Effect of housing and husbandry practices on adrenocortical activity in captive Canada lynx (Lynx canadensis)

In recent years, there has been an increasing focus on the study and assessment of animal welfare in captive settings, such as zoological gardens and aquaria. Canada lynx (Lynx canadensis) are a relatively common species in zoos, yet are known to exhibit frequent reproductive problems in captive environments. We provide an exploratory analysis of housing and husbandry factors that are associated with patterns of adrenocortical activity in lynx. Adrenocortical activity was assessed using the non-invasive technique of monitoring faecal glucocorticoid metabolites (FGM). First, we calculated baseline FGM values for each individual and controlled for sex, age class, and reproductive status. The residual values were used to determine how levels of adrenocortical activity correlated with institutional husbandry practices. Second, we compared the occurrence of FGM peaks to events and disturbances recorded by keepers. Our results highlighted that adrenocortical activity is strongly correlated with: (i) the size of the enclosure, (ii) the number of hiding locations available, and (iii) the social environment. Based on our findings, we recommend that lynx should generally be housed alone (unless with dependant offspring or temporarily paired up for mating purposes), in larger enclosures and with the provision of several species-appropriate hiding locations.

Formation of cortical plasticity in older adults following tDCS and motor training

Neurodegeneration accompanies the process of natural aging, reducing the ability to perform functional daily activities. Transcranial direct current stimulation (tDCS) alters neuronal excitability and motor performance; however its beneficial effect on the induction of primary motor cortex (M1) plasticity in older adults is unclear. Moreover, little is known as to whether the tDCS electrode arrangement differentially affects M1 plasticity and motor performance in this population. In a double-blinded, cross-over trial, we compared unilateral, bilateral and sham tDCS combined with visuomotor tracking, on M1 plasticity and motor performance of the non-dominant upper limb, immediately post and 30 min following stimulation. We found (a) unilateral and bilateral tDCS decreased tracking error by 12–22% at both time points; with sham decreasing tracking error by 10% at 30 min only, (b) at both time points, motor evoked potentials (MEPs) were facilitated (38–54%) and short-interval intracortical inhibition was released (21–36%) for unilateral and bilateral conditions relative to sham, (c) there were no differences between unilateral and bilateral conditions for any measure. These findings suggest that tDCS modulated elements of M1 plasticity, which improved motor performance irrespective of the electrode arrangement. The results provide preliminary evidence indicating that tDCS is a safe non-invasive tool to preserve or improve neurological function and motor control in older adults.

Influence of age and gender on fat mass, fat-free mass and skeletal muscle mass among Australian adults: the Australian diabetes, obesity and lifestyle study (AUSDIAB)

Background
Bioelectrical impedance (BIA) represents a simple, inexpensive and non-invasive method that is often used to assess fat-mass (FM) and fat-free mass (FFM) in large population-based cohorts.

Objective
The aim of this study was to describe the reference ranges and examine the influence of age and gender on FM, FFM and skeletal muscle mass (SMM) as well as height-adjusted estimates of FM [fat mass index (FMI)], FFM [fat-free mass index (FFMI)] and SMM [SMM index (SMI)] in a national, population-based cohort of Australian adults.

Design and Participants
The analytical sample included a total of 8,582 adults aged 25–91 years of Europid origin with complete data involved in the cross-sectional 1999–2000 Australian, Diabetes, Obesity and Lifestyle (AusDiab) Study.

Measurements
Bioelectrical impedance analysis was used to examine components of body composition. Demographic information was derived from a household interview.

Results
For both genders, FFM, SMM and SMI decreased linearly from the age of 25 years, with the exception that in men SMI was not related to age and FFM peaked at age 38 years before declining thereafter. The relative loss from peak values to ≥75 years in FFM (6–8%) and SMM (11–15%) was similar between men and women. For FM and FMI, there was a curvilinear relationship with age in both genders, but peak values were detected 6–7 years later in women with a similar relative loss thereafter. For FFMI there was no change with age in men and a modest increase in women.

Conclusion
In Australian adults there is heterogeneity in the age of onset, pattern and magnitude of changes in the different measures of muscle and fat mass derived from BIA, but overall the agerelated losses were similar between men and women.

RNAi mediated Tiam1 gene knockdown inhibits invasion of retinoblastoma

T lymphoma invasion and metastasis protein (Tiam1) is up-regulated in variety of cancers and its expression level is related to metastatic potential of the type of cancer. Earlier, Tiam1 was shown to be overexpressed in retinoblastoma (RB) and we hypothesized that it was involved in invasiveness of RB. This was tested by silencing Tiam1 in RB cell lines (Y79 and Weri-Rb1) using siRNA pool, targeting different regions of Tiam1 mRNA. The cDNA microarray of Tiam1 silenced cells showed gene regulations altered by Tiam1 were predominantly on the actin cytoskeleton interacting proteins, apoptotic initiators and tumorogenic potential targets. The silenced phenotype resulted in decreased growth and increased apoptosis with non-invasive characteristics. Transfection of full length and N-terminal truncated construct (C1199) clearly revealed membrane localization of Tiam1 and not in the case of C580 construct. F-actin staining showed the interaction of Tiam1 with actin in the membrane edges that leads to ruffling, and also imparts varying invasive potential to the cell. The results obtained from our study show for the first time that Tiam1 modulates the cell invasion, mediated by actin cytoskeleton remodeling in RB.

