Medial prefrontal dopamine dynamics reflect allocation of selective attention.

The mesocortical dopamine system is comprised of midbrain dopamine neurons that predominantly innervate the medial prefrontal cortex (mPFC) and exert a powerful neuromodulatory influence over this region 1,2 . mPFC dopamine activity is thought to be critical for fundamental neurobiological processes including valence coding and decision-making 3,4 . Despite enduring interest in this pathway, the stimuli and conditions that engage mPFC dopamine release have remained enigmatic due to inherent limitations in conventional methods for dopamine monitoring which have prevented real-time in vivo observation 5 . Here, using a fluorescent dopamine sensor enabling time-resolved recordings of cortical dopamine activity in freely behaving mice, we reveal the coding properties of this system and demonstrate that mPFC dopamine dynamics conform to a selective attention signal. Contrary to the long-standing theory that mPFC dopamine release preferentially encodes aversive and stressful events 6-8 , we observed robust dopamine responses to both appetitive and aversive stimuli which dissipated with increasing familiarity irrespective of stimulus intensity. We found that mPFC dopamine does not evolve as a function of learning but displays striking temporal precedence with second-to-second changes in behavioral engagement, suggesting a role in allocation of attentional resources. Systematic manipulation of attentional demand revealed that quieting of mPFC dopamine signals the allocation of attentional resources towards an expected event which, upon detection triggers a sharp dopamine transient marking the transition from decision-making to action. The proposed role of mPFC dopamine as a selective attention signal is the first model based on direct observation of time-resolved dopamine dynamics and reconciles decades of competing theories.

Space Launch System acoustics: Far-field noise measurements of the Artemis-I launch.

To improve understanding of super heavy-lift rocket acoustics, this letter documents initial findings from noise measurements during liftoff of the Space Launch System's Artemis-I mission. Overall sound pressure levels, waveform characteristics, and spectra are described at distances ranging from 1.5 to 5.2 km. Significant results include: (a) the solid rocket boosters' ignition overpressure is particularly intense in the direction of the pad flame trench exit; (b) post-liftoff maximum overall levels range from 127 to 136 dB, greater than pre-launch predictions; and (c) the average maximum one-third-octave spectral peak occurred at 20 Hz, causing significant deviation between flat and A-weighted levels.

Prevention of Postoperative Constipation in Urogynecology Patients: A Systematic Review.

IMPORTANCE: Constipation is common after pelvic surgery, and studies suggest that surgeons underestimate the negative impact of constipation on patients. Patients undergoing pelvic reconstructive surgery are a unique population requiring special consideration in the prevention and management of constipation. OBJECTIVE: This study aimed to systematically review the literature to identify evidence for prevention of postoperative constipation with medications or fiber in patients undergoing reconstructive pelvic surgery. STUDY DESIGN: A structured literature search was performed of five databases (MEDLINE, Embase, Scopus, Web of Science, the Cochrane Library) from inception to June 2022 for studies of postoperative laxative or fiber use in adult patients undergoing benign pelvic reconstructive surgery. Studies of preoperative bowel preparation and nonsurgical patients were excluded. Data on postoperative constipation were extracted for a qualitative analysis of the literature. Grading of Recommendations Assessment, Development, and Evaluation methodology was applied to assess the quality of evidence. RESULTS: We identified 86 references after deduplication. Only 4 studies with a total of 344 patients were eligible for inclusion in the review. The included studies were all randomized controlled trials assessing time to first bowel movement with the earliest published in 2010. Laxative use decreased constipation more than placebo. Multiple-agent laxative use appeared to decrease bothersome constipation more than single-agent docusate. Preoperative fiber did not decrease constipation. By Grading of Recommendations Assessment, Development, and Evaluation criteria, all four studies provide moderate-quality evidence. CONCLUSIONS: Few studies have investigated laxative regimens in patients after urogynecologic surgery. The available literature is moderate quality and suggests benefit of multiple-agent treatment over docusate only or no treatment.

Scapholunate Ligament: Comparing the Native Strength of the Ligament to an All-suture Anchor Construct.

