Long-term outcomes following Medtronic Open Pivot valved conduit

Aortic root replacement is a complex procedure, though subsequent modifications of the original Bentall procedure have made surgery more reproducible. The study aim was to examine the outcomes of a modified Bentall procedure, using the Medtronic Open PivotTM valved conduit. Whilst short-term data on the conduit and long-term data on the valve itself are available, little is known of the long-term results with the valved conduit. Patients undergoing aortic root replacement between February 1999 and February 2010, using the Medtronic Open Pivot valved conduit were identified from the prospectively collected Cardiothoracic Register at The Prince Charles Hospital, Brisbane, Australia. All patients were followed up echocardiographically and clinically. The primary end-point was death, and a Cox proportional model was used to identify factors associated.with survival. Secondary end-points were valve-related morbidity (as defined by STS guidelines) and postoperative morbidity. Predictors of morbidity were identified using logistic regression. A total of 246 patients (mean age 50 years) was included in the study. The overall mortality was 12%, with actuarial 10-year survival 79% and a 10-year estimate of valve-related death of 0.04 (95% CI: 0.004, 0.07). Preoperative myocardial infarction (p = 0.004, HR 4.74), urgency of operation (p = 0.038, HR 2.8) and 10% incremental decreases in ejection fraction (p = 0.046, HR 0.69) were predictive of mortality. Survival was also affected by the valve gradients, with a unit increase in peak gradient reducing mortality (p = 0.021, HR 0.93). Valve-related morbidity occurred in 11 patients. Urgent surgery (p <0.001, OR 4.12), aortic dissection (p = 0.015, OR 3.35), calcific aortic stenosis (p = 0.016, OR 2.35) and Marfan syndrome (p 0.009, OR 3.75) were predictive of postoperative morbidity. The reoperation rate was 1.2%. The Medtronic Open Pivot valved conduit is a safe and durable option for aortic root replacement, and is associated with low morbidity and 10-year survival of 79%. However, further studies are required to determine the effect of valve gradient on survival.

Effects of different surfaces on the perception of prey-generated noise by the Indian false vampire bat Megaderma lyra.

The low- and high-frequency components of a rustling sound, created when prey (freshly killed frog) was jerkily pulled on dry and wet sandy floors and asbestos, were recorded and played back to individual Indian false vampire bats (Megaderma lyra). Megaderma lyra responded with flight toward the speakers and captured dead frogs, that were kept as reward. The spectral peaks were at 8.6, 7.1 and 6.8 kHz for the low-frequency components of the sounds created at the dry, asbestos and wet floors, respectively. The spectral peaks for the high-frequency sounds created on the respective floors were at 36.8,27.2 and 23.3 kHz. The sound from the dry floor was more intense than that of from the other two substrata. Prey movements that generated sonic or ultrasonic sounds were both sufficient and necessary for the bats to detect and capture prey. The number of successful prey captures was significantly greater for the dry floor sound, especially to its high-frequency components. Bat-responses were low to the wet floor and moderate to the asbestos floor sounds. The bats did not respond to the sound of unrecorded parts of the tape. Even though the bats flew toward the speakers when the prey generated sounds were played back and captured the dead frogs we cannot rule out the possibility of M. lyra using echolocation to localize prey. However, the study indicates that prey that move on dry sandy floor are more vulnerable to predation by M. lyra.

