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Introduction: This short report describes the piloting of a resilience building workshop for pharmacy interns to aid with the transition from university to the workforce. Methods: A 2-hour workshop was designed focussing on responding to change and exploration of real-life examples that interns had encountered in the workplace. The workshop involved a combination of whole and small group discussions, problem-solving and self-reflection. A total of 108 interns participated in the workshop as part of The University of Sydney Pharmacy Intern Training Program. Conclusion: Pharmacy educators must continue to embed resilience training in curricula to promote graduates’ readiness to transition and deal with adversity in the contemporary workforce.

Highlights An existing sugar beet crop coefficient curve (K cr ) was modified to better represent canopy development in northeast Colorado conditions. The modified K cr curve improved the estimated soil water deficits (net irrigation requirements) calculated by the cloud-based Water Irrigation Scheduler for Efficient Application (WISE App). Feedback from sugar beet growers and agronomists helped expand WISE applicability in the northern High Plains with access to additional weather station networks and functionality to aggregate irrigation data across multiple sugar beet fields or regions. Abstract . The convergence of agrometeorological network, database, and cloud-computing technologies has enabled greater accessibility of irrigation management tools for growers. The goal of this research and outreach project was to adapt an existing cloud-based irrigation scheduler (WISE) for use by sugar beet (Beta vulgaris L.) producers in eastern Colorado and a wider area of a cooperative operating in Colorado, Nebraska, Wyoming, and Montana. Four center pivot sugar beet fields in northeast Colorado were monitored during the 2013 and 2014 growing seasons. Soil water, leaf area index (LAI), and weather data were used to estimate the soil water deficit (net irrigation requirement) and to modify a crop coefficient (Kcr) curve originally reported in the literature based on growing degree days (GDD). The average cumulative GDDs for sugar beets to mature (100% maturity) was 2,944°C·d. The localized Kcr had a peak value (Kcr,mid) occurring between 43% and 69% of maturity, which corresponded to effective full cover (LAI = 3) and start of leaf senescence, respectively. In contrast, the original Kcr curve from literature had a longer duration of Kcr,mid spanning 33% to 83% of maturity. Use of the modified Kcr curve in lieu of the original Kcr curve in WISE reduced the relative error of soil water deficits by 12% to 35%. Feedback and collaborations from representative sugar beet growers and agronomists in the Western Sugar Cooperative led to expansion of WISE weather data access in the High Plains to include sugar beet growing areas in western Nebraska, eastern and northern Wyoming, and southern Montana. Keywords: Crop coefficient, Evapotranspiration, Irrigation scheduling, Soil water balance, Soil water deficit, Sugar beets.

The glucocorticoid receptor (GR) has been shown to be important for mediating cellular responses to stress and circulating glucocorticoids. Ligand-dependent transcriptional changes induced by GR are observed across numerous tissues. However, the mechanisms by which GR achieves cell and tissue-specific effects are less clear. Epigenetic mechanisms have been proposed to explain some of these differences as well as some of the lasting, even transgenerational, effects of stress and glucocorticoid action. GR functions in tandem with epigenetic cellular machinery to coordinate transcription and shape chromatin structure. Here, we describe GR interactions with these effectors and how GR acts to reshape the epigenetic landscape in response to the environment.

In rodents, gonadal steroids play a critical yet variable role in behaviors such as social interaction and cognitive performance. Gonadal steroids organize sex differences observed in spatial working memory, while the absence of activational effects induced by castration generally impedes spatial learning and memory. Although male sexual behavior is typically inhibited following castration, a significant proportion of gonadectomized B6D2F1 hybrid males retains the complete repertoire of male reproductive behavior. In a prior study, amyloid precursor protein and tau, proteins involved in cognitive behavior, facilitated steroid-independent male sex behavior in B6D2F1 hybrid male mice. We used this strain to investigate the relationship between gonadal steroid-independent male sexual behavior and cognition. After identifying "maters" (animals retaining steroid-independent male sex behavior) and "non-maters," we tested spatial memory in an 8-arm radial arm maze. Although neither group demonstrated a decrease in errors as a function of time, maters committed fewer errors compared to non-maters overall (p 0.05). Maters also completed the maze more quickly than non-maters (p 0.05). We measured mRNA expression of APP and MAPT as well as LEPR and D2R to probe potential roles of metabolism and motivation. Uniquely among maters, increased relative expression of D2R and LEPR in the hippocampus was associated with a longer latency to complete the maze during the last 3 or across all trials, respectively. These data demonstrate that maters outperform non-maters in the radial arm maze, warranting further study of potential differences in acquisition of spatial memory tasks or learning strategy between these groups.

