Ecological validity of virtual reality daily living activities screening for early dementia: longitudinal study

Background: Dementia is a multifaceted disorder that impairs cognitive functions, such as memory, language, and executive functions necessary to plan, organize, and prioritize tasks required for goal-directed behaviors. In most cases, individuals with dementia experience difficulties interacting with physical and social environments. The purpose of this study was to establish ecological validity and initial construct validity of a fire evacuation Virtual Reality Day-Out Task (VR-DOT) environment based on performance profiles as a screening tool for early dementia. Objective: The objectives were (1) to examine the relationships among the performances of 3 groups of participants in the VR-DOT and traditional neuropsychological tests employed to assess executive functions, and (2) to compare the performance of participants with mild Alzheimer’s-type dementia (AD) to those with amnestic single-domain mild cognitive impairment (MCI) and healthy controls in the VR-DOT and traditional neuropsychological tests used to assess executive functions. We hypothesized that the 2 cognitively impaired groups would have distinct performance profiles and show significantly impaired independent functioning in ADL compared to the healthy controls. Methods: The study population included 3 groups: 72 healthy control elderly participants, 65 amnestic MCI participants, and 68 mild AD participants. A natural user interface framework based on a fire evacuation VR-DOT environment was used for assessing physical and cognitive abilities of seniors over 3 years. VR-DOT focuses on the subtle errors and patterns in performing everyday activities and has the advantage of not depending on a subjective rating of an individual person. We further assessed functional capacity by both neuropsychological tests (including measures of attention, memory, working memory, executive functions, language, and depression). We also evaluated performance in finger tapping, grip strength, stride length, gait speed, and chair stands separately and while performing VR-DOTs in order to correlate performance in these measures with VR-DOTs because performance while navigating a virtual environment is a valid and reliable indicator of cognitive decline in elderly persons. Results: The mild AD group was more impaired than the amnestic MCI group, and both were more impaired than healthy controls. The novel VR-DOT functional index correlated strongly with standard cognitive and functional measurements, such as mini-mental state examination (MMSE; rho=0.26, P=.01) and Bristol Activities of Daily Living (ADL) scale scores (rho=0.32, P=.001). Conclusions: Functional impairment is a defining characteristic of predementia and is partly dependent on the degree of cognitive impairment. The novel virtual reality measures of functional ability seem more sensitive to functional impairment than qualitative measures in predementia, thus accurately differentiating from healthy controls. We conclude that VR-DOT is an effective tool for discriminating predementia and mild AD from controls by detecting differences in terms of errors, omissions, and perseverations while measuring ADL functional ability.

A 350 ka record of climate change from Lake El'gygytgyn, Far East Russian Arctic: refining the pattern of climate modes by means of cluster analysis

Abstract. Rock magnetic, biochemical and inorganic records of the sediment cores PG1351 and Lz1024 from Lake El’gygytgyn, Chukotka peninsula, Far East Russian Arctic, were subject to a hierarchical agglomerative cluster analysis in order to refine and extend the pattern of climate modes as defined by Melles et al. (2007). Cluster analysis of the data obtained from both cores yielded similar results, differentiating clearly between the four climate modes warm, peak warm, cold and dry, and cold and moist. In addition, two transitional phases were identified, representing the early stages of a cold phase and slightly colder conditions during a warm phase. The statistical approach can thus be used to resolve gradual changes in the sedimentary units as an indicator of available oxygen in the hypolimnion in greater detail. Based upon cluster analyses on core Lz1024, the published succession of climate modes in core PG1351, covering the last 250 ka, was modified and extended back to 350 ka. Comparison to the marine oxygen isotope (�18O) stack LR04 (Lisiecki and Raymo, 2005) and the summer insolation at 67.5� N, with the extended Lake El’gygytgyn parameter records of magnetic susceptibility (�LF), total organic carbon content (TOC) and the chemical index of alteration (CIA; Minyuk et al., 2007), revealed that all stages back to marine isotope stage (MIS) 10 and most of the substages are clearly reflected in the pattern derived from the cluster analysis.

