude change (dynamics perspective). Second scheme is based on three consecutive historical observations: present value, past value and before past value (history perspective). Introduced procedures are experimentally verified and compared on several synthetic and real-world time series of various characteristics. The history-oriented time series representation turned out to be more advantageous. Quality of FCM-based time series models and one-step-ahead predictions were measured in terms of Mean Squared Error. We have shown that models designed with history-oriented time series representation generally require less FCM nodes to be of comparable quality as models built on dynamics-oriented time series representation. As a result, with the history-oriented time series representation scheme we are able to construct simpler and therefore better models.
Evolution of the spectrum and VLBI structure of W75N during the huge OH maser flare in 2003–2007

We present results of single-dish and very long baseline interferometry (VLBI) observations of a strong 1000-Jy OH maser flare in the star-forming region W75N. The flare was first seen in 2003, and persisted for at least four years. Three major spectral features were present during the whole period of observations, with N1 being the strongest initially and N2 becoming stronger later. The large velocity range of 43 km s−1 observed during the flare is not kinematic in origin, but is caused by the Zeeman splitting in the strong magnetic field generated by the central star. The maps and proper motion of the maser spots were monitored over eight epochs, between 1998 and 2006, using the European VLBI Network (EVN) supplemented by published Very Large Baseline Array (VLBA) data. Mapping of the maser spots has shown that all the new spectral features of the flare were located close to the ultracompact H ii region VLA2, while the quiescent maser features were found near VLA1. We suggest that the flare was initiated by a disturbance, probably an magnetohydrodynamic (MHD) shock launched from the massive young star, also responsible for the excitation of the ultracompact H ii region. The proper motion of the majority of the maser spots was not detected at 1665 and 1667 MHz with the upper limit of several km s−1. The only positive detection of the proper motion was made for the two brightest flare features N1 and N2. The spot N2 is moving along the filamentary spot N3, with a tangential velocity of 14 km s−1. This motion is caused by the MHD shock propagating along the filament. The measured low upper limit for the velocity of OH maser spots is consistent with models of a slowly rotating Keplerian disc rather than with outflows, jets or expanding shells.
Experimental evidence of inertial waves in a precessing spheroidal cavity

We have demonstrated experimentally the existence of inertial waves in a slowly precessing spheroid of fluid. Although such oscillatory internal shear layers have been predicted theoretically and numerically, previous precession experiments had shown no evidence of their presence. Using an ultrasonic Doppler velocimetry technique, profiles of radial velocity have been measured in our precession experiment. Comparison of these profiles with their synthetic counterparts obtained numerically, proves the presence of the predicted internal shear layers. They are emitted from the breakdown of the Ekman layer at the two critical latitudes of the fluid (around 30° and −30°) and propagate through the entire volume on conical surfaces. The asymptotic laws for these oscillatory layers, confirmed experimentally and numerically, lead us to predict an oscillatory flow of 10−6 m/s along such characteristic cones in the Earth's fluid outer core.
Steady, supercritical flow in collapsible tubes. Part 1. Experimental observations

Experimental results are presented for steady, supercritical flow of a liquid in a thin-walled compliant tube which is in a state of partial collapse due to a negative transmural pressure. Particular attention is paid to the effects of longitudinal tension. With a constant external pressure, friction acts to increase the area in the down-stream direction. With the tube tilted downward, friction may be so balanced by gravity forces as to result in an asymptotic approach to an equilibrium situation in which the area and velocity remain constant. When the downstream pressure is increased sufficiently, shock-like transitions to subcritical inflated states, with positive transmural pressure, occur. The longitudinal length scale of the shock is on the order of one to several tube diameters. The pressure rise across the shock lies between that for loss-free pressure recovery and that given by the Borda-Carnot sudden-expansion theory. The presence of longitudinal tension causes a train of standing waves of area to appear upstream of a local area disturbance, such as a shock-like transition. The standing waves are superimposed upon the more gradual area changes associated with friction and gravity. The wave amplitude grows in the downstream direction. Theoretical interpretations of the observations are presented in the companion paper (part 2).
Monuments of Culture: Minzoku Taiwan and the Search for Local History in Colonial Taiwan(1938– 1950)

