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Cover page of Foundations for California's Water Security in a Changing Climate

Foundations for California's Water Security in a Changing Climate


California’s water supplies are facing unprecedented stresses, and the state’s water-management systems are struggling to meet both environmental and human needs (agricultural, municipal, industrial). Supplies are highly vulnerable to climate variability and extreme events, limiting options to respond to the combined stresses of a changing climate, population, and land cover. Strategic, coordinated investments in California’s water infrastructure, institutions, and information will provide the foundation for a secure, equitable, and efficient water future. The cornerstone of water security, and priority need for California, is a modern, robust water-information system that enables accurate, timely, and transparent accounting through the water-supply and use cycle. This system must extend from mountain headwaters through valley groundwater. Investments are also needed in capacity building for use of water information among institutions and stakeholders across the state. Priority infrastructure improvements are needed for central elements of the state’s “green” infrastructure: restoration of Sierra Nevada and other forests in source-water areas, and additional groundwater recharge on farmland and expanded floodplains. With better-informed management, California’s existing water supplies could go further to meeting the state’s urban, agricultural, ecological, and industrial needs.

Cover page of Language processing experiments in the field

Language processing experiments in the field


This chapter discusses some of the circumstances and opportunities that arise when doing language processing experiments in the field. We focus on how resource and cultural challenges can shape the design of experiments. Because of the diversity of small-language communities, we avoid generalizing very broadly and instead draw principally on our own experiences working with the Chamorro community in the Northern Marianas Islands.

Search for heavy long-lived multicharged particles in proton-proton collisions at s=13  TeV using the ATLAS detector

Cover page of Measurement of angular and momentum distributions of charged particles within and around jets in Pb+Pb and pp collisions at sNN=5.02 TeV with the ATLAS detector

Measurement of angular and momentum distributions of charged particles within and around jets in Pb+Pb and pp collisions at sNN=5.02 TeV with the ATLAS detector

Cover page of Rethinking Model-Based Gaze Estimation

Rethinking Model-Based Gaze Estimation


Over the past several years, a number of data-driven gaze tracking algorithms have been proposed, which have been shown to outperform classic model-based methods in terms of gaze direction accuracy. These algorithms leverage the recent development of sophisticated CNN architectures, as well as the availability of large gaze datasets captured under various conditions. One shortcoming of black-box, end-to-end methods, though, is that any unexpected behaviors are difficult to explain. In addition, there is always the risk that a system trained with a certain dataset may not perform well when tested on data from a different source (the “domain gap" problem.) In this work, we propose a novel method to embed eye geometry information in an end-to-end gaze estimation network by means of a “geometric layer". Our experimental results show that our system outperforms other state-of-the-art methods in cross-dataset evaluation, while producing competitive performance over within dataset tests. In addition, the proposed system is able to extrapolate gaze angles outside the range of those considered in the training data.

Cover page of Tracker/Camera Calibration for Accurate Automatic Gaze Annotation of Images and Videos.

Tracker/Camera Calibration for Accurate Automatic Gaze Annotation of Images and Videos.


Modern appearance-based gaze tracking algorithms require vast amounts of training data, with images of a viewer annotated with "ground truth" gaze direction. The standard approach to obtain gaze annotations is to ask subjects to fixate at specific known locations, then use a head model to determine the location of "origin of gaze". We propose using an IR gaze tracker to generate gaze annotations in natural settings that do not require the fixation of target points. This requires prior geometric calibration of the IR gaze tracker with the camera, such that the data produced by the IR tracker can be expressed in the camera's reference frame. This contribution introduces a simple tracker/camera calibration procedure based on the PnP algorithm and demonstrates its use to obtain a full characterization of gaze direction that can be used for ground truth annotation.

Limits to reproduction and seed size-number trade-offs that shape forest dominance and future recovery.


The relationships that control seed production in trees are fundamental to understanding the evolution of forest species and their capacity to recover from increasing losses to drought, fire, and harvest. A synthesis of fecundity data from 714 species worldwide allowed us to examine hypotheses that are central to quantifying reproduction, a foundation for assessing fitness in forest trees. Four major findings emerged. First, seed production is not constrained by a strict trade-off between seed size and numbers. Instead, seed numbers vary over ten orders of magnitude, with species that invest in large seeds producing more seeds than expected from the 1:1 trade-off. Second, gymnosperms have lower seed production than angiosperms, potentially due to their extra investments in protective woody cones. Third, nutrient-demanding species, indicated by high foliar phosphorus concentrations, have low seed production. Finally, sensitivity of individual species to soil fertility varies widely, limiting the response of community seed production to fertility gradients. In combination, these findings can inform models of forest response that need to incorporate reproductive potential.