Development of a rapid bioassessment method and index of biotic integrity for estuaries located along the northwest Gulf of Mexico

Recently it has been proposed that the evaluation of effects of pollutants on aquatic organisms can provide an early warning system of potential environmental and human health risks (NRC 1991). Unfortunately there are few methods available to aquatic biologists to conduct assessments of the effects of pollutants on aquatic animal community health. The primary goal of this research was to develop and evaluate the feasibility of such a method. Specifically, the primary objective of this study was to develop a prototype rapid bioassessment technique similar to the Index of Biotic Integrity (IBI) for the upper Texas and Northwestern Gulf of Mexico coastal tributaries. The IBI consists of a series of "metrics" which describes specific attributes of the aquatic community. Each of these metrics are given a score which is then subtotaled to derive a total assessment of the "health" of the aquatic community. This IBI procedure may provide an additional assessment tool for professionals in water quality management.^ The experimental design consisted primarily of compiling previously collected data from monitoring conducted by the Texas Natural Resource Conservation Commission (TNRCC) at five bayous classified according to potential for anthropogenic impact and salinity regime. Standardized hydrological, chemical, and biological monitoring had been conducted in each of these watersheds. The identification and evaluation of candidate metrics for inclusion in the estuarine IBI was conducted through the use of correlation analysis, cluster analysis, stepwise and normal discriminant analysis, and evaluation of cumulative distribution frequencies. Scores of each included metric were determined based on exceedances of specific percentiles. Individual scores were summed and a total IBI score and rank for the community computed.^ Results of these analyses yielded the proposed metrics and rankings listed in this report. Based on the results of this study, incorporation of an estuarine IBI method as a water quality assessment tool is warranted. Adopted metrics were correlated to seasonal trends and less so to salinity gradients observed during the study (0-25 ppt). Further refinement of this method is needed using a larger more inclusive data set which includes additional habitat types, salinity ranges, and temporal variation. ^

Cultural beliefs and hypertension in rural Philippines

Hypertension (HTN), the major risk factor for cardiovascular disease (CVD), is emerging as a major public health problem in the Philippines. CVD has been the leading cause of mortality in the Philippines since 1990. ^ Although research has shown that certain populations have a greater propensity for HTN, and that culture may be a factor, empirical investigations of the influence of cultural beliefs on HTN are lacking. ^ The operational aims of this study were to: (a) develop and examine the reliability (test-retest, internal consistency) and validity (content) of a questionnaire which measures factors related to HTN; (b) administer the questionnaire; and (c) measure blood pressure, height, and weight of the ≥ 30 year old residents of San Antonio, Nueva Ecija, Philippines. ^ The analytic aims were to determine the: (a) cultural beliefs relating to HTN; (b) associations between cultural beliefs and HTN; and (c) extent to which cultural beliefs versus biological, behavioral, socioeconomic, and access factors are associated with HTN. ^ A cluster survey was conducted among 336 residents ≥ 30 years old in May, 1998. Sixty clusters of households were derived using probability proportionate to size sampling technique. Seven households per cluster were visited and one respondent per household was randomly chosen for interview and measurement of blood pressure, height and weight. A response rate of 84% (336/400) was achieved. ^ Results showed that the test-retest reliability of cultural belief items was 0.69–0.96. Internal consistency reliability was 0.74. ^ HTN (SBP ≥ 140; or DBP ≥ 90 mmHg; or currently taking anti-hypertensive medication) prevalence was 23/100. Univariate logistic regression showed cultural beliefs to be significantly associated (p < 0.037) with HTN. However, multivariate analysis showed that only age ≥ 50 (p = 0.000), family history of HTN (p = 0.004) and body mass index ≥ 25 (p = 0.003) were significant predictors. ^ In the absence of fully implemented programs to prevent and control HTN, the current prevalence is only expected to increase, leading to substantial increases in morbidity and mortality and health care cost. It is recommended that research which focuses on designing, implementing, and evaluating culturally appropriate community-wide programs on HTN prevention and control be undertaken in this community. ^

Clinical validity of the nerve root sedimentation sign in patients with suspected lumbar spinal stenosis

