The buy-write strategy, index investment and the efficient market hypothesis: more Australian evidence

The purpose of this study is to examine the performance of an index buy-write strategy in the using three portfolios based on the Whaley (2002) approach; one for a portfolio of bank bills, one for a benchmark index and the third for a benchmark index hedged by index call options. The study uses Australian daily data between 1991 and 2006 and confirms that the buy-write strategy outperforms the index-only portfolio on both a risk and return basis. In addition, the strategy is seen to produce abnormal returns and therefore provides further evidence that appears to violate the efficient market hypothesis

An electrophysiological signal that precisely tracks the emergence of error awareness

Recent electrophysiological research has sought to elucidate the neural mechanisms necessary for the conscious awareness of action errors. Much of this work has focused on the error positivity (Pe), a neural signal that is specifically elicited by errors that have been consciously perceived. While awareness appears to be an essential prerequisite for eliciting the Pe, the precise functional role of this component has not been identified. Twenty-nine participants performed a novel variant of the Go/No-go Error Awareness Task (EAT) in which awareness of commission errors was indicated via a separate speeded manual response. Independent component analysis (ICA) was used to isolate the Pe from other stimulus- and response-evoked signals. Single-trial analysis revealed that Pe peak latency was highly correlated with the latency at which awareness was indicated. Furthermore, the Pe was more closely related to the timing of awareness than it was to the initial erroneous response. This finding was confirmed in a separate study which derived IC weights from a control condition in which no indication of awareness was required, thus ruling out motor confounds. A receiver-operating-characteristic (ROC) curve analysis showed that the Pe could reliably predict whether an error would be consciously perceived up to 400 ms before the average awareness response. Finally, Pe latency and amplitude were found to be significantly correlated with overall error awareness levels between subjects. Our data show for the first time that the temporal dynamics of the Pe trace the emergence of error awareness. These findings have important implications for interpreting the results of clinical EEG studies of error processing

Gene expression correlates of social evolution in coral reef butterflyfishes

Animals display remarkable variation in social behaviour. However, outside of rodents, little is known about the neural mechanisms of social variation, and whether they are shared across species and sexes, limiting our understand- ing of how sociality evolves. Using coral reef butterflyfishes, we examined gene expression correlates of social variation (i.e. pair bonding versus solitary living) within and between species and sexes. In several brain regions, we quantified gene expression of receptors important for social variation in mammals: oxytocin (OTR), arginine vasopressin (V1aR), dopamine (D1R, D2R) and mu-opioid (MOR). We found that social variation across individuals of the oval butterflyfish, Chaetodon lunulatus, is linked to differences in OTR, V1aR, D1R, D2R and MOR gene expression within several forebrain regions in a sexually dimorphic manner. However, this contrasted with social variation among six species representing a single evolutionary transition from pair- bonded to solitary living. Here, OTR expression within the supracommissural part of the ventral telencephalon was higher in pair-bonded than solitary species, specifically in males. These results contribute to the emerging idea that nonapeptide, dopamine and opioid signalling is a central theme to the evolution of sociality across individuals, although the precise mechanism may be flexible across sexes and species

Assessing mangrove restoration practices using species‐interaction networks

Mangroves are uniquely important ecosystems, for preserving biodiversity, sustaining livelihoods and mitigating against climate change. However they are degraded globally and are therefore a priority for ecosystem restoration. To date, the assessment of mangrove restoration outcomes is generally poor, and the limited studies that do exist are focussed largely on forest area. Thus, more holistic ways of assessing the outcomes of mangrove restoration projects on biodiversity and associated ecological processes are urgently needed. Ecological networks are a useful tool for simultaneously examining both. Here, we assessed the utility of using species-interaction networks for evaluating mangrove restoration outcomes for the first time. We compared the structure and complexity of mangrove ecological networks in replicated ‘Monoculture Reforestation’, ‘Mixed Species Regeneration’ and ‘Reference Forest’ plots in two study areas in Sulawesi, Indonesia, an estuarine and a coastal fringe mangrove system. We also combined and evaluated sampling methods, utilising traditional plant-animal sampling while also integrating video recording data in a novel way. We found significant differences in the structure and complexity of mangrove networks between restored and natural plots, with contrasting effects between the two sites. Our results show differences in the complex ways in which taxa interact in mangrove restoration projects, which would be overlooked if common biodiversity metrics such as species-richness were used alone, with consequences for the restoration of ecosystem functioning. We also highlight the utility of video recording data collection for constructing species interaction networks, overcoming the detrimental impacts of observer presence for some key species

Point of (no) return? Vegetation structure and diversity of restored mangroves in Sulawesi, Indonesia, 14–16 years on

