Miracle-dz/UniFAR-FTUs huggingface dataset:
Point-projection x-ray radiography using an X pinch as the radiation source

Using an X pinch as a source of radiation for point-projection radiography, it is possible to project a high-resolution (1–10 μm) shadow image of dense plasma or test objects onto x-ray-sensitive film. The emission characteristics of X pinches composed of a wide variety of materials have been studied using several diagnostics. The pulse duration and shape of the x-ray bursts were measured in the 1.5–6 keV band using fast diamond PCDs and an x-ray streak camera with sweep speeds as fast as 10 ns for the full sweep (3.5 cm). To investigate the line and continuum radiation emitted by the X pinches, a convex spectrograph using a mica or KAP crystal, and a spectrograph based on a spherically bent mica crystal were used. Summarizing the data, including radiography results, wires known to have slower expansion rates and high boiling temperatures (NiCr, Ti, Nb, Mo, Pd, Ta, W, and Pt) appeared to yield the smallest x-ray source sizes, i.e., gave the best spatial resolution in radiographs and provided subnanosecond.
Improved laser processing of lithium niobate

Successful laser processing of lithium niobate has so far only been done with lasers using photon energies well above the band gap energy (3.75 eV=330 nm). We report a highly improved method which enables us to do laser processing using a continuous wave (cw) laser operating at low power densities below the band gap energy of lithium niobate, giving us significantly higher removal rates than previously reported in the literature. Using 351 nm cw laser light (Ar+), high scan speed (100 mm/s), a spot size of 8 μm and 300 mW of laser power results in removal rates in excess of 106 μm3/s. Combined with the possibility of precise focusing (1 μm) and high positioning accuracy (100 nm) of the laser beam, this opens up several new possibilities: micromachining of small piezoelectric structures, simple etching of grooves for a controlled positioning of optical fibers, or etching of grooves in SAW-devices
Mental Health and the COVID-19 Pandemic: Analysis of Twitter Discourse

This study analyzed Twitter discourse to understand the association of the COVID-19 pandemic with mental health. The study compared tweets' volume over time, tweets' volume per mental health category, emotions, and the top hashtags on mental health before and after November 2019, the month on which the first COVID-19 case was reported. We analyzed a total of 273 million English tweets on mental health collected from 56 million unique users. Results and analysis showed a significant shift in trend for the volume of tweets on mental health over time. There was also a notable increase in the volume of tweets on depression, anxiety, stress, and suicide mental health groups. The volume of tweets posted by males and females was comparable. Finally, there was a noticeable increase in the average daily tweets that mention suicide prevention and mental health during the COVID-19 pandemic. © AMCIS 2021.
Interplay between a bacterial pathogen and its host in rainbow trout isogenic lines with contrasted susceptibility to Cold Water Disease

Infectious diseases are a major constraint on aquaculture. Genetic lines with different susceptibilities to diseases are useful models to identify resistance mechanisms to pathogens and to improve prophylaxis. Bacterial cold-water disease (BCWD) caused by Flavobacterium psychrophilum represents a major threat for freshwater salmonid farming worldwide. A collection of rainbow trout (Oncorhynchus mykiss) isogenic lines was previously produced from a French domestic population. Here, we compared BCWD resistance phenotypes using a subset of isogenic lines chosen for their contrasted susceptibilities to F. psychrophilum. We applied individual monitoring to document the infection process, including time-course quantification of bacteremia and innate immune response. Strikingly, BCWD resistance was correlated with a lower bacterial growth rate in blood. Several immune genes were expressed at higher levels in resistant fish regardless of infection: the Type II arginase (arg2), a marker for M2 macrophages involved in anti-inflammatory responses and tissue repair, and two Toll-like receptors (tlr2/tlr7), responsible for pathogen detection and inflammatory responses. This study highlights the importance of innate and intrinsic defense mechanisms in determining the outcome of F. psychrophilum infections, and illustrates that non-lethal time-course blood sampling for individual monitoring of bacteremia is a powerful tool to resolve within-host pathogen behavior in bacterial fish diseases.
The scale-invariant covariance spectrum of brain-wide activity

