The menopausal transition in human females, which is driven by a loss of cyclic ovarian function, occurs around age 50 and is thought to underlie the emergence of an array of health problems in aging ...women. Although mice do not undergo a true menopause, female mice exhibit ovarian failure long before death because of chronological age and subsequently develop many of the same age-associated health complications observed in postmenopausal women. Here we show in mice that inactivation of the proapoptotic Bax gene, which sustains ovarian lifespan into advanced age, extends fertile potential and minimizes many age-related health problems, including bone and muscle loss, excess fat deposition, alopecia, cataracts, deafness, increased anxiety, and selective attention deficit. Further, ovariectomy studies show that the health benefits gained by aged females from Bax deficiency reflect a complex interplay between ovary-dependent and -independent pathways. Importantly, and contrary to popular belief, prolongation of ovarian function into advanced age by Bax deficiency did not lead to an increase in tumor incidence. Thus, the development of methods for postponing ovarian failure at menopause may represent an attractive option for improving the quality of life in aging females.
Palliation of hypoplastic left heart syndrome with a standard nonvalved right ventricle to pulmonary artery conduit results in an inefficient circulation in part due to diastolic regurgitation. A ...composite right ventricle pulmonary artery conduit with a homograft valve has a hypothetical advantage of reducing regurgitation, but may differ in the propensity for stenosis because of valve remodeling.
This retrospective cohort study included 130 patients with hypoplastic left heart syndrome who underwent a modified stage 1 procedure with a right ventricle to pulmonary artery conduit from 2002 to 2015. A composite valved conduit (cryopreserved homograft valve anastomosed to a polytetrafluoroethylene tube) was placed in 100 patients (47 aortic, 32 pulmonary, 13 femoral/saphenous vein, 8 unknown), and a nonvalved conduit was used in 30 patients. Echocardiographic functional parameters were evaluated before and after stage 1 palliation and before the bidirectional Glenn procedure, and interstage interventions were assessed.
On competing risk analysis, survival over time was better in the valved conduit group (P = .040), but this difference was no longer significant after adjustment for surgical era. There was no significant difference between groups in the cumulative incidence of bidirectional Glenn completion (P = .15). Patients with a valved conduit underwent more interventions for conduit obstruction in the interstage period, but this difference did not reach significance (P = .16). There were no differences between groups in echocardiographic parameters of right ventricle function at baseline or pre-Glenn.
In this cohort of patients with hypoplastic left heart syndrome, inclusion of a valved right ventricle to pulmonary artery conduit was not associated with any difference in survival on adjusted analysis and did not confer an identifiable benefit on right ventricle function.
This study used the psycho-structural taxonomy proposed by King et al. (
International Journal of Mental Health and Addiction, 8
(1), 90–106,
2010a
) to examine the structural characteristics of two ...genres of Facebook games (Tile Matching games and Simulation/RPGs) to investigate their potential to encourage and maintain Problem Video Game Play (PVGP). Ten of the most popular Facebook games were played by the first author for between two and three hours per game. Recurring structural characteristics influencing the researcher’s behaviour or considered to be problematic were noted and compiled according to the taxonomy. Both genres appeared to have the capacity to encourage the development and maintenance of PVGP. While Simulation/RPGs appear to promote more problematic use than do Tile Matching games, both tended to use similar features to promote player engagement. Further in-depth research is needed to understand the psychological impact of playing Social Network Games, and how this may lead to, or encourage problematic use of these games.
As physicians and caregivers of children with congenital heart disease, we are aware of the increasing need for procedures requiring anesthesia. While these procedures may be ideal for medical and ...cardiac surgical management, the risks and benefits must be assessed carefully. There are well known risks of cardiovascular and respiratory complications from anesthesia and sedation and a potentially under-appreciated risk of neurocognitive dysfunction. Both animal and human studies support the detrimental effects of repeated anesthetic exposure on the developing brain. Although the studies in humans are less convincing of this risk, the Society of Pediatric Anesthesia jointly with SmartTots provided a consensus statement on the use of anesthetic and sedative drugs in infants and toddlers when speaking to families. (www.pedsanesthesia.org; http://smarttots.org/wp-content/uploads/2015/10/ConsensusStatementV910.5.2015.pdf). An excerpt of the statement is "Concerns regarding the unknown risk of anesthetic exposure to your child's brain development must be weighed against the potential harm associated with cancelling or delaying a needed procedure. Each child's care must be evaluated individually based on age, type, and urgency of the procedure and other health factors. This review provides a summary of the current evidence regarding anesthesia-induced neurotoxicity and the developing brain and its implications for children with congenital heart disease.
Purpose This study aims to use the dual-continuum model of mental health to explore mental health in Australian construction apprentices from the perspective of key stakeholders in the apprenticeship ...model. In particular, this study explored how construction apprentices, Vocational Education and Training (VET) teachers, industry employers and mental health workers understood the construct of mental health, factors associated with the dimension of psychological distress/symptoms of mental illness, and factors associated with the dimension of mental wellbeing. Design/methodology/approach This study used an exploratory qualitative research design. Data from 36 semi-structured interviews were analysed using thematic analysis. Participants comprised 19 Australian construction apprentices, 5 VET teachers, 7 industry employers and 5 mental health workers. Findings In total, 14 themes were generated from the data set. Participants across stakeholder groups reported a limited understanding about mental health. Participants cited a range of negative personal, workplace and industry factors associated with psychological distress/symptoms of mental illness, but only reported a few factors associated with mental wellbeing. Originality/value To the best of the authors’ knowledge, this study is one of the first to use the dual-continuum model of mental health to explore the mental health of Australian construction apprentices, and to explore the factors associated with both dimensions of this model from the perspective of key stakeholders in the Australian construction apprenticeship model.
