Prospective progression from high-prevalence disorders to bipolar disorder: exploring characteristics of pre-illness stages

BACKGROUND: Identification of risk factors within precursor syndromes, such as depression, anxiety or substance use disorders (SUD), might help to pinpoint high-risk stages where preventive interventions for Bipolar Disorder (BD) could be evaluated.

METHODS: We examined baseline demographic, clinical, quality of life, and temperament measures along with risk clusters among 52 young people seeking help for depression, anxiety or SUDs without psychosis or BD. The risk clusters included Bipolar At-Risk (BAR) and the Bipolarity Index as measures of bipolarity and the Ultra-High Risk assessment for psychosis. The participants were followed up for 12 months to identify conversion to BD. Those who converted and did not convert to BD were compared using Chi-Square and Mann Whitney U tests.

RESULTS: The sample was predominantly female (85%) and a majority had prior treatment (64%). Four participants converted to BD over the 1-year follow up period. Having an alcohol use disorder at baseline (75% vs 8%, χ(2)=14.1, p<0.001) or a family history of SUD (67% vs 12.5%, χ(2)=6.0, p=0.01) were associated with development of BD. The sub-threshold mania subgroup of BAR criteria was also associated with 12-month BD outcomes. The severity of depressive symptoms and cannabis use had high effects sizes of association with BD outcomes, without statistical significance.

CONCLUSIONS AND LIMITATIONS: The small number of conversions limited the power of the study to identify associations with risk factors that have previously been reported to predict BD. However, subthreshold affective symptoms and SUDs might predict the onset of BD among help-seeking young people with high-prevalence disorders.

Instruments that prospectively predict bipolar disorder - a systematic review

BACKGROUND: Identification of earlier stages of Bipolar Disorder (BD), even prior to the first manic episode, may help develop interventions to prevent or delay the onset of BD. However, reliable and valid instruments are necessary to ascertain such earlier stages of BD. The aim of the current review was to identify instruments that had predictive validity and utility for BD for use in early intervention (EI) settings for the prevention of BD. METHODS: We undertook a systematic examination of studies that examined participants without BD I or II at baseline and prospectively explored the predictive abilities of instruments for BD onset over a period of 6 months or more. The instruments and the studies were rated with respect to their relative validity and utility predicting onset of BD for prevention or early intervention. Odds ratios and area under the curve (AUC) values were derived when not reported. RESULTS: Six studies were included, identifying five instruments that examined sub-threshold symptoms, family history, temperament and behavioral regulation. Though none of the identified instruments had been examined in high-quality replicated studies for predicting BD, two instruments, namely the Child Behavioral Checklist - Pediatric BD phenotype (CBCL-PBD) and the General Behavioral Inventory - Revised (GBI-R), had greater levels of validity and utility. LIMITATION: Non-inclusion of studies and instruments that incidentally identified BD on follow-up limited the breadth of the review. CONCLUSION: Instruments that test domains such as subthreshold symptoms, behavioral regulation, family history, and temperament hold promise in predicting BD onset.

Muscle strength and areal bone mineral density at the hip in women: a cross-sectional study

BACKGROUND: Muscle strengthening exercises are promoted for building and maintaining a healthy skeleton. We aimed to investigate the relationship between muscle strength and areal bone mineral density (BMD) at the hip in women aged 26-97 years.

METHODS: This cross-sectional study utilises data from 863 women assessed for the Geelong Osteoporosis Study. Measures of hip flexor and abductor strength were made using a hand-held dynamometer (Nicholas Manual Muscle Tester). The maximal measure from three trials on each leg was used for analyses. BMD was measured at the hip using dual energy x-ray absorptiometry (DXA; Lunar DPX-L). Total lean mass, body fat mass and appendicular lean mass were determined from whole body DXA scans. Linear regression techniques were used with muscle strength as the independent variable and BMD as the dependent variable. Models were adjusted for age and indices of body composition.

RESULTS: Measures of age-adjusted hip flexor strength and hip abductor strength were positively associated with total hip BMD. For each standard deviation (SD) increase in hip flexor strength, the increase in mean total hip BMD (SD) was 10.4 % (p = 0.009). A similar pattern was observed for hip abductor strength, with an increase in mean total hip BMD of 22.8 % (p = 0.025). All associations between hip muscle strength and total hip BMD were independent of height, but were nullified after adjusting for appendicular lean mass or total lean mass.

