Behavioral Evidence for Chemosensory and Thermosensory Pathway Convergence in the Caenorhabditis Elegans Nervous System

The nematode, Caenorhabditis elegans, is an established model system to explore the ways simple nervous systems detect and direct organismal responses to environmental changes. C. elegans possesses specialized receptor cells for the detection of a variety of environmental stimuli. Separate cell types respond to volatile chemical and thermal stimuli and the neural pathways for these show anatomical evidence of convergence. This work reports findings from behavioral assays during simultaneous exposure of nematodes to both thermal differences and attractant volatile chemicals. Combined exposure to benzaldehyde and cold neutralized the behavioral responses to both stimuli in 24°C acclimated worms. Diacetyl and mild thermal stimulation produced the same effect with 16°C acclimated worms. Benzaldehyde appears to interfere with thermophilic circuitry while diacetyl acts similarly with cryophilic circuitry

Time-variant nonparametric extreme quantile estimation with application to US temperature data

Statistical modelling for several years of daily temperature data is somewhat challenging due to remarkable variations of negative and positive temperatures throughout the year. A scatter plot of day and daily temperature shows the high magnitude of variations among data points as dots fall only in the first and fourth quadrants. One parametric modelling approach to this data is to use quantile regression to obtain regression lines on different quantiles. However, these quantile lines cannot make reliable predictions on extreme quantiles when time-variant quantiles differ significantly. In this paper, we develop several two-step nonparametric smoothing estimators and show their superiority over quantile regression for smoothing estimation of nonparametric quantiles with a novel application to temperature data. Narrower bootstrap confidence bands, smaller Minimum Absolute Distance (MAD), smaller bias and MSE, and higher coverage from the application and simulation results show that smoothing curves obtained from these smoothing estimators outperform the quantile regression line

Linguistic Discrimination in Writing Assessment: How Raters React to African American “Errors,” ESL Errors, and Standard English Errors on a State-Mandated Writing Exam

Raters of Georgia\u27\u27s (USA) state-mandated college-level writing exam, which is intended to ensure a minimal university-level writing competency, are trained to grade holistically when assessing these exams. A guiding principle in holistic grading is to not focus exclusively on any one aspect of writing but rather to give equal weight to style, vocabulary, mechanics, content, and development. This study details how raters react to “errors” typical of African American English writers, of ESL writers, and of standard American English writers. Using a log-linear model to generate odds ratios for comparison of essays with these error types, results indicate linguistic discrimination against African American “errors” and a leniency for ESL errors in writing assessment

A Study of the Average Run Length Characteristics of the National Notifiable Diseases Surveillance System

This study examines the statistical properties (that is, false positive and negative signals) in detecting unusual patterns of reported cases of diseases from the Centers for Disease Control and Prevention\u27s National Notifiable Diseases Surveillance System. Control charts are applied to the residuals of one-step ahead forecasts based on Box–Jenkins models of reported cases of disease. Simulation and analytical techniques are used to study the average run length characteristics of these control charts for various types of changes in the levels of the series, including spike, trend and step changes. The average run lengths for the highly correlated disease series are much longer than for the usual independent data case. This increase in the average run lengths is strongly influenced by the type of change in the level of the series and by the type of control chart. Understanding the average run length characteristics of the control charts can lead to timely detection of changes in the levels of disease series, and subsequent timely public health actions to decrease unnecessary morbidity and mortality

EWMA and CUSUM Control Charts in the Presence of Correlation

The statistical properties of control charts are usually evaluated under the assumption that the observations from the process are independent. For many processes however, observations which are closely spaced in time will be correlated. This paper considers EWMA and CUSUM control charts for the process mean when the observations are from an AR(1) process with additional random error. This simple model may be a reasonable model for many processes encountered in practice. The ARL and steady state ARL of the EWMA and CUSUM charts are evaluated numerically using an integral equation approach and a Markov chain approach. The numerical results show that correlation can have a significant effect on the properties of these charts. Tables are given to aid in the design of these charts when the observations follow the assumed model

An Examination of Age, Race, and Sex as Predictors of Success in the First Programming Course

The goal of this study was to examine correlations among age, race and sex as predictors of success in a first programming course, particularly for computer science and information systems majors. In addition to age, race, and sex, other possible explanatory variables considered included SAT and declared major. This research stems from concern about the declining proportion of women and minorities in the information technology (II) workforce. Dominant portals to a professional career in IT include a baccalaureate degree in either computer science and information systems. Thus, another concern motivating this research is that the majority of the data suggesting this decline is based solely on computer science (CS), neglecting information systems (IS) graduates. This paper reports results from a study of success rates in the first programming course because it is often the first IT course interested students encounter. Considered a necessary component in standard curriculum guidelines, the first programming course often functions as a gateway to an IT career, and certainly may influence self-perceptions and attitudes about IT as a career. Statistical analysis of the data indicates that the proportion ofwomen is higher in IS than CS, and that CS majors have a higherprobability ofpassing the first programming course than IS majors. The results also show that neither sex nor age is a good predictor of success in the first programming class

Effect of Education on a Chest Pain Mnemonic on Door-to-ECG Time

Introduction: Acute myocardial infarction (AMI) continues to contribute to both death and disability in both men and women. The first step in early intervention is an ECG. Atypically presenting patients, especially those who present by self-transport, are more likely to experience delays. The purpose of this study was to evaluate the effect of a new chest pain mnemonic (CPM) as a teaching tool for rapid recognition of AMI patients arriving by self-transport in ED triage in an effort to improve door-to-ECG (DTE) time. Methods: This study is a longitudinal, quasi-experimental quantitative study. Instruction and evaluation of nurses\u27 knowledge related to identification of AMI before and after instruction on the CPM education (intervention) were coordinated by the emergency clinical nurse specialist. The study sample for the educational intervention included 26 nurses (15% of total population) from 4 emergency departments. Ad hoc queries of the National Registry for Myocardial Infarction database for patients arriving by self-transport to the emergency department were done to examine DTE before and after intervention. The pretests and post-tests of the nurses were analyzed with a paired t test, and the pre- and post-intervention DTE times were analyzed by log-linear modeling. Results: Evaluation of nurses\u27 knowledge before and after CPM education indicated an improvement in DTE time, although it was not statistically significant. There was a significant improvement in DTE time for 2 hospitals that was somewhat negated in the aggregate data. There was a noted trend that showed an advantage in DTE time associated with male patients. Discussion: Inclusion of tools such as the CPM in education programs for emergency nurses improved rapid recognition of AMI patients presenting via self-transport to the emergency department. Attention to gender differences in patient presentation should be included in future CPM education, and tools to assist nurses in the early recognition of AMI need to be developed. Investigation regarding intra-hospital differences is warranted

An Evaluation of a Sitter Reduction Program Intervention

Hospitals use sitters as an alternative to reduce patient falls. The purpose of the study was to evaluate the effectiveness of a sitter reduction program by examining the differences between sitter use and falls in an acute care hospital. Findings indicate that a significant decrease in sitter use and falls remained constant. Reducing sitter use is possible without significantly increasing fall rates