Abstract:This study reconsiders the way in which “folklore,” or “local culture,” was documented and narrated, and thus “discovered” by the increasingly transnational intellectual society of 1940s Taiwan. By invoking the term discover, I propose to trace the historical roots of the construction of legitimacy for such subjects as “folklore,” “local culture and custom,” and the emerging discipline folklore studies/native ethnology in a modernizing society facing colonial rule and the globalizing processes of nation building in mid-twentieth-century East Asia. Ultimately, this study proposes that the act of documenting and discovering “folk life” was not necessarily the product but part of the globalizing process of inventing or reinventing traditions among communities establishing historical narratives in a postcolonial world.
Methyl cyanide as tracer of bow shocks in L1157-B1

Context. L1157-mm is a low-mass protostar driving an outflow which is considered the proto-type of the so-called chemically active outflows. In particular, the blue-shifted lobe B1 stands out for its rich mm-wave spectrum.Aims. Our aim is to infer the physical conditions of the molecular gas within L1157-B1.Methods. We carried out CH3CN(8(K)-7(K)) observations at 2 mm with the IRAM Plateau de Bure Interferometer to map L1157-B1.Results. The CH3CN image shows a clumpy structure superimposed to the classical B1 arch-like shape, displaying a unique continuous structure tracing the propagation of a large bow shock. The CH3CN spatial distribution well agrees with that of CH3OH, one of the most abundant species evaporated from dust grain mantles. Thanks to the present CH3CN observations at unprecedented spatial resolution, we determine for the first time the temperature distribution of the B1 bow shock. We obtain values between 57 and 132 K, with the highest temperature at the shock apex, thus confirming the association of CH3CN with gas affected by the passage of a shock wave. The N-CH3CN column densities are similar or equal to 8-40 x 10(12) cm(-2), depending on the position, leading to CH3CN/CH3OH abundance ratios similar or equal to 0.2-1.3 x 10(-3), i.e. values on average smaller than those found in hot-corinos. This suggests that a significant amount of CH3CN is formed in the gas phase: in the shocked L1157-B1 regions the CH3CN abundance may not have reached its maximum yet.
PDRs and XDRs

Abstract An overview of the important thermal and chemical processes in “photon-dominated regions” or “photo-dissociation regions” (PDRs) and “X-ray dominated regions” (XDRs) is presented. Applications of the models are shown to observations of the ultra-luminous infrared galaxy Mrk 231, and the starburst galaxy M 82.
Multiple Sources of Uncertainty Confound Inference of Historical Human Generation Times

Wang et al. (2023) recently proposed an approach to infer the history of human generation intervals from changes in mutation profiles over time. As the relative proportions of different mutation types depend on the ages of parents, binning variants by the time they arose allows for the inference of average paternal and maternal generation intervals over times. Applying this approach to published allele age estimates, Wang et al. (2023) inferred long-lasting sex differences in average generation times and surprisingly found that ancestral generation times of West African populations remained substantially higher than those of Eurasian populations extending tens of thousands of generations into the past. Here we argue that the results and interpretations in Wang et al. (2023) are primarily driven by noise and biases in input data and a lack of validation using independent approaches for estimating allele ages. With the recent development of methods to reconstruct genome-wide gene genealogies, coalescence times, and allele ages, we caution that downstream analyses may be strongly influenced by uncharacterized biases in their output.
ABUNDANCE DIFFERENCES AMONG GLOBULAR CLUSTER GIANTS: PRIMORDIAL VS. EVOLUTIONARY SCENARIOS