BACKGROUND CONTEXT The nerve root sedimentation sign in transverse magnetic resonance imaging has been shown to discriminate well between selected patients with and without lumbar spinal stenosis (LSS), but the performance of this new test, when used in a broader patient population, is not yet known. PURPOSE To evaluate the clinical performance of the nerve root sedimentation sign in detecting central LSS above L5 and to determine its potential significance for treatment decisions. STUDY DESIGN Retrospective cohort study. PATIENT SAMPLE One hundred eighteen consecutive patients with suspected LSS (52% women, median age 62 years) with a median follow-up of 24 months. OUTCOME MEASURES Oswestry disability index (ODI) and back and leg pain relief. METHODS We performed a clinical test validation study to assess the clinical performance of the sign by measuring its association with health outcomes. Subjects were patients referred to our orthopedic spine unit from 2004 to 2007 before the sign had been described. Based on clinical and radiological diagnostics, patients had been treated with decompression surgery or nonsurgical treatment. Changes in the ODI and pain from baseline to 24-month follow-up were compared between sedimentation sign positives and negatives in both treatment groups. RESULTS Sixty-nine patients underwent surgery. Average baseline ODI in the surgical group was 54.7%, and the sign was positive in 39 patients (mean ODI improvement 29.0 points) and negative in 30 (ODI improvement 28.4), with no statistically significant difference in ODI and pain improvement between groups. In the 49 patients of the nonsurgical group, mean baseline ODI was 42.4%; the sign was positive in 18 (ODI improvement 0.6) and negative in 31 (ODI improvement 17.7). A positive sign was associated with a smaller ODI and back pain improvement than negative signs (both p<.01 on t test). CONCLUSIONS In patients commonly treated with decompression surgery, the sedimentation sign does not appear to predict surgical outcome. In nonsurgically treated patients, a positive sign is associated with more limited improvement. In these cases, surgery might be effective, but this needs investigation in prospective randomized trials (Australian New Zealand Clinical Trial Registry, number ACTRN12610000567022).

Completeness of Follow-Up Determines Validity of Study Findings: Results of a Prospective Repeated Measures Cohort Study.

BACKGROUND Current reporting guidelines do not call for standardised declaration of follow-up completeness, although study validity depends on the representativeness of measured outcomes. The Follow-Up Index (FUI) describes follow-up completeness at a given study end date as ratio between the investigated and the potential follow-up period. The association between FUI and the accuracy of survival-estimates was investigated. METHODS FUI and Kaplan-Meier estimates were calculated twice for 1207 consecutive patients undergoing aortic repair during an 11-year period: in a scenario A the population's clinical routine follow-up data (available from a prospective registry) was analysed conventionally. For the control scenario B, an independent survey was completed at the predefined study end. To determine the relation between FUI and the accuracy of study findings, discrepancies between scenarios regarding FUI, follow-up duration and cumulative survival-estimates were evaluated using multivariate analyses. RESULTS Scenario A noted 89 deaths (7.4%) during a mean considered follow-up of 30±28months. Scenario B, although analysing the same study period, detected 304 deaths (25.2%, P<0.001) as it scrutinized the complete follow-up period (49±32months). FUI (0.57±0.35 versus 1.00±0, P<0.001) and cumulative survival estimates (78.7% versus 50.7%, P<0.001) differed significantly between scenarios, suggesting that incomplete follow-up information led to underestimation of mortality. Degree of follow-up completeness (i.e. FUI-quartiles and FUI-intervals) correlated directly with accuracy of study findings: underestimation of long-term mortality increased almost linearly by 30% with every 0.1 drop in FUI (adjusted HR 1.30; 95%-CI 1.24;1.36, P<0.001). CONCLUSION Follow-up completeness is a pre-requisite for reliable outcome assessment and should be declared systematically. FUI represents a simple measure suited as reporting standard. Evidence lacking such information must be challenged as potentially flawed by selection bias.

False normal Lung Clearance Index in infants with cystic fibrosis due to software algorithms.

