Civic Purpose in Late Adolescence: Factors that Prevent Decline in Civic Engagement After High School

This study investigated the effects of internal and demographic variables on civic development in late adolescence using the construct civic purpose. We conducted surveys on civic engagement with 480 high school seniors, and surveyed them again two years later. Using multivariate regression and linear mixed models, we tested the main effects of civic purpose dimensions (beyond-the-self motivation, future civic intention), ethnicity, and education on civic development from Time 1 to Time 2. Results showed that while there is an overall decrease in civic engagement in the transition out of high school, both internal and social factors protected participants from steep civic decline. Interaction effects varied. Ethnicity and education interacted in different ways with the dimensions of civic purpose to predict change in traditional and expressive political engagement, and community service engagement

Point and interval forecasts of mortality rates and life expectancy: A comparison of ten principal component methods

Using the age- and sex-specific data of 14 developed countries, we compare the point and interval forecast accuracy and bias of ten principal component methods for forecasting mortality rates and life expectancy. The ten methods are variants and extensions of the Lee-Carter method. Based on one-step forecast errors, the weighted Hyndman-Ullah method provides the most accurate point forecasts of mortality rates and the Lee-Miller method is the least biased. For the accuracy and bias of life expectancy, the weighted Hyndman-Ullah method performs the best for female mortality and the Lee-Miller method for male mortality. While all methods underestimate variability in mortality rates, the more complex Hyndman-Ullah methods are more accurate than the simpler methods. The weighted Hyndman-Ullah method provides the most accurate interval forecasts for mortality rates, while the robust Hyndman-Ullah method provides the best interval forecast accuracy for life expectancy.forecasting, forecasting time series, interval forecasts, Lee-Carter method, life expectancy, mortality forecasting, principal components analysis

Neutrino masses and lepton-number violation in the Littlest Higgs scenario

We investigate the sources of neutrino mass generation in Little Higgs theories, by confining ourselves to the "Littlest Higgs" scenario. Our conclusion is that the most satisfactory way of incorporating neutrino masses is to include a lepton-number violating interaction between the scalar triplet and lepton doublets. The tree-level neutrino masses generated by the vacuum expectation value of the triplet are found to dominate over contributions from dimension-five operators so long as no additional large lepton-number violating physics exists at the cut-off scale of the effective theory. We also calculate the various decay branching ratios of the charged and neutral scalar triplet states, in regions of the parameter space consistent with the observed neutrino masses, hoping to search for signals of lepton-number violating interactions in collider experiments.Comment: 27 pages, 4 figures. v2: minor clarifications in discussion, version to appear in PR

Discovering an Invisibly Decaying Higgs at Hadron Colliders

A Higgs boson lighter than 2 m_W that decays mostly into invisible channels (e.g., dark matter particles) is theoretically well-motivated. We study the prospects for discovery of such an invisible Higgs, h_inv, at the LHC and the Tevatron in three production modes: (1) in association with a Z, (2) through Weak Boson Fusion (WBF), and (3) accompanied by a jet. In the Z+h_inv channel, we show that the LHC can yield a discovery signal above 5 sigma with 10 fb-1 of integrated luminosity for a Higgs mass of 120 GeV. With 30 fb-1 the discovery reach extends up to a Higgs mass of 160 GeV. We also study the extraction of the h_inv mass from production cross sections at the LHC, and find that combining WBF and Z+h_inv allows a relatively model-independent determination of the h_inv mass with an uncertainty of 35-50 GeV (15-20 GeV) with 10 (100) fb-1. At the Tevatron, a 3 sigma observation of a 120 GeV h_inv in any single channel is not possible with less than 12 fb-1 per detector. However, we show that combining the signal from WBF with the previously-studied Z+h_inv channel allows a 3 sigma observation of h_inv with 7 fb-1 per detector. Because of overwhelming irreducible backgrounds, h_inv+j is not a useful search channel at either the Tevatron or the LHC, despite the larger production rate.Comment: 21 pages, 1 figure; v2: added refs, added discussion of invisible Higgs mass extraction from cross sections at LHC; v3: minor clarifications in text, version to appear in PR

A comparison of ten principal component methods for forecasting mortality rates

Using the age- and sex-specific data of 14 developed countries, we compare the short- to medium-term accuracy of ten principal component methods for forecasting mortality rates and life expectancy. These ten methods include the Lee-Carter method and many of its variants and extensions. For forecasting mortality rates, the weighted Hyndman-Ullah method provides the most accurate point forecasts, while the Lee-Miller method gives the best point forecast accuracy of life expectancy. Furthermore, the weighted Hyndman-Ullah method provides the most accurate interval forecasts of mortality rates, while the robust Hyndman-Ullah method provides the best interval forecast accuracy of life expectancy.Mortality forecasting, life expectancy forecasting, principal component methods, Lee-Carter method, interval forecasts, forecasting time series