Retinal tissue thickness is reduced in diabetic peripheral neuropathy

Aim Retinal tissue integrity in relation to diabetic neuropathy is not known. The aim of this study was to investigate retinal tissue thickness in relation to diabetic peripheral neuropathy (DPN) with and without diabetic retinopathy (DR). Methods Full retinal thickness at the parafoveal and perifoveal macula and neuro-retinal thickness around the optic nerve head (ONH) and at the macula was examined using spectral domain optical coherence tomography. The eye on the hand-dominant side of 85 individuals with type 1 diabetes and 66 individuals with type 2 diabetes, with or without DR and DPN, were compared to the eyes (n=45) of age-matched non-diabetic controls. Diabetic neuropathy was defined as Neuropathy Disability Score (NDS) ≥3 on a scale of 0-10. A general linear model was used to examine the relationship between diabetic neuropathy and foveal, parafoveal and perifoveal retinal thickness and neuro-retinal thickness, in relation to DR status, age, gender, HbA1c levels and duration of diabetes. A p-value of <0.05 was considered statistically significant. Results Perifoveal retinal thickness is reduced with increasing severity of neuropathy, especially in the inferior hemisphere (p=0.004); this effect was not related to age (p=0.088). For every unit increase in NDS score, the inferior perifoveal retinal thickness reduced by 1.64 μm. Neuro-retinal thickness around the ONH decreased with increasing severity of neuropathy (p<0.014 for average and hemisphere thicknesses); for every unit increase in NDS, neuro-retinal thickness around the ONH reduced by 1.23 μm. Retinal thickness in the parafovea was increased in the absence of DR (p<0.017 for average and hemisphere thicknesses). Neuro-retinal thickness at the macula was inversely related to age alone (p<0.001). All retinal parameters, except the inferior perifovea, reduced with advancing age (p<0.007 for all). Conclusions Diabetic neuropathy is associated with changes in full retinal thickness and neuro-retinal layers. This may represent a second threat to vision integrity, in addition to the better-characterised retinopathy. This study provides new knowledge about the anatomical aspects of the retinal tissue in relation to neuropathy and retinopathy.

Pathogenesis of Fallopian tube damage caused by Chlamydia trachomatis infections

Chlamydia trachomatis is the leading cause of bacterial sexually transmitted disease worldwide resulting in 4–5 million new cases of Chlamydia annually and an estimated 100 million cases per annum. Infections of the lower female genital tract (FGT) frequently are asymptomatic so they often remain undiagnosed or untreated. If infections are either not resolved, or are left untreated, chlamydia can ascend to the upper FGT and infect the fallopian tubes (FTs) causing salpingitis that may lead to functional damage of the FTs and tubal factor infertility (TFI). Clinical observations and experimental data have indicated a role for antibodies against C. trachomatis proteins such as the 60 kDa heat-shock protein 60 (cHSP60) in the immunopathogenesis of TFI. When released from infected cells cHSP60 can induce pro-inflammatory immune responses that may functionally impair the FTs leading to fibrosis and luminal occlusion. Chlamydial pathogenesis of irreversible and permanent tubal damage is a consequence of innate and adaptive host immune responses to ongoing or repeated infections. The extracellular matrix (ECM) that is regulated by metalloproteinases (MMPs) may also be modified by chlamydial infections of the FGT. This review will highlight protective and pathogenic immune responses to ongoing and repeated chlamydial infections of the FGT. It will also present two recent hypotheses to explain mechanisms that may contribute to FT damage during a C. trachomatis infection. If Chlamydia immunopathology can be controlled it might yield a method of inducing fibrosis and thus provide a means of non-surgical permanent contraception for women.

Method of symptom assessment influences cognitive, affective and somatic post-concussion-like symptom base rates

Primary objective: To investigate whether assessment method influences the type of post-concussion-like symptoms. Methods and procedures: Participants were 73 Australian undergraduate students (Mage = 24.14, SD = 8.84; 75.3% female) with no history of mild traumatic brain injury (mTBI). Participants reported symptoms experienced over the previous 2 weeks in response to an open-ended question (free report), mock interview and standardized checklist (British Columbia Post-concussion Symptom Inventory; BC-PSI). Main outcomes and results: In the free report and checklist conditions, cognitive symptoms were reported significantly less frequently than affective (free report: p < 0.001; checklist: p < 0.001) or somatic symptoms (free report: p < 0.001; checklist: p = 0.004). However, in the mock structured interview condition, cognitive and somatic symptoms were reported significantly less frequently than affective symptoms (both p < 0.001). No participants reported at least one symptom from all three domains when assessed by free report, whereas most participants did so when symptoms were assessed by a mock structured interview (75%) or checklist (90%). Conclusions: Previous studies have shown that the method used to assess symptoms affects the number reported. This study shows that the assessment method also affects the type of reported symptoms.

