Battle of the sections: Student outcomes and course feedback support combined prosection and dissection laboratory formats to maximize student success.

Gross anatomy laboratories frequently utilize dissection or prosection formats within medical curricula. Practical examination scores are consistent across the formats, yet these examinations assessed larger anatomical structures. In contrast, a single report noted improved scores when prosection was used in the hand and foot regions, areas that are more difficult to dissect. The incorporation of prosected donors within "Head and Neck" laboratories provided an opportunity to further characterize the impact of prosection in a structurally complex area. Retrospective analysis of 21 Head and Neck practical examination questions was completed to compare scores among cohorts that utilized dissection exclusively or incorporated prosection. Mean scores of practical examination questions were significantly higher in the prosection cohort (84.27% ± 12.69) as compared with the dissection cohort (75.59% ± 12.27) (p < 0.001). Of the 12 questions that performed better in the prosection cohort (88.42% ± 8.21), 10 items mapped to deeper anatomical regions. By comparison, eight of nine questions in the dissection cohort outperformed (88.44% ± 3.34) the prosection cohort (71.74% ± 18.11), and mapped to anatomically superficial regions. Despite the mean score increase with positional location of the questions, this effect was not statically significant across cohorts (p = 1.000), suggesting that structure accessibility in anatomically complex regions impacts performance. Student feedback cited structure preservation (71.5%) and time savings (55.8%) as advantages to prosection; however, dissection was the perceived superior and preferred laboratory format (88.6%). These data support combined prosection and dissection formats for improving student recognition of deeply positioned structures and maximizing student success.

Skeletal muscle mitochondrial correlates of critical power and W' in healthy active individuals.

The asymptote (critical power; CP) and curvature constant (W') of the hyperbolic power-duration relationship can predict performance within the severe-intensity exercise domain. However, the extent to which these parameters relate to skeletal muscle mitochondrial content and respiratory function is not known. Fifteen males (peak O2 uptake, 52.2 ± 8.7 mL kg-1 min-1; peak work rate, 366 ± 40 W; and gas exchange threshold, 162 ± 41 W) performed three to five constant-load tests to task failure for the determination of CP (246 ± 44 W) and W' (18.6 ± 4.1 kJ). Skeletal muscle biopsies were obtained from the vastus lateralis to determine citrate synthase (CS) activity, as a marker of mitochondrial content, and the ADP-stimulated respiration (P) and maximal electron transfer (E) through mitochondrial complexes (C) I-IV. The CP was positively correlated with CS activity (absolute CP, r = 0.881, P < 0.001; relative CP, r = 0.751, P = 0.001). The W' was not correlated with CS activity (P > 0.05). Relative CP was positively correlated with mass-corrected CI + IIE (r = 0.659, P = 0.038), with absolute CP being inversely correlated with CS activity-corrected CIVE (r = -0.701, P = 0.024). Relative W' was positively correlated with CS activity-corrected CI + IIP (r = 0.713, P = 0.021) and the phosphorylation control ratio (r = 0.661, P = 0.038). There were no further correlations between CP or W' and mitochondrial respiratory variables. These findings support the assertion that skeletal muscle mitochondrial oxidative capacity is positively associated with CP and that this relationship is strongly determined by mitochondrial content.

Circulating N-lactoyl-amino acids and N-formyl-methionine reflect mitochondrial dysfunction and predict mortality in septic shock.

