Impact of Obstructive Sleep Apnea Syndrome on Time to Complete Recovery of Continence After Robot-Assisted Radical Prostatectomy: A Propensity Score Matching Analysis.

Background: Postoperative urinary incontinence after robot-assisted radical prostatectomy (RARP) represents a bothersome side effect, which may permanently affect patient's quality of life. Several studies have demonstrated that obstructive sleep apnea syndrome (OSAS) is associated with urinary symptoms such as urge incontinence, overactive bladder, and nocturia. In this study, we sought to further explore the effect of OSAS on urinary continence after RARP. Methods: We queried our prospectively collected institutional RARP database and identified 82 patients with OSAS and 131 controls, which were matched for age and body mass index (BMI), with available follow-up data for continence. To minimize selection bias, we conducted a propensity score-matched analysis. Patient's characteristics and urinary continence outcomes were compared between the two groups before and after propensity-score matching. Kaplan-Meier curves were constructed to assess the difference in continence between the two groups. Results are presented as means with standard deviations and percentages with 95% confidence intervals (CIs). Results: A total of 213 patients were included in the analysis, of whom 82 with OSAS and 131 with non-OSAS (control group). The mean age of the total cohort was 61.7 ± 6.96 years, the mean BMI was 30.4 ± 5.36, and 52% of the cohort were classified as obese (BMI ≥30). In post-propensity score-matched analyses, there was no significant difference in baseline demographics and tumor characteristics between the two groups (included 82 cases in each group). The median time to continence was 6.6 months for the control group as compared with 13.0 months for the OSAS group (p < 0.001). At 12 months the continence rate for the OSAS group was 41.2% (95% CI: 28.9%-51.4%) as compared with 61.7% (95% CI: 28.5%-71.5%) for the control group. At 24 months the continence rate for the OSAS group was 68.7% (95% CI: 56%-77.7%) as compared with 90.8% (95% CI: 79%-96%) for the control group. Conclusion: On matched analysis, we found that patients with OSAS tended to demonstrate worse urinary continence recovery as compared with patients without OSAS. Additional investigation will be necessary to confirm these initial findings.

Reusing personal protective equipment (PPE) did not increase surgical site infection in trauma surgical patients during the COVID-19 pandemic: A retrospective cohort study in Michigan Trauma Centers.

BACKGROUND: Reuse of personal protective equipment (PPE), masks more specifically, during the COVID-19 pandemic was common. The primary objective of this study was to compare pre-pandemic surgical site infection (SSI) rates prior to reuse of PPE, to pandemic SSI rates after reuse of PPE in trauma surgical patients. METHODS: A retrospective cohort analysis collected from the Michigan Trauma Quality Improvement Program database was performed. The pre-COVID cohort was from March 1, 2019 to December 31, 2019 and post-COVID cohort was March 1, 2020 to December 31,2020. Descriptive statistics were used to assess differences between variables in each cohort. RESULTS: Nearly half (49.8%) of our cohort (n = 48,987) was in the post-COVID group. There was no significant difference in frequency of operative intervention between groups (p > .05). There was no significant increase (p > .05) between pre- and post-COVID cohorts for superficial, deep, or organ space SSI when reuse of masks was common. CONCLUSION: Reuse of PPE did not lead to an increase in SSI in surgical patients. These findings are consistent with previous studies, but the first to be described in the trauma surgical patient population. Studies such as this may help inform further discussion regarding PPE usage as we continue to emerge from the current pandemic with the continuous threat of future pandemics.

Effects of dietary methionine restriction on age-related changes in perivascular and beiging adipose tissues in the mouse.

OBJECTIVE: Perivascular adipose tissue (PVAT) regulates vascular health. Dietary methionine restriction (MetR) impacts age-related adiposity, and this study addresses its effects in PVAT. METHODS: Male C57BL/6 mice at 8, 52, and 102 weeks of age were fed a standard (0.86%) or low-methionine (0.12%) diet for 52 weeks in 8-week-old and 52-week-old mice and for 15 weeks in 102-week-old mice. RESULTS: Mice with dietary MetR were resistant to weight gain and maintained a healthy blood profile. Aging increased lipid accumulation, and MetR reversed this phenotype. Notch signaling in inguinal white adipose tissue (iWAT) was decreased by MetR but increased in gonadal white adipose tissue. However, the Notch phenotype of brown adipose tissue (BAT) was not affected by MetR. Uncoupling protein 1 (UCP1) was increased in PVAT, iWAT, and BAT by MetR when initiated in young mice, but this effect was lost in middle-aged mice. CONCLUSIONS: Lipid in mouse PVAT peaked at 1 year of age, consistent with peak body mass. MetR reduced body weight, normalized metabolic parameters, and decreased lipid in PVAT in all age cohorts. Mice fed a MetR diet from early maturity to 1 year of age displayed an increased thermogenic adipocyte phenotype in iWAT, PVAT, and BAT, all tissues with thermogenic capacity.

