16 research outputs found
Last Layer Marginal Likelihood for Invariance Learning
Data augmentation is often used to incorporate inductive biases into models.
Traditionally, these are hand-crafted and tuned with cross validation. The
Bayesian paradigm for model selection provides a path towards end-to-end
learning of invariances using only the training data, by optimising the
marginal likelihood. We work towards bringing this approach to neural networks
by using an architecture with a Gaussian process in the last layer, a model for
which the marginal likelihood can be computed. Experimentally, we improve
performance by learning appropriate invariances in standard benchmarks, the low
data regime and in a medical imaging task. Optimisation challenges for
invariant Deep Kernel Gaussian processes are identified, and a systematic
analysis is presented to arrive at a robust training scheme. We introduce a new
lower bound to the marginal likelihood, which allows us to perform inference
for a larger class of likelihood functions than before, thereby overcoming some
of the training challenges that existed with previous approaches
Trieste: Efficiently Exploring The Depths of Black-box Functions with TensorFlow
We present Trieste, an open-source Python package for Bayesian optimization
and active learning benefiting from the scalability and efficiency of
TensorFlow. Our library enables the plug-and-play of popular TensorFlow-based
models within sequential decision-making loops, e.g. Gaussian processes from
GPflow or GPflux, or neural networks from Keras. This modular mindset is
central to the package and extends to our acquisition functions and the
internal dynamics of the decision-making loop, both of which can be tailored
and extended by researchers or engineers when tackling custom use cases.
Trieste is a research-friendly and production-ready toolkit backed by a
comprehensive test suite, extensive documentation, and available at
https://github.com/secondmind-labs/trieste
Формирование эмоциональной культуры как компонента инновационной культуры студентов
Homozygosity has long been associated with rare, often devastating, Mendelian disorders1 and Darwin was one of the first to recognise that inbreeding reduces evolutionary fitness2. However, the effect of the more distant parental relatedness common in modern human populations is less well understood. Genomic data now allow us to investigate the effects of homozygosity on traits of public health importance by observing contiguous homozygous segments (runs of homozygosity, ROH), which are inferred to be homozygous along their complete length. Given the low levels of genome-wide homozygosity prevalent in most human populations, information is required on very large numbers of people to provide sufficient power3,4. Here we use ROH to study 16 health-related quantitative traits in 354,224 individuals from 102 cohorts and find statistically significant associations between summed runs of homozygosity (SROH) and four complex traits: height, forced expiratory lung volume in 1 second (FEV1), general cognitive ability (g) and educational attainment (nominal p<1 × 10−300, 2.1 × 10−6, 2.5 × 10−10, 1.8 × 10−10). In each case increased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing convincing evidence for the first time that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples5,6, no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein (LDL) cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection7, this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been
Genome-wide association study identifies a second prostate cancer susceptibility variant at 8q24.
Contains fulltext :
51723.pdf (publisher's version ) (Closed access)Prostate cancer is the most prevalent noncutaneous cancer in males in developed regions, with African American men having among the highest worldwide incidence and mortality rates. Here we report a second genetic variant in the 8q24 region that, in conjunction with another variant we recently discovered, accounts for about 11%-13% of prostate cancer cases in individuals of European descent and 31% of cases in African Americans. We made the current discovery through a genome-wide association scan of 1,453 affected Icelandic individuals and 3,064 controls using the Illumina HumanHap300 BeadChip followed by four replication studies. A key step in the discovery was the construction of a 14-SNP haplotype that efficiently tags a relatively uncommon (2%-4%) susceptibility variant in individuals of European descent that happens to be very common (approximately 42%) in African Americans. The newly identified variant shows a stronger association with affected individuals who have an earlier age at diagnosis