Semi-Supervised Learning in the Few-Shot Zero-Shot Scenario

Semi-Supervised Learning (SSL) is a framework that utilizes both labeled and unlabeled data to enhance model performance. Conventional SSL methods operate under the assumption that labeled and unlabeled data share the same label space. However, in practical real-world scenarios, especially when the labeled training dataset is limited in size, some classes may be totally absent from the labeled set. To address this broader context, we propose a general approach to augment existing SSL methods, enabling them to effectively handle situations where certain classes are missing. This is achieved by introducing an additional term into their objective function, which penalizes the KL-divergence between the probability vectors of the true class frequencies and the inferred class frequencies. Our experimental results reveal significant improvements in accuracy when compared to state-of-the-art SSL, open-set SSL, and open-world SSL methods. We conducted these experiments on two benchmark image classification datasets, CIFAR-100 and STL-10, with the most remarkable improvements observed when the labeled data is severely limited, with only a few labeled examples per clas

Dexterity and Finger Sense: A Possible Dissociation in Children With Cerebral Palsy

Both hand and finger sensory perception and motor abilities are essential for the development of skilled gestures and efficient bimanual coordination. While finger dexterity and finger sensory perception can be impaired in children with cerebral palsy (CP), the relationship between these two functions in this population is not clearly established. The common assumption that CP children with better sensory function also demonstrate better motor outcomes has been recently challenged. To study these questions further, we assessed both finger dexterity and finger gnosia, the ability to perceive one's own fingers by touch, in groups of 11 children with unilateral (i.e., hemiplegic CP) and 11 children with bilateral spastic CP (i.e., diplegic CP) and compared them with typical children. In our sample, children with hemiplegia exhibited finger dexterity deficit in both hands and finger gnosia deficit only in their paretic hand. In contrast, children with diplegia exhibited finger gnosia deficits in both hands and finger dexterity deficit only in their dominant hand. Thus, our results indicated that children with spastic hemiplegia and diplegia present different sensory and motor profiles and suggest that these two subgroups of CP should be considered separately in future experimental and clinical research. We discuss the implications of our results for rehabilitation

Partial Rhombencephalosynapsis and Chiari Type II Malformation in a Child: a True Association Supported by DTI Tractography

Partial rhombencephalosynapsis (PRECS) has been recently reported in association with Chiari II (CII). However, its existence as a true malformation is challenged due to the anatomical changes potentially induced by CII. The aim of this report was to investigate the contribution of midbrain/hindbrain tractography in this setting. A 13-year-old boy with a known CII malformation and operated myelomeningocele was referred for brain imaging after a first complex partial seizure. In addition to the classical features of CII, MRI showed partially fused cerebellar hemispheres and multiple supratentorial abnormalities. Diffusion tensor imaging (DTI) color map and tractography showed absent transverse fibers on the midsection of the cerebellum, scarce fibers of the middle cerebellar peduncle (MCP), absence of the middle pontine crossing tract, and fibers running vertically in the medial part of the cerebellum. Vertical mediocerebellar fibers are a feature of classical RECS and the paucity or absence of MCP fibers is mainly described in CII. In our patient, DTI and FT therefore demonstrated structural characteristics of both RECS and CII confirming their potential coexistence and suggesting possible shared embryological pathwa