Exploring retinal and functional markers of diabetic neuropathy

Diabetic peripheral neuropathy (DPN) is one of the most debilitating complications of diabetes. DPN is a major cause of foot ulceration and lower limb amputation. Early diagnosis and management are key factors in reducing morbidity and mortality. Current techniques for clinical assessment of DPN are relatively insensitive for detecting early disease or involve invasive procedures such as skin biopsies. There is a need for less painful, non-invasive, safe evaluation methods. Eye-care professionals already play an important role in the management of diabetic retinopathy but recent studies have indicated that the eye may also be an important site for the diagnosis and monitoring of neuropathy. Corneal nerve morphology is a promising marker of diabetic neuropathy occurring elsewhere in the body. Emerging evidence tentatively suggests that retinal anatomical markers and a range of functional visual indicators could similarly provide useful information regarding neural damage in diabetes, although this line of research is less well established. This review outlines the growing body of evidence supporting a potential diagnostic role for retinal structure and visual functional markers in the diagnosis and monitoring of peripheral neuropathy in diabetes.

Condition monitoring of induction motors : A review and an application of an ensemble of hybrid intelligent models

In this paper, a review on condition monitoring of induction motors is first presented. Then, an ensemble of hybrid intelligent models that is useful for condition monitoring of induction motors is proposed. The review covers two parts, i.e.; (i) a total of nine commonly used condition monitoring methods of induction motors; and (ii) intelligent learning models for condition monitoring of induction motors subject to single and multiple input signals. Based on the review findings, the Motor Current Signature Analysis (MCSA) method is selected for this study owing to its online, non-invasive properties and its requirement of only single input source; therefore leading to a cost-effective condition monitoring method. A hybrid intelligent model that consists of the Fuzzy Min-Max (FMM) neural network and the Random Forest (RF) model comprising an ensemble of Classification and Regression Trees is developed. The majority voting scheme is used to combine the predictions produced by the resulting FMM-RF ensemble (or FMM-RFE) members. A benchmark problem is first deployed to evaluate the usefulness of the FMM-RFE model. Then, the model is applied to condition monitoring of induction motors using a set of real data samples. Specifically, the stator current signals of induction motors are obtained using the MCSA method. The signals are processed to produce a set of harmonic-based features for classification using the FMM-RFE model. The experimental results show good performances in both noise-free and noisy environments. More importantly, a set of explanatory rules in the form of a decision tree can be extracted from the FMM-RFE model to justify its predictions. The outcomes ascertain the effectiveness of the proposed FMM-RFE model in undertaking condition monitoring tasks, especially for induction motors, under different environments. © 2014 Elsevier Ltd. All rights reserved.

The effect of known cardiovascular risk factors on carotid-femoral pulse wave velocity in school-aged children: a population based twin study

Childhood cardiovascular risk factors affect vascular function long before overt cardiovascular disease. Twin studies provide a unique opportunity to examine the influence of shared genetic and environmental influences on childhood cardiovascular function. We examined the relationship between birth parameters, markers of adiposity, insulin resistance, lipid profile and blood pressure and carotid-femoral pulse wave velocity (PWV), a validated non-invasive measure of arterial stiffness in a healthy cohort of school-aged twin children. PWV was performed on a population-based birth cohort of 147 twin pairs aged 7-11 years. Fasting blood samples, blood pressure and adiposity measures were collected concurrently. Mixed linear regression models were used to account for twin clustering, within- and between-twin pair associations. There were positive associations between both markers of higher adiposity, insulin resistance, elevated triglycerides and PWV, which remained significant after accounting for twin birth-set clustering. There was a positive association between both diastolic and mean arterial blood pressure and PWV in within-pair analysis in dizygotic, but not monozygotic twins, indicating genetic differences evident in dizygotic not monozygotic twins may affect these associations. Increased blood pressure, triglycerides and other metabolic markers are associated with increased PWV in school-aged twins. These results support both the genetic and environmental contribution to higher PWV, as a marker of arterial stiffness, and reiterate the importance of preventing metabolic syndrome from childhood.