BACKGROUND Lung clearance index (LCI), a marker of ventilation inhomogeneity, is elevated early in children with cystic fibrosis (CF). However, in infants with CF, LCI values are found to be normal, although structural lung abnormalities are often detectable. We hypothesized that this discrepancy is due to inadequate algorithms of the available software package. AIM Our aim was to challenge the validity of these software algorithms. METHODS We compared multiple breath washout (MBW) results of current software algorithms (automatic modus) to refined algorithms (manual modus) in 17 asymptomatic infants with CF, and 24 matched healthy term-born infants. The main difference between these two analysis methods lies in the calculation of the molar mass differences that the system uses to define the completion of the measurement. RESULTS In infants with CF the refined manual modus revealed clearly elevated LCI above 9 in 8 out of 35 measurements (23%), all showing LCI values below 8.3 using the automatic modus (paired t-test comparing the means, P < 0.001). Healthy infants showed normal LCI values using both analysis methods (n = 47, paired t-test, P = 0.79). The most relevant reason for false normal LCI values in infants with CF using the automatic modus was the incorrect recognition of the end-of-test too early during the washout. CONCLUSION We recommend the use of the manual modus for the analysis of MBW outcomes in infants in order to obtain more accurate results. This will allow appropriate use of infant lung function results for clinical and scientific purposes.

Risk Index Score (RISc)

The main objective of this study was to develop and validate a computer-based statistical algorithm based on a multivariable logistic model that can be translated into a simple scoring system in order to ascertain stroke cases using hospital admission medical records data. This algorithm, the Risk Index Score (RISc), was developed using data collected prospectively by the Brain Attack Surveillance in Corpus Christ (BASIC) project. The validity of the RISc was evaluated by estimating the concordance of scoring system stroke ascertainment to stroke ascertainment accomplished by physician review of hospital admission records. The goal of this study was to develop a rapid, simple, efficient, and accurate method to ascertain the incidence of stroke from routine hospital admission hospital admission records for epidemiologic investigations. ^ The main objectives of this study were to develop and validate a computer-based statistical algorithm based on a multivariable logistic model that could be translated into a simple scoring system to ascertain stroke cases using hospital admission medical records data. (Abstract shortened by UMI.)^

Body mass index of Vietnamese children ages 6--15 years old

Childhood overweight can increase the risk of chronic diseases later in life. To determine the prevalence, trends and determinants of overweight among children ages 6-15 years old in Vietnam, we assessed data on body mass index (BMI) and demographic and socio-economic characteristics obtained from the 1992 Vietnam Living Standard Survey (1992 VLSS), the 1997 Vietnam Living Standard Survey (1997 VLSS), and the 2000 General Nutrition Survey (2000 GNS). These surveys used multi-stage cluster sample designs to produce nationally representative samples of Vietnamese children ages 6-15 years in 1992-1993, 1997-1998 and 2000. BMI classification was determined using cut-off values set by the International Obesity Task Force (IOTF). The mean prevalence of at risk of overweight and overweight among Vietnamese children rapidly increased from 0.4% in 1992 to 2.0% in 2000, along with a high prevalence of underweight (33.4% in 2000). Increases in weight, height and BMI varied according to gender, area of residence and socioeconomic status. Age, areas of residence and education of the household head are statistically significant predictors of at risk of overweight and overweight. This study identified the prevalence and trends of weight among children crucial to understanding the prevention of child overweight in Vietnam. ^

Relationship between dietary patterns and body mass index in Hispanic children ages 4--19 years of age

