Unveiling success determinants for AMB-assisted phase expansion of fusion proteins in ARP/wARP.

Fusion proteins (FPs) are frequently utilized as a biotechnological tool in the determination of macromolecular structures using X-ray methods. Here, we explore the use of different protein tags in various FP, to obtain initial phases by using them in a partial molecular replacement (MR) and constructing the remaining FP structure with ARP/wARP. Usually, the tag is removed prior to crystallization, however leaving the tag on may facilitate crystal formation, and structural determination by expanding phases from known to unknown segments of the complex. In this study, the Protein Data Bank was mined for an up-to-date list of FPs with the most used protein tags, Maltose Binding Protein (MBP), Green Fluorescent Protein (GFP), Thioredoxin (TRX), Glutathione transferase (GST) and the Small Ubiquitin-like Modifier Protein (SUMO). Partial MR using the protein tag, followed by automatic model building, was tested on a subset of 116 FP. The efficiency of this method was analyzed and factors that influence the coordinate construction of a substantial portions of the fused protein were identified. Using MBP, GFP, and SUMO as phase generators it was possible to build at least 75 % of the protein of interest in 36 of the 116 cases tested. Our results reveal that tag selection has a significant impact; tags with greater structural stability, such as GFP, increase the success rate. Further statistical analysis identifies that resolution, Wilson B factor, solvent percentage, completeness, multiplicity, protein tag percentage in the FP (considering amino acids), and the linker length play pivotal roles using our approach. In cases where a structural homologous is absent, this method merits inclusion in the toolkit of protein crystallographers.

Muscle forces acting on the greater trochanter lead to a dorsal warping of the apophyseal growth plate.

The apophyseal growth plate of the greater trochanter, unlike most other growth plates of the human body, exhibits a curved morphology that results in a divergent pattern resembling an open crocodile mouth on plain antero-posterior radiographs. To quantify the angular alignment of the growth plate and to draw conclusions about the function of the muscles surrounding it, we analyzed 57 MRI images of 51 children and adolescents aged 3-17 years and of six adults aged 18-52 years. We measured the angulation of the plate relative to the horizontal plane (AY angle) and the trajectories of the muscles attaching to the greater trochanter of the proximal femur. From anterior to posterior, the AY angle shows a decrease of 33.44°. In the anterior third, the cartilage is angled at a mean of 51.64°, and in the posterior third, the mean angulation is 18.6°. This indicates that the cartilage in the anterior region of the greater trochanteric apophysis is subject to more vertically oriented force vectors compared to the posterior region, as the growth plates align perpendicular to the force vectors acting on them. Combining the measured muscle trajectories with the physiological cross-sectional areas (PCSA) available from the literature revealed that, in addition to the known internal and external lateral traction ligament systems, a third, dorsally located traction ligament system exists that may be responsible for the dorsal deformation of the AY angle.

Dynamic time warp analysis of individual symptom trajectories in individuals with bipolar disorder.

BACKGROUND: Manic and depressive mood states in bipolar disorder (BD) may emerge from the non-linear relations between constantly changing mood symptoms exhibited as a complex dynamic system. Dynamic Time Warp (DTW) is an algorithm that may capture symptom interactions from panel data with sparse observations over time. METHODS: The Young Mania Rating Scale and Quick Inventory of Depressive Symptomatology were repeatedly assessed in 141 individuals with BD, with on average 5.5 assessments per subject every 3-6 months. Dynamic Time Warp calculated the distance between each of the 27 × 27 pairs of standardized symptom scores. The changing profile of standardized symptom scores of BD participants was analyzed in individual subjects, yielding symptom dimensions in aggregated group-level analyses. Using an asymmetric time-window, symptom changes that preceded other symptom changes (i.e., Granger causality) yielded a directed network. RESULTS: The mean age of the BD participants was 40.1 (SD 13.5) years old, and 60% were female participants. Idiographic symptom networks were highly variable between subjects. Yet, nomothetic analyses showed five symptom dimensions: core (hypo)mania (6 items), dysphoric mania (5 items), lethargy (7 items), somatic/suicidality (6 items), and sleep (3 items). Symptoms of the "Lethargy" dimension showed the highest out-strength, and its changes preceded those of "somatic/suicidality," while changes in "core (hypo)mania" preceded those of "dysphoric mania." CONCLUSION: Dynamic Time Warp may help to capture meaningful BD symptom interactions from panel data with sparse observations. It may increase insight into the temporal dynamics of symptoms, as those with high out-strength (rather than high in-strength) could be promising targets for intervention.