INTRODUCTION: Sepsis is a highly morbid condition characterized by multi-organ dysfunction resulting from dysregulated inflammation in response to acute infection. Mitochondrial dysfunction may contribute to sepsis pathogenesis, but quantifying mitochondrial dysfunction remains challenging. OBJECTIVE: To assess the extent to which circulating markers of mitochondrial dysfunction are increased in septic shock, and their relationship to severity and mortality. METHODS: We performed both full-scan and targeted (known markers of genetic mitochondrial disease) metabolomics on plasma to determine markers of mitochondrial dysfunction which distinguish subjects with septic shock (n = 42) from cardiogenic shock without infection (n = 19), bacteremia without sepsis (n = 18), and ambulatory controls (n = 19) - the latter three being conditions in which mitochondrial function, proxied by peripheral oxygen consumption, is presumed intact. RESULTS: Nine metabolites were significantly increased in septic shock compared to all three comparator groups. This list includes N-formyl-L-methionine (f-Met), a marker of dysregulated mitochondrial protein translation, and N-lactoyl-phenylalanine (lac-Phe), representative of the N-lactoyl-amino acids (lac-AAs), which are elevated in plasma of patients with monogenic mitochondrial disease. Compared to lactate, the clinical biomarker used to define septic shock, there was greater separation between survivors and non-survivors of septic shock for both f-Met and the lac-AAs measured within 24 h of ICU admission. Additionally, tryptophan was the one metabolite significantly decreased in septic shock compared to all other groups, while its breakdown product kynurenate was one of the 9 significantly increased. CONCLUSION: Future studies which validate the measurement of lac-AAs and f-Met in conjunction with lactate could define a sepsis subtype characterized by mitochondrial dysfunction.

Scalable manufacture of therapeutic mesenchymal stromal cell products on customizable microcarriers in vertical wheel bioreactors that improve direct visualization, product harvest, and cost.

BACKGROUND AIMS: Human mesenchymal stromal cells (hMSCs) and their secreted products show great promise for treatment of musculoskeletal injury and inflammatory or immune diseases. However, the path to clinical utilization is hampered by donor-tissue variation and the inability to manufacture clinically relevant yields of cells or their products in a cost-effective manner. Previously we described a method to produce chemically and mechanically customizable gelatin methacryloyl (GelMA) microcarriers for culture of hMSCs. Herein, we demonstrate scalable GelMA microcarrier-mediated expansion of induced pluripotent stem cell (iPSC)-derived hMSCs (ihMSCs) in 500 mL and 3L vertical wheel bioreactors, offering several advantages over conventional microcarrier and monolayer-based expansion strategies. METHODS: Human mesenchymal stromal cells derived from induced pluripotent cells were cultured on custom-made spherical gelatin methacryloyl microcarriers in single-use vertical wheel bioreactors (PBS Biotech). Cell-laden microcarriers were visualized using confocal microscopy and elastic light scattering methodologies. Cells were assayed for viability and differentiation potential in vitro by standard methods. Osteogenic cell matrix derived from cells was tested in vitro for osteogenic healing using a rodent calvarial defect assay. Immune modulation was assayed with an in vivo peritonitis model using Zymozan A. RESULTS: The optical properties of GelMA microcarriers permit noninvasive visualization of cells with elastic light scattering modalities, and harvest of product is streamlined by microcarrier digestion. At volumes above 500 mL, the process is significantly more cost-effective than monolayer culture. Osteogenic cell matrix derived from ihMSCs expanded on GelMA microcarriers exhibited enhanced in vivo bone regenerative capacity when compared to bone morphogenic protein 2, and the ihMSCs exhibited superior immunosuppressive properties in vivo when compared to monolayer-generated ihMSCs. CONCLUSIONS: These results indicate that the cell expansion strategy described here represents a superior approach for efficient generation, monitoring and harvest of therapeutic MSCs and their products.

Black Pastors' Experiences of Occupational and Life Stress During COVID-19 in the USA.

This study sought to identify the occupational stressors Black pastors experience, who serve in Black Church denominations and Black nondenominational churches. A total of 218 pastors completed the survey out of 2786 for a response rate of 10.1%. Black pastors identified their most challenging stressors as member dynamics, financial stress, leading a church to fulfill its mission, and pastor's workload. Black women pastors faced the additional stressor of having their pastoral leadership challenged by male congregants. Black pastors faced more stressors during the COVID-19 pandemic including church closures, transitioning to virtual services, unexpected deaths, and an increased workload with 72.5% of pastors reporting moderate to extreme stress levels. Approximately 77% of pastors acknowledged experiencing from moderate to extreme stress levels during social protests for the deaths of Black people by law enforcement. Black pastors further acknowledged experiencing an additional three to six life stressors outside of their pastoral roles.

Health factors that influence sustainable behaviour in a single-player resource management game.