The structure of high-dimensional neural activity plays a pivotal role in various sensory and behavioral processes. Here, we analyze whole-brain calcium activity in larval zebrafish, captured by fast light-field volumetric imaging during hunting and spontaneous behavior. We find that brain-wide activity is distributed across many principal component dimensions described by the covariance spectrum. Intriguingly, this spectrum shows an invariance to spatial subsampling: That is, the distribution of the eigenvalues of a smaller and randomly sampled cell assembly is statistically similar to that of the entire brain. We propose that this property can be understood using a Euclidean random matrix model (ERM), where pairwise correlation between neurons can be mapped onto a distance function between two points in a low-dimensional functional space. We numerically and analytically calculate the eigenspectrum in our model and identify three key factors that lead to the experimentally observed scale invariance: (i) the slow decay of the distance-correlation function, (ii) the higher dimension of the functional space, and (iii) the heterogeneity of neural activity. Our theory can quantitatively recapitulate the scale-invariant spectrum in zebrafish data, as well as two-photon and multi-area electrode recordings in mice. Furthermore, fitting the model to the experimental data uncovers a reorganization of neurons in the functional space when the zebrafish is engaged in hunting behavior. Our results therefore provide new insights and interpretations of brain-wide neural activity and offer clues about circuit mechanisms for coordinating global neural activity patterns.
Fixed Accuracy Estimation of an Autoregressive Parameter

Abstract : For a first order non-explosive autoregressive process with unknown parameter beta epsilon (1,1), it is shown that if data are collected according to a particular stopping rule, the least squares estimator of beta is asymptotically normally distributed uniformly in beta. In the case of normal residuals, the stopping rule may be interpreted as sampling until the observed Fisher information reaches a preassigned level. The situation is contrasted with the fixed sample size case, where the estimator has a non-normal limiting distribution when (beta) = 1. (Author)
A two‐dimensional mixed finite‐element pair on rectangles

Mixed finite‐element discretizations provide a promising method for extending highly desirable C‐grid properties to high order on quasi‐uniform horizontal grids. For the degree 1 Raviart–Thomas–quadrilateral (RT1–Q1) finite‐element discretization of the one‐dimensional linear gravity‐wave equations, it has recently been shown that the group velocity goes to zero for waves with wavelength close to or equal to twice the element width, but that this problem can be addressed by partially lumping mass matrices. As an essential stepping stone to generalization to the two‐dimensional linear shallow‐water equations, recent analysis is extended herein to the one‐dimensional linear shallow‐water equations. It is found that the previous two‐parameter partial mass lumping no longer, in general, addresses the dispersion problem; in particular, and surprisingly, there is an unanticipated spectral gap for the asymptotic limit of pure inertial oscillations. Fortunately, the ensuing dispersion problems can be addressed by deducing an additional constraint on parameter values. This is most easily obtained by ensuring removal of the spectral gap for pure inertial oscillations and leads to the original (generally) asymmetric two‐parameter partial mass lumping reducing to a symmetric single‐parameter one.
Stability problems in point contact solar cells

Single-crystal silicon point-contact solar cells show a degradation in their efficiency after being exposed to concentrated sunlight. Two mechanisms appear to be responsible: an increase in surface recombination velocity caused by ultraviolet light, possibly due to electron injection from the silicon into the oxide, and a gradual lowering of the effective carrier lifetime that occurs when the cell is under high-level injection for an extended period of time. Point-contact solar cells whose front-side passivation has a phosphorus as well as a thermal oxide diffusion are dramatically more resistant to ultraviolet radiation damage. Modeling results indicate that it is possible to make a point-contact solar cell that is 26.8% efficient after massive ultraviolet exposure. <<ETX>>
Quasi-Biennial Oscillations of Ozone and Diabatic Circulation in the Equatorial Stratosphere

Abstract The quasi-biennial oscillation (QBO) in ozone in the equatorial stratosphere is obtained by analyzing the Stratospheric Aerosol and Gas Experiment (SAGE) data from 1984 to 1989. The phase of the ozone QBO in the lower stratosphere is found to precede the zonal wind QBO by several months as opposed to the theoretically expected in-phase relationship between the two. A mechanistic model is developed to explore possible reasons for this disagreement. The model is capable of simulating the actual time evolution of the ozone QBO by introducing the observed zonal wind profile as input. The modeled results confirm the conventional view that the ozone QBO is generated by the vertical ozone advection that is driven to maintain the temperature structure against radiative damping. However, a series of experiments emphasizes the importance of the feedback of the ozone QBO to the diabatic heating through the absorption of solar radiation. Due to this effect, the phase of the ozone QBO shifts up to a quarter c.
Numerical Calculation of Pressure Fluctuations in the Volute of a Centrifugal Fan