A dynamic subset of network interactions underlies tuning to natural movements in marmoset sensorimotor cortex.

Mechanisms of computation in sensorimotor cortex must be flexible and robust to support skilled motor behavior. Patterns of neuronal coactivity emerge as a result of computational processes. Pairwise spike-time statistical relationships, across the population, can be summarized as a functional network (FN) which retains single-unit properties. We record populations of single-unit neural activity in forelimb sensorimotor cortex during prey-capture and spontaneous behavior and use an encoding model incorporating kinematic trajectories and network features to predict single-unit activity during forelimb movements. The contribution of network features depends on structured connectivity within strongly connected functional groups. We identify a context-specific functional group that is highly tuned to kinematics and reorganizes its connectivity between spontaneous and prey-capture movements. In the remaining context-invariant group, interactions are comparatively stable across behaviors and units are less tuned to kinematics. This suggests different roles in producing natural forelimb movements and contextualizes single-unit tuning properties within population dynamics.

Targeted Next-Generation Sequencing Reveals Divergent Clonal Evolution in Components of Composite Pleomorphic Xanthoastrocytoma-Ganglioglioma.

Composite pleomorphic xanthoastrocytoma-ganglioglioma (PXA-GG) is an extremely rare central nervous system neoplasm with 2 distinct but intermingled components. Whether this tumor represents a "collision tumor" of separate neoplasms or a monoclonal neoplasm with divergent evolution is poorly understood. Clinicopathologic studies and capture-based next generation sequencing were performed on extracted DNA from all available PXA-GG at 2 medical centers. Five PXA-GG were diagnosed in 1 male and 4 female patients ranging from 13 to 25 years in age. Four arose within the cerebral hemispheres; 1 presented in the cerebellar vermis. DNA was sufficient for analysis in 4 PXA components and 3 GG components. Four paired PXA and GG components harbored BRAF p.V600E hotspot mutations. The 4 sequenced PXA components demonstrated CDKN2A homozygous deletion by sequencing with loss of p16 (protein product of CDKN2A) expression by immunohistochemistry, which was intact in all assessed GG components. The PXA components also demonstrated more frequent copy number alterations relative to paired GG components. In one PXA-GG, shared chromosomal copy number alterations were identified in both components. Our findings support divergent evolution of the PXA and GG components from a common BRAF p.V600E-mutant precursor lesion, with additional acquisition of CDKN2A homozygous deletion in the PXA component as is typically seen in conventional PXA.

Validating markerless pose estimation with 3D X-ray radiography.

To reveal the neurophysiological underpinnings of natural movement, neural recordings must be paired with accurate tracking of limbs and postures. Here, we evaluated the accuracy of DeepLabCut (DLC), a deep learning markerless motion capture approach, by comparing it with a 3D X-ray video radiography system that tracks markers placed under the skin (XROMM). We recorded behavioral data simultaneously with XROMM and RGB video as marmosets foraged and reconstructed 3D kinematics in a common coordinate system. We used the toolkit Anipose to filter and triangulate DLC trajectories of 11 markers on the forelimb and torso and found a low median error (0.228 cm) between the two modalities corresponding to 2.0% of the range of motion. For studies allowing this relatively small error, DLC and similar markerless pose estimation tools enable the study of increasingly naturalistic behaviors in many fields including non-human primate motor control.

Microwave Radiometry at Frequencies From 500 to 1400 MHz: An Emerging Technology for Earth Observations.