Encouraging sustainable use of limited natural, social, and economic resources requires understanding the variety of ways in which people think about how resources work and how they adjust their behaviour (or not) as available resources fluctuate. Previous investigations which have focused on understanding how individuals navigate erodible resources, have tended to use group-based, common pool games. However, such social games make it difficult to disentangle whether resource erosion is linked to difficulty navigating the dynamics of the resource or caused by social factors. Here, in two experiments, we recruited 781 participants to play a single-player resource management game in which individuals were invited to harvest monetary rewards from a fully depletable but stochastically replenishing resource over time. We find that the ability to sustain a resource over successive harvesting opportunities (in order to maximize the total harvested rewards) is reliably worse in individuals reporting elevated psychological distress, the often cooccurring hazardous alcohol use, and elevated rates of delay discounting. The associations between resource outcomes, harmful alcohol use, and psychological distress remained substantial even once we had controlled for elevated discounting rates (as a form of impulsivity and a strong risk factor for these health challenges). By contrast, individuals who reported higher levels of financial literacy and general well-being achieved better resource outcomes. Our observations demonstrate that the capacity to respond effectively to the dynamics of a resource are compromised in individuals at risk of psychological and alcohol-related disorders.

Student perceptions of remote versus on-campus gross anatomy laboratories during COVID-19.

At Kansas City University, anatomy laboratories were delivered via remote (REM) or on-campus (OC) formats due to COVID-19, creating an opportunity to evaluate student perceptions of differences in laboratory delivery format. A six-item survey of Likert scale and open-ended questions explored the utility of anatomy software, prelab instruction handouts, and prosection reviews. Likert scale validity was analyzed using Cronbach's α; responses were compared among REM and OC formats using Chi-square. Descriptive codes were applied to summarize responses, which were grouped and converted into percentages. Statistically significant differences in REM versus OC formats were determined for the helpfulness of the prelab handouts (χ2 , 28.00; df, 4; p < 0.001) and effectiveness of cadavers in learning anatomy (χ2 , 20.58; df, 4; p < 0.0004). Trends in responses noted disagreement in the effectiveness of anatomy software (REM, 69.8%; OC, 51.08%), but agreement with the helpfulness of prosection reviews (REM, 85.9%; OC, 61.6%) (Cronbach α: REM, 0.648; OC, 0.646). Themes from narrative REM comments (n = 496) noted anatomy software was difficult to use (33.1%) and had issues with orientation (15.5%), as well as a student preference for OC laboratories (12.5%). The OC format responses (n = 456) noted poor software design (47.9%), unnecessary for studying (35.4%), and preference for in-person laboratories (7.4%). Qualitative analysis of narrative comments detailed other resources used, including Complete Anatomy™ and YouTube™. Trends highlighted the prelab handouts and prosection reviews for learning, the ineffectiveness of anatomy software, and a preference for OC laboratories. We highlight student perspectives of REM versus OC laboratory formats in response to COVID-19.

Hypoxia extends lifespan and neurological function in a mouse model of aging.

There is widespread interest in identifying interventions that extend healthy lifespan. Chronic continuous hypoxia delays the onset of replicative senescence in cultured cells and extends lifespan in yeast, nematodes, and fruit flies. Here, we asked whether chronic continuous hypoxia is beneficial in mammalian aging. We utilized the Ercc1 Δ/- mouse model of accelerated aging given that these mice are born developmentally normal but exhibit anatomic, physiological, and biochemical features of aging across multiple organs. Importantly, they exhibit a shortened lifespan that is extended by dietary restriction, the most potent aging intervention across many organisms. We report that chronic continuous 11% oxygen commenced at 4 weeks of age extends lifespan by 50% and delays the onset of neurological debility in Ercc1 Δ/- mice. Chronic continuous hypoxia did not impact food intake and did not significantly affect markers of DNA damage or senescence, suggesting that hypoxia did not simply alleviate the proximal effects of the Ercc1 mutation, but rather acted downstream via unknown mechanisms. To the best of our knowledge, this is the first study to demonstrate that "oxygen restriction" can extend lifespan in a mammalian model of aging.

Examining the Relationship of Clergy Distress, Spiritual Well-Being, Stress Management and Irritation to Life Satisfaction among Black Pastors in the USA.