Adaptation to the environment is indispensable for organismal fitness. The brain is responsible for detection of and adaptation to stressful stimuli. Few molecular mechanisms facilitating this response have been described including neuronal plasticity, neurogenesis, and changes in gene expression. With the advent of next-generation sequencing technologies, large swathes of the noncoding genome have been identified and a role for the deep genome in governing the neural response to stress has been outlined. For instance, in the hippocampus heterochromatin remodeling is observed in gene deserts, here, marking repetitive retroelements selectively for transcriptional silencing. Aberrant retroelement expression is predicted to contribute to functional deficits in stress-sensitive brain regions. Though not yet fully realized, this “junk” represents a novel frontier in stress physiology relevant to many stress-related pathologies.

Background In healthcare, preceptors act as a role model and supervisor, thereby facilitating the socialisation and development of the preceptee into a professional fit to practice. To ensure a consistent approach to every preceptorship experience, preceptor competencies should be measured or assessed to ensure that the desired outcomes are achieved. Defining these would ensure quality management and could inform development of an preceptor competency framework. This review aimed to evaluate the evidence for preceptor competencies and assessment in health professions. Methods This study followed the PRISMA ScR scoping review guidelines. A database search was conducted in Embase, Medline, CINAHL and IPA in 2019. Articles were included if they defined criteria for competency, measured or assessed competency, or described performance indicators of preceptors. A modified GRADE CERQual approach and CASP quality assessment were used to appraise identified competencies, performance indicators and confidence in evidence. Results Forty one studies identified 17 evidence-based competencies, of which 11 had an associated performance indicator. The competency of preceptors was most commonly measured using a preceptee completed survey (moderate to high confidence as per CERQual), followed by preceptor self-assessment, and peer-assessment. Preceptee outcomes as a measure of preceptor performance had good but limited evidence. Conclusions Competencies with defined performance indicators allow for effective measurement and may be modifiable with training. To measure preceptor competency, the preceptor perspective, as well as peer and preceptee assessment is recommended. These findings can provide the basis for a common preceptor competency framework in health professions.

Brain kappa-opioid receptors (KORs) are implicated in the pathophysiology of depressive and anxiety disorders, stimulating interest in the therapeutic potential of KOR antagonists. Research on KOR function has tended to focus on KOR-expressing neurons and pathways such as the mesocorticolimbic dopamine system. However, KORs are also expressed on non-neuronal cells including microglia, the resident immune cells in the brain. The effects of KOR antagonists on microglia are not understood despite the potential contributions of these cells to overall responsiveness to this class of drugs. Previous work in vitro suggests that KOR activation suppresses proinflammatory signaling mediated by immune cells including microglia. Here, we examined how KOR antagonism affects microglia function in vivo, together with its effects on physiological and behavioral responses to an immune challenge. Pretreatment with the prototypical KOR antagonist JDTic potentiates levels of proinflammatory cytokines (IL-1ß, IL-6) in blood following administration of lipopolysaccharide (LPS), an immune-activating agent, without triggering effects on its own. Using magnetic-activated cell sorting (MACs), we found that KOR antagonism potentiates LPS-induced cytokine expression within microglia. This effect is accompanied by potentiation of LPS-induced hyperthermia, although reductions in body weight and locomotion were not affected. Histological analyses confirm that LPS produces visible changes in microglia morphology consistent with activation, but this effect is not altered by KOR antagonism. Considering that inflammation is increasingly implicated in depressive and anxiety disorders, these findings raise the possibility that KOR antagonist actions on microglia may detract from actions on neurons that contribute to their therapeutic potential.

