Ascus function: From squirt guns to ooze tubes.

Unlike the mechanism of ballistospore discharge, which was not solved until the 1980s, the operation of asci as pressurized squirt guns is relatively straightforward and was understood in the nineteenth century. Since then, mycologists have sought to understand how structural adaptations to asci have allowed the ascomycetes to expel spores of different shapes and sizes over distances ranging from a few millimeters to tens of centimeters. These modifications include the use of valves at the tips of asci that maintain ascus pressure and expel spores at the highest speeds, and gelatinous appendages that connect spores after release and create larger projectiles with greater momentum than single spores. Clever experiments in the twentieth century coupled with meticulous microscopic studies led investigators to understand how asci with complicated apical structures worked and mathematical models produced estimates of launch speeds. With the recent application of high-speed video microscopy, these inferences about ascus function have been tested by imaging the motion of spores on a microsecond timescale. These experiments have established that ascospore discharge is the fastest fungal movement and is among the fastest movements in biology. Beginning with the history of the study of asci, this review article explains how asci are pressurized, how spores are released, and how far spores travel after their release. We also consider the efficiency of ascospore discharge relative to the mechanism of ballistospore discharge and examine the way that the squirt gun mechanism has limited the morphological diversity of ascomycete fruit bodies.

Sex differences in college students' knowledge of concussion and concussion education sources.

Aim: To understand sex differences and sources of concussion education for college students. The literature for college students primarily focuses on sports concussions and general knowledge. Understanding how non-students-athletes learn is critical to developing interventions to improve concussion knowledge. Participants: A random sample of 208 students from four-year institutions. Methods: A 22-question online survey explored postsecondary students' current knowledge and education regarding concussions. Results: Findings indicated that sex differences emerged with concussion knowledge and sources of concussion knowledge (e.g., leaflets, pamphlets, parents, and television). The top choices for where they wanted to learn about concussions were health educators, health centers, and campus peer educators. Conclusion: This study provides an initial evaluation and implications for future research on providing concussion education.

Relationship Building Interventions for Caregivers of Adults With Traumatic Brain Injury (2013-2020).

Systematic Review Briefs provide a summary of the findings from systematic reviews developed in conjunction with the American Occupational Therapy Association's Evidence-Based Practice Program. Each Systematic Review Brief summarizes the evidence on a theme related to a systematic review topic. This Systematic Review Brief presents findings from the systematic review on interventions for caregivers of persons with traumatic brain injury (TBI) that facilitate participation in the caregiver role.

Goal- and Client-Directed Interventions for Adults With Traumatic Brain Injury (2013-2020).

Systematic Review Briefs provide a summary of the findings from systematic reviews developed in conjunction with the American Occupational Therapy Association's Evidence-Based Practice Program. Each Systematic Review Brief summarizes the evidence on a theme related to a systematic review topic. This Systematic Review Brief presents findings from the systematic review on goal- and client-directed interventions to improve psychosocial outcomes for people with traumatic brain injury.

Cognitive Behavioral Therapy Interventions for Adults With Traumatic Brain Injury (2013-2020).

Systematic Review Briefs provide a summary of the findings from systematic reviews developed in conjunction with the American Occupational Therapy Association's Evidence-Based Practice Program. Each Systematic Review Brief summarizes the evidence on a theme related to a systematic review topic. This Systematic Review Brief presents findings from the systematic review on interventions that address psychosocial, behavioral, and emotional skills for people with traumatic brain injury (TBI).

Education and Skill-Building Interventions for Caregivers of Adults With Traumatic Brain Injury (2013-2020).

Systematic Review Briefs provide a summary of the findings from systematic reviews developed in conjunction with the American Occupational Therapy Association's Evidence-Based Practice Program. Each Systematic Review Brief summarizes the evidence on a theme related to a systematic review topic. This Systematic Review Brief presents findings from the systematic review on interventions for caregivers of persons with traumatic brain injury that facilitate participation in the caregiver role.

Health and Well-Being Interventions for Caregivers of Adults With Traumatic Brain Injury (2013-2020).