CONCLUSIONS: There was a positive association observed between muscle strength and BMD at the hip. However, this association was explained by measures of lean mass.

Examining performance of aggregation algorithms for neural network-based electricity demand forecasting

The aim of this research is to examine the efficiency of different aggregation algorithms to the forecasts obtained from individual neural network (NN) models in an ensemble. In this study an ensemble of 100 NN models are constructed with a heterogeneous architecture. The outputs from NN models are combined by three different aggregation algorithms. These aggregation algorithms comprise of a simple average, trimmed mean, and a Bayesian model averaging. These methods are utilized with certain modifications and are employed on the forecasts obtained from all individual NN models. The output of the aggregation algorithms is analyzed and compared with the individual NN models used in NN ensemble and with a Naive approach. Thirty-minutes interval electricity demand data from Australian Energy Market Operator (AEMO) and the New York Independent System Operator's web site (NYISO) are used in the empirical analysis. It is observed that the aggregation algorithm perform better than many of the individual NN models. In comparison with the Naive approach, the aggregation algorithms exhibit somewhat better forecasting performance.

Symptoms of PTSD associated with painful and nonpainful vicarious reactivity following amputation

Although the experience of vicarious sensations when observing another in pain have been described postamputation, the underlying mechanisms are unknown. We investigated whether vicarious sensations are related to posttraumatic stress disorder (PTSD) symptoms and chronic pain. In Study 1, 236 amputees completed questionnaires about phantom limb phenomena and vicarious sensations to both innocuous and painful sensory experiences of others. There was a 10.2% incidence of vicarious sensations, which was significantly more prevalent in amputees reporting PTSD-like experiences, particularly increased arousal and reexperiencing the event that led to amputation (φ = .16). In Study 2, 63 amputees completed the Empathy for Pain Scale and PTSD Checklist-Civilian Version. Cluster analyses revealed 3 groups: 1 group did not experience vicarious pain or PTSD symptoms, and 2 groups were vicarious pain responders, but only 1 had increased PTSD symptoms. Only the latter group showed increased chronic pain severity compared with the nonresponder group (p = .025) with a moderate effect size (r = .35). The findings from both studies implicated an overlap, but also divergence, between PTSD symptoms and vicarious pain reactivity postamputation. Maladaptive mechanisms implicated in severe chronic pain and physical reactivity posttrauma may increase the incidence of vicarious reactivity to the pain of others.

Resistive vibration exercise reduces lower limb muscle atrophy during 56-day bed-rest

OBJECTIVES: The current study aimed to examine the effectiveness of a resistive vibration exercise countermeasure during prolonged bed-rest in preventing lower-limb muscle atrophy. METHODS: 20 male subjects underwent 56-days of bed-rest and were assigned to either an inactive control, or a countermeasure group which performed high-load resistive exercises (including squats, heel raises and toe raises) with whole-body vibration. Magnetic resonance imaging of the lower-limbs was performed at two-weekly intervals. Volume of individual muscles was calculated. RESULTS: Countermeasure exercise reduced atrophy in the triceps surae and the vastii muscles (F>3.0, p<.025). Atrophy of the peroneals, tibialis posterior and toe flexors was less in the countermeasure-subjects, though statistical evidence for this was weak (F

Hypertrophy in the cervical muscles and thoracic discs in bed rest?

The impact of prolonged bed rest on the cervical and upper thoracic spine is unknown. In the 2nd Berlin BedRest Study (BBR2-2), 24 male subjects underwent 60-day bed rest and performed either no exercise, resistive exercise, or resistive exercise with whole body vibration. Subjects were followed for 2 yr after bed rest. On axial cervical magnetic resonance images from the skull to T3, the volumes of the semispinalis capitis, splenius capitis, spinalis cervicis, longus capitis, longus colli, levator scapulae, sternocleidomastoid, middle and posterior scalenes, and anterior scalenes were measured. Disc height, anteroposterior width, and volume were measured from C2/3 to T6/7 on sagittal images. The volume of all muscles, with the exception of semispinalis capitis, increased during bed rest (P < 0.025). There were no significant differences between the groups for changes in the muscles. Increased upper and midthoracic spine disc height and volume (P < 0.001) was seen during bed rest, and disc height increases persisted at least 6 mo after bed rest. Increases in thoracic disc height were greater (P = 0.003) in the resistive vibration exercise group than in control. On radiological review, two subjects showed new injuries to the mid-lower thoracic spine. One of these subjects reported a midthoracic pain incident during maximal strength testing before bed rest and the other after countermeasure exercise on day 3 of bed rest. We conclude that bed rest is associated with increased disc size in the thoracic region and increases in muscle volume at the neck. The exercise device needs to be modified to ensure that load is distributed in a more physiological fashion.