Our aim was to compare the tensile strength of the native scapholunate ligament (SLL) with that of an all-suture anchor construct in a cadaveric model. The scaphoid and lunate were isolated, preserving all segments of the SLL. Using a servohydraulic testing machine, we increased the load until peak load-to-failure of the native SLL was reached in nine specimens (mean ± standard deviation, 273 ± 132 N). Using the same specimens, two JuggerKnot 1.4-mm suture anchors (Zimmer Biomet) were placed into the lunate and tensioned through transosseous tunnels in the scaphoid. Sutures were tied over the radial nonarticular aspect of the scaphoid. Load-to-failure testing was repeated. The mean peak load-to-failure for the all-suture anchor constructs was 172 ± 59 N versus 231 ± 117 N for the native group (p = 0.157). This represents approximately 75% of the native ligament strength. (Journal of Surgical Orthopaedic Advances 29(3):169-172, 2020).

Prevalence and Intensity of Salmincola edwardsii in Brook Trout in Northwest New Brunswick, Canada.

Parasites can compromise the health and fitness of individual fish, and it is important to generate baseline information that can then be used to document changes in the abundance and distribution of potentially pathogenic parasites. The ectoparasitic copepod Salmincola edwardsii was assessed with respect to prevalence (percentage of infected fish per site), infection intensity (number of parasites per infected fish), and attachment location on Brook Trout Salvelinus fontinalis in northwest New Brunswick, Canada. Ten sample sites were assessed, with six sites on two streams in the Quisibis River basin and four sites on three streams in the Restigouche River basin. Parasite species identity was supported by 100% sequence identity with S. edwardsii in a variable region within 28S rDNA. The prevalence of fish infected per site ranged from 19.0% to 79.6%, with an overall prevalence of 48.5 ± 19.1% (mean ± SD) per site. Mean infection intensity was 1.5 ± 0.9 copepods/fish (range = 1-7), with parasites almost exclusively surrounding the dorsal fin and/or adipose fin (97.6%). There was no influence of trout age-class on parasite prevalence. Some fish presented with fin erosion at the site of parasite attachment (12.5%), and 6.2% also presented with hyperplastic skin lesions where no parasites were observed, that could be misinterpreted as secondary bacterial or fungal infections. Skin and fin damage were significantly more common when fish were infected with three or more individual parasites. The pathogenic potential of this parasite makes its presence noteworthy as a risk to salmonids that are both recreationally and ecologically important.

Grooming M.D. Leaders.

CEOs need to target and develop physicians to play leading roles in the transformation of health care--and of their organizations.

The mediating role of mental toughness in sport.

AIM: We conducted two studies that examined different models, which included mental toughness and psychological constructs that are thought to be related to this construct. METHODS: In Study 1, 531 athletes completed measures of mental toughness, resilience, and emotional intelligence. In Study 2, 522 athletes completed measures of mental toughness, sport motivation, and self-efficacy. RESULTS: There were positive paths between the constructs in the model, which were mediated by mental toughness in Study 1. Further, there was a positive path between mental toughness and self-efficacy, but negative paths with introjected regulation and amotivation in Study 2. CONCLUSION: This two study paper suggests that it might also be the presence of constructs such as resilience, emotional intelligence, motivation, and/or self-efficacy that enable mentally tough individuals to excel under stressful circumstances rather than just coping.

The mediating role of mental toughness in sport.

AIM: We conducted two studies that examined different models, which included mental toughness and psychological constructs that have been found to be related to this construct. METHODS: In Study 1, 531 athletes completed measures of mental toughness, resilience, and emotional intelligence. In Study 2, 522 athletes completed measures of mental toughness, sport motivation, and self-efficacy. RESULTS: There were positive paths between the constructs in the model, which were mediated by mental toughness in Study 1. Further, there was a positive path between mental toughness and self-efficacy, but negative paths with introjected regulation and amotivation in Study 2. CONCLUSION: This two study paper suggests that it might also be the presence of constructs such as resilience, emotional intelligence, motivation, and/or self-efficacy that enable mentally tough individuals to excel under stressful circumstances rather than just coping.

Building strong partnerships with CMOs.

CFOs and chief medical officers (CMOs) can build on common traits to form productive partnerships in guiding healthcare organizations through the changes affecting the industry. CFOs can strengthen bonds with CMOs by taking steps to engage physicians on their own turf--by visiting clinical locations and attending medical-executive committee meetings, for example. Steps CFOs can take to help CMOs become more acquainted with the financial operations of health systems include demonstrating the impact of clinical decisions on costs and inviting CMOs to attend finance-related meetings.

