296 research outputs found
ConvNets Match Vision Transformers at Scale
Many researchers believe that ConvNets perform well on small or moderately
sized datasets, but are not competitive with Vision Transformers when given
access to datasets on the web-scale. We challenge this belief by evaluating a
performant ConvNet architecture pre-trained on JFT-4B, a large labelled dataset
of images often used for training foundation models. We consider pre-training
compute budgets between 0.4k and 110k TPU-v4 core compute hours, and train a
series of networks of increasing depth and width from the NFNet model family.
We observe a log-log scaling law between held out loss and compute budget.
After fine-tuning on ImageNet, NFNets match the reported performance of Vision
Transformers with comparable compute budgets. Our strongest fine-tuned model
achieves a Top-1 accuracy of 90.4%
Two-point phase correlations of a one-dimensional bosonic Josephson junction
We realize a one-dimensional Josephson junction using quantum degenerate Bose
gases in a tunable double well potential on an atom chip. Matter wave
interferometry gives direct access to the relative phase field, which reflects
the interplay of thermally driven fluctuations and phase locking due to
tunneling. The thermal equilibrium state is characterized by probing the full
statistical distribution function of the two-point phase correlation.
Comparison to a stochastic model allows to measure the coupling strength and
temperature and hence a full characterization of the system
Unlocking Accuracy and Fairness in Differentially Private Image Classification
Privacy-preserving machine learning aims to train models on private data
without leaking sensitive information. Differential privacy (DP) is considered
the gold standard framework for privacy-preserving training, as it provides
formal privacy guarantees. However, compared to their non-private counterparts,
models trained with DP often have significantly reduced accuracy. Private
classifiers are also believed to exhibit larger performance disparities across
subpopulations, raising fairness concerns. The poor performance of classifiers
trained with DP has prevented the widespread adoption of privacy preserving
machine learning in industry. Here we show that pre-trained foundation models
fine-tuned with DP can achieve similar accuracy to non-private classifiers,
even in the presence of significant distribution shifts between pre-training
data and downstream tasks. We achieve private accuracies within a few percent
of the non-private state of the art across four datasets, including two medical
imaging benchmarks. Furthermore, our private medical classifiers do not exhibit
larger performance disparities across demographic groups than non-private
models. This milestone to make DP training a practical and reliable technology
has the potential to widely enable machine learning practitioners to train
safely on sensitive datasets while protecting individuals' privacy
Digital acrometastase as a primary manifestation of a bronchial adenocarcinoma
Bone metastases of the hands and feet (acrometastases) are rare. Their presentation is variable and is generally confused with certain inflammatory conditions such as rheumatoid arthritis, gout, tenosynovitis, fracture or infection (panartius, osteomyelitis). The etiology of non-digital acrometastases is common to primary tumors with bone metastases (prostate, lung, kidney, breast, thyroid, and digestive tube). However, digital acrometastases are seen almost exclusively during bronchial neoplasia. We describe the case of a 43 year-old man admitted for pain and swelling of the middle finger distal phalanx of the left hand. Etiological assessement was in favor of an unusual secondary localization of bronchial adenocarcinoma. Tumoral causes must always be evoked before any inflammatory digital symptomatology, from where the interest of a good interrogation and a targeted paraclinical assessment.
Metrology in Africa: role of the CAFMET
This article presents the CAFMET (African Committee of Metrology), a non-profit organization that aims to meet the needs of African countries in the field of metrology. Its objectives are to spread a metrology culture in Africa via various domains in metrology such as, analysis, tests, and calibration. The difficulties of the development of metrology in Africa and the different activities, events and projects of the CAFMET are all presented
Diversity of Francisella Species in Environmental Samples from Martha’s Vineyard, Massachusetts
We determined whether Francisella spp. are present in water, sediment, and soil from an active tularemia natural focus on Martha’s Vineyard, Massachusetts, during a multiyear outbreak of pneumonic tularemia. Environmental samples were tested by polymerase chain reaction (PCR) targeting Francisella species 16S rRNA gene and succinate dehydrogenase A (sdhA) sequences; evidence of the agent of tularemia was sought by amplification of Francisella tularensis-specific sequences for the insertion element ISFTu2, 17-kDa protein gene tul4, and the 43-kDa outer membrane protein gene fopA. Evidence of F. tularensis subsp. tularensis, the causative agent of the human infections in this outbreak, was not detected from environmental samples despite its active transmission among ticks and animals in the sampling site. Francisella philomiragia was frequently detected from a brackish-water pond using Francisella species PCR targets, and subsequently F. philomiragia was isolated from an individual brackish-water sample. Distinct Francisella sp. sequences that are closely related to F. tularensis and Francisella novicida were detected from samples collected from the brackish-water pond. We conclude that diverse Francisella spp. are present in the environment where human cases of pneumonic tularemia occur
The sudden change phenomenon of quantum discord
Even if the parameters determining a system's state are varied smoothly, the
behavior of quantum correlations alike to quantum discord, and of its classical
counterparts, can be very peculiar, with the appearance of non-analyticities in
its rate of change. Here we review this sudden change phenomenon (SCP)
discussing some important points related to it: Its uncovering,
interpretations, and experimental verifications, its use in the context of the
emergence of the pointer basis in a quantum measurement process, its appearance
and universality under Markovian and non-Markovian dynamics, its theoretical
and experimental investigation in some other physical scenarios, and the
related phenomenon of double sudden change of trace distance discord. Several
open questions are identified, and we envisage that in answering them we will
gain significant further insight about the relation between the SCP and the
symmetry-geometric aspects of the quantum state space.Comment: Lectures on General Quantum Correlations and their Applications, F.
F. Fanchini, D. O. Soares Pinto, and G. Adesso (Eds.), Springer (2017), pp
309-33
Distribution of antioxidant components in roots of different red beets (Beta vulgaris L.) cultivars
The beetroot is typically on the table in winter in form of pickles or juice, but for its nutritional values it would deserve more common consumption. Its curative effect in great part is due to the several vitamins, minerals, and compounds with antioxidant activity. But the division of biological active compounds is very different in the parts of the root. Based on our results, we could compare the differences between the morphology and some inner contents (soluble solid content, colour, betacyanin, betaxanthin, and polyphenol contents, antioxidant activity, and some flavonoids) of two beetroot cultivars. The results of the morphological investigations showed that the ‘Cylindre’ cultivar had more favourable crop parameters than the ‘Alto F1’ cultivar. In the ‘Cylindre’ cultivar the polyphenol content and the antioxidant capacity were significantly higher than in the ‘Alto F1’ cultivar. By determination of the betanin contents of the investigated beetroots, our results showed both betacyanin and betaxanthin contents were higher in the ‘Cylindre’ cultivar. The chlorogenic acid, gallic acid, the cumaric acid have been identified based on the peaks of HPLC in the studied beetroot cultivars
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