This study sought to determine the level of clergy distress and other psychological characteristics of Black pastors and their relationship to life satisfaction through a convenience sample of 2786 Black pastors in historically Black Protestant denominations and nondenominational Black churches. The response rate equaled 10.1% (283/2786) while the survey completion rate equaled 77% (218/283). These 218 Black pastors were serving as either senior pastors (86.3%) or co-pastors (13.7%). This study found clergy distress in Black pastors did not differ based on gender or age but differed by church size and denomination. Clergy distress (r = - .187, p = .023) and irritation (r = - .293, p = .003) possessed significant relationships with satisfaction with life as expected, but stress management (r = .039, p = .641), spiritual well-being in daily life (r = .140, p = .140), and spiritual well-being in ministry (r = - .064, p = .475) did not, which was surprising. Notably strong relationships existed between stress management and spiritual well-being in daily life (r = .469, p = .003) and stress management and irritation (r = - .359, p = .003). These two important relationships may offer some guideposts for Black pastors in developing strategies to combat the impact of both clergy distress and irritation. The study concludes with implications for Black pastors and suggestions for future research.

Forelimb Resistance Exercise Protects Against Neuromuscular Junction Denervation in the SOD1-G93A Rat Model of ALS.

Introduction: The symptoms of Amyotrophic Lateral Sclerosis (ALS) include muscle weakness and eventual paralysis. These symptoms result from denervation of the neuromuscular junction (NMJ) and motor neuron cell death in the brain and spinal cord. Due to the "dying back" pattern of motor neuron degeneration, protecting NMJs should be a therapeutic priority. Although exercise has the potential to protect against NMJ denervation, its use in ALS has been controversial. Most preclinical studies have focused on aerobic exercise, which report that exercise can be beneficial at moderate intensities. The effects of resistance exercise on NMJ preservation in limb muscles have not been explored. Methods: We trained male SOD1-G93A rats, which model ALS, to perform a unilateral isometric forelimb resistance exercise task. This task allows within-animal comparisons of trained and untrained forelimbs. We then determined the effects of isometric resistance exercise on NMJ denervation and AMP kinase (AMPK) activation in forelimb muscles. Results: Our results revealed that SOD1-G93A rats were able to learn and perform the task similarly to wildtype rats, even after loss of body weight. SOD1-G93A rats exhibited significantly greater NMJ innervation in their trained vs their untrained forelimb biceps muscles. Measures of activated (phosphorylated) AMPK (pAMPK) were also greater in the trained vs untrained forelimb triceps muscles. Discussion: These results demonstrate that isometric resistance exercise may protect against NMJ denervation in ALS. Future studies are required to determine the extent to which our findings generalize to female SOD1-G93A rats and to other subtypes of ALS.

Melanoma-Secreted Amyloid Beta Suppresses Neuroinflammation and Promotes Brain Metastasis.

Brain metastasis is a significant cause of morbidity and mortality in multiple cancer types and represents an unmet clinical need. The mechanisms that mediate metastatic cancer growth in the brain parenchyma are largely unknown. Melanoma, which has the highest rate of brain metastasis among common cancer types, is an ideal model to study how cancer cells adapt to the brain parenchyma. Our unbiased proteomics analysis of melanoma short-term cultures revealed that proteins implicated in neurodegenerative pathologies are differentially expressed in melanoma cells explanted from brain metastases compared with those derived from extracranial metastases. We showed that melanoma cells require amyloid beta (Aß) for growth and survival in the brain parenchyma. Melanoma-secreted Aß activates surrounding astrocytes to a prometastatic, anti-inflammatory phenotype and prevents phagocytosis of melanoma by microglia. Finally, we demonstrate that pharmacologic inhibition of Aß decreases brain metastatic burden. SIGNIFICANCE: Our results reveal a novel mechanistic connection between brain metastasis and Alzheimer's disease, two previously unrelated pathologies; establish Aß as a promising therapeutic target for brain metastasis; and demonstrate suppression of neuroinflammation as a critical feature of metastatic adaptation to the brain parenchyma. This article is highlighted in the In This Issue feature, p. 1171.

Development and Validation of a Deep Learning Strategy for Automated View Classification of Pediatric Focused Assessment With Sonography for Trauma.