Heart failure (HF) is the most common reason for admission to the hospital in people over the age of 65 and has been found to be a possible complication following a joint replacement. Self-management education has been shown to reduce hospital readmissions rates among patients with HF and to cause significant improvements. The purpose of this case report was to describe physical therapy (PT) self-management education in the care of a patient with both a recent hip replacement (THR) surgery and HF. Case description 85-year-old female with a THR and HF. Objective measurements included Timed Up and Go Test (TUG); 10-meter walk test (10MWT) and the 6-minute walk test (6MWT). Standard PT care for THR and self-management education strategies was provided. The patient was seen two times per week for nine weeks. Improvements were noted in all outcome measures: (TUG, 10MWT, 6MWT). The patient was able to meet all ambulation goals and become independent in transfers. In this case, self-management education was shown to provide positive benefits by increasing functional mobility and helping prevent further complications from HF. Self- management education in the home health setting is important for older adult patients who had a THR.

The brain is responsible for both recognition and adaptation to stressful stimuli. Many molecular mechanisms have been implicated in this response including those governing neuronal plasticity, neurogenesis and, changes gene expression. Far less is known regarding effects of stress on the deep genome. In the hippocampus, stress appears to regulate expression of non-coding elements of the genome as well as the chromatin permissive for their transcription. Specifically, hippocampal retrotransposon (RT) elements are regulated by acute stress via the accumulation of the repressive H3K9me3 mark at RT loci. Further, corticosteroids appear to induce changes in heterochromatin status as well as RT expression in both adrenalectomized animal and rat cell culture models. Dysregulation of RT expression is predicted to result in functional deficits in affected brain areas. More broadly, however, transposons may have a variety of adaptive functions. As techniques improve to probe the deep genome, this approach to understanding stress neurobiology has the potential to yield insights into environment and genome interactions that may contribute to the physiology underlying a number of stress-related mental health disorders.

The hippocampus is a highly plastic brain region sensitive to environmental stress. It shows dynamic changes in epigenetic marks associated with stress related learning. Previous work has shown that acute stress induces substantial transient changes in histone H3 lysine 9 trimethylation (H3K9me3). Moreover, increased H3K9me3 is enriched in hippocampal gene deserts accumulating within endogenous retroviruses and transposable elements. We have found that in response to acute glucocorticoid treatment, a similar change in global H3K9me3 is observed. However, when localized we found that H3K9me3 is markedly decreased at B2 short interspersed nuclear elements but not within intracisternal-A particle endogenous retroviruses. Further, decreased H3K9me3 valence within B2 elements was associated with increased transcript abundance. These data demonstrate the capacity for acute glucocorticoids to mobilize transposable elements via epigenetic unmasking. Reconciled with previous findings following acute stress, this suggests the capacity for mobile elements to potentially function as novel regulators given their dynamic regulation by stress and glucocorticoids.

Neuropsychiatric disorders are highly prevalent (e.g., affecting children 2-8 years old at a rate of 14%). Many of these disorders are highly heritable such as major depressive disorder and schizophrenia. Despite this, genome-wide association has failed to identify gene(s) significantly associated with diagnostic status suggesting a strong role for environmental factors and the epigenome. From a molecular standpoint, the study of DNA-protein interactions yields fruitful information regarding the regulation of cellular processes above the level of the nucleotide sequence. Understanding chromatin dynamics may continue to explain individual variation to environmental perturbation and subsequent behavioral response. Chromatin immunoprecipitation (ChIP) techniques have allowed for probing of epigenetic effectors at specific regions of the genome. The following article reviews the current techniques and considerations when incorporation ChIP into neuropsychiatric models.