Systematic Review Briefs provide a summary of the findings from systematic reviews developed in conjunction with the American Occupational Therapy Association's Evidence-Based Practice Program. Each Systematic Review Brief summarizes the evidence on a theme related to a systematic review topic. This Systematic Review Brief presents findings from the systematic review on interventions for caregivers of persons with traumatic brain injury that facilitate participation in the caregiver role.

Physical Activity Interventions for Adults With Traumatic Brain Injury (2013-2020).

Systematic Review Briefs provide a summary of the findings from systematic reviews developed in conjunction with the American Occupational Therapy Association's Evidence-Based Practice Program. Each Systematic Review Brief summarizes the evidence on a theme related to a systematic review topic. This Systematic Review Brief presents findings from the systematic review on physical activity interventions to improve psychosocial outcomes for people with traumatic brain injury.

Education and Skills Training Interventions for Adults With Traumatic Brain Injury (TBI) (Dates of Review: 2013-2020).

Systematic Review Briefs provide a summary of the findings from systematic reviews developed in conjunction with the American Occupational Therapy Association's Evidence-Based Practice Program. Each Systematic Review Brief summarizes the evidence on a theme related to a systematic review topic. This Systematic Review Brief presents findings from the systematic review on education and skills training interventions that address psychosocial, behavioral, and emotional skills for people with traumatic brain injury (TBI).

Self-Regulation and Relaxation-Based Interventions for Adults With Traumatic Brain Injury (2013-2020).

Systematic Review Briefs provide a summary of the findings from systematic reviews developed in conjunction with the American Occupational Therapy Association's Evidence-Based Practice Program. Each Systematic Review Brief summarizes the evidence on a theme related to a systematic review topic. This Systematic Review Brief presents findings from the systematic review on self-regulation and relaxation-based interventions to improve psychosocial outcomes for people with traumatic brain injury.

Occupational Performance Limitations After Concussion in College Students.

IMPORTANCE: Occupational performance limitations (OPLs) are poorly understood sequelae of concussion. This study aimed to establish the need for occupational therapy services for people who have sustained a concussion and to support the profession's role in facilitating occupational performance for college students experiencing signs and symptoms after concussion. OBJECTIVE: To describe the types and frequency of, and assess risk factors for, OPLs in college students after concussion. DESIGN: Cross-sectional descriptive study. SETTING: Web-based survey on Qualtrics. PARTICIPANTS: A total of 220 participants completed the survey; of those, 52 (23.6%) self-identified as having sustained a concussion and were further asked about OPLs after the concussion. RESULTS: Eighty-nine percent (n = 46) of the participants reported an OPL in at least one area, and higher OPL scores were associated with the number of concussion symptoms (r = .34, p = .02) and increased recovery time (≥3 days vs. <3 days, p = .006). CONCLUSIONS AND RELEVANCE: College students reporting concussions with more symptoms that persisted for longer periods were more likely to experience occupational performance loss. Frequent OPLs were reported in occupations associated with the participants' primary role of student. These results indicate a unique need for occupational therapy intervention with students to facilitate their continued success in academic pursuits. What This Article Adds: People who have sustained a concussion experience OPLs. Occupational therapy has a role in facilitating a return to occupational performance during recovery, especially in helping college students with concussion return to the classroom.

Predicting Student Success on the National Board for Certification in Occupational Therapy® Examination.

IMPORTANCE: A predictive tool to support academic and practice outcomes for occupational therapy students is needed for use in advising students. OBJECTIVE: To determine whether characteristics of academic and professional behavior across cohorts could indicate the likelihood of student success in passing the National Board for Certification in Occupational Therapy® examination. DESIGN: Causal-comparative research. PARTICIPANTS: Master of occupational therapy students (N = 315; eight cohorts). MEASURES: Demographics, college entrance exams, grade point average, program benchmarks (i.e., specific course grades, fieldwork grades, Occupational Therapy Knowledge Exam scores), licensure exam. RESULTS: Baseline and in-program characteristics were used to determine success; for each unit increase in the success score, the odds of passing the exam were 4.11 (95% confidence interval [2.23, 7.60]). CONCLUSIONS AND RELEVANCE: Case studies that have used this success score suggest that additional resources and targeted interventions could be allocated to help students at highest risk of not passing the licensure exam. WHAT THIS ARTICLE ADDS: Using a predictive tool to support student success can enable more effective academic advising throughout an occupational therapy program and result in positive outcomes on the licensure exam.