Technical skills are critical for dentists. Computer‐based simulation offers a range of potential benefits for surgical training, but to date the development of simulators has not been characterized ...by a structured investigation of specific mechanisms by which trainees attain competence. This two‐part study contributes to the understanding of the manner in which surgical psychomotor skills are acquired so that this knowledge can be incorporated into the design of training simulations. We studied participant groups of varying skill levels as they performed a drilling task in oral surgery. In this first part of our study, we investigated the elements of surgical technique and differences in the drilling performance of novice, competent, and expert dentists. Our results indicate that novice dentists employ a technique that differs considerably in drilling stroke length and duration from that employed by experts. Expert dentists perform faster, apply more force, lift the bur off the bone less, and produce superior results compared with novices.
Fracture surface analysis is a powerful technique to investigate bone failure mechanisms. Previously, emu tibiae were endocortically treated with 1 M potassium hydroxide (KOH) solution for 14 days. ...This treatment caused in situ collagen degradation rather than removal, with no differences in geometrical parameters, but with significant changes in mechanical properties. KOH-treated tibiae showed significant decreases in failure stress and increased failure strain and toughness. The fracture surfaces of untreated and 14-day KOH-treated failed specimens were examined to further identify differences in the failure process to explain the previously observed increase in toughness. Areas of ‘tension,’ ‘compression,’ and ‘transition’ were identified using digital images of the fracture surfaces. Within these areas, the degree of ‘roughness’ and ‘smoothness’ was identified and estimated, using an optical profiler and SEM images. The fracture surfaces of 14-day KOH-treated bones showed a significantly higher ‘roughness’ compared to untreated bones. Furthermore, additional toughening mechanisms, which are important features for dissipating energy during the failure process, were observed in KOH-treated samples, but were absent in untreated samples. These results indicate that the significant increase in toughness of KOH treated bones is the result of structural alterations that enhance the ability of the microstructure to dissipate energy during the failure process, thereby slowing crack propagation. Fracture surface analysis has helped explain why KOH-treated bones have increased toughness compared to untreated bones, namely via toughening mechanisms on the compressive failure side.
Cultural intelligence is an important capacity related to effective functioning in intercultural contexts, but questions remain as to how international experience supports its development. This ...longitudinal study assessed how the four facets of cultural intelligence developed during a semester-long student exchange program with Australian (N = 203, age M = 20.94, 66.5% female) and French students (N = 232, age M = 20.72, 69.8% female). Participants completed measures before, during, and directly after their exchange experience. Longitudinal multilevel modelling results showed that exchange enhanced cognitive, metacognitive and motivational cultural intelligence for both Australian and French students, while behavioral cultural intelligence only increased in Australian students. Importantly, the identified changes were found to be linear for all cultural intelligence facets, with the exception of metacognitive cultural intelligence in the Australian sample, showing that increases in cultural intelligence occurred throughout the duration of the exchange experience. Neither cultural distance nor previous travel experience influenced the amount of cultural intelligence change that occurred. The findings confirm that university student exchange is a valuable tool for promoting the development of cultural intelligence, supporting graduates to acquire abilities relevant to a global work environment.
Prolonged exposure of postnatal day (PND) 7 rat pups to anesthetics, which act via N-methyl-D-aspartate antagonism and/or gamma-amino butyric acid enhancement, causes neurodegeneration and persistent ...behavioral deficits. We studied these findings in vitro and determined whether the age of rat pups used for study or duration of anesthetic exposure modulates resultant neurodegeneration. Organotypic hippocampal slices (OHSs) were prepared from rat pups on PNDs 4, 7, and 14 and cultured 7 or 14 days in vitro. The slices were exposed to 1.5% isoflurane or fresh gas for durations of 1, 3, or 5 h. Hippocampal CA1, CA3, and dentate gyrus neuronal survival was assessed 3 days later. Neuronal cell death was greatest in OHSs prepared from PND 7 rat pups (P < 0.001) and was most evident after 5 h exposure to isoflurane (P < 0.001). By eliminating variables such as hemodynamics, nutrition, oxygenation, and carbon dioxide elimination, this in vitro investigation supports both an age- and duration-dependent relationship between 1.5% isoflurane exposure and perinatal neuronal death.
The study of expertise in surgery aims to facilitate the development of improved training methods by understanding the characteristics of expert practitioners. In this article and its companion, we ...present our study of the characteristics of competence and expertise in the field of oral surgery. We observed participants of different skill levels as they performed an ex vivo drilling task designed to test the psychomotor skill of distinguishing the material boundaries between tooth and bone. Part 1 of this study examined the physical characteristics of drilling performance, while this article examines the cognitive aspects of performance. In this article we investigate the psychomotor cues used for decision making during drilling and explore other factors that affect a participant's ability to distinguish tooth from bone. Our results suggest that visual and tactile cues were the most important cues guiding drilling performance in all participant groups. Our results also suggest that when compared to experts, novices relied more on visual cues rather than tactile cues and lacked the psychomotor skills required to utilize the broader range of cues used by experts.
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