The ability to adapt to stressful circumstances, known as emotional resilience, is a key factor in the maintenance of mental health. Several individual biomarkers of the stress response (e.g., corticosterone) that influence an animal's position along the continuum that ranges from adaptive allostasis to maladaptive allostatic load have been identified. Extending beyond specific biomarkers of stress responses, however, it is also important to consider stress-related responses relative to other relevant responses for a thorough understanding of the underpinnings of adaptive allostasis. In this review, behavioral, neurobiological, developmental and genomic variables are considered in the context of emotional resilience [e.g., explore/exploit behavioral tendencies; DHEA/CORT ratios and relative proportions of protein-coding/nonprotein-coding (transposable) genomic elements]. As complex and multifaceted relationships between pertinent allostasis biomediators are identified, translational applications for optimal resilience are more likely to emerge as effective therapeutic strategies.

Neuropsychiatric disorders are highly prevalent (e.g., affecting children 2-8 years old at a rate of 14%). Many of these disorders are highly heritable such as major depressive disorder and schizophrenia. Despite this, genome-wide association has failed to identify gene(s) significantly associated with diagnostic status suggesting a strong role for environmental factors and the epigenome. From a molecular standpoint, the study of DNA-protein interactions yields fruitful information regarding the regulation of cellular processes above the level of the nucleotide sequence. Understanding chromatin dynamics may continue to explain individual variation to environmental perturbation and subsequent behavioral response. Chromatin immunoprecipitation (ChIP) techniques have allowed for probing of epigenetic effectors at specific regions of the genome. The following article reviews the current techniques and considerations when incorporation ChIP into neuropsychiatric models.

Teaching large cohorts of pharmacy students with a team of multiple tutors in a feedback intensive course poses challenges in relation the amount of data generated, data integrity, interpretation of the data and importantly application of the insights gained from the data. The dispensing and counselling course in the third year BPharm at the University of Sydney has implemented the USyd Pharmacy Dashboard, developed to address these challenges following the Technological Pedagogical Content Knowledge Framework (TPACK) to integrate technology into teaching. The dashboard was designed to improve the student experience through more consistent feedback, gain insights to improve teaching delivery and provide efficiencies in maintaining data integrity. The tool has been developed using an action-based research approach whereby ideas are put into practice as the means to further develop the idea and improve practice. Refinement of the USyd Pharmacy Dashboard over three years has shown improvements in teaching delivery as teachers can respond to emerging trends. Student performance and satisfaction scores have increased, mainly due to improved consistency between tutors and improved delivery of feedback. Time involved with administrative tasks such as data maintenance is reduced. Opportunities for further refinements such as real time benchmarking and developing an open learner model have become apparent.

Oxytocin is important for postnatal developmental experiences for mothers, infants, and transactions between them. Oxytocin is also implicated in adult affiliative behaviors, including social buffering of stress. There is evidence for connections between early life experience and adult oxytocin system functioning, but effects of early experience on behavioral, endocrine, and neurophysiological outcomes related to adult social buffering are not well explored. We use a limited bedding and nesting (LBN) material paradigm as an environmental disruption of early experiences and assessed central oxytocin systems in brain regions related to hypothalamic-pituitary-adrenal (HPA) axis regulation (paraventricular nucleus of the hypothalamus, amygdala, hippocampus). We also assessed developmentally-appropriate social behaviors and HPA reactivity during social buffering testing in adulthood. LBN litters had larger huddles and more pups visible compared to control litters during the first two weeks of life. LBN also altered the developmental trajectory of oxytocin-expressing cells and oxytocin receptor cells, with increases in oxytocin receptor cells at P15 in LBN pups. By adulthood, LBN females had more and LBN males had fewer oxytocin and oxytocin receptor cells in these areas compared to sex-matched controls. Adult LBN females, but not LBN males, had behavioral changes during social interaction and social buffering testing. The sex-specific effects of early experience on central oxytocin systems and social behavior may contribute to female resilience to early life adversity.