Achieving true alignment with physicians.

With true physician alignment, physicians act in accord with the organization's mission and vision. Many alignment efforts, such as co-management models and physician compensation formulas, are doomed from the start because they appear to give health systems power over physicians. True mission-vision alignment is accomplished by engaging physicians as equal partners.

Interspecific interactions between primates, birds, bats, and squirrels may affect community composition on Borneo.

For several decades, primatologists have been interested in understanding how sympatric primate species are able to coexist. Most of our understanding of primate community ecology derives from the assumption that these animals interact predominantly with other primates. In this study, we investigate to what extent multiple community assembly hypotheses consistent with this assumption are supported when tested with communities of primates in isolation versus with communities of primates, birds, bats, and squirrels together. We focus on vertebrate communities on the island of Borneo, where we examine the determinants of presence or absence of species, and how these communities are structured. We test for checkerboard distributions, guild proportionality, and Fox's assembly rule for favored states, and predict that statistical signals reflecting interactions between ecologically similar species will be stronger when nonprimate taxa are included in analyses. We found strong support for checkerboard distributions in several communities, particularly when taxonomic groups were combined, and after controlling for habitat effects. We found evidence of guild proportionality in some communities, but did not find significant support for Fox's assembly rule in any of the communities examined. These results demonstrate the presence of vertebrate community structure that is ecologically determined rather than randomly generated, which is a finding consistent with the interpretation that interactions within and between these taxonomic groups may have shaped species composition in these communities. This research highlights the importance of considering the broader vertebrate communities with which primates co-occur, and so we urge primatologists to explicitly consider nonprimate taxa in the study of primate ecology.

Purinergic neuromuscular transmission is selectively attenuated in ulcerated regions of inflamed guinea pig distal colon.

This study was undertaken to investigate neuromuscular transmission in regions of the inflamed colon in which motility is disrupted. Propulsive motility was evaluated in segments of control guinea pigs and those treated 6 days previously with trinitrobenzene sulfonic acid. Intracellular recordings were then obtained from circular muscle cells to examine excitatory and inhibitory junction potentials (EJPs and IJPs). In inflamed preparations, propulsion of fecal pellets was temporarily halted or obstructed at sites of mucosal damage, whereas the propulsive motility was linear in control colons. The amplitudes of evoked and spontaneous IJPs were significantly reduced in ulcerated regions of inflamed preparations, but EJPs were comparable to controls. Pharmacological dissection of the IJP revealed that the purinergic component was reduced, while the nitrergic IJP was slightly increased. Furthermore, the reduction in the purinergic IJP in inflamed preparations persisted in the presence of hexamethonium, suggesting that the deficit involved the inhibitory motor neuron and/or smooth muscle. Nerve fibre density was not altered in the circular muscle, and pre-contracted rings of inflamed colon relaxed normally to ATP, suggesting that the deficit involves altered ATP release and/or degradation. The P2Y(1) receptor antagonist MRS2179 slowed propulsive motility indicating that decreased purinergic neuromuscular transmission could contribute to the inflammation-induced motor deficit. We conclude that purinergic inhibitory neuronal input to the circular muscle is selectively reduced in regions of the colon in experimental colitis where the mucosa is damaged, and this is likely to contribute to altered motility in colitis by diminishing downstream relaxation during the peristaltic reflex.

The facilitative nature of avoidance coping within sports injury rehabilitation.

Avoidance coping has commonly been reported within literature to be a debilitative process. However, in situations where goal attainment is reduced or eradicated avoidance coping strategies appear to have some benefit. The aim of this study was to identify the role of avoidance coping within the sports injury rehabilitation setting. A mixed methodological approach was utilized with four professional male rugby union players, concurrent with their rehabilitation from anterior cruciate ligament (ACL) surgery. Twice monthly interviews were conducted with each player, along with a self-report diary and the Coping with Health, Injuries and Problems (CHIP; Endler & Parker, 2000) inventory. Content analysis showed six higher-order themes split into two general dimensions: (a) behavioral avoidance coping (physical distraction, social interaction, maladaptive behaviors), and (b) cognitive avoidance coping (denial, thought stopping, cognitive distraction). Results suggest avoidance coping strategies facilitate control of short-term emotional states, as well has appearing to have long-term benefits for injured players. Particular benefits were associated with undertaking alternate work within the sports organization.