OBJECTIVE: Pediatric focused assessment with sonography for trauma (FAST) is a sequence of ultrasound views rapidly performed by clinicians to diagnose hemorrhage. A technical limitation of FAST is the lack of expertise to consistently acquire all required views. We sought to develop an accurate deep learning view classifier using a large heterogeneous dataset of clinician-performed pediatric FAST. METHODS: We developed and conducted a retrospective cohort analysis of a deep learning view classifier on real-world FAST studies performed on injured children less than 18 years old in two pediatric emergency departments by 30 different clinicians. FAST was randomly distributed to training, validation, and test datasets, 70:20:10; each child was represented in only one dataset. The primary outcome was view classifier accuracy for video clips and still frames. RESULTS: There were 699 FAST studies, representing 4925 video clips and 1,062,612 still frames, performed by 30 different clinicians. The overall classification accuracy was 97.8% (95% confidence interval [CI]: 96.0-99.0) for video clips and 93.4% (95% CI: 93.3-93.6) for still frames. Per view still frames were classified with an accuracy: 96.0% (95% CI: 95.9-96.1) cardiac, 99.8% (95% CI: 99.8-99.8) pleural, 95.2% (95% CI: 95.0-95.3) abdominal upper quadrants, and 95.9% (95% CI: 95.8-96.0) suprapubic. CONCLUSION: A deep learning classifier can accurately predict pediatric FAST views. Accurate view classification is important for quality assurance and feasibility of a multi-stage deep learning FAST model to enhance the evaluation of injured children.

The Interface between Cell Signaling Pathways and Pregnane X Receptor.

Highly expressed in the enterohepatic system, pregnane X receptor (PXR, NR1I2) is a well-characterized nuclear receptor (NR) that regulates the expression of genes in the liver and intestines that encode key drug metabolizing enzymes and drug transporter proteins in mammals. The net effect of PXR activation is to increase metabolism and clear drugs and xenobiotics from the body, producing a protective effect and mediating clinically significant drug interaction in patients on combination therapy. The complete understanding of PXR biology is thus important for the development of safe and effective therapeutic strategies. Furthermore, PXR activation is now known to specifically transrepress the inflammatory- and nutrient-signaling pathways of gene expression, thereby providing a mechanism for linking these signaling pathways together with enzymatic drug biotransformation pathways in the liver and intestines. Recent research efforts highlight numerous post-translational modifications (PTMs) which significantly influence the biological function of PXR. However, this thrust of research is still in its infancy. In the context of gene-environment interactions, we present a review of the recent literature that implicates PXR PTMs in regulating its clinically relevant biology. We also provide a discussion of how these PTMs likely interface with each other to respond to extracellular cues to appropriately modify PXR activity.

Carrots for the donkey: Influence of evaluative conditioning and training on self-paced exercise intensity and delay discounting of exercise in healthy adults.

To choose exercise over alternative behaviours, subjective reward evaluation of the potential choices is a principal step in decision making. However, the selection of exercise intensity might integrate acute visceral responses (i.e. pleasant or unpleasant feelings) and motives related to goals (i.e. enjoyment, competition, health). To understand the factors determining the selection of exercise in its intensity and evaluation as a modality, we conducted a study combining exercise training and evaluative conditioning. Evaluative conditioning was performed by using a novel technique using a primary reinforcer (sweetness) as the unconditioned stimulus and physical strain i.e. heart rate elevation as the conditioned stimulus during interval training, using a randomized control design (N = 58). Pre, post-three weeks interval training w/o conditioning, and after 4 weeks follow-up, participants were tested on self-paced speed selection on treadmill measuring heart rate, subjective pleasantness, and effort levels, as well as delay-discounting of exercise and food rewards. Results revealed that the selection of exercise intensity was significantly increased by adaptation to training and evaluative conditioning, revealing the importance of visceral factors as well as learned expected rewards. Delay discounting rates of self-paced exercise were transiently reduced by training but not affected by evaluative conditioning. In conclusion, exercise decisions are suggested to separate the decision-making process into a modality-specific cognitive evaluation of exercise, and an exercise intensity selection based on acute visceral experience integrating effort, pleasantness, and learned rewards.

A scalable system for generation of mesenchymal stem cells derived from induced pluripotent cells employing bioreactors and degradable microcarriers.