Rapid domino [3+2] cycloaddition, [4+2] cycloreversion, ring-opening and aromatisation of a fused oxanorbornane substrate

Heating a dioxa-bridged diene with a cyclobutane epoxide for 10 min under microwave conditions (150 °C) gave an unexpected aryloxanorbornane product (20%). This adduct is proposed to occur via a [3+2] dipolar cycloaddition, retro-Diels-Alder reaction, ring-opening and subsequent aromatisation.

New insights into ordering and dynamics in organic ionic plastic crystal electrolytes

Solid state phases of organic salts, whose chemistry is closely related to that of ionic liquids, often show interesting phase behavior and dynamics resulting in solid-state conductors that have potential application in electrochemical devices such as solid state batteries. The mechanism of conduction in these solid-state plastic crystal phases is still not entirely understood. We have recently shown using molecular dynamics (MD) simulations that the introduction of defects, such as vacancies, leads to heterogeneous dynamics in the OIPC arising from amorphous and mobile domains in these materials. Advanced magnetic resonance imaging (MRI) analysis indicates that these domains can exhibit distinct orientations, leading to anisotropic ionic conductivity with enhanced values in a particular direction. This paper will review this new understanding, drawing links between the molecular and macroscopic-level information provided by these two techniques.

Taking the LEAP with the Oculus HMD and CAD - plucking at thin air?

Achieving adequate visualisation of designs within CAD packages remains a challenge for designers with current methods of 3D CAD visualisation requiring either a high level of technical ability, or expensive hardware and software. The recent re-emergence of consumer VR has lowered the barrier for everyday developers wanting to visualise their designs in true 3D. This paper presents the CAD Interaction Lab (CIL) which employs the Oculus Rift Head Mounted Display (HMD) and Leap Motion Controller (LMC) to provide a low cost method enabling users to use their hands to dissect a mechanic model to manipulate and inspect individual components in realistic 3D. Qualitative observations of user interactions with the CIL show that users were able to intuitively manipulate the CAD model using natural hand movements with only minimal instruction.

Human threats to sandy beaches: a meta-analysis of ghost crabs illustrates global anthropogenic impacts

Beach and coastal dune systems are increasingly subjected to a broad range of anthropogenic pressures that on many shorelines require significant conservation and mitigation interventions. But these interventions require reliable data on the severity and frequency of adverse ecological impacts. Such evidence is often obtained by measuring the response of 'indicator species'.Ghost crabs are the largest invertebrates inhabiting tropical and subtropical sandy shores and are frequently used to assess human impacts on ocean beaches. Here we present the first global meta-analysis of these impacts, and analyse the design properties and metrics of studies using ghost-crabs in their assessment. This was complemented by a gap analysis to identify thematic areas of anthropogenic pressures on sandy beach ecosystems that are under-represented in the published literature.Our meta-analysis demonstrates a broad geographic reach, encompassing studies on shores of the Pacific, Indian, and Atlantic Oceans, as well as the South China Sea. It also reveals what are, arguably, two major limitations: i) the near-universal use of proxies (i.e. burrow counts to estimate abundance) at the cost of directly measuring biological traits and bio-markers in the organism itself; and ii) descriptive or correlative study designs that rarely extend beyond a simple 'compare and contrast approach', and hence fail to identify the mechanistic cause(s) of observed contrasts.Evidence for a historically narrow range of assessed pressures (i.e., chiefly urbanisation, vehicles, beach nourishment, and recreation) is juxtaposed with rich opportunities for the broader integration of ghost crabs as a model taxon in studies of disturbance and impact assessments on ocean beaches. Tangible advances will most likely occur where ghost crabs provide foci for experiments that test specific hypotheses associated with effects of chemical, light and acoustic pollution, as well as the consequences of climate change (e.g. species range shifts).