Microwave radiometry has provided valuable spaceborne observations of Earth's geophysical properties for decades. The recent SMOS, Aquarius, and SMAP satellites have demonstrated the value of measurements at 1400 MHz for observing surface soil moisture, sea surface salinity, sea ice thickness, soil freeze/thaw state, and other geophysical variables. However, the information obtained is limited by penetration through the subsurface at 1400 MHz and by a reduced sensitivity to surface salinity in cold or wind-roughened waters. Recent airborne experiments have shown the potential of brightness temperature measurements from 500-1400 MHz to address these limitations by enabling sensing of soil moisture and sea ice thickness to greater depths, sensing of temperature deep within ice sheets, improved sensing of sea salinity in cold waters, and enhanced sensitivity to soil moisture under vegetation canopies. However, the absence of significant spectrum reserved for passive microwave measurements in the 500-1400 MHz band requires both an opportunistic sensing strategy and systems for reducing the impact of radio-frequency interference. Here, we summarize the potential advantages and applications of 500-1400 MHz microwave radiometry for Earth observation and review recent experiments and demonstrations of these concepts. We also describe the remaining questions and challenges to be addressed in advancing to future spaceborne operation of this technology along with recommendations for future research activities.

Chronic wireless neural population recordings with common marmosets.

Marmosets are an increasingly important model system for neuroscience in part due to genetic tractability and enhanced cortical accessibility, due to a lissencephalic neocortex. However, many of the techniques generally employed to record neural activity in primates inhibit the expression of natural behaviors in marmosets precluding neurophysiological insights. To address this challenge, we have developed methods for recording neural population activity in unrestrained marmosets across multiple ethological behaviors, multiple brain states, and over multiple years. Notably, our flexible methodological design allows for replacing electrode arrays and removal of implants providing alternative experimental endpoints. We validate the method by recording sensorimotor cortical population activity in freely moving marmosets across their natural behavioral repertoire and during sleep.

Sex and Race-Ethnic Disparities in Door-to-CT Time in Acute Ischemic Stroke: The Florida Stroke Registry.

Background Less than 40% of acute stroke patients have computed tomography (CT) imaging performed within 25 minutes of hospital arrival. We aimed to examine the race-ethnic and sex differences in door-to-CT (DTCT) ≤25 minutes in the FSR (Florida Stroke Registry). Methods and Results Data were collected from 2010 to 2018 for 63 265 patients with acute ischemic stroke from the FSR and secondary analysis was performed on 15 877 patients with intravenous tissue plasminogen activator-treated ischemic stroke. Generalized estimating equation models were used to determine predictors of DTCT ≤25. DTCT ≤25 was achieved in 56% of cases of suspected acute stroke, improving from 36% in 2010 to 72% in 2018. Women (odds ratio [OR], 0.90; 95% CI, 0.87-0.93) and Black (OR, 0.88; CI, 0.84-0.94) patients who had strokes were less likely, and Hispanic patients more likely (OR, 1.07; CI, 1.01-1.14), to achieve DTCT ≤25. In a secondary analysis among intravenous tissue plasminogen activator-treated patients, 81% of patients achieved DTCT ≤25. In this subgroup, women were less likely to receive DTCT ≤25 (0.85, 0.77-0.94) whereas no significant differences were observed by race or ethnicity. Conclusions In the FSR, there was considerable improvement in acute stroke care metric DTCT ≤25 in 2018 in comparison to 2010. However, sex and race-ethnic disparities persist and require further efforts to improve performance and reduce these disparities.

The immunohistochemical, DNA methylation, and chromosomal copy number profile of cauda equina paraganglioma is distinct from extra-spinal paraganglioma.

