Short communication: Utilisation of n-alkanes to estimate feed intake in horses fed known amounts of a labelled concentrate supplement

The assessment of feed intake in stabled horses is a difficult task to accomplish. Faecal markers, namely n-alkanes, have been used successfully for the estimation of this important nutritional parameter. This usually involves the dosing of synthetic n-alkanes via different matrices, a laborious task that may also influence the animal normal foraging behaviour. An experiment was conducted to evaluate a relative simple methodology to quantify feed intake in horses, based on the provision of measured amounts of a concentrate supplement labelled with beeswax and the utilisation of n-alkanes as faecal markers. Four Lusitano horses were used in three consecutive experimental periods. Animals were fed on cereal straw and different proportions of a previously prepared beeswax-labelled concentrate supplement (BLCS; 0.05, 0.10 and 0.20, DM basis). Beeswax labelling was performed to provide a distinct n-alkane profile for the concentrate feed. Prior to feed intake calculations, proportions of labelled concentrate supplement in the diets were estimated using n-alkanes C₂₅ to C₃₃ by least-square optimisation procedures. Results showed that the beeswax labelling resulted in high n-alkane concentrations in the concentrate feed, especially for the odd-chain n-alkanes. Estimates of diet composition did not differ from the measured values, except for the diet with highest BLCS incorporation, with an underestimation of 10%. DM intake was accurately estimated by the "labelled supplement method" in all diets. However, for the lowest BLCS incorporation, DM intake was underestimated by 16% whereas for the higher levels of BLCS in the diet, measured and estimated DM intake values were almost identical with a slight overestimation of only 0.7 and 0.2% (10 and 20% of BLCS, respectively). Results indicate that both diet composition and feed intake can be accurately estimated in horses using the "labelled supplement method", even when very low levels of the labelled concentrate supplement are included in the animals' diet. This method eliminates the need for daily dosing with external synthetic markers, providing advantages in terms of minimising animal management and interference with their normal foraging behaviour.

On the outside looking in: a phenomenological study of the lived experience of Australian adults with a disorder of the corpus callosum

Background

While classified as a rare condition, a congenital disorder of the corpus callosum (DCC) is one of the most commonly identified brain anomalies in newborns, occurring in 1:4000 live births. Advances in imaging techniques have improved early diagnosis for children, yet adults with a DCC—who may present with extreme heterogeneity in cause and impact—often experience challenges in receiving a definitive diagnosis and accessing appropriate services and supports. To date, the dearth of evidence documenting the lived experiences of adults with DCC has made it difficult to determine adequate policy and service responses. This exploratory research aims to address this gap by presenting the first qualitative examination of the experiences and impact of complete or partial agenesis of the corpus callosum among adults.

Results

Eight face-to-face interviews were conducted with Australian adults, aged 23–72 years, to explore their lived experience. Data was collected in four Australian states from June to August 2017. Thematic and interpretive analyses were employed to analyse data. Three emergent themes described difficulties related to: (1) reactions to the diagnosis; (2) access to supports and key life domains, and (3) identifying as an adult. Interview analysis described lived experiences typically outlining a lifetime of exclusion and misunderstanding from family, educators and disability and health support services.

Conclusions

This paper contributes to filling the knowledge gap around a rare congenital brain disorder affecting the lives of adults. Findings confirm a considerable lack of information and support for adults living with corpus callosum disorders. Greater professional and societal understanding is needed to improve access to the key life domains of education, employment and social inclusion for adults with a DCC. To instigate truly effective change, social research must tackle the issues of applicability and impact to alter the dominance of uninformed practices, hindered by prevailing myths. This research paves the way for further phenomenological studies in which participant narrative is vital. Further research will elicit stronger policy and service responses for all current and emerging adults with a DCC.

The rates of second lung cancers and the survival of surgically-resected second primary lung cancers in patients undergoing resection of an initial primary lung cancer

BACKGROUND

The Lung Cancer Screening Trial demonstrated improved overall survival (OS) and lung cancer specific survival (LCSS), likely due to finding early-stage NSCLC. The purpose of our investigation is to evaluate whether long-term surveillance strategies (4+ years after surgical resection of the initial lung cancer(1LC)) would be beneficial in NSCLC patients by assessing the rates of second lung cancers(2LC) and the OS/LCSS in patients undergoing definitive surgery in 1LC as compared to 2LC (>48 months after 1LC) populations.

