SOURCES 4C : a code for calculating ([alpha],n), spontaneous fission, and delayed neutron sources and spectra.

SOURCES 4C is a computer code that determines neutron production rates and spectra from ({alpha},n) reactions, spontaneous fission, and delayed neutron emission due to radionuclide decay. The code is capable of calculating ({alpha},n) source rates and spectra in four types of problems: homogeneous media (i.e., an intimate mixture of a-emitting source material and low-Z target material), two-region interface problems (i.e., a slab of {alpha}-emitting source material in contact with a slab of low-Z target material), three-region interface problems (i.e., a thin slab of low-Z target material sandwiched between {alpha}-emitting source material and low-Z target material), and ({alpha},n) reactions induced by a monoenergetic beam of {alpha}-particles incident on a slab of target material. Spontaneous fission spectra are calculated with evaluated half-life, spontaneous fission branching, and Watt spectrum parameters for 44 actinides. The ({alpha},n) spectra are calculated using an assumed isotropic angular distribution in the center-of-mass system with a library of 107 nuclide decay {alpha}-particle spectra, 24 sets of measured and/or evaluated ({alpha},n) cross sections and product nuclide level branching fractions, and functional {alpha}-particle stopping cross sections for Z < 106. The delayed neutron spectra are taken from an evaluated library of 105 precursors. The code provides the magnitude and spectra, if desired, of the resultant neutron source in addition to an analysis of the'contributions by each nuclide in the problem. LASTCALL, a graphical user interface, is included in the code package

Reduced processing speed in rugby union players reporting three or more previous concussions

The issue pertaining to the effect of multiple self-reported sports-related concussions on cognitive function is controversial. Although this topic has received increased attention in the literature recently, the issue remains unresolved. Evidence supporting a detrimental cognitive effect has been reported at a sub-concussive level and following one, two, and three or more previous concussions. However, numerous studies have been unable to replicate these findings. Additionally, discrepancies between neuropsychological testing formats have been identified, where studies utilizing traditional tests tend to support the notion of detrimental cognitive effects whereas studies with computerized tests have tended to demonstrate no effect. The present study sought to examine possible detrimental cognitive effects in a sample of adult male rugby union players who reported a history of three or more concussions (n = 34) compared with those who reported no previous concussions (n = 39). A computerized neuropsychological battery and a traditional neuropsychological measure of processing speed were administered for this purpose. Findings revealed that there were differences between groups on two processing speed measures from both traditional and computerized tests. Athletes with a history of multiple concussions performed significantly lower on these measures than those with no history of concussion. These results provide further evidence to suggest that a history of three or more self-reported concussions in active athletes may have a detrimental effect on cognitive function. Future research may focus on identifying moderating factors in an attempt to resolve some of the conflicting findings and identify potential athletes at risk for sustaining cognitive deficits.8 page(s

The Abbreviated Westmead Post-traumatic Amnesia Scale and Pocket Concussion Recognition Tool : data from amateur sports players in live-match conditions

Sports-related concussion is a growing public health concern. A short, simple sideline assessment tool is essential for evaluation of concussion at an amateur participation level. The current study examined responses to sideline assessment measures in a sample of amateur Australian Rules Football players competing in real-time live matches who had not sustained a concussion on the day of testing. Participants (N = 127) completed the Abbreviated Westmead Post-traumatic Amnesia Scale (A-WPTAS) and the Pocket Concussion Recognition Tool (Pocket CRT), which contains the Maddocks Questions (assessing orientation and recent memory) and the Postconcussion Symptom Scale (PCSS). The study showed 98.4% of participants passed the A-WPTAS, while 81.9% passed the Maddocks Questions. Participants endorsed a mean of 4.16 (SD = 4.02) symptoms on the PCSS, with 86.6% endorsing at least 1 symptom at a mild level or greater and 40.2% endorsing at least 1 symptom at a moderate or severe level. The current results suggest the Maddocks Questions may not be sufficient for use in an amateur sports context. To reduce the risk for a false positive diagnosis of concussion, it is recommended that the Pocket CRT be complemented with the A-WPTAS for use in an amateur sports context.12 page(s

Australian norms and retest data for the Rey Auditory and Verbal Learning Test

This article presents normative data for the Rey Auditory and Verbal Learning Test (RAVLT). A representative sample of 390 healthy young adults aged between 18 and 34 living within the Sydney metropolitan area, Australia, completed Form AB of the RAVLT as part of the Macquarie University Neurological Normative Study. Retest data were collected from a subsample of 98 participants after an interval of 1 year. Norms were derived for commonly used measures of the RAVLT and are presented for the whole sample as well as separately for males and females with different levels of education. Age was not found to impact significantly on test performance for this group of young adults, and therefore age-adjusted norms are not provided. An excel program to calculate RAVLT standard scores (mean of 10 and standard deviation of 3) can be downloaded from http://www.psy.mq.edu.au/RAVLT. Poor test-retest reliability raises concerns about the use of the RAVLT in clinical diagnosis.7 page(s