Expression of transposable elements (TE) is transiently activated during human preimplantation embryogenesis in a developmental stage- and cell type-specific manner and TE-mediated epigenetic regulation is intrinsically wired in developmental genetic networks in human embryos and embryonic stem cells. However, there are no systematic studies devoted to a comprehensive analysis of the TE transcriptome in human adult organs and tissues, including human neural tissues. To investigate TE expression in the human Dorsolateral Prefrontal Cortex (DLPFC), we developed and validated a straightforward analytical approach to chart quantitative genome-wide expression profiles of all annotated TE loci based on unambiguous mapping of discrete TE-encoded transcripts using a de novo assembly strategy. To initially evaluate the potential regulatory impact of DLPFC-expressed TE, we adopted a comparative evolutionary genomics approach across humans, primates, and rodents to document conservation patterns, lineage-specificity, and colocalizations with transcription factor binding sites mapped within primate- and human-specific TE. We identified 654,665 transcripts expressed from 477,507 distinct loci of different TE classes and families, the majority of which appear to have originated from primate-specific sequences. We discovered 4,687 human-specific and transcriptionally active TEs in DLPFC, of which the prominent majority (80.2%) appears spliced. Our analyses revealed significant associations of DLPFC-expressed TE with primate- and human-specific transcription factor binding sites, suggesting potential cross-talks of concordant regulatory functions. We identified 1,689 TEs differentially expressed in the DLPFC of Schizophrenia patients, a majority of which is located within introns of 1,137 protein-coding genes. Our findings imply that identified DLPFC-expressed TEs may affect human brain structures and functions following different evolutionary trajectories. On one side, hundreds of thousands of TEs maintained a remarkably high conservation for ∼8 My of primates’ evolution, suggesting that they are likely conveying evolutionary-constrained primate-specific regulatory functions. In parallel, thousands of transcriptionally active human-specific TE loci emerged more recently, suggesting that they could be relevant for human-specific behavioral or cognitive functions.

Anxiety disorders are highly prevalent psychiatric disorders often comorbid with depression and substance abuse. Twin studies have shown that anxiety disorders are moderately heritable. Yet, genome-wide association studies (GWASs) have failed to identify gene(s) significantly associated with diagnosis suggesting a strong role for environmental factors and the epigenome. A number of anxiety disorder subtypes are considered "stress related." A large focus of research has been on the epigenetic and anxiety-like behavioral consequences of stress. Animal models of anxiety-related disorders have provided strong evidence for the role of stress on the epigenetic control of the hypothalamic-pituitary-adrenal (HPA) axis and of stress-responsive brain regions. Neuroepigenetics may continue to explain individual variation in susceptibility to environmental perturbations and consequently anxious behavior. Behavioral and pharmacological interventions aimed at targeting epigenetic marks associated with anxiety may prove fruitful in developing treatments.

Anxiety disorders are highly prevalent psychiatric disorders often comorbid with depression and substance abuse. Twin studies have shown that anxiety disorders are moderately heritable. Yet, genome-wide association studies (GWASs) have failed to identify gene(s) significantly associated with diagnosis suggesting a strong role for environmental factors and the epigenome. A number of anxiety disorder subtypes are considered “stress related.” A large focus of research has been on the epigenetic and anxiety-like behavioral consequences of stress. Animal models of anxiety-related disorders have provided strong evidence for the role of stress on the epigenetic control of the hypothalamic-pituitary-adrenal (HPA) axis and of stress-responsive brain regions. Neuroepigenetics may continue to explain individual variation in susceptibility to environmental perturbations and consequently anxious behavior. Behavioral and pharmacological interventions aimed at targeting epigenetic marks associated with anxiety may prove fruitful in developing treatments.

Large stores of seismic information currently exist on paper, film, and other media, containing unique records of earthquakes, geological exploration, and nuclear testing events. In order to become useful, the seismic data from the traces on these seismograms need to be extracted and outputted as computer‐readable digital data, a process referred to in this paper as digitization. Individual paper or microfilm seismograms can be digitized by hand and this tedious process has been ongoing since the 1950s. A few software packages were developed for semi‐automatic digitization, for example, the Teseo software for digitizing scanned seismogram images by Pintore et al. (2005). However, there is a pressing need to automate this process as much as possible, in order to realize the possibility of extracting the vast stores of information that reside in large archives worldwide. Although seismograms created since the 1980s are now readily available online in digital format, the need to digitize old seismograms is still necessary in order to apply modern techniques in studying pre‐1980 earthquakes (e.g., see Kanamori et al. , 2010; 2012) and nuclear explosions. We have made significant progress on this problem, working under a DOE SBIR Phase I grant, No. DE‐SC002717. The objective of our Phase I work was to create computer code that automatically extracts x – y digital data files of the seismic traces in seismogram image files, while addressing some of the problems associated with noise, distortions, and image discontinuities. In accomplishing this goal, we have developed a preliminary start‐to‐finish digitization process that begins with the inputted raster image, and ends with a digital data file representing trace center‐line coordinates. This process applies corrections to the images via our filters, and outputs, if desired, image overlays to allow for direct visual checking of the accuracy of the work. In this work, we used …