Mangrove forests, benefitting millions of people, experience significant degradation. Global recognition of the urgency of halting and reversing this trend have initiated numerous restoration activities. Restoration success is typically evaluated by estimating mangrove survival and area restored, while diversity and structure of vegetation, as proxies for functional forests, are rarely considered. Here we assess mangrove species richness along sea-landward transects and evaluate restoration outcomes by comparing number of mangrove species, relative species abundance, biomass, diameter, and canopy cover in “Monoculture Reforestation”, “Mixed Species Regeneration” and adjacent “Reference” forest stands, 14 (Tiwoho site) and 16 years (Likupang site) after restoration activities took place. In the “Monoculture Reforestation” plots, mangrove diversity and structure still closely reflected the original restoration actions, with only one and two “new” species having established among the originally densely planted “foundation” species. In contrast, the “Mixed Species Regeneration” plots were more similar to the “Reference” plots in terms of tree diameter and canopy coverage, but species number, abundance and biomass were still lower. The trajectory of the “Mixed Species Regeneration” plots suggests their similarity with the “Reference” stands will increase over time, whereas such “smooth” transition is unlikely to happen in the planted “Monoculture Reforestation” stands, in the foreseeable future. Implementing frequent small-scale disturbances in restored forest management would increase stand structure and diversity, accelerating the establishment of a more natural, and likely more functional and resilient forest

Aspirin compared to enoxaparin or rivaroxaban for thromboprophylaxis following hip and knee replacement.

Background:The risk of venous thromboembolism following major orthopaedic surgery is among the highest for all surgical specialties. Our hospital guidelines for thromboprophylaxis following elective primary total hip or knee replacement are based on American College of Chest Physicians guidance. The most recent change to local guidelines was the introduction of the extended aspirin regimen as standard thromboprophylaxis. Objective: To establish the appropriateness of this regimen by comparing venous thromboembolism rates in patients receiving extended aspirin to previous regimens. Setting The largest dedicated orthopaedic hospital in Ireland. Methods: This was a retrospective cohort study. Data were collected from patient record software. All eligible patients undergoing primary total hip or knee replacement between 1st January 2010 and 30th June 2016 were included. Main outcome measure Venous thromboembolism up to 6 months post-operatively. Results Of the 6548 participants (55.3% female, mean age 65.4 years (± 11.8 years, 55.8% underwent total hip replacement), venous thromboembolism occurred in 65 (0.99%). Venous thromboembolism rate in both the inpatient enoxaparin group (n = 961) and extended aspirin group (n = 3460) was 1.04% and was 0.66% in the modified rivaroxaban group (n = 1212). Non-inferiority analysis showed the extended aspirin regimen to be equivalent to the modified rivaroxaban regimen. History of venous thromboembolism was the only significant demographic risk factor for post-operative venous thromboembolism (0.87% vs. 3.54%, p  = 0.0002). Conclusion: In daily clinical practice, extended aspirin regimen is at least as effective as modified rivaroxaban for preventing clinically important venous thromboembolism among patients undergoing hip or knee arthroplasty who are discharged from the hospital without complications. Aspirin can be considered a safe and effective agent in the prevention of venous thromboembolism after total hip or total knee replacement

“Teach to Goal”: Theory and Design Principles of an Intervention to Improve Heart Failure Self-Management Skills of Patients with Low Health Literacy

Self-management is vital for achieving optimal health outcomes for patients with heart failure (HF). We sought to develop an intervention to improve self-management skills and behaviors for patients with HF, especially those with low health literacy. Individuals with low health literacy have difficulty reading and understanding written information and comprehending numerical information and performing calculations, and they tend to have worse baseline knowledge, short-term memory, and working memory compared to individuals with higher health literacy. This paper describes theoretical models that suggest methods to improve the design of educational curricula and programs for low literate audiences, including cognitive load theory and learning mastery theory. We also outline the practical guiding principles for designing our intervention, which includes a multi-session educational strategy that teaches patients self-care skills until they reach behavioral goals (“Teach to Goal”). Ourintervention strategy is being tested in a randomized controlled trial to determine if it is superior to a single-session brief educational intervention for reducing hospitalization and death. If this trial shows that the “Teach to Goal” approach is superior, this would support the value of incorporating these design principles into educational interventions for other diseases

The role of microRNA-155/liver X receptor pathway in experimental and idiopathic pulmonary fibrosis