In this work, a numerical model has been applied in order to obtain the wall pressure fluctuations at the volute of an industrial centrifugal fan. The numerical results have been compared to experimental results obtained in the same machine. A three-dimensional numerical simulation of the complete unsteady flow on the whole impeller-volute configuration has been carried out using the computational fluid dynamics code FLUENT®. This code has been employed to calculate the time-dependent pressure both in the impeller and in the volute. In this way, the pressure fluctuations in some locations over the volute wall have been obtained. The power spectra of these fluctuations have been obtained, showing an important peak at the blade passing frequency. The amplitude of this peak presents the highest values near the volute tongue, but the spatial pattern over the volute extension is different depending on the operating conditions. A good agreement has been found between the numerical and the experimental results.
Variable Asymmetry of the Circumstellar Envelope in IK Tauri Traced by SiO Maser Emission

We observed the SiO (v = 1 and v = 2, J = 1–0) maser emissions toward the Mira variable IK Tauri (IK Tau, NML Tau, IRC +10050) over nine epochs from 2003 November to 2005 April using the VLBI Exploration of Radio Astrometry (VERA) telescope array. We found that the SiO maser distributions around IK Tau are highly variable, depending on the stellar pulsation phase. The velocity structures were complex and also time-variable, and are inconsistent with a simply rotating shell that was suggested by previous observations. Based on fittings of the SiO maser distributions to elliptical ring models, we found that the ring size seems to vary in correlation with the pulsation phase, as previously found for TX Cam. Comparisons of the v = 1 and v = 2 maser distributions reveal that 42–50% of the maser pairs have a positional offset less than 0.5 mas, suggesting that the maser pumping in these spots is likely to be dominated by line overlapping or collisional pumping, rather than pure radiative pumping. In order to model the velocity structure of the spoke-like features observed in IK Tau, we propose a ballistic-orbit model, in which a gas clump ejected from the stellar surface moves radially outward with a gravitational deceleration, and argue that the stellar mass can be deduced from that model.
Long-Term Evolution of Objects in the Kuiper Belt Zone—Effects of Insolation and Radiogenic Heating

Abstract The Kuiper Belt zone is unique insofar as the major heat sources of objects a few tens of kilometers in size—solar radiation on the one hand and radioactive decay on the other—have comparable power. This leads to unique evolutionary patterns, with heat waves propagating inward from the irradiated surface and outward from the radioactively heated interior. A major radioactive source that is considered in this study is 26 Al. The long-term evolution of several models with characteristics typical of Kuiper Belt objects is followed by means of a 1-D numerical code that solves the heat and mass balance equations on a spherically symmetric grid. The free parameters considered are radius (10–500 km), heliocentric distance (30–120 AU), and initial 26 Al content (0–5×10 −8 by mass). The initial composition assumed is a porous mixture of ices (H 2 O, CO, and CO 2 ) and dust. Gases released in the interior are allowed to escape to the surface. It is shown that, depending on parameters, the interior may reach quite high temperatures (up to 180 K). The models suggest that Kuiper Belt objects are likely to lose the ices of very volatile species during early evolution; ices of less volatile species are retained in a surface layer, about 1 km thick. The models indicate that the amorphous ice crystallizes in the interior, and hence some objects may also lose part of the volatiles trapped in amorphous ice. Generally, the outer layers are far less affected than the inner part, resulting in a stratified composition and altered porosity distribution. These changes in structure and composition should have significant consequences for the short-period comets, which are believed to be descendants of Kuiper Belt objects.
Additive Outlier Detection Via Extreme‐Value Theory