Breaking the cycle: Identifying key symptom pathways of eating disorders and the influence of childhood maltreatment.

BACKGROUND: Most network analyses on central symptoms in eating disorders (EDs) have been cross-sectional. Longitudinal within-person analyses of therapy processes are scarce. Our aim was to investigate central change processes in therapy in a transdiagnostic sample, considering the influence of childhood maltreatment. METHOD: We employed dynamic time warping analyses to identify clusters of symptoms that tended to change similarly across therapy on a within-person level. Symptoms were measured by a 28-item Eating Disorder Examination Questionnaire (EDE-Q). Furthermore, we examined the temporal direction of symptom change to identify symptoms that tended to precede and predict other symptoms. Finally, we estimated two directed, temporal networks in patients with and without a history of childhood maltreatment. RESULTS: Our analysis included 122 ED patients (mean age = 30.9, SD = 9.7; illness duration = 14.2 years, SD = 8.9; prior treatment = 5.6 years, SD = 5.1). The initial network revealed three robust clusters of symptoms over time: (1) ED behavior, (2) inhibition, and (3) cognitions and feelings about body and weight. Overvaluation of shape had the highest out-strength preceding and predicting other symptoms. Dissatisfaction with weight preceded and predicted other symptoms in the maltreatment network. The non-maltreatment network showed a similar structure to the transdiagnostic network. CONCLUSION: Targeting and monitoring feelings and cognitions related to shape may be crucial for achieving lasting symptom improvement in a transdiagnostic sample. Furthermore, our findings highlight the need for further investigation into the different processes driving EDs based on maltreatment status. PUBLIC SIGNIFICANCE: There is limited understanding of the processes that occur for patients with eating disorders between admission and discharge in therapy, especially for patients with a history of childhood maltreatment. Our analyses suggest that changes in cognitions regarding shape precede and predict changes in cognitions about weight. Different processes may be driving the eating disorder according to maltreatment status, which might further illuminate the riddle of dropout and relapse in therapy for patients with a history of childhood maltreatment. These findings suggest the need for further investigation into the specific dynamics occurring during therapy for individuals with a history of childhood maltreatment.

Temporal Directionality Between Symptoms During Treatment of Depressed Inpatients: A Dynamic Time Warp Network Analysis.

BACKGROUND: Depression is generally perceived from the perspective of the common-cause disease model. However, the network perspective assumes mutual influence of individual symptoms and stresses the importance of investigating symptom dynamics. Gaining a better understanding of symptom dynamics within individuals might contribute to more effective treatments. METHODS: Current exploratory longitudinal research studied the associations and directionality between 43 symptoms from the generic questionnaire Symptom Questionnaire-48 (SQ-48) using dynamic time warp (DTW) analyses, in which trajectories with similar time-dependent patterns can be identified. Data from individuals were analysed first, yielding distance matrices for all symptom trajectories, after which the data were aggregated. RESULTS: The 148 included patients were all admitted for the treatment of their clinical depression. Undirected DTW analyses of three patients with longer time series but otherwise randomly chosen showed large variability among individuals. Group-level undirected DTW analyses showed numerous significant edges between symptoms, largely clustering symptoms according to the eight pre-existing subscales of the SQ-48. Group-level directed DTW analyses showed five symptoms with significant outstrength: 'hopeless', 'restless', 'down/depressed', 'feeling tense' and 'no enjoyment', meaning that change in these key symptoms preceded change in other symptoms. LIMITATIONS: The 43 included symptoms of the SQ-48 primarily focus on internalizing problems in severely depressed inpatients, potentially limiting generalizability. CONCLUSIONS: DTW networks provided us with five key symptoms based on the dynamics of symptom scores. Future studies could explore whether process-based therapy targeted at symptoms with high outstrength might result in more effectivity as part of personalized treatment.

