David A. C. Mollinedo.

Source: Brazilian Journal of Probability and Statistics, Volume 34, Number 1, 188--201.

Abstract:
We consider the stochastic transport equation with a possibly unbounded Hölder continuous vector field. Well-posedness is proved, namely, we show existence, uniqueness and strong stability of $W^{1,p}$-weak solutions.

Adaptive importance samplers are adaptive Monte Carlo algorithms to estimate expectations with respect to some target distribution which extit{adapt} themselves to obtain better estimators over a sequence of iterations. Although it is straightforward to show that they have the same $mathcal{O}(1/sqrt{N})$ convergence rate as standard importance samplers, where $N$ is the number of Monte Carlo samples, the behaviour of adaptive importance samplers over the number of iterations has been left relatively unexplored. In this work, we investigate an adaptation strategy based on convex optimisation which leads to a class of adaptive importance samplers termed extit{optimised adaptive importance samplers} (OAIS). These samplers rely on the iterative minimisation of the $chi^2$-divergence between an exponential-family proposal and the target. The analysed algorithms are closely related to the class of adaptive importance samplers which minimise the variance of the weight function. We first prove non-asymptotic error bounds for the mean squared errors (MSEs) of these algorithms, which explicitly depend on the number of iterations and the number of samples together. The non-asymptotic bounds derived in this paper imply that when the target belongs to the exponential family, the $L_2$ errors of the optimised samplers converge to the optimal rate of $mathcal{O}(1/sqrt{N})$ and the rate of convergence in the number of iterations are explicitly provided. When the target does not belong to the exponential family, the rate of convergence is the same but the asymptotic $L_2$ error increases by a factor $sqrt{ ho^star} > 1$, where $ ho^star - 1$ is the minimum $chi^2$-divergence between the target and an exponential-family proposal.

Delta said it is making the move to protect employees amid the coronavirus pandemic, but planes have been flying near empty

Austin-Bergstrom International Airport said it was "aware of an individual that was struck and killed on runway 17-R by a landing aircraft."

The infections and deaths are spread across roughly two farms and 189 meat and processed food factories.

Peter J. Diggle, Emanuele Giorgi, Julienne Atsame, Sylvie Ntsame Ella, Kisito Ogoussan, Katherine Gass.

Source: Statistical Science, Volume 35, Number 1, 42--50.

Abstract:
Vector-borne diseases have long presented major challenges to the health of rural communities in the wet tropical regions of the world, but especially in sub-Saharan Africa. In this paper, we describe the contribution that statistical modelling has made to the global elimination programme for one vector-borne disease, onchocerciasis. We explain why information on the spatial distribution of a second vector-borne disease, Loa loa, is needed before communities at high risk of onchocerciasis can be treated safely with mass distribution of ivermectin, an antifiarial medication. We show how a model-based geostatistical analysis of Loa loa prevalence survey data can be used to map the predictive probability that each location in the region of interest meets a WHO policy guideline for safe mass distribution of ivermectin and describe two applications: one is to data from Cameroon that assesses prevalence using traditional blood-smear microscopy; the other is to Africa-wide data that uses a low-cost questionnaire-based method. We describe how a recent technological development in image-based microscopy has resulted in a change of emphasis from prevalence alone to the bivariate spatial distribution of prevalence and the intensity of infection among infected individuals. We discuss how statistical modelling of the kind described here can contribute to health policy guidelines and decision-making in two ways. One is to ensure that, in a resource-limited setting, prevalence surveys are designed, and the resulting data analysed, as efficiently as possible. The other is to provide an honest quantification of the uncertainty attached to any binary decision by reporting predictive probabilities that a policy-defined condition for action is or is not met.

Laura Anderlucci, Angela Montanari, Cinzia Viroli.

Source: Statistical Science, Volume 34, Number 2, 280--300.

Abstract:
In this paper, we retrace the recent history of statistics by analyzing all the papers published in five prestigious statistical journals since 1970, namely: The Annals of Statistics , Biometrika , Journal of the American Statistical Association , Journal of the Royal Statistical Society, Series B and Statistical Science . The aim is to construct a kind of “taxonomy” of the statistical papers by organizing and clustering them in main themes. In this sense being identified in a cluster means being important enough to be uncluttered in the vast and interconnected world of the statistical research. Since the main statistical research topics naturally born, evolve or die during time, we will also develop a dynamic clustering strategy, where a group in a time period is allowed to migrate or to merge into different groups in the following one. Results show that statistics is a very dynamic and evolving science, stimulated by the rise of new research questions and types of data.

Víctor Elvira, Luca Martino, David Luengo, Mónica F. Bugallo.

Source: Statistical Science, Volume 34, Number 1, 129--155.