The effectiveness of psychosocial interventions for cognitive dysfunction in cancer patients who have received chemotherapy : a systematic review

Background: Chemotherapy-related cognitive dysfunction (CRCD) refers to problems with memory,attention span, or concentration, experienced by patients with cancer who have had chemotherapy. CRCD can have a significant negative effect on a patient’s quality of life. The exact cause of CRCD is unknown but is presumed to be multifactorial. Objective: To conduct a systematic review of the effectiveness of psychosocial interventions designed to treat CRCD. Methods: Participants of interest to the review were over 18 years of age, diagnosed with cancer, and receiving chemotherapy or had received chemotherapy in the past. Interventions of interest were methods to improve cognitive function. Included study designs were randomized controlled trials, quasi-experimental trials, and quantitative observational studies. The primary outcome of interest was level of cognitive function. A three-step search strategy was utilized to identify studies published from 1985 to 2011 from a wide range of databases. Joanna Briggs Institute systematic review methods were used but findings were analyzed using the Cochrane Collaboration Review Manager 5.1 program.Weightedmean differences with 95% confidence intervals were calculated from the continuous data. Results: Searching identified 3,109 potentially relevant articles and 120 full-text articles were retrieved. Two further papers were sourced from reference lists of retrieved articles. From 122 papers, six were suitable for critical appraisal and six were included in the analysis. Meta-analysis was conducted on two cognitive behavioral therapy (CBT) trials for the outcome of inability to concentrate. Significant effect was seen for one CBT intervention at 20 weeks (p = .004). Significant effect from CBT on quality of life was seen at 6-month follow-up (p < .05). Conclusions: Despite some evidence of an effect, there is insufficient evidence at this stage to strongly recommend any of the interventions to assist in decreasing the effects of CRCD, except in terms of improving quality of life.

Institutional investors, risk/performance and corporate governance

Modern portfolio theory suggests that investors minimize risk for a given level of expected return by carefully choosing the proportions of various assets. This study sets out to determine the role of the institutional investor in monitoring risk and firm performance. Using a sample of Australian firms from 2006 to 2008, our empirical study shows a positive association between firm-specific risk, risk-management policy, and performance for firms with increasing institutional shareholdings. The study also finds that the significance of this association depends on the institutional investor's ability to influence management, which in turn depends on the size of ownership and whether the investee firm does not have potential business dealings with the investor. We also find that when firms are financially distressed, institutional investors engage in promoting short-term performance or exit rather than support long-term value creation. The results are robust while controlling the potential for endogeneity and using sensitivity tests to control for variants of performance and risk. These findings add to the growing body of literature examining institutional ownership and the importance of understanding the role of risk-management in the risk and return relation.

Bioprocess engineering of microalgae to produce a variety of consumer products

Microalgae biotechnology has recently emerged into the lime light owing to numerous consumer products that can be harnessed from microalgae. Product portfolio stretches from straightforward biomass production for food and animal feed to valuable products extracted from microalgal biomass, including triglycerides which can be converted into biodiesel. For most of these applications, the production process is moderately economically viable and the market is developing. Considering the enormous biodiversity of microalgae and recent developments in genetic and metabolic engineering, this group of organisms represents one of the most promising sources for new products and applications. With the development of detailed culture and screening techniques, microalgal biotechnology can meet the high demands of food, energy and pharmaceutical industries. This review article discusses the technology and production platforms for development and creation of different valuable consumer products from microalgal biomass.

Associations between early shared music activities in the home and later child outcomes : findings from the Longitudinal Study of Australian Children

The benefits of early shared book reading between parents and children have long been established,yet the same cannot be said for early shared music activities in the home. This study investigated the parent–child home music activities in a sample of 3031 Australian children participating in Growing Up in Australia: The Longitudinal Study of Australian Children (LSAC) study. Frequency of shared home music activities was reported by parents when children were 2–3 years and a range of social, emotional,and cognitive outcomes were measured by parent and teacher report and direct testing two years later when children were 4–5 years old. A series of regression analyses (controlling for a set of important socio-demographic variables) found frequency of shared home music activities to have a small significant partial association with measures of children’s vocabulary, numeracy, attentional and emotional regulation, and prosocial skills. We then included both book reading and shared home music activities in the same models and found that frequency of shared home music activities maintained small partial associations with measures of prosocial skills, attentional regulation, and numeracy. Our findings suggest there may be a role for parent-child home music activities in supporting children’s development.