Program Pu Futures 2006

The coordination chemistry of plutonium remains relatively unexplored. Thus, the fundamental coordination chemistry of plutonium is being studied using simple multi-dentate ligands with the intention that the information gleaned from these studies may be used in the future to develop plutonium-specific sequestering agents. Towards this goal, hard Lewis-base donors are used as model ligands. Maltol, an inexpensive natural product used in the commercial food industry, is an ideal ligand because it is an all-oxygen bidentate donor, has a rigid structure, and is of small enough size to impose little steric strain, allowing the coordination preferences of plutonium to be the deciding geometric factor. Additionally, maltol is the synthetic precursor of 3,4-HOPO, a siderophore-inspired bidentate moiety tested by us previously as a possible sequestering agent for plutonium under acidic conditions. As comparisons to the plutonium structure, Ce(IV) complexes of the same and related ligands were examined as well. Cerium(IV) complexes serve as good models for plutonium(IV) structures because Ce(IV) has the same ionic radius as Pu(IV) (0.94 {angstrom}). Plutonium(IV) maltol crystals were grown out of a methanol/water solution by slow evaporation to afford red crystals that were evaluated at the Advanced Light Source at Lawrence Berkeley National Laboratory using single crystal X-ray diffraction. Cerium(IV) complexes with maltol and bromomaltol were crystallized via slow evaporation of the mother liquor to afford tetragonal, black crystals. All three complexes crystallize in space group I4{sub 1}/a. The Ce(IV) complex is isostructural with the Pu(IV) complex, in which donating oxygens adopt a trigonal dodecahedral geometry around the metal with the maltol rings parallel to the crystallographic S{sub 4} axis and lying in a non-crystallographic mirror plane of D{sub 2d} molecular symmetry (Fig 1). The metal-oxygen bonds in both maltol complexes are equal to within 0.04 {angstrom} for each oxygen type. In contrast to the maltol structures, the cerium(IV) bromomaltol complex arranges the maltol rings in a drastically different manner while maintaining the S{sub 4} crystallographic symmetry (Fig 2). The coordination geometry around the cerium remains a trigonal dodecahedron, but the chelating ligands span a different set of edges as in the maltol structures; the two-fold related bromomaltol ligands twist away from planarity, breaking the D{sub 2d} molecular symmetry. It is unlikely that steric interaction with a bromine on the same molecule would have caused the observed rearrangement, as there would be sufficient separation between them to accommodate their bulk in the geometry of the plutonium and cerium maltol complexes. The extended packing in the unit cell of both the plutonium and cerium maltol crystals indicates that pi stacking occurs throughout the lattice via the maltol rings with close contacts between rings of approximately 3.6 {angstrom}. Introduction of the bromine to this structure would disrupt the packing that would allow these interactions, causing the molecule to adopt the geometry present in the bromomaltol structure. In this unexpected arrangement the complex is still able to maintain some pi stacking with the maltol rings of adjacent molecules with a close contact of approximately 3.3 {angstrom}. Additionally, the bromine on each ligand is arranged such that its next closest contact is with a bromine 3.64 {angstrom} away on another molecule. Despite the different ligand geometry, the bromomaltol structure exhibits metal-oxygen bond distances that are within 0.06 {angstrom} of those in the maltol complexes

Genome-wide assessment of post-transcriptional control in the fly brain

Post-transcriptional control of gene expression has central importance during development and adulthood and in physiology in general. However, little is known about the extent of post-transcriptional control of gene expression in the brain. Most post-transcriptional regulatory effectors (e.g., miRNAs) destabilize target mRNAs by shortening their polyA tails. Hence, the fraction of a given mRNA that it is fully polyadenylated should correlate with its stability and serves as a good measure of post-transcriptional control. Here, we compared RNA-seq datasets from fly brains that were generated either from total (rRNA-depleted) or polyA-selected RNA. By doing this comparison we were able to compute a coefficient that measures the extent of post-transcriptional control for each brain-expressed mRNA. In agreement with current knowledge, we found that mRNAs encoding ribosomal proteins, metabolic enzymes, and housekeeping genes are among the transcripts with least post-transcriptional control, whereas mRNAs that are known to be highly unstable, like circadian mRNAs and mRNAs expressing synaptic proteins and proteins with neuronal functions, are under strong post-transcriptional control. Surprisingly, the latter group included many specific groups of genes relevant to brain function and behavior. In order to determine the importance of miRNAs in this regulation, we profiled miRNAs from fly brains using oligonucleotide microarrays. Surprisingly, we did not find a strong correlation between the expression levels of miRNAs in the brain and the stability of their target mRNAs; however, genes identified as highly regulated post-transcriptionally were strongly enriched for miRNA targets. This demonstrates a central role of miRNAs for modulating the levels and turnover of brain-specific mRNAs in the fly