Exact distributed kinetic Monte Carlo simulations for on-lattice chemical kinetics: lessons learnt from medium- and large-scale benchmarks.

Kinetic Monte Carlo (KMC) simulations have been instrumental in multiscale catalysis studies, enabling the elucidation of the complex dynamics of heterogeneous catalysts and the prediction of macroscopic performance metrics, such as activity and selectivity. However, the accessible length- and time-scales have been a limiting factor in such simulations. For instance, handling lattices containing millions of sites with 'traditional' sequential KMC implementations is prohibitive owing to large memory requirements and long simulation times. We have recently established an approach for exact, distributed, lattice-based simulations of catalytic kinetics which couples the Time-Warp algorithm with the Graph-Theoretical KMC framework, enabling the handling of complex adsorbate lateral interactions and reaction events within large lattices. In this work, we develop a lattice-based variant of the Brusselator system, a prototype chemical oscillator pioneered by Prigogine and Lefever in the late 60s, to benchmark and demonstrate our approach. This system can form spiral wave patterns, which would be computationally intractable with sequential KMC, while our distributed KMC approach can simulate such patterns 15 and 36 times faster with 625 and 1600 processors, respectively. The medium- and large-scale benchmarks thus conducted, demonstrate the robustness of the approach, and reveal computational bottlenecks that could be targeted in further development efforts. This article is part of a discussion meeting issue 'Supercomputing simulations of advanced materials'.

Network structure of time-varying depressive symptoms through dynamic time warp analysis in late-life depression.

OBJECTIVES: Late-life major depressive disorder (MDD) can be conceptualized as a complex dynamic system. However, it is not straightforward how to analyze the covarying depressive symptoms over time in case of sparse panel data. Dynamic time warping (DTW) analysis may yield symptom networks and dimensions both at the patient and group level. METHODS: In the Netherlands Study of Depression in Older People (NESDO) depressive symptoms were assessed every 6 months using the 30-item Inventory of Depressive Symptomatology (IDS) with up to 13 assessments per participant. Our sample consisted of 182 persons, aged ≥ 60 years, with an IDS total score of 26 or higher at baseline. Symptom networks dimensions, and centrality metrics were analyzed using DTW and Distatis analyses. RESULTS: The mean age was 69.8 years (SD 7.1), with 69.0% females, and a mean IDS score of 38.0 (SD = 8.7). DTW enabled visualization of an idiographic symptom network in a single NESDO participant. In the group-level nomothetic approach, four depressive symptom dimensions were identified: "core symptoms", "lethargy/somatic", "sleep", and "appetite/atypical". Items of the "internalizing symptoms" dimension had the highest centrality, whose symptom changes over time were most similar to those changes of other symptoms. CONCLUSIONS: DTW revealed symptom networks and dimensions based on the within-person symptom changes in older MDD patients. Its centrality metrics signal the most influential symptoms, which may aid personalized care.

Influence of head orientation and implantation site of a novel transcutaneous bone conduction implant on MRI metal artifact reduction sequence.