Functional and neurological adaptations to transcranial stimulation during strength training

This thesis found that the application of non-invasive brain stimulation during resistance training enhances gains in muscular strength and activation. The findings shed light on the contribution of the nervous system in strength development, and can be used to improve rehabilitation techniques for conditions such as musculoskeletal injury and stroke.

Breakdown in central motor control can be attenuated by motor practice and neuro-modulation of the primary motor cortex

The performance of a repetitive index finger flexion–extension task at maximal voluntary rate (MVR) begins to decline just a few seconds into the task and we have previously postulated that this breakdown has a central origin. To test this hypothesis, we have combined two objectives; to determine whether motor practice can lessen the performance deterioration in an MVR task, and whether further gains can be achieved with a transcranial magnetic stimulation (TMS) protocol that increases corticomotor excitability (CME). Eleven right-handed subjects participated in a randomized crossover study design that consisted of a 15-min interventional TMS at I-wave periodicity (ITMS) and single-pulsed Sham intervention prior to six 10-s practice sets of a repetitive finger flexion–extension task at MVR. Motor-evoked potentials (MEPs) were recorded from the first dorsal interosseous muscle. The starting movement rate, and the percentage decline in rate by the end of the MVR were quantitated. Training of the MVR task improved the sustainability of the task by reducing the decline in movement rate. CME increased steadily after each training bout, and this increase was maintained up to 20 min after the last bout. ITMS further increased CME, and was associated with an increase in both the starting rate of the MVR task and its sustainability, when compared to Sham. The results implicate central motor processes in the performance and sustainability of the MVR task, and indicate that MVR kinematics can improve with short-term training and with non-invasive neuro-modulation.

Altered response of the anterolateral abdominal muscles to simulated weight-bearing in subjects with low back pain

An important aspect of neuromuscular control at the lumbo-pelvic region is stabilization. Subjects with low back pain (LBP) have been shown to exhibit impairments in motor control of key muscles which contribute to stabilization of the lumbo-pelvic region. However, a test of automatic recruitment that relates to function has been lacking. A previous study used ultrasound imaging to show that healthy subjects automatically recruited the transversus abdominis (TrA) and internal oblique (IO) muscles in response to a simulated weight-bearing task. This task has not been investigated in subjects with LBP. The aim of this study was to compare the automatic recruitment of the abdominal muscles among subjects with and without LBP in response to the simulated weight-bearing task. Twenty subjects with and without LBP were tested. Real-time ultrasound imaging was used to assess changes in thickness of the TrA and internal oblique IO muscles as well as lateral movement ("slide") of the anterior fascial insertion of the TrA muscle. Results showed that subjects with LBP showed significantly less shortening of the TrA muscle (P < 0.0001) and greater increases in thickness of the IO muscle (P = 0.002) with the simulated weight-bearing task. There was no significant difference between groups for changes in TrA muscle thickness (P = 0.055). This study provides evidence of changes in motor control of the abdominal muscles in subjects with LBP. This test may provide a functionally relevant and non-invasive method to investigate the automatic recruitment of the abdominal muscles in people with and without LBP.

An experimental examination of interindividual variation in feather corticosterone content in the House Sparrow, Passer domesticus in southeast Australia

Non-invasive techniques for measuring glucocorticoids (GCs) have become more prevalent, due to the advantage of eliminating the effects of animal disturbance on GC levels and their potential to provide an integrated, historic estimate of circulating GC levels. In the case of birds, corticosterone (CORT) is deposited in feathers, and may reflect a bird's GC status over the period of feather synthesis. This technique thus permits a retrospective view of the average circulating GC levels during the moult period. While it is generally assumed that differences in feather CORT content (CORTf) between individuals reflects their different stress histories during either natural or induced moult, it is not clear how much of this variation is due to extrinsic versus intrinsic factors. We examined this question by determining CORTf in free-living house sparrows (Passer domesticus) from two populations, one urban and the other rural, that were plucked before and after exposure to different plasma CORT levels while held captive. We experimentally manipulated plasma CORT by implanting birds with either a corticosterone-filled, metyrapone-filled, or empty ('sham') silastic capsule as replacement feathers first emerged. The pattern of post-treatment CORTf was consistent with our expectations, based on plasma CORT levels of an experimentally implanted reference group. However, there was no statistically significant difference in CORTf between these treatment groups unless sex, population origin, and CORTf of original feathers for each individual were included in a model. Thus, birds with higher CORTf in feathers removed for this experiment tended to have higher CORTf in post-treatment replacement feathers, irrespective of treatment. In addition, we found that feather fault bar scores were significantly higher in CORT-treated birds than in the other two treatment groups, but did not vary directly with CORTf level. Our study therefore broadly confirms the use of feathers as a non-invasive tool to estimate plasma CORT during moult in birds, but importantly demonstrates the potential for intrinsic differences in stress characteristics between populations and individuals to obscure the effects extrinsic stressors might have on CORTf .