Bikeshare's impact on active travel: Evidence from the United States, Great Britain, and Australia

Over 800 cities globally now offer bikeshare programs. One of their purported benefits is increased physical activity. Implicit in this claim is that bikeshare replaces sedentary modes of transport, particularly car use. This paper estimates the median changes in physical activity levels as a result of bikeshare in the cities of Melbourne, Brisbane, Washington, D.C., London, and Minneapolis/St. Paul. This study is the first known multi-city evaluation of the active travel impacts of bikeshare programs. To perform the analysis, data on mode substitution (i.e. the modes that bikeshare replaces) were used to determine the extent of shift from sedentary to active transport modes (e.g. when a car trip is replaced by bikeshare). Potentially offsetting these gains, reductions in physical activity when walking trips are replaced by bikeshare was also estimated. Finally a Markov Chain Monte Carlo analysis was conducted to estimate confidence bounds on estimated impacts on active travel given uncertainties in data sources. The results indicate that on average 60% of bikeshare trips replace sedentary modes of transport (from 42% in Minneapolis/St. Paul to 67% in Brisbane). When bikeshare replaces a walking trip, there is a reduction in active travel time because walking a given distance takes longer than cycling. Considering the active travel balance sheet for the cities included in this analysis, bikeshare activity in 2012 has an overall positive impact on active travel time. This impact ranges from an additional 1.4 million minutes of active travel for the Minneapolis/St. Paul bikeshare program, to just over 74 million minutes of active travel for the London program The analytical approach adopted to estimate bikeshare’s impact on active travel may act as the basis for future bikeshare evaluations or feasibility studies.

Abatement of aqueous anionic contaminants by thermo-responsive nanocomposites: (Poly(N-isopropylacrylamide))-co-silylanized Magnesium/Aluminun layered double hydroxides

A series of novel thermo-responsive composite sorbents, were prepared by free-radical co-polymerization of N-isopropylacrylamide (NIPAm) and the silylanized Mg/Al layered double hydroxides (SiLDHs), named as PNIPAm-co-SiLDHs. For keeping the high affinity of Mg/Al layered double hydroxides towards anions, the layered structure of LDHs was assumed to be reserved in PNIPAm-co-SiLDHs by the silanization of the wet LDH plates as evidenced by the X-ray powder diffraction. The sorption capacity of PNIPAm-co-SiLDH (13.5 mg/g) for Orange-II from water was found to be seven times higher than that of PNIPAm (2.0 mg/g), and the sorption capacities of arsenate onto PNIPAm-co-SiLDH are also greater than that onto PNIPAm, for both As(III) and As(V). These sorption results suggest that reserved LDH structure played a significant role in enhancing the sorption capacities. NO3− intercalated LDHs composite showed the stronger sorption capacity for Orange-II than that of CO32−. After sorption, the PNIPAm-co-SiLDH may be removed from water because of its gel-like nature, and may be easily regenerated contributing to the accelerated desorption of anionic contaminants from PNIPAm-co-SiLDHs by the unique phase-transfer feature through slightly heating (to 40 °C). These recyclable and regeneratable properties of thermo-responsive nanocomposites facilitate its potential application in the in-situ remediation of organic and inorganic anions from contaminated water.

An exercise intervention during chemotherapy for women with recurrent ovarian cancer: A feasibility study

Objective: The aim of this study was to determine the feasibility of a combined supervised and home-based exercise intervention during chemotherapy for women with recurrent ovarian cancer. Secondary aims were to determine the impact of physical activity on physical and psychological outcomes and on chemotherapy completion rates. Methods: Women with recurrent ovarian cancer were recruited from 3 oncology outpatient clinics in Sydney and Canberra, Australia. All participants received an individualized exercise program that consisted of 90 minutes or more of low to moderate aerobic, resistance, core stability, and balance exercise per week, for 12 weeks. Feasibility was determined by recruitment rate, retention rate, intervention adherence, and adverse events. Aerobic capacity, muscular strength, fatigue, sleep quality, quality of life, depression, and chemotherapy completion rates were assessed at weeks 0, 12, and 24. Results: Thirty participants were recruited (recruitment rate, 63%), with a retention rate of 70%. Participants averaged 196 ± 138 min · wk of low to moderate physical activity throughout the intervention, with adherence to the program at 81%. There were no adverse events resulting from the exercise intervention. Participants who completed the study displayed significant improvements in quality of life (P = 0.017), fatigue (P = 0.004), mental health (P = 0.007), muscular strength (P = 0.001), and balance (P = 0.003) after the intervention. Participants completing the intervention had a higher relative dose intensity than noncompleters (P = 0.03). Conclusions: A program consisting of low to moderate exercise of 90 min · wk was achieved by two-thirds of women with recurrent ovarian cancer in this study, with no adverse events reported. Randomized control studies are required to confirm the benefits of exercise reported in this study.