Distributed Estimation and Inference with Statistical Guarantees

This paper studies hypothesis testing and parameter estimation in the context of the divide and conquer algorithm. In a unified likelihood based framework, we propose new test statistics and point estimators obtained by aggregating various statistics from $k$ subsamples of size $n/k$, where $n$ is the sample size. In both low dimensional and high dimensional settings, we address the important question of how to choose $k$ as $n$ grows large, providing a theoretical upper bound on $k$ such that the information loss due to the divide and conquer algorithm is negligible. In other words, the resulting estimators have the same inferential efficiencies and estimation rates as a practically infeasible oracle with access to the full sample. Thorough numerical results are provided to back up the theory

An examination of the processes by which construal level affects the implicit evaluation of goal relevant stimuli.

Previous research has found that construal level—how abstractly or concretely people represent events—can impact implicit evaluations. Abstract high-level construal (vs. concrete low-level construal) promotes evaluative responses consistent with global (strongly held, long-term) rather than local (short-term, situational) goals. It remains unclear by what cognitive process(es) this occurs. In this paper, we examine two possibilities. High-level construal might enhance the unintended influence of activated evaluative associations or facilitate the detection and implementation of intentional responses. To examine these possibilities, the current study applies a multinomial processing tree model to data from Fujita and Han (2009). Results suggest that high-level construal facilitates goal-consistent evaluations by increasing both the unintentional influence of activated goal-consistent positive associations and the intentional detection of and implementation of accurate responding to goal-relevant stimuli. These findings extend our understanding of how construal level promotes goal consistent evaluations

Point and interval forecasts of mortality rates and life expectancy: A comparison of ten principal component methods

Using the age- and sex-specific data of 14 developed countries, we compare the point and interval forecast accuracy and bias of ten principal component methods for forecasting mortality rates and life expectancy. The ten methods are variants and extensions of the Lee-Carter method. Based on one-step forecast errors, the weighted Hyndman-Ullah method provides the most accurate point forecasts of mortality rates and the Lee-Miller method is the least biased. For the accuracy and bias of life expectancy, the weighted Hyndman-Ullah method performs the best for female mortality and the Lee-Miller method for male mortality. While all methods underestimate variability in mortality rates, the more complex Hyndman-Ullah methods are more accurate than the simpler methods. The weighted Hyndman-Ullah method provides the most accurate interval forecasts for mortality rates, while the robust Hyndman-Ullah method provides the best interval forecast accuracy for life expectancy

Temporal and Spatial Analysis of Water Quality and Landscape Characteristics for Albemarle Sound, North Carolina

Albemarle Sound, a lagoonal estuarine system on the North Carolina coast, has experienced a large decline in recreational and commercial fisheries over the years and managers are concerned about water quality, including the impacts of nutrient enrichment, or eutrophication. In an effort to help the United States Geological Survey improve its water quality monitoring network, this report compiles and analyzes over 40 years of historic data for the sound using three approaches. Based on the current monitoring program and available historic data collected, five chemical and biological water quality parameters were chosen to characterize the water quality in Albemarle Sound: chlorophyll-a (Chl-a), dissolved oxygen (DO), turbidity, inorganic nitrogen (nitrate and nitrate) as N and phosphate-phosphorus as P. This project 1) statistically analyzes the relationships between water quality parameters within and among sub-sections of the Sound; 2) combines multiple sources of LULC data into sub-sections to better understand water quality drivers; 3) develops a GIS-based user interactive toolkit to identify the sensitive location(s). Statistical and geospatial analyses show: 1) Overall, water quality in Albemarle Sound is good over time. 2) Seasonal effects may influence parameter values in some parts of the sound. 3) In light of inorganic nitrogen and phosphate-phosphorus levels, we may pay more attention to the North and South sections, as these two sections were more vulnerable to nutrient problems in history. 4) There are major differences in landscape characteristics between sections, offering some explanation for differences in water quality, and 5) There are some signals in the average concentrations of the five water quality parameters from 2006-2013, indicating that terrestrial drivers such as CAFO animal density and percent cultivated area could be important for water quality in the Albemarle Sound. This report provides fundamental guidance that can be used to inform both management plans and future studies in Albemarle Sound