Abstract. This article is concerned with detecting additive outliers using extreme value methods. The test recently proposed for use with possibly non‐stationary time series by Perron and Rodriguez [Journal of Time Series Analysis (2003) vol. 24, pp. 193–220], is, as they point out, extremely sensitive to departures from their assumption of Gaussianity, even asymptotically. As an alternative, we investigate the robustness to distributional form of a test based on weighted spacings of the sample order statistics. Difficulties arising from uncertainty about the number of potential outliers are discussed, and a simple algorithm requiring minimal distributional assumptions is proposed and its performance evaluated. The new algorithm has dramatically lower level‐inflation in face of departures from Gaussianity than the Perron–Rodriguez test, yet retains good power in the presence of outliers.
Rear Shock Formation In Gravity Currents

Considered in this study is the gravity driven flow of a two-fluid system arising from the motion of a heavy fluid in a rectangular channel having a flat bottom. The mathematical model is based on shallow-water theory in connection with a two-layer Boussinesq fluid. By means of a scaling argument, it can be shown that for small density differences the gravity current can be successfully modelled by a two-by-two hyperbolic system in conservation form together with a pair of algebraic relations. This reduced system is referred to as the weak stratification model. A weakly nonlinear analysis is performed on this weak stratification model to elicit information concerning the formation of a rear shock which may form on the back side of the head of the gravity current. Predictions made by the analytical technique are then verified by numerical simulations.
Minimum-resistance shapes in linear continuum mechanics

A necessary optimality condition for the problem of the minimum-resistance shape for a rigid three-dimensional inclusion displaced in an unbounded isotropic elastic medium subject to a constraint on the volume of the inclusion is obtained through Betti's reciprocal work theorem. It generalizes Pironneau's optimality condition for the minimum-drag shape for a rigid body immersed into a uniform Stokes flow and is specialized for axisymmetric inclusions in axisymmetric and transversal translations. In both cases of translation, the three-dimensional displacement field is represented in terms of generalized analytic functions, and the three-dimensional elastostatics problem is reduced to boundary-integral equations (BIEs) via the generalized Cauchy integral formula. Minimum-resistance shapes are found in the semi-analytical form of functional series from an iterative procedure coupling the optimality condition and the BIEs. They are compared with the minimum-resistance spheroids and with the minimum-resistance spindle-shaped and lens-shaped bodies. Remarkably, in the axisymmetric translation, the minimum-resistance shapes transition from spindle-like shapes to almost prolate spheroidal shapes as the Poisson ratio changes from 1/2 to 0, whereas in the transversal translation, they are close to oblate spheroidal shapes for any Poisson ratio.
Twins in spirit part IV – [ 177 Lu] high affinity DOTATATE A promising new tracer for peptide receptor radiotherapy?

Aim: Besides the use of somatostatin analogues, small molecules like sunitinib and everolimus as well as conventional chemotherapy, peptide receptor radiotherapy (PRRT) using radiolabelled somatostatin analogues has gained an important role in the treatment of inoperable, metastasized neuroendocrine tumours (NET). There are various radiotracers in use. Based on our experience with the PET tracer [68Ga]DOTA-3-iodoTyr3-octreotate ([68Ga]HA-DOTATATE), a DOTATATE derivative with an increased binding affinity to hsst5, the current retrospective analysis is exploring the therapeutic potential of [177Lu]HA-DOTATATE. Methods: Eighteen patients with metastatic NET (G1/G2) were treated using [177Lu]DOTATATE and/or [177Lu]HA-DOTATATE, and dosimetric results of both tracers were compared. Results: Using [177Lu]HA-DOTATATE, a mean tumour dose of 5.34 Gy/GBq (median 2.53 Gy/ GBq; range 0.89–33.3 Gy/GBq) was achieved , while [177Lu]DOTATATE delivered a tumour dose of 5.53 Gy/GBq (median 2.70 Gy/GBq; range 0.44–15.3 Gy/GBq). Organ doses for [177Lu]HA-DOTATATE vs. [177Lu]DOTATATE were as follows: kidney 2.31 ± 0.85 vs. 2.03 ± 0.96 Gy/GBq, liver 1.06 ± 0.79 vs. 1.67 ± 1.73 Gy/GBq, spleen 3.89 ± 4.04 vs. 4.50 ± 3.69 Gy/GBq and whole body 0.16 ± 0.10 Gy/GBq vs. 0.15 ± 0.08 Gy/ GBq. Tumour-to-kidney dose ratio was slightly higher for [177Lu]DOTATATE (2.4 ± 5.6) compared to [177Lu]HA-DOTATATE (1.5 ± 3.6). Conclusion: Both tracers showed marked inter-patient variation in their dosimetry, and no significant differences in dosimetry of [177Lu]HADOTATATE and [177Lu]DOTATATE were observed when taking all patients into account. Thus, [177Lu]HA-DOTATATE appears viable for PRRT, although it was marginally inferior regarding kidney dose and tumour-to-kidney dose ratio compared to the established [177Lu]DOTATATE.
Technetium -99m Labelling of the IOR C EA I Monoclonal Antibody: Evaluation of Different Methods " m Tc-Markierung des monoklonalen Antikörpers IOR CEA 1: Bewertung unterschiedlicher Methoden