Background. In over 30 years, the prevalence of overweight for children and adolescents has increased across the United States (Barlow et al., 2007; Ogden, Flegal, Carroll, & Johnson, 2002). Childhood obesity is linked with adverse physiological and psychological issues in youth and affects ethnic/minority populations in disproportionate rates (Barlow et al., 2007; Butte et al., 2006; Butte, Cai, Cole, Wilson, Fisher, Zakeri, Ellis, & Comuzzie, 2007). More importantly, overweight in children and youth tends to track into adulthood (McNaughton, Ball, Mishra, & Crawford, 2008; Ogden et al., 2002). Childhood obesity affects body functions such as the cardiovascular, respiratory, gastrointestinal, and endocrine systems, including emotional health (Barlow et al., 2007, Ogden et al., 2002). Several dietary factors have been associated with the development of obesity in children; however, these factors have not been fully elucidated, especially in ethnic/minority children. In particular, few studies have been done to determine the effects of different meal patterns on the development of obesity in children. Purpose. The purpose of the study is to examine the relationships between daily proportions of energy consumed and energy derived from fat across breakfast, lunch, dinner, and snack, and obesity among Hispanic children and adolescents. Methods. A cross-sectional design was used to evaluate the relationship between dietary patterns and overweight status in Hispanic children and adolescents 4-19 years of age who participated in the Viva La Familia Study. The goal of the Viva La Familia Study was to evaluate genetic and environmental factors affecting childhood obesity and its co-morbidities in the Hispanic population (Butte et al., 2006, 2007). The study enrolled 1030 Hispanic children and adolescents from 319 families and examined factors related to increased body weight by focusing on a multilevel analysis of extensive sociodemographic, genetic, metabolic, and behavioral data. Baseline dietary intakes of the children were collected using 24-hour recalls, and body mass index was calculated from measured height and weight, and classified using the CDC standards. Dietary data were analyzed using a GEE population-averaged panel-data model with a cluster variable family identifier to include possible correlations within related data sets. A linear regression model was used to analyze associations of dietary patterns using possible covariates, and to examine the percentage of daily energy coming from breakfast, lunch, dinner, and snack while adjusting for age, sex, and BMI z-score. Random-effects logistic regression models were used to determine the relationship of the dietary variables with obesity status and to understand if the percent energy intake (%EI) derived from fat from all meals (breakfast, lunch, dinner, and snacks) affected obesity. Results. Older children (age 4-19 years) consumed a higher percent of energy at lunch and dinner and less percent energy from snacks compared to younger children. Age was significantly associated with percentage of total energy intake (%TEI) for lunch, as well as dinner, while no association was found by gender. Percent of energy consumed from dinner significantly differed by obesity status, with obese children consuming more energy at dinner (p = 0.03), but no associations were found between percent energy from fat and obesity across all meals. Conclusions. Information from this study can be used to develop interventions that target dietary intake patterns in obesity prevention programs for Hispanic children and adolescents. In particular, intervention programs for children should target dietary patterns with energy intake that is spread throughout the day and earlier in the day. These results indicate that a longitudinal study should be used to further explore the relationship of dietary patterns and BMI in this and other populations (Dubois et al., 2008; Rodriquez & Moreno, 2006; Thompson et al., 2005; Wilson et al., in review, 2008). ^

Proliferation index in ductal carcinoma in situ of the breast: Relation to estrogen, progesterone and HER2/neu receptors

Background. Ductal carcinoma in situ (DCIS) is the most prevalent precursor to invasive breast cancer (IBC), the second leading cause of death in women in the United States. The three most important prognostic markers for IBC are Estrogen receptor (ER), Progesterone receptor (PR) and HER2/neu. The four groups (IBC) defined as (1) ER and/or PR positive and HER2/neu negative, (2) ER and/or PR positive and HER2/neu positive (3) ER and/or PR negative and HER2/neu positive and (4) negative for all three of these receptors (Triple negative). However, they have not been well studied in DCIS. This is an exploratory study with a primary objective to examine the prevalence of ER, PR, and HER2/neu in DCIS, to explore if the defined groups of IBC occur in DCIS and to consider the biological relationship between these four groups and the proliferative activity of the tumor. A secondary goal of this study is to examine the relationship between grade and proliferative activity. Methods. Using immunohistochemistry, I have measured Ki-67, ER, PR and HER2/neu positivity for a series of cases of DCIS. Results. 20 ER and/or PR positive and HER2/neu negative (50%) with average PI of 0.05, 7 ER and/or PR positive and HER2/neu positive (17.5%) with average PI of 0.14, 10 ER and/or PR negative and HER2/neu positive (25%) with average PI of 0.18, and three triple negative (7.5%) with average PI of 0.18. ER and/or PR positive and HER2/neu positive group has the highest PI (p<0.001). Further, the ER and/or PR positive and HER2/neu positive group show a linear relationship between PI and average ER/PR positivity (R=0.6). PI increases with higher grades. Conclusion. PI appears to depend upon the average fraction of positive ER/PR tumor cells, possibly with a synergistic dependence when HER2/neu is positive. If ER/PR is negative, then both HER2/neu positive and the triple negative cases appear to cluster around an average PI that is higher than the average PI in HER2/neu negative ER/PR positive negative cases. In the triple negative tumors there must be another driver of proliferation.^

Index properties, calcium carbonate content and opal concentration of ODP Core 167-1016B-17H sediments

Physical properties measurements provide a relatively inexpensive and fast way to obtain high-resolution estimates of the variations in sedimentological properties. To better resolve the validity and cause of the geophysical signals measured by the Ocean Drilling Program (ODP) shipboard multisensor track (MST) instruments, 223 x 10 cm**3 core samples were collected at 4 cm intervals in Core 167-1016B-17H at the California Margin Conception Transect for the measurements of index properties, carbonate content, and opal content. This core was chosen because hole-to-hole stratigraphic correlation of MST data suggested that Core 17H corresponds to a depth interval that displays the greatest range of amplitude of many physical properties.

