TextANIMAR: Text-based 3D Animal Fine-Grained Retrieval

3D object retrieval is an important yet challenging task, which has drawn more and more attention in recent years. While existing approaches have made strides in addressing this issue, they are often limited to restricted settings such as image and sketch queries, which are often unfriendly interactions for common users. In order to overcome these limitations, this paper presents a novel SHREC challenge track focusing on text-based fine-grained retrieval of 3D animal models. Unlike previous SHREC challenge tracks, the proposed task is considerably more challenging, requiring participants to develop innovative approaches to tackle the problem of text-based retrieval. Despite the increased difficulty, we believe that this task has the potential to drive useful applications in practice and facilitate more intuitive interactions with 3D objects. Five groups participated in our competition, submitting a total of 114 runs. While the results obtained in our competition are satisfactory, we note that the challenges presented by this task are far from being fully solved. As such, we provide insights into potential areas for future research and improvements. We believe that we can help push the boundaries of 3D object retrieval and facilitate more user-friendly interactions via vision-language technologies.Comment: arXiv admin note: text overlap with arXiv:2304.0573

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

Méthodes k.p avancées pour la spinorbitronique à base de semi-conducteurs

This thesis work is essentially devoted to the development of the tunneling theory k.p 14, 30 and 40 bands for a spinorbitronic application with semiconductor. Spinorbitronic combines the effects of spin and orbit, which via spin-orbit coupling, introduces new transport properties such as spin Hall and anomalous Hall effects. The latter is characterized by a deflection of the trajectory of polarized carriers in the transverse direction of their flow. Other characteristic effects concern i) the spin transfer mechanisms for switching angular momentum transfer magnetization, thus generalizing spin transfer as well as ii) spin-charge conversion mediated by the terms Rashba or Dresselhaus. In this context, our tunnel transport theory is adaptable to semiconductor heterostructures, magnetic or not, dealing with a simple interface or tunnel junctions. It allows to take into account in a fine way the spin-orbit interactions of heart and interface. It generally uses the introduction of additional high bands, called ghosts, to deal with the spurious states inherent in the multiband k.p theory. Apart from the introduction of the "spurious" states neither deforming the electronic structure nor the polarized transport, our approach uses the continuity of the components of the wave functions at each interface and the connection of the components of wave current according to symmetry interfaces either by 1) the continuity of the components of wave current (extension of Ben Daniel Duke theory), 2) the connection conditions obeying a C2v symmetry by mixing heavy holes cd / light in the valence band (conditions from Ivchenko) or 3) discontinuity of the 'high' bands. We also demonstrate the equivalence of the continuity conditions for the case of AlAs / GaAs / AlAs III-V quantum wells, which represents a generalization of previous results developed in 14 bands.The whole of this work of analytical and numerical thesis, include several important demonstrations. We show that our theory can be used to describe the spin transport of spin-orbit coupled states in growth axis (100) or (110) semiconductor heterostructures. These results are notably materialized by the calculations of the three components of the spin current in the III-V barriers (GaAs, AlAs) acting as spin phase-shifters. Calculations show that we develop in effect, as provided by the analytic theory, a vector rotation of the spin density matrix in the thickness of the barrier and as provided by the application of an effective spin-orbit field Dresselhaus parallel to the plane of the barrier.Our theory is also successfully compared to the multiband perturbation calculations using Green's transport functions to address the mechanisms of abnormal Hall tunnel effect in the conduction band and the valence band. The results are remarkable of fidelity which shows the power of the technique used. We also calculate spin current properties in GaMnAs-based ferromagnetic tunnel junctions to derive the spin transfer torque responsible for switching the fine ferromagnetic element. We show, for example, how the transverse spin components of the current are relevant to switch a magnetization. Finally, we adapted our transport theory to III-V structures to compute confined quantum well states in the conduction band and valence band. We successfully compare our state-of-the-art 6-band and 14-band multiband results on the optical anisotropy of absorption between the directions (110 and (1-10) of the electric field when the symmetry of the heterostructure is reduced to C2v symmetry.Ce travail de thèse est essentiellement consacré au développement de la théorie de transport tunnel k.p 14, 30 et 40 bandes pour une application à la spinorbitronique avec semiconducteur. La spinorbitronique associe les effets de spin et d’orbite, qui par l’intermédiaire du couplage spin-orbite, introduit des propriétés de transport nouvelles comme les effets Hall de spin et tunnel Hall anormal. Ce dernier se caractérise par une déflection de la trajectoire des porteurs polarisés selon la direction transverse de leur flux. D’autres effets caractéristiques concernent i) les mécanismes de transfert de spin permettant de commuter une aimantation par transfert de moment angulaire, généralisant ainsi le transfert de spin ainsi que ii) la conversion spin-charge médiés par les termes Rashba ou Dresselhaus. Dans ce cadre, notre théorie de transport tunnel est adaptable aux hétérostructures semiconductrices, magnétiques ou non, traitant d’une simple interface ou de jonctions tunnel. Elle permet de tenir compte de façon fine des interactions spin-orbite de cœur et d’interface. Elle utilise de façon générale l’introduction de bandes hautes supplémentaires, dites fantômes, pour traiter les états spurious inhérents à la théorie k.p multibandes. Outre l’introduction des états ‘fantômes’ ne déformant ni la structure électronique, ni le transport polarisé, notre approche utilise la continuité des composantes des fonctions d’onde à chaque interface ainsi que le raccordement des composantes du courant d’onde selon la symétrie des interfaces soit par 1) la continuité des composantes du courant d’onde (extension de la théorie Ben Daniel Duke), 2) les conditions de raccordement obéissant à une symétrie C2v par mélange cd trous lourds/légers dans la bande de valence (conditions d’Ivchenko) ou 3) discontinuité des bandes p ‘hautes’. Nous démontrons, en outre, l’équivalence des conditions de continuité pour le cas de puits quantiques III-V de type AlAs/GaAs/AlAs ce qui représente ainsi une généralisation de résultats précédents développés en 14 bandes.L’ensemble de ce travail de thèse analytique et numérique, comportent plusieurs démonstrations importantes. Nous montrons que notre théorie permet de décrire le transport de spin d’états couplés spin-orbite dans les hétérostructures semiconductrices d’axe de croissance (100) ou (110). Ces résultats sont notamment matérialisés par les calculs les trois composantes du courant de spin dans les barrières III-V (GaAs, AlAs) jouant le rôle de déphaseur de spin. Les calculs que nous développons montrent en effet, comme le prévoit la théorie analytique, une rotation vectorielle de la matrice densité de spin dans l’épaisseur de la barrière et comme prévue par l’application d’un champ e spin-orbite effectif de Dresselhaus parallèle au plan de la barrière.Notre théorie est également comparée avec succès aux calculs de perturbation multibandes utilisant les fonctions de Green pour le transport pour traiter les mécanismes de l’effet tunnel Hall anormal dans la bande conduction et dans la bande de valence. Les résultats sont remarquables de fidélité ce qui montre la puissance de la technique utilisée. Nous calculons également les propriétés de courant de spin dans les jonctions tunnel ferromagnétiques à base de GaMnAs pour en déduire le couple de transfert de spin responsable de la commutation de l’élément ferromagnétique fin. Nous montrons par exemple, comment les composantes de spin transverses du courant sont pertinents pour commuter une aimantation. Enfin, nous avons adapté notre théorie de transport aux structures III-V pour calculer les états confinés de puits quantiques dans la bande de conduction et bande de valence. Nous comparons avec succès, nos résultats multibandes à l’état de l’art 6 bandes et 14 bandes, sur l’anisotropie optique de l’absorption entre les directions (110 et (1-10) du champ électrique lorsque la symétrie de l’hétérostructure est réduite à une symétrie C2v