PURPOSE: The use of magnetic resonance imaging (MRI) is often limited in patients with auditory implants because of the presence of metallic components and magnets. The aim of this study was to evaluate the clinical usefulness of a customized MRI sequence for metal artifact suppression in patients with BONEBRIDGETM BCI 602 implants (MED-EL, Innsbruck, Austria), the successor of the BCI 601 model. METHODS: Using our in-house developed and customized metal artifact reduction sequence (SEMAC-VAT WARP), MRI artifacts were evaluated qualitatively and quantitatively. MRI sequences were performed with and without artifact reduction on two whole head specimens with and without the BCI 602 implant. In addition, the influence of two different implantation sites (mastoid versus retrosigmoid) and head orientation on artifact presence was investigated. RESULTS: Artifact volume was reduced by more than the 50%. Results were comparable with those obtained with the BCI 601, showing no significant differences in the dimensions of artifacts caused by the implant. CONCLUSION: SEMAC-VAT WARP was once more proved to be efficient at reducing metal artifacts on MR images. The dimensions of artifacts associated with the BCI 602 are not smaller than those caused by the BCI 601.

Eating disorder psychopathology dimensions based on individual co-occurrence patterns of symptoms over time: a dynamic time warp analysis in a large naturalistic patient cohort.

PURPOSE: Most of the network approaches in eating disorders found the highest degree of centrality for symptoms related to weight and shape concerns. However, longitudinal analyses are scarce and may increase our insight of the complex characteristics and dynamics over time. In the current study, an alternative non-linear method to perform longitudinal network analyses, the dynamic time warp approach, was used to examine whether robust dimensions of eating disorder psychopathology symptoms could be found based on the individual dynamic interplay of eating disorder symptoms co-occurrence patterns in time. METHODS: The study sample included a naturalistic cohort of patients (N = 255) with all eating disorder subtypes who were assessed with the eating disorder examination questionnaire (EDE-Q) at a minimum of four times during treatment. Dynamic time warp analyses yielded distance matrices within each individual patient, which were subsequently aggregated into symptom networks and dimensions at the group level. RESULTS: Aggregation of the individual distance matrices at the group level yielded four robust symptom dimensions: 1. restraint/rules, 2. secret eating/fasting, 3. worries/preoccupation, and 4. weight and shape concern. The items 'fear of weight gain' and 'guilt' were bridge symptoms between the dimensions 1, 3 and 4. CONCLUSION: Dynamic time warp could capture the within-person dynamics of eating disorder symptoms. Sumscores of the four dimensions could be used to follow patients over time. This approach could be applied in the future to visualize eating disorder symptom dynamics and signal the central symptoms within an individual and groups of patients. LEVEL OF EVIDENCE: Level III: evidence obtained from well-designed cohort or case-control analytic studies. .

New classes of tests for the Weibull distribution using Stein's method in the presence of random right censoring.

We develop two new classes of tests for the Weibull distribution based on Stein's method. The proposed tests are applied in the full sample case as well as in the presence of random right censoring. We investigate the finite sample performance of the new tests using a comprehensive Monte Carlo study. In both the absence and presence of censoring, it is found that the newly proposed classes of tests outperform competing tests against the majority of the distributions considered. In the cases where censoring is present we consider various censoring distributions. Some remarks on the asymptotic properties of the proposed tests are included. We present another result of independent interest; a test initially proposed for use with full samples is amended to allow for testing for the Weibull distribution in the presence of censoring. The techniques developed in the paper are illustrated using two practical examples.

COVID-19 Vaccines: "Warp Speed" Needs Mind Melds, Not Warped Minds.

In this review, we address issues that relate to the rapid "Warp Speed" development of vaccines to counter the COVID-19 pandemic. We review the antibody response that is triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of humans and how it may inform vaccine research. The isolation and properties of neutralizing monoclonal antibodies from COVID-19 patients provide additional information on what vaccines should try to elicit. The nature and longevity of the antibody response to coronaviruses are relevant to the potency and duration of vaccine-induced immunity. We summarize the immunogenicity of leading vaccine candidates tested to date in animals and humans and discuss the outcome and interpretation of virus challenge experiments in animals. By far the most immunogenic vaccine candidates for antibody responses are recombinant proteins, which were not included in the initial wave of Warp Speed immunogens. A substantial concern for SARS-CoV-2 vaccines is adverse events, which we review by considering what was seen in studies of SARS-CoV-1 and Middle East respiratory syndrome coronavirus (MERS-CoV) vaccines. We conclude by outlining the possible outcomes of the Warp Speed vaccine program, which range from the hoped-for rapid success to a catastrophic adverse influence on vaccine uptake generally.