METHODS

SEER13/18 database was reviewed for patients during 1998-2013. Log-rank tests were used to determine the OS/LCSS differences between the 1LC and 2LC in the entire surgical group(EG) and in those having an early-stage resectable tumors (ESR, tumors <4 cm, node negative). Joinpoint analysis was used to determine rates of second cancers 4-10 year after 1LC using SEER-9 during years 1985-2014.

RESULTS

The rate of 2LCs was significantly less than all other second cancers until 2001 when the incidence of 2LCs increased sharply and became significantly greater than all other second cancers in females starting in year 2005 and in men starting in year 2010. OS/LCSS, adjusted for propensity score by using inverse probability weighting, demonstrated similar OS, but worse LCSS for 2LCs in the EG, but similar OS/LCSSs in the ESR group.

CONCLUSION

Because the rate of 2LCs are increasing and because the OS/LCSS of the 1LC and 2LC are similar in early-stage lesions, we feel that continued surveillance of patients in order to find early-stage disease may be beneficial.

A-47 Self-reported Difficulties in Retrospective Memory Predict Poor Verbal Memory Performance

Objective

Prospective and retrospective memory complaints are common among older adults with mixed results regarding their relationship with objective memory performance. This study investigated how subjective memory reports relate to objective memory function in a clinical sample.

Method

Participants (N = 139, Mage = 69.9, SD = 9.2) completed a cognitive screen at a university clinic. The assessment included the Hopkins Verbal Learning Test (verbal memory), the Brief Visuospatial Memory Test – Revised (visual memory) and the Prospective and Retrospective Memory Questionnaire, a subjective memory measure with higher scores indicating greater perceived difficulties. Correlations and linear regressions were used to evaluate the relationship between subjective and objective memory (a priori p-value = .01).

Results

Retrospective memory was correlated with immediate (r = -.35, p < .001) and delayed verbal memory (r = -.31, p < .001) but unrelated to visual memory (p > .05). Prospective memory was not correlated with performance on visual or verbal memory tasks (p > .05). Retrospective memory accounted for 12.3% of the variation in immediate (adjusted R2 = 11.6%; medium effect size), and 9.3% of the variation in delayed verbal memory (adjusted R2 = 8.6%; small effect size). Retrospective memory significantly predicted immediate [F(1, 132) = 18.48, p < .001, 95% CI = -1.04 to -0.38] and delayed verbal memory scores [F(1, 132) = 13.51, p < .001, 95% CI = -1.09 to -0.33].

Conclusions

Subjective reports of retrospective memory may be a better indicator of objective verbal memory performance than prospective memory in a clinical sample of older adults.

Cost-effectiveness of levonorgestrel subdermal implants. Comparison with other contraceptive methods available in the United States

The objective of this analysis was to evaluate and compare the cost-effectiveness of eight contraceptive methods: condoms, diaphragms, oral contraceptives, intrauterine devices, medroxyprogesterone acetate suspension, levonorgestrel subdermal implants, tubal ligation and vasectomy. Based on a comprehensive review of the literature and various additional data sources, this analysis identified, measured and compared direct costs of the methods, physician visits, treatment of adverse effects and cost of failure (i.e., mean cost for all types of deliveries or first-trimester abortion). Medical benefits (if any) resulting from each contraceptive method were calculated and considered in the analysis as cost savings. The cost of method failure proved to be the greatest influence on cost-effectiveness. Sterilization was identified as the most cost-effective method overall. Of the reversible methods, the intrauterine device was found to be the most cost-effective, followed by levonorgestrel implants.

Measures of central tendency, variability, and relative standing in nonnormal distributions: alternatives to the mean and standard score

There are two major disadvantages to reporting test results in standardized scores such as z-scores or t-scores when describing individuals with disabilities. (1) Raw scores on many tasks from disabled individuals are notoriously nonnormal. They are asymmetric, in that they are skewed toward poor scores. (2) Low z-scores give a false impression of dysfunction because able-bodied subjects are often grossly overqualified for the application in question; they may have levels of strength or quickness several orders of magnitude greater than what is needed to do the assessment task. A recommended alternative is to describe the performance of disabled individuals using nonparametric statistics, and to report scores in boxplots, showing the extremes, the median, and the quartiles. Such points are easy to calculate and to interpret, and they are robust against outliers.