Precipitation and GP-zone structures in AlZnMg (Cu, Zn) alloys

Precipitation processes taking place in high strength AlZnMg alloys (7xxx series) were investigated by compression test TEM and EDX. The results show that addition of Cu changes strongly the temperature of GP zone intermediate phase transition. The addition of Zr leads to an extremely fine-grained structure and in the AlZnMgCuZn alloy a 'duplex' GP-zone structure is formed, causing a 'duplex' behaviour of this alloy

Spin-Orbit Currents, Spin-Transfer Torque and Anomalous Tunneling in III–V Heterostructures Probed by Advanced 30- and 40-Bands k⋅p{k}\cdot{p} Tunneling Methods

International audienceOn the basis of tunneling magnetoresistance (TMR) spin-transfer torque (STT) experiments in (Ga,Mn)As/GaAs/(Ga,Mn)As submicronic magnetic tunnel junctions, we have analyzed the anatomy of the spin-current profiles within the heterostructures, location of strong spin-orbit interactions. Beyond the TMR, our robust 30- and 40-band k · p numerical methods reveal the strong peculiarity of the spin-currents in the antiparallel state with the evidence of a tunneling anomalous Hall effect. Using the boundary conditions corresponding to heavy-hole (HH)-to-light-hole (LH) mixing of the relevant C 2v symmetry at III-V interfaces of the junctions, we demonstrate that the efficiency of the transverse spin-current necessary to STT is surprisingly enhanced by the HH-to-LH mixing taking benefit of the lighter mass of the LH state

