Animal models of amyotrophic lateral sclerosis： a comparison of model validity

Animal models are necessary to investigate the pathogenic features underlying motor neuron degeneration and for therapeutic development in amyotrophic lateral sclerosis（ALS）. Measures of model validity allow for a critical interpretation of results from each model and caution from over-interpretation of experimental models. Face and construct validity refer to the similarity in phenotype and the proposed causal factor to the human disease, respectively. More recently developed models are restricted by limited phenotype characterization, yet new models hold promise for novel disease insights, thus highlighting their importance. In this article, we evaluate the features of face and construct validity of our new zebrafish model of environmentally-induced motor neuron degeneration and discuss this in the context of current environmental and genetic ALS models, including C9 orf72, mutant Cu/Zn superoxide dismutase 1 and TAR DNA-binding protein 43 mouse and zebrafish models. In this mini-review, we discuss the pros and cons to validity criteria in each model. Our zebrafish model of environmentally-induced motor neuron degeneration displays convincing features of face validity with many hallmarks of ALS-like features, and weakness in construct validity. However, the value of this model may lie in its potential to be more representative of the pathogenic features underlying sporadic ALS cases, where environmental factors may be more likely to be involved in disease etiology than single dominant gene mutations. It may be necessary to compare findings between different strains and species modeling specific genes or environmental factors to confirm findings from ALS animal models and tease out arbitrary strain-and overexpression-specific effects.

Validation and adaptation of the Physical Activity Enjoyment Scale (PACES) in fitness group exercisers

Background:Recently,Mullen et al.(2011)presented an 8-item version of the Physical Activity Enjoyment Scale(PACES)that provides a valid instrument for assessing enjoyment in physical activity.The present paper investigated the psychometric properties of a Portuguese adaptation of PACES.Methods:After a process of back-to-back translation into Portuguese,395 members of fitness centers who ranged in age from 18 to 66 years(31.11§8.90,mean§SD)completed the translated version of the PACES.On average,participants had 3.2 years of experience in fitness group classes and practiced for approximately 3.3 times per week.Results:An initial exploratory factor analysis(n=139)revealed a unidimensional structure with factor loadings ranging from 0.79 to 0.89.Results also showed acceptable internal consistency.A confirmatory factor analysis in an independent sample(n=256)provided additional support for the unidimensional structure of the questionnaire.In addition,moderate positive correlations between enjoyment and intrinsic and identified regulation,and moderate negative correlations between enjoyment and external and amotivation,demonstrate the convergent validity of the instrument.Finally,measurement invariance between 2 independent samples was also found.Conclusion:The 8-item Portuguese version of PACES is a valid and reliable instrument for measuring enjoyment of physical activity in Portuguese adult fitness exercisers,and it is therefore suitable to use as a measure of affect in exercise adherence interventions studies.

A factor analytic assessment of the English translation of the neuropsychological vertigo inventory(NVI)

Purpose:Vestibular impairments have been associated with a variety of cognitive deficits,most notably deficits in visuo-spatial memory.The Neuropsychological Vertigo Inventory(NVI)was developed to measure self-reported cognitive deficits in patients with dizziness and/or vertigo.The original French language version of the NVI includes 28 items and 7 subscales.The purpose of the present investigation was to determine whether the statistical assessment of an English language version supported the presence of the same cognitive constructs as the French version of the NVI.Method:The English language adaptation of the NVI(referred to here as the NVIe)was administered to an unselected sample of 280 patie nts that were being evaluated for dizziness and/or vertigo in a tertiary care dizziness clinic.The individual item scores from the NVIe were subjected to an exploratory factor analysis(EFA).Results:The results of the data analysis supported a 22-item NVIe consisting of 4 constructs:affective state,temporal memory,spatial memory,visual spatial cognition.Conclusions:The NVIe is a new tool for screening cognitive constructs that may be affected by vestibular impairments.Prior to clinical implementation of the NVIe,additional studies of reliability and convergent validity are needed.

Development and psychometric evaluation of the Ethical Behavior for Thai Nurses Scale

Background:Ethical problems in the nursing profession are mostly found in the undesirable ethical behavior(EBE)of nurses.If there is no concern about these problems,it may negatively affect the quality of nursing care,patients’safety,and trust in the nursing profession.In assessing nurses’EBE,it is important to develop an instrument that reflects the actual EBE of nurses.Objectives:To develop and evaluate the psychometric properties of the Ethical Behavior for Thai Nurses Scale(EBTNS).Methods:The construct definition,5 sub-constructs,43 items,and the hypothesized model were synthesized and generated from a comprehensive literature review and existing research instruments by using document analysis.The EBTNS was verified for content validity by 4 experts.Of the 43 items,37 items were retained for psychometric testing.The construct validity was tested by using second-order confirmatory factor analysis(CFA).The EBTNS was tested on 1500 professional nurses working at tertiary,secondary,and primary hospitals in 6 regions(the central,northern,northeast,eastern,western,and southern)of Thailand.Proportional quota sampling was applied to recruit participants.Results:The hypothesized model fitted the empirical data.All 37 first-order indicators and 5 second-order sub-constructs showed significantly standardized factor loadings and effect sizes.The standardized factor loadings of 37 first-order indicators ranged from 0.58 to 0.89,and the construct reliabilities were moderate to substantial(R2=0.34-0.79).The 5 second-order sub-constructs displayed the standardized effect sizes,ranging from 0.81 to 0.96,and accounted for 65%-96%of the total explained variance.In addition,the construct validity was supported by convergent validity and discriminant validity.It also satisfied Cronbach’s alpha coefficients of 5 sub-constructs from 0.87 to 0.94,and a full scale was 0.97.Conclusions:The psychometric properties of the EBTNS are acceptable.This instrument has the potential to be used for evaluating and monitoring to prevent ethical problems of Thai nurses.