The pervasive effects of timing of parental mental health disorders on adolescent deliberate self-harm risk

Children whose parents have mental health disorders are at increased risk for deliberate self-harm (DSH). However, the effect of timing of parental mental health disorders on adolescent DSH risk remains under-researched. The aim of this study was to investigate how parental hospital admissions for mental health disorders and/or DSH in different developmental periods impact on the child’s DSH risk in adolescence. A nested case-control sample was compiled from a total population cohort sample drawn from administrative health records in Western Australia. The sample comprised 7,151 adolescents who had a DSH-related hospital admission (cases), and 143,020 matched controls who hadn’t had a DSH-related hospital admission. The occurrence of parental hospital admissions related to mental health disorders and/or DSH behaviours was then analysed for the cases and controls. The timing of the parental hospital admissions was partitioned into four stages in the child’s life course: (1) pre-pregnancy, (2) pregnancy and infancy, (3) childhood, and (4) adolescence. We found that adolescents of a parent with mental health and/or DSH-related hospital admissions in all developmental periods except pregnancy and infancy were significantly more likely than controls to have a DSH-related hospital admission. Compared to parental hospital admissions that occurred during childhood and adolescence, those that occurred before pregnancy conferred a higher risk for adolescent DSH: adjusted odds ratio (aOR) = 1.25 for having only one parent hospitalised and 1.66 for having both parents hospitalised for mental health disorders; aOR = 1.97 for having any parent hospitalised for DSH, all being significant at the level of p < .001. This study shows that timing is important for understanding intergenerational transmission of DSH risk. The pre-pregnancy period is as critical as period after childbirth for effective intervention targeting adult mental health disorders and DSH, highlighting the important role of adult mental health services in preventing DSH risk in future generations

Minimum Induced Drag for Tapered Wings Including Structural Constraints

For a wing in steady level flight, the lift distribution that minimizes induced drag depends on a tradeoff between wingspan and wing-structure weight. In 1933, Prandtl suggested that tapered wings have an advantage over rectangular wings due to this tradeoff. However, Prandtl’s solutions were obtained using assumptions that correspond to rectangular wings. Therefore, his claim was not analytically proven by his 1933 publication. Here, an approach similar to Prandtl’s is taken with more general approximations that apply to wings of arbitrary planform. This more general development is used to study Prandtl’s claim about tapered wings. Closed-form solutions for the optimum wingspan and corresponding induced drag are presented for wings having elliptic and linearly-tapered planforms with constraints of fixed wing loading and maximum stress. It is shown that induced drag is minimized with a triangular planform, which gives a reduction in induced drag of up to 24.44% over the rectangular planform and up to 11.71% over the elliptic planform. Numerical solutions for the lift distributions that minimize induced drag for each planform are also presented. It is shown that the optimum lift distribution produces up to 5.94% less induced drag than the elliptic lift distribution when the triangular planform is used

The Role of NF-κB in PPARα-Mediated Hepatocarcinogenesis

In this review, the role of NF-κB in the induction of hepatocarcinogenesis by peroxisome proliferators is examined. The administration of peroxisome proliferators for more than a three-day period leads to the activation of NF-κB in the livers of rats and mice. On the other hand, peroxisome proliferator activated receptor-α (PPARα) activation in non-hepatic tissues can lead to the inhibition of NF-κB activation. Several lines of evidence support the hypothesis that the activation of NF-κB by peroxisome proliferators in the liver is mediated by oxidative stress. The role of NF-κB in peroxisome proliferator-induced hepatocarcinogenesis has been examined using NF-κB knockout models. Specifically, the induction of cell proliferation and the promotion of liver carcinogenesis are inhibited in mice lacking the p50 subunit of NF-κB. Overall, the activation of NF-κB appears to be important in the carcinogenic activity of peroxisome proliferators

Experimental and Computational Investigation for In-Line Boundary Layer Ingestion

The aerodynamic characteristics of an aft-body, in-line mounted, boundary layer ingesting, electric ducted fan, propulsion installation system has been investigated through experimental and computational analysis. A modular wind-tunnel model allows variation in the geometry of the propulsion installation system to be assessed, in combination with fan speed. Various experimental measurement techniques, including LDA, seven-hole-probe and surface pressures are employed. The propulsion installation system has also been investigated using RANS CFD and comparison with experimental data is presented. An investigation of the boundary conditions for efficiently representing the fan in CFD is described. Initial results show reasonably good agreement between CFD and experiment, in terms of velocity profiles and surface pressures, but highlight remaining differences for cases exhibiting flow separation