Paragangliomas are neuroendocrine tumors of the autonomic nervous system that are variably clinically functional and have a potential for metastasis. Up to 40% occur in the setting of a hereditary syndrome, most commonly due to germline mutations in succinate dehydrogenase (SDHx) genes. Immunohistochemically, paragangliomas are characteristically GATA3-positive and cytokeratin-negative, with loss of SDHB expression in most hereditary cases. In contrast, the rare paragangliomas arising in the cauda equina (CEP) or filum terminale region have been shown to be hormonally silent, clinically indolent, and have variable keratin expression, suggesting these tumors may represent a separate pathologic entity. We retrospectively evaluated 17 CEPs from 11 male and 6 female patients with a median age of 38 years (range 21-82), none with a family history of neuroendocrine neoplasia. Six of the 17 tumors demonstrated prominent gangliocytic or ganglioneuromatous differentiation. By immunohistochemistry, none of the CEPs showed GATA3 positivity or loss of SDHB staining; all 17 CEPs were cytokeratin positive. Genome-wide DNA methylation profiling was performed on 12 of the tumors and compared with publicly available genome-wide DNA methylation data. Clustering analysis showed that CEPs form a distinct epigenetic group, separate from paragangliomas of extraspinal sites, pheochromocytomas, and other neuroendocrine neoplasms. Copy number analysis revealed diploid genomes in the vast majority of CEPs, whereas extraspinal paragangliomas were mostly aneuploid with recurrent trisomy 1q and monosomies of 1p, 3, and 11, none of which were present in the cohort of CEP. Together, these findings indicate that CEPs likely represent a distinct entity. Future genomic studies are needed to further elucidate the molecular pathogenesis of these tumors.

A Matador-like Predator Diversion Strategy Driven by Conspicuous Coloration in Guppies.

Understanding the adaptive function of conspicuous coloration has been a major focus of evolutionary biology for much of the last century. Although considerable progress has been made in explaining how conspicuous coloration can be used in functions as diverse as sexual and social signaling, startling predators, and advertising toxicity [1], there remain a multitude of species that display conspicuous coloration that cannot be explained by existing theory. Here we detail a new "matador-like" divertive antipredator strategy based on conspicuous coloration in Trinidadian guppies (Poecilia reticulata). Guppies encountering predatory fish rapidly enhance the conspicuousness of their eyes by blackening their irises. By pitting biomimetic robotic guppies against real predatory fish, we show this conspicuous eye coloration diverts attacks away from the guppies' center of mass to their head. To determine the function of this seemingly counterintuitive behavior, we developed a method for simulating escape probabilities when live prey interact with ballistic attacking predators, and find this diversion effect significantly benefits black-eyed guppies because they evade capture by rapidly pivoting away from the predator once it has committed to its attack. Remarkably, this antipredator strategy reverses the commonly observed negative scaling relationship between prey size and evasive ability, with larger fish benefiting most from diverting predators. Taken together, our results introduce a new antipredator divertive strategy that may be widely used by conspicuously colored prey that rely on agility to escape their predators.

A platform for semiautomated voluntary training of common marmosets for behavioral neuroscience.

Generally behavioral neuroscience studies of the common marmoset employ adaptations of well-established training methods used with macaque monkeys. However, in many cases these approaches do not readily generalize to marmosets indicating a need for alternatives. Here we present the development of one such alternate: a platform for semiautomated, voluntary in-home cage behavioral training that allows for the study of naturalistic behaviors. We describe the design and production of a modular behavioral training apparatus using CAD software and digital fabrication. We demonstrate that this apparatus permits voluntary behavioral training and data collection throughout the marmoset's waking hours with little experimenter intervention. Furthermore, we demonstrate the use of this apparatus to reconstruct the kinematics of the marmoset's upper limb movement during natural foraging behavior.NEW & NOTEWORTHY The study of marmosets in neuroscience has grown rapidly and presents unique challenges. We address those challenges with an innovative platform for semiautomated, voluntary training that allows marmosets to train throughout their waking hours with minimal experimenter intervention. We describe the use of this platform to capture upper limb kinematics during foraging and to expand the opportunities for behavioral training beyond the limits of traditional training sessions. This flexible platform can easily incorporate other tasks.

Accuracy of the NSQIP risk calculator for predicting complications following adrenalectomy.