The Utility of the CVLT-C as an Embedded Validity Indicator After Pediatric Mild Traumatic Brain Injury.

Results of neuropsychological examinations depend on valid data. Whereas clinicians previously believed that clinical skill was sufficient to identify non-credible performance by examinees on standard tests, research demonstrates otherwise. Consequently, studies on measures to detect suspect effort in adults have received tremendous attention in the previous twenty years, and incorporation of validity indicators into neuropsychological examinations is now seen as integral. Few studies exist that validate methods appropriate for the measurement of effort in pediatric populations. Of extant studies, most evaluate standalone measures originally developed for use with adults. The present study examined the utility of indices from the California Verbal Learning Test – Children's Version (CVLT-C) as embedded validity indicators in a pediatric sample. Participants were 225 outpatients aged 8 to 16 years old referred for clinical assessment after mild traumatic brain injury (mTBI). Non-credible performance (n = 39) was defined as failure of the Medical Symptom Validity Test (MSVT). Logistic regression demonstrated that only the Recognition Discriminability index was predictive of MSVT failure (OR = 2.88, p < .001). A cutoff of z ≤ -1.0 was associated with sensitivity of 51% and specificity of 91%. In the current study, CVLT-C Recognition Discriminability was useful in the identification of non-credible performance in a sample of relatively high-functioning pediatric outpatients with mTBI. Thus, this index can be added to the short list of embedded validity indicators appropriate for pediatric neuropsychological assessment.

Deep observation of the NGC1275 region with MAGIC: search of diffuse gamma-ray emission from cosmic rays in the Perseus cluster

Clusters of galaxies are expected to be reservoirs of cosmic rays (CRs) that should produce diffuse γ-ray emission due to their hadronic interactions with the intra-cluster medium. The nearby Perseus cool-core cluster, identified as the most promising target to search for such an emission, has been observed with the MAGIC telescopes at very-high energies (VHE, E ≥ 100 GeV) for a total of 253 hr from 2009 to 2014. The active nuclei of NGC 1275, the central dominant galaxy of the cluster, and IC 310, lying at about 0.6º from the centre, have been detected as point-like VHE γ-ray emitters during the first phase of this campaign. We report an updated measurement of the NGC 1275 spectrum, which is described well by a power law with a photon index Γ = 3.6 ± 0.2_(stat) ± 0.2_(syst) between 90 GeV and 1200 GeV. We do not detect any diffuse γ-ray emission from the cluster and so set stringent constraints on its CR population. To bracket the uncertainties over the CR spatial and spectral distributions, we adopt different spatial templates and power-law spectral indexes α. For α = 2.2, the CR-to-thermal pressure within the cluster virial radius is constrained to be ≤ 1 − 2%, except if CRs can propagate out of the cluster core, generating a flatter radial distribution and releasing the CR-to-thermal pressure constraint to ≤ 20%. Assuming that the observed radio mini-halo of Perseus is generated by secondary electrons from CR hadronic interactions, we can derive lower limits on the central magnetic field, B_(0), that depend on the CR distribution. For α = 2.2, B_(0) ≥ 5 − 8 µG, which is below the ∼25 µG inferred from Faraday rotation measurements, whereas for α ≤ 2.1, the hadronic interpretation of the diffuse radio emission contrasts with our γ-ray flux upper limits independently of the magnetic field strength.

ERP-CDI : Enterprise Resource Planning - Capacity Development Index : Africa : [research report 2012]

credits: Constanze Couzens, Kevin Rosenberger, Frances Weiß, Patrick Wirz [editor], Catharina Zschieck ; Magdeburg Research and Competence Cluster for Very Large Business Applications, Very Large Business Applications Lab