Can counseling add value to an exercise intervention for improving quality of life in breast cancer survivors? A feasibility study

Background: Improved survivorship has led to increased recognition of the need to manage the side effects of cancer and its treatment. Exercise and psychological interventions benefit survivors; however, it is unknown if additional benefits can be gained by combining these two modalities. Objective: Our purpose was to examine the feasibility of delivering an exercise and counseling intervention to 43 breast cancer survivors, to determine if counseling can add value to an exercise intervention for improving quality of life (QOL) in terms of physical and psychological function. Methods: We compared exercise only (Ex), counseling only (C), exercise and counseling (ExC), and usual care (UsC) over an 8 week intervention. Results: In all, 93% of participants completed the interventions, with no adverse effects documented. There were significant improvements in VO2max as well as upper body and lower body strength in the ExC and Ex groups compared to the C and UsC groups (P < .05). Significant improvements on the Beck Depression Inventory were observed in the ExC and Ex groups, compared with UsC (P < .04), with significant reduction in fatigue for the ExC group, compared with UsC, and no significant differences in QOL change between groups, although the ExC group had significant clinical improvement. Limitations: Limitations included small subject number and study of only breast cancer survivors. Conclusions: These preliminary results suggest that a combined exercise and psychological counseling program is both feasible and acceptable for breast cancer survivors and may improve QOL more than would a single-entity intervention.

Sectionalizing strategies for minimizing outage durations of critical loads in parallel power system restoration with bi-level programming

Fast restoration of critical loads and non-black-start generators can significantly reduce the economic losses caused by power system blackouts. In a parallel power system restoration scenario, the sectionalization of restoration subsystems plays a very important role in determining the pickup of critical loads before synchronization. Most existing research mainly focuses on the startup of non-black-start generators. The restoration of critical loads, especially the loads with cold load characteristics, has not yet been addressed in optimizing the subsystem divisions. As a result, sectionalized restoration subsystems cannot achieve the best coordination between the pickup of loads and the ramping of generators. In order to generate sectionalizing strategies considering the pickup of critical loads in parallel power system restoration scenarios, an optimization model considering power system constraints, the characteristics of the cold load pickup and the features of generator startup is proposed in this paper. A bi-level programming approach is employed to solve the proposed sectionalizing model. In the upper level the optimal sectionalizing problem for the restoration subsystems is addressed, while in the lower level the objective is to minimize the outage durations of critical loads. The proposed sectionalizing model has been validated by the New-England 39-bus system and the IEEE 118-bus system. Further comparisons with some existing methods are carried out as well.

Self-reported circumstances and consequences of driving while sleepy

Driver surveys are indispensable sources of information when estimating the role of sleepiness in crash causation. The purpose of the study was to (1) identify the prevalence of driving while sleepy among Finnish drivers, (2) determine the circumstances of such instances, and (3) identify risk factors and risk groups. Survey data were collected from a representative sample of active Finnish drivers (N = 1121). One-fifth of the drivers (19.5%) reported having fallen asleep at the wheel during their driving career, with 15.9% reporting having been close to falling asleep or having difficulty staying awake when driving during the previous twelve months. Epworth Sleepiness Scale scores were found to be associated with both types of sleepiness-related driving instances, while sleep quality was associated only with the latter. Compared to women, men more often reported falling asleep at the wheel; the differences were somewhat smaller with respect to fighting sleep while driving during the previous twelve months. The reported discrepancy in sleepiness-related instances (high prevalence of fighting sleep while driving during the previous twelve months and lower proportion of actually falling asleep) identifies young men (⩽25 years) as one of the main target groups for safety campaigns. Approximately three-quarters of drivers who had fallen asleep while driving reported taking action against falling asleep before it actually happened. Furthermore, almost all drivers who had fallen asleep while driving offered at least one logical reason that could have contributed to their falling asleep. These data indicate some degree of awareness about driving while sleepy and of the potential pre-trip factors that could lead to sleepiness while driving, and supports the notion that falling asleep at the wheel does not come as a (complete) surprise to the driver.