An examination of lexical and sublexical reading skills in children with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is an inherited neurocutaneous disorder associated with a high frequency of cognitive and learning difficulties. Based on discrepancies between IQ and academic achievement, approximately 17% of children with NF1 have been classified as having reading impairments. In this study, the lexical and sublexical reading skills of children with NF1 (n = 30) were examined using the Castles' Word/Non-Word Test (modified version), together with measures of neuropsychological functioning and academic achievement. Twenty children (67%) demonstrated deficits in one or more reading subskills, with 75% of these meeting criteria for phonological dyslexia and 20% classified with mixed dyslexia. These findings indicate that a large proportion of children with NF1 may be characterized by a specific difficulty with the sublexical procedure, suggesting a difficulty employing spelling-to-sound rules to assemble a pronunciation when reading. In line with previous studies, the present findings also suggest that discrepancy-based methods may not be sufficiently sensitive to identify children who experience reading difficulties.18 page(s

A Comparison of methods to estimate premorbid intelligence in an Australian sample : data from the Macquarie University Neuropsychological Normative Study (MUNNS)

A variety of methods for estimating premorbid intelligence were compared in an Australian sample participating in the Macquarie University Neuropsychological Normative Study (MUNNS). Predictors included a contextual version of the AUSNART, the WRAT-3 Reading subtest, Spot-the-Word Test and sub-tests from the WAIS-R. The study involved 244 healthy participants aged between 18 and 34 years, with half of them serving as a cross-validation sample. Multiple regression was used for all analyses. When taking into account both the statistical results and clinical utility of the methods, the Sydney Premorbid Intelligence Estimate (SPIE), consisting of Vocabulary and Picture Completion subtests from the WAIS-R, was considered to be the best predictor. Combining all measures into one regression did not substantially increase the amount of variance explained. Base rate tables for predicted IQ versus obtained IQ, and the discrepancy between predicted 10 and Delayed Recall Index of the WMS-R are provided for each of the prediction methods. Further research to examine the clinical utility of these methods is required.11 page(s

Does effort suppress cognition after traumatic brain injury? : a re-examination of the evidence for the word memory test

Green, Rohling, Lees-Haley, and Allen (2001) suggested that scores on a test of "effort," the Word Memory Test (WMT), explains more variance in outcome after brain injury than does injury severity. As a consequence, Green and colleagues recommend using the WMT to control for sub-optimal effort in neuropsychological evaluations and group research. We re-examine the evidence for their conclusions and argue that identifying a larger proportion of explained variance is not in itself evidence of validity unless the premise to be proven is already assumed, namely, that the test is a valid measure of effort. Instead, the crux of Green and colleagues claim for the validity of the WMT implies an interaction between effort and injury severity on outcome scores, although the specific interaction has not been tested in their previous research. We failed to find any evidence for this interaction in a sample of 100 Australian litigants. We conclude that our data do not support the view that effort, as measured by the WMT, interacts with injury severity to suppress cognition after brain injury.15 page(s

Learning disabilities in children with neurofibromatosis type 1 : subtypes, cognitive profile, and attention-deficit-hyperactivity disorder

Cognitive deficits are the most common complication in children with neurofibromatosis type 1 (NF1), and academic achievement is broadly affected. There is a lack of consensus in the literature regarding the frequency of general and specific learning disabilities, which seems to be related to the lack of a consensus on diagnostic criteria. The present study examined the frequency of specific learning disabilities (SLDs) in NF1, using an intellect-achievement discrepancy for diagnosis, as well as general learning difficulty associated with a lowering of general intellectual ability. The cohort consisted of 81 children with NF1 (43 males, 38 females; mean age 11y 6mo [SD 2y 4mo]; range 8y–16y 9mo) and 49 comparison children (20 males, 29 females; mean age 12y [SD 2y 6mo]; range 8y 2mo–16y 8mo). Problems with academic achievement were present in 52% of children with NF1; however, only 20% of the children with NF1 were diagnosed with an SLD (32% had more general learning problems). Only males with NF1 were at significant risk for SLD, and Verbal IQ<Performance IQ discrepancies were predictive of the presence of an SLD. There was a significant comorbidity of literacy-based learning disabilities and attention-deficit-hyperactivity disorder. We were able to define three subtypes of children with NF1 having distinct cognitive profiles, each with important implications for assessment and remediation.5 page(s

Excluded letter fluency test (ELF) : norms and test-retest reliability data for healthy young adults

Normative and reliability data for the Excluded Letter Fluency (ELF) Test are provided. A stratified random sample of 399 healthy young adults aged 18 to 34 years from Sydney, Australia, completed the ELF Test as well as a full-length WAIS-R, as part of a larger battery of tests. After a 1-year interval 99 of these individuals were retested on the same forms of the tests. The influence of age, sex and education was investigated on the ELF and only education was found to have a significant overall effect on the total scores. However, gender was found to have an effect on the error scores, with males making more rule-breaks than females. Tables are provided for converting ELF raw scores, corrected for years of education, to standard scores with 90% and 95% confidence intervals for both test and retest purposes. A table for calculating the base rate of errors, for males and for females, on the ELF is also provided.7 page(s