MRI with fibre tracking in Cogan congenital oculomotor apraxia

Background: Congenital ocular motor apraxia (COMA) occasionally shares with Joubert syndrome (JS) and related disorders (JSRDs) a peculiar malformation, the ‘molar tooth sign' (MTS). In JSRDs, the absence of superior cerebellar peduncles (SCP) decussation is reported. Objective: To investigate whether COMA demonstrates similar abnormal axonal pathways. Materials and methods: Eight healthy age-matched controls, three children with clinical COMA and one child with clinical JSRD underwent examination with a 1.5-T MRI scanner. Diffusion-weighted imaging (DWI), colour-coded fractional anisotropy maps and three-dimensional diffusion tensor imaging (DTI) tractography of the cerebellorubral network were analyzed. Results: On DTI cartography, the ‘red dot' originally supposed to represent the SCP decussation in the midbrain was present in controls as well in those with COMA but absent in the single case with JS. In none of the subjects including controls was 3-D FT able to depict the SCP decussation. When seeded, the red dot resulted in the ventral tegmental decussation (VTD). It was normal in controls and in patients with COMA but was absent in our single patient with JSRD. MTS was identified in alla patients with COMA and in the patient with JSRD. Conclusion: MTS can be present in both COMA and JSRD but the underlying anatomy depicted by fibre tracking is distinct. The main difference is the integrity of the VTD in COM

Experimental determination of metal fuel point defect parameters

Nuclear metallic fuels are one of many options for advanced nuclear fuel cycles because they provide dimensional stability, mechanical integrity, thermal efficiency, and irradiation resistance while the associated pyro-processing is technically relevant to concerns about proliferation and diversion of special nuclear materials. In this presentation we will discuss recent success that we have had in studying isochronal annealing of damage cascades in Pu and Pu(Ga) arising from the self-decay of Pu as well as the annealing characteristics of non-interacting point defect populations produced by ion accelerator irradiation. Comparisons of the annealing properties of these two populations of defects arising from very different source terms are enlightening and point to complex defect and mass transport properties in the plutonium specimens which we are only now starting to understand as a result of many follow-on studies. More importantly however, the success of these measurements points the way to obtaining important mass transport parameters for comparison with theoretical predictions or to use directly in existing and future materials modelling of radiation effects in nuclear metallic fuels. The way forward on such measurements and the requisite theory and modelling will be discussed. We bring to the attention of the reader that this article is based wholly or in part on earlier publications of the authors.Ядерне металеве паливо є одним із багатьох варіантів прогресивного ядерного паливного циклу, оскільки воно забезпечує розмірну стабільність, механічну цілісність, тепловий коефіцієнт корисної дії і радіаційну стійкість, в той час, як піротехнологія технічно відноситься до проблем про розповсюдження спеціальних ядерних матеріалів та їх перенасичення. У даному повідомленні ми обговоримо останні успіхи, досягнуті нами при вивченні ізохронного відпалу каскадів пошкоджень в Pu і Pu(Ga), які виникають в результаті саморозпаду Pu, а також характеристики відпалу невзаємодіючих точкових дефектів, які утворились при опроміненні у прискорювачі іонів. Порівняння цих двох популяцій дефектів, виникаючих при різних вихідних умовах, проливають світло та вказують на складні властивості дефектів і масопередачі в зразках плутонію, які ми починаємо розуміти тільки зараз у результаті багатьох модифікованих досліджень, Однак, і це більш важливе, успіх цих вимірювань вказує шлях отримання важливих параметрів масо переносу для порівняння з теоретичними прогнозуваннями, або для безпосереднього використання при моделюванні радіаційних ефектів у вже існуючих та майбутніх матеріалах у якості ядерного металевого палива. Ми звертаємо увагу читача на те, що ця стаття заснована повністю або частково на більш ранніх публікаціях авторів.Ядерное металлическое топливо является одним из многих вариантов прогрессивного ядерного топливного цикла, поскольку оно обеспечивает размерную стабильность, механическую целостность, тепловой коэффициент полезного действия и радиационную стойкость, в то время, как пиротехнология технически относится к проблемам распространения специальных ядерных материалов и их перенацеливания. В данном сообщении мы обсудим последние успехи, достигнутые нами при изучении изохронного отжига каскадов повреждений в Pu и Pu(Ga), которые возникают в результате самораспада Pu, а также характеристики отжига невзаимодействующих точечных дефектов, образованных при облучении в ускорителе ионов. Сравнения этих двух популяций дефектов, возникающих при разных исходных условиях, проливают свет и указывают на сложные свойства дефектов и массопередачи в образцах плутония, которые мы только сейчас начинаем понимать в результате многих модифицированных исследований. Однако, что более важно, успех этих измерений указывает на путь получения важных параметров массопереноса для сравнения с теоретическими предсказаниями или для непосредственного использования при моделировании радиационных эффектов в уже существующих и будущих материалах в качестве ядерного металлического топлива. Мы обращаем внимание читателя на то, что эта статья основана целиком или частично на более ранних публикациях авторов