An efficient hydrogenation catalytic model hosted in a stable hyper-crosslinked porous-organic-polymer: from fatty acid to bio-based alkane diesel synthesis

In this study, a Pd-based catalytic model over a nitrogen enriched fibrous Porous-Organic-Polymer (POP) is established to execute hydrodeoxygenation of various vegetable oils in producing potential large-scale renewable diesel. Here we report a cost-effective synthesis strategy for a new microporous hypercrosslinked POP through the FeCl3 assisted Friedel-Crafts alkylation reaction, followed by fabrication of Pd-0-NPs (2-3 nm) using a solid gas phase hydrogenation route to deliver a novel catalytic system. This catalyst (called Pd@PPN) exhibits versatile catalytic performance for different types of vegetable oils including palm oil, soybean oil, sunflower oil and rapeseed oil to furnish long chain diesel range alkanes. The catalyst is comprehensively characterized using various spectroscopic tools and it shows high stability during five runs of recycling without leaching of Pd. Our results further reveal that a direct decarbonylation (DCN) pathway of fatty acids to produce alkanes with one fewer carbon is the dominant mechanism. Under optimized conditions, using stearic acid to represent the long linear carboxylic acids in the vegetable oils, up to 90% conversion with 83% selectivity of C17-alkane has been achieved on our fabricated catalyst. Density functional theory (DFT) calculations are performed to provide insights into the electronic properties of the catalyst, the mechanistic reaction pathway, the crucial role of the catalyst surface and the product selectivity trend. The strong interaction between the corrugated polymer-frame-structure and the Pd-NPs suggests the presence of high density step sites on the fabricated Pd-NP anchored within the cage of the polymer structure. DFT calculations also reveal the strong promotional effect of step sites and charge transfer in facilitating rate-limiting steps during the decarbonylation (DCN) pathway and removal of strongly bound intermediates formed during the process, therefore explaining the high activity of the fabricated Pd@PPN catayst for the hydrodeoxygenation (HDO) conversion to produce bio-based alkane diesel

Twelve-Month Outcomes of the AFFINITY Trial of Fluoxetine for Functional Recovery After Acute Stroke: AFFINITY Trial Steering Committee on Behalf of the AFFINITY Trial Collaboration

Background and Purpose: The AFFINITY trial (Assessment of Fluoxetine in Stroke Recovery) reported that oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and seizures. After trial medication was ceased at 6 months, survivors were followed to 12 months post-randomization. This preplanned secondary analysis aimed to determine any sustained or delayed effects of fluoxetine at 12 months post-randomization. Methods: AFFINITY was a randomized, parallel-group, double-blind, placebo-controlled trial in adults (n=1280) with a clinical diagnosis of stroke in the previous 2 to 15 days and persisting neurological deficit who were recruited at 43 hospital stroke units in Australia (n=29), New Zealand (4), and Vietnam (10) between 2013 and 2019. Participants were randomized to oral fluoxetine 20 mg once daily (n=642) or matching placebo (n=638) for 6 months and followed until 12 months after randomization. The primary outcome was function, measured by the modified Rankin Scale, at 6 months. Secondary outcomes for these analyses included measures of the modified Rankin Scale, mood, cognition, overall health status, fatigue, health-related quality of life, and safety at 12 months. Results: Adherence to trial medication was for a mean 167 (SD 48) days and similar between randomized groups. At 12 months, the distribution of modified Rankin Scale categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio, 0.93 [95% CI, 0.76–1.14]; P =0.46). Compared with placebo, patients allocated fluoxetine had fewer recurrent ischemic strokes (14 [2.18%] versus 29 [4.55%]; P =0.02), and no longer had significantly more falls (27 [4.21%] versus 15 [2.35%]; P =0.08), bone fractures (23 [3.58%] versus 11 [1.72%]; P =0.05), or seizures (11 [1.71%] versus 8 [1.25%]; P =0.64) at 12 months. Conclusions: Fluoxetine 20 mg daily for 6 months after acute stroke had no delayed or sustained effect on functional outcome, falls, bone fractures, or seizures at 12 months poststroke. The lower rate of recurrent ischemic stroke in the fluoxetine group is most likely a chance finding. REGISTRATION: URL: http://www.anzctr.org.au/ ; Unique identifier: ACTRN12611000774921