Human mesenchymal stem cells (hMSCs) are effective in treating disorders resulting from an inflammatory or heightened immune response. The hMSCs derived from induced pluripotent stem cells (ihMSCs) share the characteristics of tissue derived hMSCs but lack challenges associated with limited tissue sources and donor variation. To meet the expected future demand for ihMSCs, there is a need to develop scalable methods for their production at clinical yields while retaining immunomodulatory efficacy. Herein, we describe a platform for the scalable expansion and rapid harvest of ihMSCs with robust immunomodulatory activity using degradable gelatin methacryloyl (GelMA) microcarriers. GelMA microcarriers were rapidly and reproducibly fabricated using a custom microfluidic step emulsification device at relatively low cost. Using vertical wheel bioreactors, 8.8 to 16.3-fold expansion of ihMSCs was achieved over 8 days. Complete recovery by 5-minute digestion of the microcarriers with standard cell dissociation reagents resulted in >95% viability. The ihMSCs matched or exceeded immunomodulatory potential in vitro when compared with ihMSCs expanded on monolayers. This is the first description of a robust, scalable, and cost-effective method for generation of immunomodulatory ihMSCs, representing a significant contribution to their translational potential.

Intrinsic Aerobic Capacity Affects Hippocampal pAkt and HSP72 Response to an Acute High Fat Diet and Heat Treatment in Rats.

BACKGROUND: Aerobic capacity is associated with metabolic, cardiovascular, and neurological health. Low-capacity runner (LCR) rats display low aerobic capacity, metabolic dysfuction, and spatial memory deficits. A heat treatment (HT) can improve metabolic dysfunction in LCR peripheral organs after high fat diet (HFD). Little is known about metabolic changes in the brains of these rats following HT. OBJECTIVE: Our objective was to examine the extent to which high or low aerobic capacity impacts Akt (a protein marker of metabolism) and heat shock protein 72 (HSP72, a marker of heat shock response) after HFD and HT in hippocampus. METHODS: We measured phosphorylated Akt (pAkt) in the striatum and hippocampus, and HSP72 in the hippocampus, of HFD-fed and chow-fed LCR and high-capacity runner (HCR) rats with and without HT. RESULTS: pAkt was lower in the hippocampus of chow-fed LCR than HCR rats. HFD resulted in greater pAkt in LCR but not HCR rats, but HT resulted in lower pAkt in the LCR HFD group. HSP72 was greater in both HCR and LCR rat hippocampus after HT. The HFD blunted this effect in LCR compared to HCR hippocampus. CONCLUSION: The abnormal phosphorylation of Akt and diminished HSP response in the hippocampus of young adult LCR rats might indicate early vulnerability to metabolic challenges in this key brain region associated with learning and memory.

Oxaloacetate treatment preserves motor function in SOD1G93A mice and normalizes select neuroinflammation-related parameters in the spinal cord.

Amyotrophic lateral sclerosis (ALS) remains a devastating motor neuron disease with limited treatment options. Oxaloacetate treatment has a neuroprotective effect in rodent models of seizure and neurodegeneration. Therefore, we treated the ALS model superoxide dismutase 1 (SOD1) G93A mice with oxaloacetate and evaluated their neuromuscular function and lifespan. Treatment with oxaloacetate beginning in the presymptomatic stage significantly improved neuromuscular strength measured during the symptomatic stage in the injected mice compared to the non-treated group. Oxaloacetate treatment starting in the symptomatic stage significantly delayed limb paralysis compared with the non-treated group. For lifespan analysis, oxaloacetate treatment did not show a statistically significant positive effect, but the treatment did not shorten the lifespan. Mechanistically, SOD1G93A mice showed increased levels of tumor necrosis factor-α (TNFα) and peroxisome proliferative activated receptor gamma coactivator 1α (PGC-1α) mRNAs in the spinal cord. However, oxaloacetate treatment reverted these abnormal levels to that of wild-type mice. Similarly, the altered expression level of total NF-κB protein returned to that of wild-type mice with oxaloacetate treatment. These results suggest that the beneficial effects of oxaloacetate treatment in SOD1G93A mice may reflect the effects on neuroinflammation or bioenergetic stress.

"Just not knowing" can make life sweeter (and saltier): Reward uncertainty alters the sensory experience and consumption of palatable food and drinks.