Rapid growth in the COVID-19 era.

ABSTRACT: From Operation Warp Speed to the lipid mRNA vaccine, the COVID-19 pandemic has been a watershed moment for technological development, production, and implementation. The scale and pace of innovation and global collaboration has likely not been experienced since World War II. This article highlights some of the engineering accomplishments that occurred during the pandemic. We provide a broad overview of the technological achievements in vaccine design, antibody engineering, drug repurposing, and rapid diagnostic testing. We also discuss what the future of these technologies and the future of large-scale collaborations might look like moving forward.

Many paths, one destination: mapping the movements of a kleptoparasitic spider on the host's web.

Kleptoparasitic spiders live and forage in the webs of other spiders. Using vibratory cues generated by the host spider during prey capture, they leave their resting positions in the upper peripheries of the host web and move towards the centre of the web where they feed along with the host spider or steal small pieces of prey. While the triggers for initiating the foraging raids are known, there is little information about the fine-scale trajectory dynamics in this model system. We mapped the movement of the kleptoparasite Argyrodes elevatus in the web of the host Trichonephila clavipes. We filmed the movement of the kleptoparasite spiders and quantified the trajectory shape, speed, heading directions and path revisitation. Our results show that kleptoparasitic spider movement is spatially structured, with higher levels of speed at the peripheries and slower in the centre of the web. We found a high level of variation in trajectory shapes between individuals. We found that the majority of heading orientations were away from the hub suggesting that detouring or repeated approaches are an essential component of kleptoparasite movement strategies. Our results of the revisitation rate also confirm this pattern, where locations close to the hub were revisited more often than in the periphery. The kleptoparasite-host spider system is a promising model to study fine-scale movement patterns in small bounded spaces.

Helpful Lessons and Cautionary Tales: How Should COVID-19 Drug Development and Access Inform Approaches to Non-Pandemic Diseases?

After witnessing extraordinary scientific and regulatory efforts to speed development of and access to new COVID-19 interventions, patients facing other serious diseases have begun to ask "where's our Operation Warp Speed?" and "why isn't Emergency Use Authorization an option for our health crises?" Although this pandemic bears a number of unique features, the response to COVID-19 offers translatable lessons, in both its successes and failures, for non-pandemic diseases. These include the importance of collaborating across sectors, supporting the highest-priority research efforts, adopting rigorous and innovative trial designs, and sharing reliable information quickly. In addition, the regulatory response to the pandemic demonstrates that lowering standards for marketing authorization can result in increased safety concerns, missed opportunities for research and treatment, and delays in determining what works. Accordingly, policymakers and patient advocates seeking to build on the COVID-19 experience for non-pandemic diseases with unmet treatment needs should focus their efforts on promoting robust and efficient research designs, improving access to clinical trials, and facilitating use of the Food and Drug Administration's existing Expanded Access pathway.

MRI Metal Artifact Reduction Sequence for Auditory Implants: First Results with a Transcutaneous Bone Conduction Implant.