Numerical Method for Rapid Aerostructural Design and Optimization

During early phases of wing design, analytic and low-fidelity methods are often used to identify promising design concepts. In many cases, solutions obtained using these methods provide intuition about the design space that is not easily obtained using higher-fidelity methods. This is especially true for aerostructural design. However, many analytic and low-fidelity aerostructural solutions are limited in application to wings with specific planforms and weight distributions. Here, a numerical method for minimizing induced drag with structural constraints is presented that uses approximations that apply to wings with arbitrary planforms and weight distributions. The method is applied to the NASA Ikhana airframe to show how it can be used for rapid aerostructural optimization and design-space exploration. The design space around the optimum solution is visualized, and the sensitivity of the optimum solution to changes in weight distribution, structural properties, wing loading, and taper ratio is shown. The optimum lift distribution and wing-structure weight for the Ikhana airframe are shown to be in good agreement with analytic solutions. Whereas most modern high-fidelity solvers obtain solutions in a matter of hours, all of the solutions shown here can be obtained in a matter of seconds

Risk factors for repetition of a deliberate self-harm episode within seven days in adolescents and young adults: A population-level record linkage study in Western Australia

Objective: The risk of repetition of deliberate self-harm peaks in the first 7 days after a deliberate self-harm episode. However, thus far no studies have examined the risk factors for repeating deliberate self-harm during this short-term period. We aimed to investigate the effects of socio-demographic factors, self-harm method and mental health factors in adolescents (10-19 years old) and young adults (20-29 years old). Methods: We used data linkage of population-wide administrative records from hospital inpatients and emergency departments to identify all the deliberate self-harm-related episodes that occurred in adolescents and young adults in Western Australia from 2000 to 2011. Logistic regression with generalised estimating equations was used for the analyses. Results: The incidence of repeating deliberate self-harm within the first 7 days after an index episode was 6% (403/6,768) in adolescents and 8% (842/10,198) in young adults. Socio-demographic risk factors included female gender and socioeconomic disadvantage. Compared with non-poisoning, self-poisoning predicted increased risk of having a repeated deliberate self-harm episode in males, but not in females. Borderline personality, impulse-control and substance use disorders diagnosed within one week before and one week after an index deliberate self-harm episode conferred the highest risk, followed by depressive and anxiety disorders. Having a preceding deliberate self-harm episode up to 7 days before an index episode was a strong predictor for the future repetition of a deliberate self-harm episode.Conclusion: Having a repeated deliberate self-harm episode within the first 7 days was related to a wide range of factors present at an index deliberate self-harm episode including socio-demographic characteristics, deliberate self-harm method and co-existing psychiatric conditions. These factors can inform risk assessments tailored to adolescents and young adults respectively to reduce the repetition of deliberate self-harm within a short but critical period, potentially contributing to reduce the repetition of deliberate self-harm in the long term

Sensing of minute airflow motions near walls using pappus-type nature-inspired sensors

This work describes the development and use of pappus-like structures as sensitive sensors to detect minute air-flow motions. We made such sensors from pappi taken from nature-grown seed, whose filiform hairs' length-scale is suitable for the study of large-scale turbulent convection flows. The stem with the pappus on top is fixated on an elastic membrane on the wall and tilts under wind-load proportional to the velocity magnitude in direction of the wind, similar as the biological sensory hairs found in spiders, however herein the sensory hair has multiple filiform protrusions at the tip. As the sensor response is proportional to the drag on the tip and a low mass ensures a larger bandwidth, lightweight pappus structures similar as those found in nature with documented large drag are useful to improve the response of artificial sensors. The pappus of a Dandelion represents such a structure which has evolved to maximize wind-driven dispersion, therefore it is used herein as the head of our sensor. Because of its multiple hairs arranged radially around the stem it generates uniform drag for all wind directions. While still being permeable to the flow, the hundreds of individual hairs on the tip of the sensor head maximize the drag and minimize influence of pressure gradients or shear-induced lift forces on the sensor response as they occur in non-permeable protrusions. In addition, the flow disturbance by the sensor itself is limited. The optical recording of the head-motion allows continuously remote-distance monitoring of the flow fluctuations in direction and magnitude. Application is shown for the measurement of a reference flow under isothermal conditions to detect the early occurrence of instabilities

The implications of temporal variability in wave‐particle interactions in Earth's radiation belts

Changes in electron flux in Earth's outer radiation belt can be modeled using a diffusion‐based framework. Diffusion coefficients D for such models are often constructed from statistical averages of observed inputs. Here, we use stochastic parameterization to investigate the consequences of temporal variability in D. Variability time scales are constrained using Van Allen Probe observations. Results from stochastic parameterization experiments are compared with experiments using D constructed from averaged inputs and an average of observation‐specific D. We find that the evolution and final state of the numerical experiment depends upon the variability time scale of D; experiments with longer variability time scales differ from those with shorter time scales, even when the time‐integrated diffusion is the same. Short variability time scale experiments converge with solutions obtained using an averaged observation‐specific D, and both exhibit greater diffusion than experiments using the averaged‐input D. These experiments reveal the importance of temporal variability in radiation belt diffusion