Fabricating large single crystals with colloidal spheres as building blocks is challenging and of competitive interest. Spin-coating of colloids offers a robust technique, which is highly reproducible in obtaining colloidal crystals even at fast dynamical regimes; however, these crystals are intrinsically polycrystalline due to the axial symmetry of spin-coating. We report a new method that applies a nonuniform electric field during the spin-coating process. By arranging the field direction to be stationary in the rotating frame, we are able to break the axial symmetry and to orient the colloids along one predefined direction. By regulating the applied field strength, we demonstrate local control over the orientation of the crystallites, and thus, the orientation is determined by the applied field strength.

Order-disorder transitions in colloidal systems are an attractive option for making switchable materials. Electric-field-driven order-disorder transitions are especially attractive for this purpose because the tuning parameter is easily and externally controllable. However, precise positional control of 3D structure is immensely challenging. Using patterned electrodes, we demonstrate that ac electric fields-dominantly dielectrophoresis (DEP) coupled with an electrohydrodynamic mechanism consisting of induced-charge electro-osmosis (ICEO)-can be used to template colloidal order dynamically in three dimensions. We find that the electric field geometry dictates the location, size, and shape of colloidal patterns and can produce patterns with surprising complexity.

Estimates of canine and feline euthanasia at U.S. animal shelters--largely based on voluntary surveys with low response rates--make it difficult to estimate the population from which the euthanized animals derive. Estimates of euthanasia rates (animals euthanized per unit of population) have varied widely and been available only sporadically. This study used requirements of Michigan state law (Pet Shops, Dog Pounds, and Animal Shelters Act, 1969) for animal shelters to collect admission and discharge data for all 176 Michigan-licensed animal shelters. In 2003, Michigan shelters discharged 140,653 dogs: Of these, 56,972 (40%) were euthanized; 40,005 (28%) were adopted. This annual euthanasia rate is 2.6% of the estimated 2003 Michigan dog population. Michigan shelters discharged 134,405 cats in 2003: 76,321 (57%) by euthanasia and (24%) by adoption. The estimated ratio of euthanized cats to cats who had owners was 3.1%. Small shelters and privately owned shelters were associated with higher adoption rates. Comparison with historical information from the past 10 to 20 years suggests the number of companion animals being euthanized in shelters has decreased and that progress has been made in reducing the companion animal overpopulation problem.

OBJECTIVES:: HIV-1 tropism needs to be determined before the use of CCR5 antagonist drugs such as maraviroc (MVC), which are ineffective against CXCR4-using HIV-1. This study assessed how different computational methods for predicting tropism from HIV sequence data performed in a large clinical cohort. The value of adding clinical data to these algorithms was also investigated. DESIGN AND METHODS:: PCR amplification and sequence analysis of the HIV-1 gp120 V3 loop region was performed on triple replicates of plasma viral RNA or proviral DNA extracted from peripheral blood monocytes (PBMCs) in 242 patients. Coreceptor usage was predicted from V3 sequences using seven bioinformatics interpretation algorithms, combined with clinical data where appropriate. An intention-to-treat approach was employed for exploring outcomes and performance for different viral subtypes was examined. RESULTS:: The frequency of R5 predictions varied by 22.6%, with all seven algorithms agreeing for only 75.3% of tests. The identification of individuals likely to fail was poor for all algorithms. The addition of clinical data improved this, but at the expense of their ability to predict success. The clinical algorithms varied across subtypes, whereas other algorithms were more consistent. Furthermore, individuals with discordant clonal and clinical predictions were more likely to fail MVC treatment. CONCLUSION:: Eligibility for MVC varied depending on the algorithm method used. The addition of clinical parameters alongside sequence data may help predict X4 emergence during treatment. It could be that V3 loop analysis in isolation may not be the best method for selecting individuals for MVC.