PURPOSE: Adrenalectomy is performed to treat functional pathology and remove tumors of malignant concern. The National Surgical Quality Improvement Program (NSQIP) risk calculator predicts 30-day complications and length of stay following index surgical procedures. We assess whether this tool accurately predicts complications following adrenalectomy procedures at a tertiary care academic medical center. METHODS: A retrospective review was performed for all adrenalectomies at a single institution from 2004 to 2016. 197 patients underwent adrenalectomy without concurrent resections. Predicted risk for NSQIP complications was calculated for each patient. The mean predicted and observed risks (%) at 30 days across all patients within each category were determined, and these were compared with two-sided one-sample t tests. RESULTS: Of 197 adrenalectomies, 180 were laparoscopic and 17 were open. For laparoscopic adrenalectomy, ten (5.5%) complications were observed including nine (5%) graded Clavien III or greater. All observed complication rates were significantly different than predicted (p values for all < 0.005). Mean observed length of stay was also significantly less than predicted (1.6 versus 2.1 days, p < 0.001). In the open adrenalectomy subgroup, there were no observed complications with observed mean length of stay equivalent to predicted (5.8 versus 5.3, p = 0.08) without a higher readmission rate (5.9 versus 6.0%). CONCLUSIONS: Statistical differences were noted between the actual complication rates of adrenalectomy versus those predicted by the NSQIP calculator. Certain observed differences may not necessarily have clinical significance. Urology procedure-specific calculators may better refine predictions for sub-specialty procedures with future work requisite to determine performance across all practice settings.

Computed Tomography Imaging Characteristics of Histologically Confirmed Papillary Renal Cell Carcinoma-Implications for Ancillary Imaging.

Low-attenuation renal lesions on non-contrast computed tomography (CT) are often considered to be benign cysts without need for further imaging. However, the papillary subtype of renal cell carcinoma (RCC) may have similar radiographic characteristics. A single-center retrospective review was therefore performed to identify extirpated papillary RCC (pRCC) specimens with correlation made to preoperative tumor imaging characteristics. A total of 108 pRCC specimens were identified of which 84 (27 type I, 17 type 2, 40 unspecified) had CT imaging available for review. Non-contrast CT was available for 73 tumors with 16 (22%) demonstrating Hounsfield units (HU) measurements fewer than 20 at baseline without differences between papillary subtypes. Mean attenuation following contrast administration was similar between papillary subtypes (45 HU for type 1 pRCC and 49 HU for type 2). This study highlights that pathologically proven pRCC is a heterogeneous entity in terms of density on preoperative CT imaging. A non-contrast CT scan with HU fewer than 20 may not be an adequate evaluation for incidental renal masses, as over 1 in 5 pRCCs demonstrate lower attenuation than this cutoff. Further study is needed to identify the appropriate role of ancillary imaging in the workup of seemingly benign-appearing renal lesions.

Development and Assessment of the SMAP Enhanced Passive Soil Moisture Product.

Launched in January 2015, the National Aeronautics and Space Administration (NASA) Soil Moisture Active Passive (SMAP) observatory was designed to provide frequent global mapping of high-resolution soil moisture and freeze-thaw state every two to three days using a radar and a radiometer operating at L-band frequencies. Despite a hardware mishap that rendered the radar inoperable shortly after launch, the radiometer continues to operate nominally, returning more than two years of science data that have helped to improve existing hydrological applications and foster new ones. Beginning in late 2016 the SMAP project launched a suite of new data products with the objective of recovering some high-resolution observation capability loss resulting from the radar malfunction. Among these new data products are the SMAP Enhanced Passive Soil Moisture Product that was released in December 2016, followed by the SMAP/Sentinel-1 Active-Passive Soil Moisture Product in April 2017. This article covers the development and assessment of the SMAP Level 2 Enhanced Passive Soil Moisture Product (L2_SM_P_E). The product distinguishes itself from the current SMAP Level 2 Passive Soil Moisture Product (L2_SM_P) in that the soil moisture retrieval is posted on a 9 km grid instead of a 36 km grid. This is made possible by first applying the Backus-Gilbert optimal interpolation technique to the antenna temperature (TA) data in the original SMAP Level 1B Brightness Temperature Product to take advantage of the overlapped radiometer footprints on orbit. The resulting interpolated TA data then go through various correction/calibration procedures to become the SMAP Level 1C Enhanced Brightness Temperature Product (LiC_TB_E). The LiC_TB_E product, posted on a 9 km grid, is then used as the primary input to the current operational SMAP baseline soil moisture retrieval algorithm to produce L2_SM_P_E as the final output. Images of the new product reveal enhanced visual features that are not apparent in the standard product. Based on in situ data from core validation sites and sparse networks representing different seasons and biomes all over the world, comparisons between L2_SM_P_E and in situ data were performed for the duration of April 1, 2015 - October 30, 2016. It was found that the performance of the enhanced 9 km L2_SM_P_E is equivalent to that of the standard 36 km L2_SM_P, attaining a retrieval uncertainty below 0.040 m3/m3 unbiased root-mean-square error (ubRMSE) and a correlation coefficient above 0.800. This assessment also affirmed that the Single Channel Algorithm using the V-polarized TB channel (SCA-V) delivered the best retrieval performance among the various algorithms implemented for L2_SM_P_E, a result similar to a previous assessment for L2_SM_P.