OBJECTIVE: Magnetic resonance imaging (MRI) is often limited in patients with auditory implants because of the presence of metallic components and magnets. The aim of this study was to evaluate the clinical usefulness of a customized MRI sequence for metal artifact suppression for patients with implants in the temporal bone region, specifically patients with a transcutaneous bone conduction implant. METHODS: Two whole head specimens were unilaterally implanted with a transcutaneous bone conduction implant. MRI examinations with and without a primarily self-build sequence (SEMAC-VAT WARP) for metal artifact suppression were performed. The diagnostic usefulness of the acquired MRI scans was rated independently by two neuroradiologists. The sequence was also used to acquire postimplantation follow-up MRI in a patient with a transcutaneous bone conduction implant. RESULTS: The customized SEMAC-VAT WARP sequence significantly improved the diagnostic usefulness of the postimplantation MRIs. The image acquisition time was 12 min and 20 s for the T1-weighted and 12 min and 12 s for the T2-weighted MRI. There was good agreement between the two blinded raters (Cohen's κ = 0.61, p < 0.001). CONCLUSION: The sequence for metal artifact reduction optimized in Bern enables MRI at 1.5 T in patients with active transcutaneous bone conduction implants without sacrificing diagnostic imaging quality. Particularly on the implanted side, imaging of intracranial and supra- and infratentorial brain pathologies is clinically more valuable than standard diagnostic MRI without any artifact reduction sequences.

Comparative Analysis of Warp Function for Digital Image Correlation-Based Accurate Single-Shot 3D Shape Measurement.

Digital image correlation (DIC)-based stereo 3D shape measurement is a kind of single-shot method, which can achieve high precision and is robust to vibration as well as environment noise. The efficiency of DIC has been greatly improved with the proposal of inverse compositional Gauss-Newton (IC-GN) operators for both first-order and second-order warp functions. Without the algorithm itself, both the registration accuracy and efficiency of DIC-based stereo matching for shapes with different complexities are closely related to the selection of warp function, subset size, and convergence criteria. Understanding the similarity and difference of the impacts of prescribed subset size and convergence criteria on first-order and second-order warp functions, and how to choose a proper warp function and set optimal subset size as well as convergence criteria for different shapes are fundamental problems in realizing efficient and accurate 3D shape measurement. In this work, we present a comparative analysis of first-order and second-order warp functions for DIC-based 3D shape measurement using IC-GN algorithm. The effects of subset size and convergence criteria of first-order and second-order warp functions on the accuracy and efficiency of DIC are comparatively examined with both simulation tests and real experiments. Reference standards for the selection of warp function for different kinds of 3D shape measurement and the setting of proper convergence criteria are recommended. The effects of subset size on the measuring precision using different warp functions are also concluded.

The Cartilage Warp Prevention Suture.

BACKGROUND: Costal cartilage graft warping can challenge rhinoplasty surgeons and compromise outcomes. We propose a technique, the "warp control suture," for eliminating cartilage warp and examine outcomes in a pilot group. METHODS: The warp control suture is performed in the following manner: Harvested cartilage is cut to the desired shape and immersed in saline to induce warping. A 4-0 or 5-0 PDS suture, depending the thickness of the cartilage, is passed from convex to concave then concave to convex side several times about 5-6 mm apart, finally tying the suture on the convex side with sufficient tension to straighten the cartilage. First an ex vivo experiment was performed in 10 specimens from 10 different patients. Excess cartilage was sutured and returned to saline for a minimum of 15 min and then assessed for warping compared to cartilage cut in the identical shape also soaked in saline. Then, charts of nine subsequent patients who received the warp control suture on 16 cartilage grafts by the senior author (BG) were retrospectively reviewed. Inclusion of study subjects required at least 6 months of follow-up with standard rhinoplasty photographs. Postoperative complications and evidence of warping were recorded. RESULTS: In the ex vivo experiment, none of the 10 segments demonstrated warping after replacement in saline, whereas all the matching segments demonstrated significant additional warping. Clinically, no postoperative warping was observed in any of the nine patients at least 6 months postoperatively. One case of minor infection was observed in an area away from the graft and treated with antibiotics. No warping or other complications were noted. CONCLUSION: The warp control suture technique presented here effectively straightens warped cartilage graft and prevents additional warping. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Quantitative susceptibility mapping at 3 T: comparison of acquisition methodologies.