Abstract:
Importance sampling (IS) methods are broadly used to approximate posterior distributions or their moments. In the standard IS approach, samples are drawn from a single proposal distribution and weighted adequately. However, since the performance in IS depends on the mismatch between the targeted and the proposal distributions, several proposal densities are often employed for the generation of samples. Under this multiple importance sampling (MIS) scenario, extensive literature has addressed the selection and adaptation of the proposal distributions, interpreting the sampling and weighting steps in different ways. In this paper, we establish a novel general framework with sampling and weighting procedures when more than one proposal is available. The new framework encompasses most relevant MIS schemes in the literature, and novel valid schemes appear naturally. All the MIS schemes are compared and ranked in terms of the variance of the associated estimators. Finally, we provide illustrative examples revealing that, even with a good choice of the proposal densities, a careful interpretation of the sampling and weighting procedures can make a significant difference in the performance of the method.

Hedok Lee
Aug 5, 2015; 35:11034-11044
Neurobiology of Disease

Italian translation of the BIS press release about the BIS Quarterly Review, December 2017

Italian version of BIS Press Release - Big tech in finance: opportunities and risks, 23 June 2019

French translation of the BIS Quarterly Review, March 2018

French translation of the BIS press release about the BIS Quarterly Review, March 2018

French translation of the BIS Quarterly Review, June 2018

French translation of the Annual Economic Report 2018 of the BIS, June 2018 - Les responsables des politiques publiques peuvent prolonger la phase de croissance actuelle en engageant des réformes structurelles, en restaurant les marges de manœuvre monétaires et budgétaires pour faire face aux menaces futures et en encourageant une mise en œuvre rapide des réformes réglementaires, indique la Banque des Règlements Internationaux (BRI) dans son Rapport économique annuel.

French translation of press release - the Basel Committee on Banking Supervision is finalising stress-testing principles, reviews ways to stop regulatory arbitrage behaviour, agrees on annual G-SIB list, discusses leverage ratio, crypto-assets, market risk framework and implementation, 20 September 2018.

French translation of the BIS press release about the BIS Quarterly Review, September 2018

French translation of the BIS Quarterly Review, September 2018

French translation of the BIS press release about the BIS Quarterly Review, December 2018

French translation of the BIS Quarterly Review, December 2018

French translation of the BIS press release about the BIS Quarterly Review, March 2019

French translation of the BIS Quarterly Review, March 2019

French version of BIS Press Release - Big tech in finance: opportunities and risks, 23 June 2019

French translation of the BIS press release on the presentation of the Annual Economic Report 2019, 30 June 2019. La politique monétaire ne peut plus être le principal moteur de la croissance économique, et d'autres leviers de politique publique doivent être actionnés pour faire en sorte que l'économie mondiale connaisse une dynamique durable ...

Spanish version of BIS Press Release - Big tech in finance: opportunities and risks, 23 June 2019

To view more press releases, please visit http://www.snl.com/irweblinkx/news.aspx?iid=1024452.

To view more press releases, please visit http://www.snl.com/irweblinkx/news.aspx?iid=1024452.

To view more press releases, please visit http://www.snl.com/irweblinkx/news.aspx?iid=1024452.

Eradicating hunger must be accompanied by strenuous efforts to end malnutrition and its devastating effects. That was a pivotal message at the launch of FAO’s key publication The State of Food and Agriculture, which this year focuses on Food systems for better nutrition. “FAO’s message is that we must strive for nothing less than the eradication of hunger and malnutrition,” said Director-General [...]

Today leading international experts on climate change, the IPCC, presented their latest report on the impacts of climate change on humanity, and what we can do about it. It’s a lengthy report, so we’ve shrunk it down to Oxfam's five key takeaways on climate change and hunger. 1. Climate change: the impacts on crops are worse than we thought Climate change has [...]

Every year, FAO publishes a number of major ‘State of the World’ reports containing balanced, science-based reviews of issues related to food, agriculture, forestry, fisheries and natural resources. The reports also cover vital areas such as food production and hunger alleviation, which are at the heart of FAO’s work. With close to 800 million people currently chronically undernourished and an extra [...]

Four years into the 2030 Agenda and there is a pressing need to understand where the world stands in eradicating hunger and food insecurity, as well as ensuring sustainable [...]

The latest FAO + Switzerland partnership report shows the catalytic achievements and innovative solutions of FAO’s collaboration with one of our strongest partners.

From 2008 to 2018, Switzerland supported FAO in [...]

The 2019 Report of the Technical Cooperation Programme (TCP) examines the role of the TCP to deliver FAO technical assistance for agriculture, food and nutrition in response to countries’ most [...]

The new findings raises questions about the authenticity of a collection of texts known as the "post-2002" scrolls

The findings further refute the outdated notion that humans' capacity for complex artistic expression evolved exclusively in Europe