Isothermal and cyclic heat treatments of a plasma-sprayed zirconia-8 wt% yttria thermal barrier coating on a nickel superalloy substrate highlighted coating failure mechanisms. A reaction layer formed at the bond coat/ceramic interface, and failure of the coating initiated in the reaction layer due to opening thermal expansion mismatch stresses associated with a nonplanar interface. Crack propagation occurred in the ceramic in all cases, due to the high fracture energy of the interface. The relatively low fracture energy of the coating, in planes parallel to the interface, is the ultimate factor limiting coating lifetime.

Frequency domain properties of uncertain rational functions depending on two independent interval polynomials are investigated. Several simplifications for efficient computation of the envelope of the Nyquist plots of the uncertain family are reported. Stronger computational reduction results are given for the Bode magnitude and phase plots of an interval plant-controller family of transfer functions. These results allow for a clear understanding of the extremality properties of several frequency domain performance specifications commonly used in control system design. >

Computation of all possible frequency responses of a linear system that depends on m uncertain parameters is the subject of this paper. Using a brute force approach, this computation could be carried out using an (m + l)-dimensional parameter sweep, i.e. there is the usual frequency sweep plus one sweep for each uncertain parameter. A much simpler computational alternative is possible if the uncertain system's transfer function has a linear dependence on the parameters and if the set of possible parameter values has a polytopic structure. For this class of uncertain systems, it has previously been shown that, for a single fixed frequency, all possible responses can be determined using several 1-dimensional sweeps. Thus, for a range of frequencies, the obvious extension would involve several 2-dimensional sweeps. However, this obvious extension is not the simplest way to carry out the computation. Indeed, this paper will show that all possible responses for a range of frequencies can be determined...

Determination of the steady state response of a system to an input composed of steps, ramps, and various other signals is considered. If the system and/or the input depend on uncertain parameters then a worst-case philosophy dictates that the analysis goal should be to determine the maximum and minimum possible equilibrium values of the output. It is shown that the system is robustly stable and if the dependence on the uncertain parameters is to an extent multiaffine, then the extreme values of the steady state response over the entire set of parameters is equal to the extreme values over just the vertices of the parameter set. This vertex result is doubly useful because it is valid in both continuous-time and discrete-time. For the transient response of stable systems, the vertices do not provide sufficient information for a complete analysis. Examples are presented which show that the maximum overshoot to the step response of a robustly stable uncertain system does not necessarily occur at a vertex. The systems in these examples have an affine dependence on a single uncertain parameter. >

This paper presents a design methodology for the synthesis of a robust controller that accounts for both unmodeled dynamics and structured real-parameter uncertainty for multiple-input/multiple-output systems. The unmodeled dynamics are assumed to be characterized as a single block dynamic uncertainty at a point in the closed-loop system. In a design aimed at constraining both the H^ norm of a certain disturbance transfer matrix and a quadratic Gaussian performance index under their respective bounds, a surrogate system may be formed by modeling the structured real-parameter uncertainty as additional noise inputs and additional weights at the existing noise inputs and measurement outputs of the system. Application of a Riccati equation approach to this surrogate system then yields a robust controller that, when used in the actual system, will result in a closed-loop system that has the same H^ bound and quadratic Gaussian performance index bound as the surrogate system, even in the presence of given real-parameter variations.

A number of procedures exist for determining the stability of a linear system that is subject to parametric uncertainty provided the system order is constant over the range of parameter variations. This paper extends these tests to systems with parametric uncertainties that induce order change. The extended tests are also shown to apply to systems with nonparametric (unstructured) uncertainty through an equivalent parameterization of the nonparametric uncertainty class. The results are applied to the stability analysis of a crane model with a flexible cable.