Reward uncertainty can prompt exploration and learning, strengthening approach and consummatory behaviors. For humans, these phenomena are exploited in marketing promotions and gambling products, sometimes spurring hedonic consumption. Here, in four experiments, we sought to identify whether reward uncertainty-as a state of "not knowing" that exists between an action and a positively valanced outcome-enhances the in-the-moment consumption and experience of other palatable food and drink rewards. In Experiment 1, we demonstrate that reward uncertainty can increase consumption of commercial alcoholic drinks and energy-dense savory snacks. In Experiment 2, we show that reward uncertainty is unlikely to promote consumption through gross increases in impulsivity (expressed as higher discounting rates) or risk tolerance (expressed as lower probability discounting rates). In Experiment 3, we find that reward uncertainty intensifies the taste of, and hedonic responses to, sucrose solutions in a concentration-dependent manner among individuals with heightened preferences for sweet tastes. Finally, in Experiment 4, we replicate and extend these findings by showing that reward uncertainty intensifies the taste of palatable foods and drinks in ways that are independent of individuals' discounting rates, motor control, reflection impulsivity, and momentary happiness but are strongly moderated by recent depressive symptoms. These data suggest a working hypothesis that (incidental) reward uncertainty, as a state of not knowing, operates as a mood-dependent "taste intensifier" of palatable food and drink rewards, possibly sustaining reward seeking and consumption. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Automated mesenchymal stem cell segmentation and machine learning-based phenotype classification using morphometric and textural analysis.

Purpose: Mesenchymal stem cells (MSCs) have demonstrated clinically relevant therapeutic effects for treatment of trauma and chronic diseases. The proliferative potential, immunomodulatory characteristics, and multipotentiality of MSCs in monolayer culture is reflected by their morphological phenotype. Standard techniques to evaluate culture viability are subjective, destructive, or time-consuming. We present an image analysis approach to objectively determine morphological phenotype of MSCs for prediction of culture efficacy. Approach: The algorithm was trained using phase-contrast micrographs acquired during the early and mid-logarithmic stages of MSC expansion. Cell regions are localized using edge detection, thresholding, and morphological operations, followed by cell marker identification using H-minima transform within each region to differentiate individual cells from cell clusters. Clusters are segmented using marker-controlled watershed to obtain single cells. Morphometric and textural features are extracted to classify cells based on phenotype using machine learning. Results: Algorithm performance was validated using an independent test dataset of 186 MSCs in 36 culture images. Results show 88% sensitivity and 86% precision for overall cell detection and a mean Sorensen-Dice coefficient of 0.849 ± 0.106 for segmentation per image. The algorithm exhibited an area under the curve of 0.816 ( CI 95 = 0.769 to 0.886) and 0.787 ( CI 95 = 0.716 to 0.851) for classifying MSCs according to their phenotype at early and mid-logarithmic expansion, respectively. Conclusions: The proposed method shows potential to segment and classify low and moderately dense MSCs based on phenotype with high accuracy and robustness. It enables quantifiable and consistent morphology-based quality assessment for various culture protocols to facilitate cytotherapy development.

MitoCarta3.0: an updated mitochondrial proteome now with sub-organelle localization and pathway annotations.

The mammalian mitochondrial proteome is under dual genomic control, with 99% of proteins encoded by the nuclear genome and 13 originating from the mitochondrial DNA (mtDNA). We previously developed MitoCarta, a catalogue of over 1000 genes encoding the mammalian mitochondrial proteome. This catalogue was compiled using a Bayesian integration of multiple sequence features and experimental datasets, notably protein mass spectrometry of mitochondria isolated from fourteen murine tissues. Here, we introduce MitoCarta3.0. Beginning with the MitoCarta2.0 inventory, we performed manual review to remove 100 genes and introduce 78 additional genes, arriving at an updated inventory of 1136 human genes. We now include manually curated annotations of sub-mitochondrial localization (matrix, inner membrane, intermembrane space, outer membrane) as well as assignment to 149 hierarchical 'MitoPathways' spanning seven broad functional categories relevant to mitochondria. MitoCarta3.0, including sub-mitochondrial localization and MitoPathway annotations, is freely available at http://www.broadinstitute.org/mitocarta and should serve as a continued community resource for mitochondrial biology and medicine.