Contrary to historical expectation, stars within a given globular cluster often exhibit wide variations in the abundance of C, N, and O as well as certain light metals, particularly Na and Al. Owing to flux limitations, studies have been confined to evolved stars, especially to giants, but in few instances variations have been detected among main sequence stars. Variations in the Fe-peak elements exceeding ~0.1 dex are firmly established in the case of omega Centauri, the most massive cluster, and are strongly suspected in the case of M22, but in no other cluster. Among field halo giants of comparable Fe-peak metallicity, variations in the C, N, O group appear to be much less pronounced than in globular cluster giants. Among giants, the variations are of two kinds: (1) those related on the average to evolutionary state, and (2) variations among stars in the same apparent evolutionary state. In addition, clusters having the same Fe-peak abundances often contain stars with very different "signatures" of oxygen and CN-band strengths. The abundances of C and N are often anticorrelated, and in the limited number of cases in which both have been measured, O and N abundances have also often proved to be anticorrelated (Pilachowski 1988, Sneden et al. 1991, Brown et al. 1991, Kraft et al. 1992). Following pioneering work by Cohen (1978) and Peterson (1980), strong evidence has recently emerged for the existence of a significant global anticorrelation between O and Na abundances (Drake et al. 1992, Kraft et al. 1993). The observations are discussed in terms of contrasting hypotheses: evolutionary vs. primordial. In the former, the variations are attributed to the dredgeup of material that has been processed through the CNO cycle in the globular cluster stars themselves. In the latter, the variations are attributed to the primordial chemical inhomogeneities in the material out of which the cluster stars were formed, the composition of these "clumps" having been determined by nuclear processing in a prior generation of more massive stars. Observational evidence supporting each of these scenarios is cited. Recent studies of stellar rotation among horizontal branch stars in certain clusters (Peterson 1993) as well as new calculations of 23Na and 27Al production in te CNO processing regions of evolving low mass giants (Langer et al. 1993) lend fresh support to the evolutionary hypothesis. However, such calculations do not explain the variation of C and N abundances found among cluster main sequence stars (Suntzeff 1989, Briley et al. 1991) which seem explicable therefore only on the basis of a primordial scenario. Among mildly metal-poor giants, i.e., those in the range from solar metallicity to [Fe/H] ~-1, recent observational evidence suggesting the existence of a substructure in the [el/Fe]-ratios of the heavier alpha elements, e.g., Si, Mg, Ca and Ti, is discussed. The possible influence of this effect on the interpretation of the integrated spectra of extragalactic globular clusters and E galaxies is noted.
Formation of binary millisecond pulsars by accretion-induced collapse of white dwarfs

It has generally been assumed that neutron stars (NSs) that become millisecond pulsars (MSPs) originated in a core-collapse supernova. The possibility of formation by accretion-induced collapse (AIC) of an oxygen/neon white dwarf (WD) has largely been ignored or considered negligible. Here, we demonstrate that population synthesis calculations with generic assumptions yield birthrates of binary MSPs via AIC that are comparable to and can exceed those for core collapse. Allowing both modes for NS formation, we estimate birthrates and orbital period distributions and compare these with observations of binary MSPs and low-mass X-ray binaries. Our calculations show that both the core-collapse and AIC routes lead to populations of binary systems that can be identified with X-ray binaries while transferring matter and binary MSPs at the end of an accretion phase. The estimated birthrates indicate that the often-neglected AIC route cannot be ignored. It also appears that this route can provide a better match to the period distributions of some types of binary MSPs. In particular, it appears to be the major route to the orbital period distribution of long-period (a few days or greater) systems with helium WD companions under certain model assumptions. The birthrate problem confronting the low- and intermediate-mass X-ray binaries remains but can still be resolved by invocation of irradiation-driven limit cycles.
The Functional Significance of Delayed Stall in Insect Flight

Navier-Stokes simulations over an idealized flapping insect wing reveal a new strategy for vertical force generation in inclined stroke plane hovering: insects use their wing as bluff and streamlined bodies during downstroke and upstroke, respectively. This strategy helps insects to stay aloft. Furthermore, qualitative and quantitative results from our 2-D simulations determine to what extent the delayed stall mechanism is significant for enhanced flight performance in inclined plane hovering.
Detection of Interaural Time Differences in Short‐Duration Low‐Frequency Tones

The detectability of interaural time differences (Δt) was investigated as a function of stimulus duration, level, and frequency. Temporally dichotic tone bursts of 250, 500, and 1000 Hz were presented in a two‐interval forced choice, in such a way that the signal to one ear led by Δt μsec during either the first or second interval. The tone bursts were 10, 25, 50, 100, and 205 msec in duration and were gated with a rise‐decay time of 2.5 msec. The levels used were 50 and 70 dB SPL. Threshold values of Δt were maximal for the shortest durations, then fell rapidly to asymptote in the region from 50 to 100 msec. In addition, thresholds decreased at higher frequencies. Finally, all conditions showed lower thresholds for 70 dB than for 50 dB. The data are fit by a model that treats increased duration as an increase in the number of samples of the interaural difference and describes the improvements found with higher frequencies and levels as a result of the steeper slopes of the displacement waveforms.