Controllers are usually implemented in a digital computer. Figure 11.1 shows a single-loop sampled-data control system with c z (z) representing the z-transfer function of the digital controller, and (1 - e - s T s as the transfer function of the hold element, T is the sampling interval.

In this paper we present our positive experience with use of Aquaplast thermoplastic as a tie-down dressing for securing and maintaining skin grafts in good position against their nutrient recipient beds. This unique polymer is safe to use, simple to apply, and maintains uniform pressure across the entire surface of the skin graft, no matter how contoured the shape of the anatomical region.

When applying the parameter space design method of the preceding chapter, regions of controller coefficients are first determined, guaranteeing simultaneous Γ-stability of a finite plant family. The design method of [111,110], which will be presented in this chapter, also searches for simultaneously stabilizing controller coefficients. However, in contrast to the parameter space method no stability boundaries in the space of controller coefficients are generated. Rather, the coefficients are determined by optimizing a vector performance index, the components of which rate different design specifications.

With Chapter 11 we are entering into Part IV of this book, the part that deals with design. For an uncertain closed-loop characteristic polynomial p(s, q, k) we want to find a k = k0 such that the polynomial p(s, q, k0) is Γ-stable for all q ∈ Q. Generic situations are:1. There exists such a k0 and also a neighborhood KΓ of k0 has the same property, see Fig. 3.10. We want to pick the “best” k ∈ KΓ in consideration of further design requirements.

The examples of Chapter 1 have in common that the plant is insufficiently damped or even unstable in its operating domain Q. Thus, a primary task of a control system is stabilization with sufficient damping for all q ⋲ Q. Since eigenvalues cannot be shifted by a feedforward control system, we need a feedback structure. Fig. 2.1 shows an example of a control system with a plant family G(s,Q) = {g{s,q) |q ⋲ Q}, a feedback compensator (or controller) c(s), and a feedforward path (or prefilter) Ƒ(s).

In Chapters 8 and 9, the stability of polynomial families $$ P\left( {s,Q} \right)\; = \;\left\{ {p\left( {s,q} \right)\;|\;q\; \in \;Q} \right\}$$ (1) with p(s, q) = ao(4) + ai(4)s +… + an(q)sn and q, E [4,; 4:], i = 1, 2,…, € was investigated. The primary interest was necessary and sufficient conditions for stability. These conditions give primarily a yes or no answer to the robust stability problem. If the answer is yes, then there is some kind of stability margin of the uncertain parameters, the domain Q of the parameters can be enlarged without loosing stability. The next question is: what is the smallest perturbation in the parameters q that destabilizes the system?

It is well known that a linear time-invariant system is stable if the roots of its characteristic polynomial have a negative real part. In short we speak of “stability of a polynomial”.

In the previous chapter the stability test by zero exclusion from the value set at all frequencies was used as a concept for proofs of Kharitonov’s theorem and the edge theorem. For nonlinear parameter dependency there are no such simple results, it may be possible, however, to construct the value set and to use it for the stability test by zero exclusion. We will see that the construction of value sets can be performed extremely fast if the system has a so-called tree structure.

With Chapter 8 we are entering into Prt III of this book.It deals with specific feedback structures and with additional robustness requirements on the closed-loop system,like sector uncertainty of a nonlinearity,Gamma-stability and discrete-time implementation of a robust controller.

By assuming controller structures in Chapter 2 we have generated several examples of closed-loop characteristic polynomials p(s, q,k), where the vector k contains the free design parameters in the fixed controller structure and q contains the uncertain plant parameters in a given operating domain Q, i.e. q ∈Q.

A mathematical model for the plant dynamics is the basis for analysis and design of control systems. For linear time-invariant systems we commonly have a state space model of the form $$\eqalign{{\bf\it{\dot x}}(t)= {\bf\it Ax}(t)+ {\bf\it Bu}(t)\cr{\bf\it y}(t)= {\bf\it Cx}(t)}$$ (1.0.1) with u the vector x of input signals (manipulated variables), the state vector , and the vector of output signals y (performance variables). The output signals are often comprised of those variables that are measured and hence available for feedback.