Optimal Control of Spreading Biological Invasions: For How Long Should We Apply the Brake?

Identifying the optimal switching point between different invasive alien species (IAS) management policies is a very complex task and policy makers are in need of modelling tools to assist them. In this paper we develop an optimal control bioeconomic model to estimate the type of optimal policy and switching point of control efforts against a spreading IAS. We apply the models to the case study of Colorado potato beetle in the UK. The results demonstrate that eradication is optimal for small initial sizes of invasion at discovery. High capacity of the agency to reduce spread velocity for several years leads to smaller total overall costs of invasion and makes eradication optimal for larger sizes of initial invasion. In many cases, it is optimal to switch from control to acceptance within the time horizon. The switching point depends on the capacity of the agency, initial size of invasion, spread velocity of the IAS and the ratio of unit cost of damage and removal. We encourage the integration of the dispersal patterns of the invader and the geometry of the invasion in the theoretical development of the economics of IAS invasion management.barrier zone, biosecurity, dynamic optimization, eradication, Leptinotarsa decemlineata, pest risk analysis, reaction-diffusion., Risk and Uncertainty, Q1, Q28, Q57,

Reducing parental anxiety using a family based intervention for youth mental health : a randomized controlled trial

This paper presents findings on parent anxiety and attachment relationship style from the Deakin Family Options (DFO) pilot study, a randomized controlled pilot study comparing a family-based treatment (BEST Plus), versus a youth only treatment (CBT) versus a group who received both of these treatments (COMBINED). Eligible participants were families with a young person (aged 12 - 25 years) with a high prevalence mental health problem. Youth from participating families scored in the clinical or subclinical range for depression, anxiety and/or substance misuse symptoms on standardized measures during the initial assessment. The collected sample was drawn from regional and urban centers in Victoria, Australia and allocated to treatment condition using a simple randomization procedure (parallel design). It was hypothesized that families receiving the BEST Plus would experience greater reductions in youth and parent mental health symptoms, and improved parent-child relationships, compared with those in the CBT condition. This paper describes and discusses changes in parent anxiety and parent attachment, according to whether the parent participated in a treatment (BEST Plus) or did not (NONBEST Plus). Participants were blind to the study hypotheses. In total 71 parent participants returned pre data and were allocated to a treatment group. In this paper, data from parent participants who completed pre and post measures (n = 48) and pre, post, and 6-month follow-up measures (n = 28) on anxiety and attachment were analyzed by group (BEST Plus versus NONBEST Plus). The results of this study suggest that parent anxiety decreased significantly more following parent involvement in a group treatment, than for parents that did not receive treatment. Unexpectedly, avoidant attachment increased in the no treatment group, but remained relatively stable following the BEST Plus group. There were no significant findings in relation to compulsive traits and anxious attachment. These findings are discussed in light of the study limitations.<br /

An experimental evaluation of software redundancy as a strategy for improving reliability

The strategy of using multiple versions of independently developed software as a means to tolerate residual software design faults is suggested by the success of hardware redundancy for tolerating hardware failures. Although, as generally accepted, the independence of hardware failures resulting from physical wearout can lead to substantial increases in reliability for redundant hardware structures, a similar conclusion is not immediate for software. The degree to which design faults are manifested as independent failures determines the effectiveness of redundancy as a method for improving software reliability. Interest in multi-version software centers on whether it provides an adequate measure of increased reliability to warrant its use in critical applications. The effectiveness of multi-version software is studied by comparing estimates of the failure probabilities of these systems with the failure probabilities of single versions. The estimates are obtained under a model of dependent failures and compared with estimates obtained when failures are assumed to be independent. The experimental results are based on twenty versions of an aerospace application developed and certified by sixty programmers from four universities. Descriptions of the application, development and certification processes, and operational evaluation are given together with an analysis of the twenty versions

Consumer feedback following participation in a family-based intervention for youth mental health

Background. This paper presents findings derived from consumer feedback, following a multicentre randomised controlled trial for adolescent mental health problems and substance misuse. The paper focuses on the implementation of a family-based intervention, including fidelity of delivery, family members&rsquo; experiences, and their suggestions for program improvements. Methods. Qualitative and quantitative data

Glyoxal Formation and Its Role in Endogenous Oxalate Synthesis

Calcium oxalate kidney stones are a common condition affecting many people in the United States. The concentration of oxalate in urine is a major risk factor for stone formation. There is evidence that glyoxal metabolism may be an important contributor to urinary oxalate excretion. Endogenous sources of glyoxal include the catabolism of carbohydrates, proteins, and fats. Here, we review all the known sources of glyoxal as well as its relationship to oxalate synthesis and crystal formation

