Approximation of density functions by orthogonal series with grouped data

Summary Letg(x) andf(x) be continuous density function on (a, b) and let {ϕ_j} be a complete orthonormal sequence of functions onL ₂(g), which is the set of squared integrable functions weighted byg on (a, b). Suppose that over (a, b). Given a grouped sample of sizen fromf(x), the paper investigates the asymptotic properties of the restricted maximum likelihood estimator of density, obtained by setting all but the firstm of the ϑ_j’s equal to0. Practical suggestions are given for performing estimation via the use of Fourier and Legendre polynomial series. Research partially supported by: CNR grant, n. 93. 00837. CT10.     

Mental health services for Chinese in a community health center

Serious mental health problems exist within the Chinese population of the United States. This article describes one center's attempt to meet the psychiatric needs of both nonpsychotic and psychotic Chinese patients through bilingual, culturally relevant treatments.     

The FARSEEING real-world fall repository: a large-scale collaborative database to collect and share sensor signals from real-world falls

Background

Real-world fall events objectively measured by body-worn sensors can improve the understanding of fall events in older people. However, these events are rare and hence challenging to capture. Therefore, the FARSEEING (FAll Repository for the design of Smart and sElf-adaptive Environments prolonging Independent livinG) consortium and associated partners started to build up a meta-database of real-world falls.

Results

Between January 2012 and December 2015 more than 300 real-world fall events have been recorded. This is currently the largest collection of real-world fall data recorded with inertial sensors. A signal processing and fall verification procedure has been developed and applied to the data. Since the end of 2015, 208 verified real-world fall events are available for analyses. The fall events have been recorded within several studies, with different methods, and in different populations. All sensor signals include at least accelerometer measurements and 58 % additionally include gyroscope and magnetometer measurements. The collection of data is ongoing and open to further partners contributing with fall signals. The FARSEEING consortium also aims to share the collected real-world falls data with other researchers on request.

Conclusions

The FARSEEING meta-database will help to improve the understanding of falls and enable new approaches in fall risk assessment, fall prevention, and fall detection in both aging and disease.

     

Estimating the Size of Street-Dwelling Populations Using Mark-Resighting Counts

Mark-resighting constitutes an advanced technology for estimating animal abundance. Joint hypergeometric maximum likelihood, Minta-Mangel and Bowden estimators are usually adopted with mark-resighting data. In presence of any tendency of animals to aggregate into groups, the Bowden estimator is the sole reliable method, providing that marks are quite evenly distributed among groups. In some cetacean surveys, marking disturbances are avoided through natural marking. Natural marking with Bowden criterion is used to estimate the abundance of street-dwelling populations. The marked individuals are persons identified and recorded in the initial part of the survey and recognizable in subsequent occasions. A simulation helps determine the performance of the Bowden estimator under a wide set of situations, taking into account key features of street-dwelling populations. When marked individuals are evenly distributed among groups, the strategy is efficient.     

Calibration of FI‐ISK,an Invasiveness Screening Tool for Nonnative Freshwater Invertebrates

The Freshwater Invertebrate Invasiveness Scoring Kit (FI‐ISK) is proposed as a screening tool for identifying potentially invasive freshwater invertebrates. FI‐ISK was adapted from the Fish Invasiveness Scoring Kit (FISK) of Copp, Garthwaite, and Gozlan, which is an adapted form of the Weed Risk Assessment (WRA) of Pheloung, Williams, and Halloy. Initial assessments using FI‐ISK, which include confidence (certainty/uncertainty) rankings by the assessor to each response, were calibrated to determine the most appropriate score thresholds for classifying nonnative species into low‐, medium‐, and high‐risk categories, using both the original medium‐to‐high risk threshold scores for the WRA (i.e., ≥6) and for FISK (i.e., ≥19). Patterns of the assessor's confidence, when making the responses during the FI‐ISK assessments, were also examined. Using receiver operating characteristic (ROC) curves, FI‐ISK was shown to distinguish accurately (and with statistical confidence) between potentially invasive and noninvasive species of nonnative crayfish (Decapoda: Astacidae, Cambaridae, Parastacidae), with the statistically appropriate threshold score for high‐risk species scores being ≥16. FI‐ISK represents a useful and viable tool to aid decision‐ and policymakers in assessing and classifying freshwater invertebrates according to their potential invasiveness.     

Government Debt and Excess Sensitivity of Private Consumption: Estimates from OECD Countries

This article investigates the role of government debt in the degree of excess sensitivity of private consumption to current disposable income. Because this type of excess sensitivity is generally attributed to liquidity constraints, this amounts to a test of the impact of government debt on the amount of credit extended to individuals. Controlling for financial liberalization we find that, for a panel of OECD countries in the 1990s, a high government debt leads to more excess sensitivity. This result supports the idea that a high government debt induces lenders to tighten credit conditions. Our findings survive several robustness checks.     

Human mobility in the context of environmental and climate change: Recent data collection tools from the International Organization for Migration to address key methodological and conceptual issues

This paper outlines recent data collection tools and methodologies that the International Organization for Migration (IOM) has been using in order to gather information on human mobility as influenced by environmental factors and their impacts. It looks at alternative ways for collecting and analysing data in the face of methodological challenges related to the multicausality of movements, the voluntary/involuntary continuum in human (im)mobility decisions in the context of environmental and climate change, and the policy and epistemological imperative from viewing migration as an adaptation strategy. The paper finds that certain data collection approaches can be quickly deployed in rapid-onset disasters as well as applied in contexts of gradual, slow-onset environmental change to provide information useful for operational responses to immediate crises and/or for developing policies in response. Some of the tools can be useful in both contexts and may support both immediate and long-term operational, policy and research objectives.     

Calibration of FISK, an Invasiveness Screening Tool for Nonnative Freshwater Fishes

Adapted from the weed risk assessment (WRA) of Pheloung, Williams, and Halloy, the fish invasiveness scoring kit (FISK) was proposed as a screening tool for freshwater fishes. This article describes improvements to FISK, in particular the incorporation of confidence (certainty/uncertainty) ranking of the assessors' responses, and reports on the calibration of the score system, specifically: determination of most appropriate score thresholds for classifying nonnative species into low-, medium-, and high-risk categories, assessment of the patterns of assessors' confidences in their responses in the FISK assessments. Using receiver operating characteristic (ROC) curves, FISK was demonstrated to distinguish accurately (and with statistical confidence) between potentially invasive and noninvasive species of nonnative fishes, with the statistically appropriate threshold score for high-risk species scores being ≥19. Within the group of species classed as high risk using this new threshold, a "higher risk" category could be visually identified, at present consisting of two species (topmouth gudgeon Pseudorasbora parva and gibel carp Carassius gibelio ). FISK represents a useful and viable tool to aid decision- and policymakers in assessing and classifying freshwater fishes according to their potential invasiveness.