Background: Idiopathic Pulmonary Fibrosis (IPF) is progressive and rapidly fatal. Improved understanding of pathogenesis is required to prosper novel therapeutics. Epigenetic changes contribute to IPF therefore microRNAs may reveal novel pathogenic pathways. Objectives: To determine the regulatory role of microRNA(miR)-155 in the pro-fibrotic function of murine lung macrophages and fibroblasts, IPF lung fibroblasts and its contribution to experimental pulmonary fibrosis. Methods: Bleomycin-induced lung fibrosis in wild-type and miR-155-/- mice was analyzed by histology, collagen and pro-fibrotic gene expression. Mechanisms were identified by in silico and molecular approaches; validated in mouse lung fibroblasts and macrophages, and in IPF lung fibroblasts, using loss-and-gain of function assays, and in vivo using specific inhibitors. Results: miR-155-/- mice developed exacerbated lung fibrosis, increased collagen deposition, collagen 1 and 3 mRNA expression, TGFβ production, and activation of alternatively-activated macrophages, contributed by deregulation of the microRNA-155 target gene the liver X receptor (LXR)α in lung fibroblasts and macrophages. Inhibition of LXRα in experimental lung fibrosis and in IPF lung fibroblasts reduced the exacerbated fibrotic response. Similarly, enforced expression of miR-155 reduced the pro-fibrotic phenotype of IPF and miR-155-/- fibroblasts. Conclusion: We describe herein a molecular pathway comprising miR-155 and its epigenetic LXRα target that when deregulated enables pathogenic pulmonary fibrosis. Manipulation of the miR-155/LXR pathway may have therapeutic potential for IPF

Populációk térbeli fenotípusos és neutrális genetikai változatosságának vizsgálata óceáni szigeteken és szárazföldön

Az élőhelyek fragmentációjának, végsőképpen elszigetelődésének globális méreteire tekintettel szükségessé vált olyan prediktív ökológiai modellek kidolgozása, amelyek időben előre jelezhetik az izolációval járó kockázatokat. Ehhez mindenek előtt az elszigetelődés fogalmának tisztázása szükséges. Az óceáni szigetvilágra kidolgozott szigetjelenség aspektusai (egyensúlyi dinamika, izolált populációkat érintő új ökológiai-evolúciós nyomások) a szárazföldön is azonosíthatók. Azonban a szárazföldi populációk közötti génáramlást gyakran megkönnyíti az élőhelyek térbeli és időbeli érintkezése, mely esetben a térbeli variabilitás fő várható oka a földrajzi távolság általi elszigetelődés. Az óceáni szigetek és szárazföldi populációk térbeli változatosságának összehasonlítása tágabb fogalmi keretet nyújthat a földrajzi elszigetelődés mechanizmusainak vizsgálatára. Ugyanakkor a populációk térbeli változatosságát kiváltó okok nem mindig földrajzi jellegűek, hiszen gyakran még a szigetvilág egyediségét is az ökológiai, és nem a földrajzi távolság határozza meg. Tanulmányunkban megvizsgáltuk a földrajzi és ökológiai távolság hatását a növény- és állatpopulációk térbeli fenotípusos és neutrális genetikai változatosságára, összehasonlításban óceáni szigeteken és a szárazföldön. A vizsgálathoz 129 olyan publikáció adatait digitalizáltuk, amely egyazon faj legalább két-két populációját tanulmányozta szigeteken, illetve a szárazföldön (összesen 1193 szigeti és 1021 szárazföldi populáció 13037 adatát használva fel). A Bayes-i inferenciára épülő modellekben a függő változó a populáció-párok arányának logaritmusa volt, a fix hatás a földrajzi helyzet (sziget vagy szárazföld), földrajzi távolság, ökológiai (klimatikus) távolság és a taxonómiai besorolás (növény vagy állat), a random hatás a tanulmány, faj, filogenetika, taxonómiai csoportok voltak. A genetikai modellek heterozigótaság, lókuszonkénti allélszám, genetikai polimorfizmus, genotípus változatosság stb. értékeket, míg a tágabb értelemben vett fenotípusokra vonatkozó modellek jellegeket (méret, súly), életmenet-összetevőket (túlélés, szaporodás), fiziológiai stb. méréseket foglaltak össze. A genetikai sokféleséget nem befolyásolta jelentősen a populációk földrajzi és ökológiai távolsága, földrajzi helyzete vagy taxonómiai besorolása, habár a földrajzi távolság valamivel gyakrabban növelte a populációk közötti különbségeket. A szigeteken már minimális földrajzi távolság mellett is magas volt a populációk térbeli fenotípusos variabilitása (jóval magasabb, mint a szárazföldön), míg a szárazföldi populációk között csupán a földrajzi távolság növekedése emelte némileg a különbségeket. Tehát az óceáni szigeteken erőteljesebben megmutatkozott, hogy a fenotípusos variabilitás és a neutrális genetikai diverzitás eltérő folyamatok eredménye. A szigeteken a neutrális genetikai diverzitási mintázatoknál kifejezettebb volt a fenotípusok változatossága, jelezve a szigetek kapcsán jól ismert erőteljes evolúciós folyamatokat. Eközben a szárazföldi populációk valószínűleg kedvezőbb térbeli és időbeli kapcsolatai a fenotípusos változatosságot alacsonyabb szinten tartották. Összefoglalásként elmondható, hogy a populációk térbeli fenotípusos variabilitása elsősorban az élőhely-rendszerek alacsony átjárhatóságának köszönhető, míg a neutrális genetikai diverzitási mintázatokra a földrajzi, és különösen a klimatikus távolság lassabban vagy ritkábban fejti ki a hatását