Postoperative Outcomes Associated With Neuraxial vs General Anesthesia Following Bilateral Total Knee Arthroplasty.

BACKGROUND: There is sparse evidence on the benefit of neuraxial (NA) vs general anesthesia (GA) as the primary anesthetic in postoperative outcomes following bilateral total knee arthroplasty. We sought to elucidate differences in outcomes in this surgical population using a national database. METHODS: We used data from the National Surgical Quality Improvement Program from 2007 to 2013 and compared rates of various postoperative outcomes in propensity-matched cohorts (NA vs GA). RESULTS: After exclusion, there were 1957 patients included in the final analysis, of which 26% received NA as the primary anesthetic. Propensity-matched cohorts were generated to ensure no differences in various comorbidities (including bleeding disorders or inadequate cessation of anticoagulation therapy), case duration, and patient demographics between both cohorts. Among the matched cohorts, there were no differences in preoperative platelet count, hematocrit, or international normalized ratio. NA was associated with decreased blood transfusion requirement and decreased total number of units of blood products transfused (P < .0001 for both outcomes). However, there were no differences in other outcomes, including hospital length of stay, pulmonary embolism, deep vein thrombosis, or urinary tract infections. CONCLUSION: Our study demonstrates that in matched cohorts, NA is associated with decreased blood transfusion requirements in patients undergoing bilateral total knee arthroplasty when compared to GA as the primary anesthetic.

Surface Soil Moisture Retrieval Using the L-Band Synthetic Aperture Radar Onboard the Soil Moisture Active-Passive Satellite and Evaluation at Core Validation Sites.

This paper evaluates the retrieval of soil moisture in the top 5-cm layer at 3-km spatial resolution using L-band dual-copolarized Soil Moisture Active-Passive (SMAP) synthetic aperture radar (SAR) data that mapped the globe every three days from mid-April to early July, 2015. Surface soil moisture retrievals using radar observations have been challenging in the past due to complicating factors of surface roughness and vegetation scattering. Here, physically based forward models of radar scattering for individual vegetation types are inverted using a time-series approach to retrieve soil moisture while correcting for the effects of static roughness and dynamic vegetation. Compared with the past studies in homogeneous field scales, this paper performs a stringent test with the satellite data in the presence of terrain slope, subpixel heterogeneity, and vegetation growth. The retrieval process also addresses any deficiencies in the forward model by removing any time-averaged bias between model and observations and by adjusting the strength of vegetation contributions. The retrievals are assessed at 14 core validation sites representing a wide range of global soil and vegetation conditions over grass, pasture, shrub, woody savanna, corn, wheat, and soybean fields. The predictions of the forward models used agree with SMAP measurements to within 0.5 dB unbiased-root-mean-square error (ubRMSE) and -0.05 dB (bias) for both copolarizations. Soil moisture retrievals have an accuracy of 0.052 m3/m3 ubRMSE, -0.015 m3/m3 bias, and a correlation of 0.50, compared to in situ measurements, thus meeting the accuracy target of 0.06 m3/m3 ubRMSE. The successful retrieval demonstrates the feasibility of a physically based time series retrieval with L-band SAR data for characterizing soil moisture over diverse conditions of soil moisture, surface roughness, and vegetation.

Monte Carlo simulation of OLS and linear mixed model inference of phenotypic effects on gene expression.