Peer observation of teaching: A decoupled process

This article details the findings of research into the academic teaching staff experience of peer observation of their teaching practice. Peer observation is commonly used as a tool to enhance a teacher’s continuing professional development. Research participants acknowledged its ability to help develop their teaching practice, but they also reported that it could operate superficially as a tick box exercise, that its outcomes were frequently decoupled from formal staff development processes, and that its purpose and usefulness therefore seemed unclear. This article argues that the presence of decoupling reinforces the need to account for structural factors that can interact with peer observation of teaching to ensure it is a meaningful exercise for all teaching staff. It concludes that the published academic literature is perhaps guilty of overplaying the role of personal choice and individual tutor characteristics when addressing the complex issue that is staff disengagement with peer observation of teaching

Adolescent depressive disorders and family based interventions in the family options multicenter evaluation: study protocol for a randomized controlled trial

BackgroundThere is increasing community and government recognition of the magnitude and impact of adolescent depression. Family based interventions have significant potential to address known risk factors for adolescent depression and could be an effective way of engaging adolescents in treatment. The evidence for family based treatments of adolescent depression is not well developed. The objective of this clinical trial is to determine whether a family based intervention can reduce rates of unipolar depressive disorders in adolescents, improve family functioning and engage adolescents who are reluctant to access mental health services.Methods/DesignThe Family Options study will determine whether a manualized family based intervention designed to target both individual and family based factors in adolescent depression (BEST MOOD) will be more effective in reducing unipolar depressive disorders than an active (standard practice) control condition consisting of a parenting group using supportive techniques (PAST). The study is a multicenter effectiveness randomized controlled trial. Both interventions are delivered in group format over eight weekly sessions, of two hours per session. We will recruit 160 adolescents (12 to 18 years old) and their families, randomized equally to each treatment condition. Participants will be assessed at baseline, eight weeks and 20 weeks. Assessment of eligibility and primary outcome will be conducted using the KID-SCID structured clinical interview via adolescent and parent self-report. Assessments of family mental health, functioning and therapeutic processes will also be conducted. Data will be analyzed using Multilevel Mixed Modeling accounting for time x treatment effects and random effects for group and family characteristics. This trial is currently recruiting. Challenges in design and implementation to-date are discussed. These include diagnosis and differential diagnosis of mental disorders in the context of adolescent development, non-compliance of adolescents with requirements of assessment, questionnaire completion and treatment attendance, breaking randomization, and measuring the complexity of change in the context of a family-based intervention

The prepower stroke conformation of myosin V

eW have used electron microscopy and single-particle image processing to study head conformation in myosin V molecules. We find that in the presence of ATP, many heads have a sharply angled conformation that is rare in its absence. The sharply angled conformation is similar to a myosin II atomic structure proposed to mimic the prepower stroke state. The leading head in molecules attached to actin by both heads has a similar conformation, but is also sharply angled in a second plane by tethering through the trail head. The lead head lever joins the motor domain ∼5 nm axially from where it joins the trail motor. These positions locate the converter subdomain and show the lead motor is in the prepower stroke conformation. Tethering by the trail head places the lead head motor domain at the correct axial position along the actin for binding, but at the wrong orientation. Attachment is achieved either by bending the lead head lever throughout its length or at the pliant point. The microscopy shows that most of the walking stride is produced by changes in lever angle brought about by converter movement, but is augmented by distortion produced by thermal energy

Real-Time Projection to Verify Plan Success During Execution

The Mission Data System provides a framework for modeling complex systems in terms of system behaviors and goals that express intent. Complex activity plans can be represented as goal networks that express the coordination of goals on different state variables of the system. Real-time projection extends the ability of this system to verify plan achievability (all goals can be satisfied over the entire plan) into the execution domain so that the system is able to continuously re-verify a plan as it is executed, and as the states of the system change in response to goals and the environment. Previous versions were able to detect and respond to goal violations when they actually occur during execution. This new capability enables the prediction of future goal failures; specifically, goals that were previously found to be achievable but are no longer achievable due to unanticipated faults or environmental conditions. Early detection of such situations enables operators or an autonomous fault response capability to deal with the problem at a point that maximizes the available options. For example, this system has been applied to the problem of managing battery energy on a lunar rover as it is used to explore the Moon. Astronauts drive the rover to waypoints and conduct science observations according to a plan that is scheduled and verified to be achievable with the energy resources available. As the astronauts execute this plan, the system uses this new capability to continuously re-verify the plan as energy is consumed to ensure that the battery will never be depleted below safe levels across the entire plan