Quantitative susceptibility mapping (QSM) is fast becoming a routine clinical tool in the evaluation and assessment of neurological diseases. Unfortunately, there is currently no established standard scanning protocol, and it is uncertain whether different acquisition strategies alter the derived estimates of magnetic susceptibility. Here, we compare some key deep grey matter susceptibility values in healthy adults acquired from various QSM sequences using either unipolar or bipolar readout gradients, accelerated imaging or not, and gradient-warp correction or not. Four healthy adult volunteers were scanned three times each within 4 days at 3 T. The eight different QSM combinations were acquired in different randomised order for each session, and then co-registered to an anatomical atlas. The average and standard deviations of magnetic susceptibilities in the caudate, putamen, red nucleus, internal and external globus pallidus were used in a linear mixed effects model to determine the influence of the various acquisition parameters. Gradient-warp correction was the only statistically significant fixed effect (p < 0.01), but its impact was small (~5% change) compared with the overall fixed effects. The random effects coefficients (i.e. the various tissues) were statistically significant. Based on our limited multiple observations in healthy adult volunteers, the susceptibilities in deep grey matter are statistically equivalent when QSM source data are acquired with or without accelerated imaging using either unipolar or bipolar readout gradients. There is, however, a statistically meaningful, but small, difference if gradient-warp correction is used or not. Copyright © 2016 John Wiley & Sons, Ltd.

Correction of gradient nonlinearity artifacts in prospective motion correction for 7T MRI.

PURPOSE: To demonstrate the effect of gradient nonlinearity and develop a method for correction of gradient nonlinearity artifacts in prospective motion correction (Mo-Co). METHODS: Nonlinear gradients can induce geometric distortions in magnetic resonance imaging, leading to pixel shifts with errors of up to several millimeters, thereby interfering with precise localization of anatomical structures. Prospective Mo-Co has been extended by conventional gradient warp correction applied to individual phase encoding steps/groups during the reconstruction. The gradient-related displacements are approximated using spherical harmonic functions. In addition, the combination of this method with a retrospective correction of the changes in the coil sensitivity profiles relative to the object (augmented sensitivity encoding (SENSE) reconstruction) was evaluated in simulation and experimental data. RESULTS: Prospective Mo-Co under gradient fields and coils sensitivity inconsistencies results in residual blurring, spatial distortion, and coil sensitivity mismatch artifacts. These errors can be considerably mitigated by the proposed method. High image quality with very little remaining artifacts was achieved after a few iterations. The relative image errors decreased from 25.7% to below 17.3% after 10 iterations. CONCLUSION: The combined correction of gradient nonlinearity and sensitivity map variation leads to a pronounced reduction of residual motion artifacts in prospectively motion-corrected data.

Morphometric variation in bluegill Lepomis macrochirus and green sunfish Lepomis cyanellus in lentic and lotic systems.

Bluegill Lepomis macrochirus and green sunfish Lepomis cyanellus were examined using geometric morphometrics to evaluate the variation in morphology between fishes that reside in lentic (e.g. lakes) and lotic (e.g. streams) ecosystems. Live fishes were collected from reservoirs and rivers in central Indiana, while additional fishes were sampled from museum collections at Ball State University and the Illinois Natural History Survey. Male and female L. macrochirus and female L. cyanellus from lentic systems display a deeper body than those from lotic systems, while no differences were found in male L. cyanellus morphometry. A deeper body promotes greater manoeuverability, typically desirable in lentic systems. In contrast, the more streamlined body of the fishes found in lotic systems reduces drag as it contends with flowing water, ultimately maximizing energy efficiency. The absence of morphological differences, such as those found in male L. cyanellus, may be caused by fish occupying both lentic and lotic systems, from the population not having been present in the body of water long enough to display any adaptations, or from a lack of statistical power caused by the small sample size.