BACKGROUND: Self-contained tests estimate and test the association between a phenotype and mean expression level in a gene set defined a priori. Many self-contained gene set analysis methods have been developed but the performance of these methods for phenotypes that are continuous rather than discrete and with multiple nuisance covariates has not been well studied. Here, I use Monte Carlo simulation to evaluate the performance of both novel and previously published (and readily available via R) methods for inferring effects of a continuous predictor on mean expression in the presence of nuisance covariates. The motivating data are a high-profile dataset which was used to show opposing effects of hedonic and eudaimonic well-being (or happiness) on the mean expression level of a set of genes that has been correlated with social adversity (the CTRA gene set). The original analysis of these data used a linear model (GLS) of fixed effects with correlated error to infer effects of Hedonia and Eudaimonia on mean CTRA expression. METHODS: The standardized effects of Hedonia and Eudaimonia on CTRA gene set expression estimated by GLS were compared to estimates using multivariate (OLS) linear models and generalized estimating equation (GEE) models. The OLS estimates were tested using O'Brien's OLS test, Anderson's permutation [Formula: see text]-test, two permutation F-tests (including GlobalAncova), and a rotation z-test (Roast). The GEE estimates were tested using a Wald test with robust standard errors. The performance (Type I, II, S, and M errors) of all tests was investigated using a Monte Carlo simulation of data explicitly modeled on the re-analyzed dataset. RESULTS: GLS estimates are inconsistent between data sets, and, in each dataset, at least one coefficient is large and highly statistically significant. By contrast, effects estimated by OLS or GEE are very small, especially relative to the standard errors. Bootstrap and permutation GLS distributions suggest that the GLS results in downward biased standard errors and inflated coefficients. The Monte Carlo simulation of error rates shows highly inflated Type I error from the GLS test and slightly inflated Type I error from the GEE test. By contrast, Type I error for all OLS tests are at the nominal level. The permutation F-tests have ∼1.9X the power of the other OLS tests. This increased power comes at a cost of high sign error (∼10%) if tested on small effects. DISCUSSION: The apparently replicated pattern of well-being effects on gene expression is most parsimoniously explained as "correlated noise" due to the geometry of multiple regression. The GLS for fixed effects with correlated error, or any linear mixed model for estimating fixed effects in designs with many repeated measures or outcomes, should be used cautiously because of the inflated Type I and M error. By contrast, all OLS tests perform well, and the permutation F-tests have superior performance, including moderate power for very small effects.

Repeatability of locomotor performance and morphology-locomotor performance relationships.

There is good evidence that natural selection drives the evolution of locomotor performance, but the processes that generate the among-individual variation for selection to act on are relatively poorly understood. We measured prolonged swimming performance, Ucrit, and morphology in a large cohort (n=461) of wild-type zebrafish (Danio rerio) at ∼6 months and again at ∼9 months. Using mixed-model analyses to estimate repeatability as the intraclass correlation coefficient, we determined that Ucrit was significantly repeatable (r=0.55; 95% CI: 0.45-0.64). Performance differences between the sexes (males 12% faster than females) and changes with age (decreasing 0.07% per day) both contributed to variation in Ucrit and, therefore, the repeatability estimate. Accounting for mean differences between sexes within the model decreased the estimate of Ucrit repeatability to 21% below the naïve estimate, while fitting age in the models increased the estimate to 14% above the naïve estimate. Greater consideration of factors such as age and sex is therefore necessary for the interpretation of performance repeatability in wild populations. Body shape significantly predicted Ucrit in both sexes in both assays, with the morphology-performance relationship significantly repeatable at the population level. However, morphology was more strongly predicative of performance in older fish, suggesting a change in the contribution of morphology relative to other factors such as physiology and behaviour. The morphology-performance relationship changed with age to a greater extent in males than females.

Flowing water affects fish fast-starts: escape performance of the Hawaiian stream goby, Sicyopterus stimpsoni.

Experimental measurements of escape performance in fishes have typically been conducted in still water; however, many fishes inhabit environments with flow that could impact escape behavior. We examined the influences of flow and predator attack direction on the escape behavior of fish, using juveniles of the amphidromous Hawaiian goby Sicyopterus stimpsoni In nature, these fish must escape ambush predation while moving through streams with high-velocity flow. We measured the escape performance of juvenile gobies while exposing them to a range of water velocities encountered in natural streams and stimulating fish from three different directions. Frequency of response across treatments indicated strong effects of flow conditions and attack direction. Juvenile S. stimpsoni had uniformly high response rates for attacks from a caudal direction (opposite flow); however, response rates for attacks from a cranial direction (matching flow) decreased dramatically as flow speed increased. Mechanical stimuli produced by predators attacking in the same direction as flow might be masked by the flow environment, impairing the ability of prey to detect attacks. Thus, the likelihood of successful escape performance in fishes can depend critically on environmental context.