Aim: The aim of this study was to investigate the in vivo and in vitro properties of 99m Tc labelled monoclonal antibody, IOR CEA 1 when radiolabelled by different methods. Methods: To achieve that purpose IOR CEA was directly radiolabeled via 2-mercaptoethanol (2-Me) and stannous ion (SnCI 2 ) reduction and indirectly via the 2-iminothiolane (2-lm) conjugation. The resulting " m Tc-MoAbs were analysed for number of free sulfhydryl groups, chemical and radiochemical purity (checked by HPLC and SDS PAGE), immunoreactivity and biological distribution in mice. Results: Experimental results indicated a similar radiochemical purity and immunoreactivity for direct labelling methods and a decrease of both for 2-lm method. 2-Me antibody reduction led to a high antibody fragmentation as indicated by non-denaturing SDS PAGE analysis. Nevertheless SnCI 2 and 2-lm labels revealed lower in vivo stability. Conclusion: 99m Tc-(2-Me) IOR CEA presented favorable in vitro and in
Subthreshold electron velocity‐field characteristics of GaAs and In0.53Ga0.47As

The electron drift velocities in GaAs and In0.53Ga0. 47As have been measured at room temperature and at liquid‐nitrogen temperature for electric fields up to the onset of the Gunn effect. The experiments were performed on samples with carrier concentrations from 4×1014 to 1×1018 cm−3. The results illustrate effects of ionized impurity scattering, polar optical phonon scattering, alloy scattering, and intervalley scattering on electron transport in this range of electric fields, and confirm the potential of In0.53Ga0. 47As for high‐speed device applications.
The nocturnal jet

Three case studies of the nocturnal jet at dawn are presented. Observations were made over southern England where the terrain is considerably less homogeneous than that over which previous published data concerning the jet have been obtained, for example the Great Plains and Wangara. It is shown that previously suggested layer models of the boundary layer can be usefully quantified to give the diurnal evolution of a layer-average wind. This model, which involves a decoupling of the flow in middle levels from surface constraints by thermal stratification at night, exhibits a nocturnal jet. Two surface-stress parameterizations, which make the stress proportional to the velocity and to the velocity squared, give a similar wind evolution. The observed abrupt transition in boundary layer structure soon after sunrise is studied by considering the growth and transfer characteristics of perturbations to a homogeneous Boussinesq fluid, which is stratified and possesses an idealized jet wind structure. Depending on the value of an average Richardson number, Ri, two regimes of dynamically unstable eddies are indicated. When +0.35 ≳ Ri −0.03 the preferred eddies are oriented transverse to the shear and when Ri ≲−0.03 they are oriented parallel to the shear. the latter regime, associated with longitudinal convective circulations, is efficient at smoothing the jet momentum distribution to give the characteristic well-mixed daytime wind profile.
Metric Diophantine approximation with two restricted variables I. Two square-free integers, or integers in arithmetic progressions

In this paper, together with [7] and [8], we shall be concerned with estimating the number of solutions of the inequality for almost all α (in the sense of Lebesgue measure on Iℝ), where , and both m and n are restricted to sets of number-theoretic interest. Our aim is to prove results analogous to the following theorem (an improvement given in [2] of an earlier result of Khintchine [10]) and its quantitative developments (for example, see [11, 12,6]): Let ψ(n) be a non-increasing positive function of a positive integer variable n. Then the inequality (1·1) has infinitely many, or only finitely many, solutions in integers to, n(n > 0) for almost all real α, according to whether the sum diverges, or converges, respectively.