Effectiveness of Interventions to Improve Occupational Performance for People With Psychosocial, Behavioral, and Emotional Impairments After Brain Injury: A Systematic Review.

OBJECTIVE: This systematic review evaluates the effectiveness of interventions to improve occupational performance for people with psychosocial, behavioral, or emotional impairments after traumatic brain injury (TBI). METHOD: Medline, PsycINFO, CINAHL, OTseeker, and the Cochrane Database of Systematic Reviews were searched. Of the 1,512 articles initially identified, 35 met the inclusion criteria. RESULTS: Six types of interventions were identified: (1) education, (2) peer mentoring, (3) goal-directed therapy, (4) physical activity, (5) skills training, and (6) cognitive-behavioral therapy (CBT). Strong evidence from well-conducted research supports the use of CBT in individual and group settings. Moderate evidence supports goal-directed interventions, aquatic exercise, and functional skills training. Limited evidence supports peer mentoring, aerobic exercise, educational interventions, and various skills training. CONCLUSION: An increasing body of evidence supports specific interventions to improve occupational performance and participation for people with psychosocial, behavioral, or emotional impairments after TBI.

Coagulation profile of liquid-state plasma.

BACKGROUND: Use of liquid plasma (LP) has been reported as early as the mid 1930s. Unlike fresh-frozen plasma (FFP), LP is maintained at 1 to 6°C for up to 40 days after collection and processing. Despite its approved use by the US Food and Drug Administration, the coagulation profile of LP is incompletely described. In this study we evaluate the coagulation profile of LP stored up to 30 days. STUDY DESIGN AND METHODS: LP was prepared by removing plasma from nonleukoreduced whole blood within 24 hours of collection. Three LP units from each ABO group were collected and stored at 1 to 6°C. Plasma aliquots were obtained at Postcollection Days 1 to 5, 10, 15, 20, 25, and 30 and then stored at -70°C. Each aliquot was tested for prothrombin time, activated partial thromboplastin time, and other coagulation and fibrinolytic factors. RESULTS: There was a significant decrease in Factor (F)V, FVII, FVIII, von Willebrand factor (VWF), protein S (PS) activity, and endogenous thrombin potential on Day 15 compared with Day 1. No significant difference was observed for PS antigen, D-dimer, or thrombin-antithrombin complex. At least 50% activity of all measured factors was noted on Day 15, compared to Day 1. Considerable heterogeneity was observed between the different blood groups for FVII, FVIII, and VWF. CONCLUSION: These data demonstrate that LP maintains at least 50% of factor activity and thrombin-generating capacity up to 15 days of refrigerated storage. It may be more appropriate to limit LP storage and supplement with FFP when used for management of massively bleeding patients.

Evaluating animal-assisted therapy in group treatment for child sexual abuse.

This study evaluates and compares the effectiveness of three group interventions on trauma symptoms for children who have been sexually abused. All of the groups followed the same treatment protocol, with two of them incorporating variations of animal-assisted therapy. A total of 153 children ages 7 to 17 who were in group therapy at a Child Advocacy Center participated in the study. Results indicate that children in the groups that included therapy dogs showed significant decreases in trauma symptoms including anxiety, depression, anger, post-traumatic stress disorder, dissociation, and sexual concerns. In addition, results show that children who participated in the group with therapeutic stories showed significantly more change than the other groups. Implications and suggestions for further research are discussed.

Solving the aerodynamics of fungal flight: how air viscosity slows spore motion.

Viscous drag causes the rapid deceleration of fungal spores after high-speed launches and limits discharge distance. Stokes' law posits a linear relationship between drag force and velocity. It provides an excellent fit to experimental measurements of the terminal velocity of free-falling spores and other instances of low Reynolds number motion (Re<1). More complex, non-linear drag models have been devised for movements characterized by higher Re, but their effectiveness for modeling the launch of fast-moving fungal spores has not been tested. In this paper, we use data on spore discharge processes obtained from ultra-high-speed video recordings to evaluate the effects of air viscosity predicted by Stokes' law and a commonly used non-linear drag model. We find that discharge distances predicted from launch speeds by Stokes' model provide a much better match to measured distances than estimates from the more complex drag model. Stokes' model works better over a wide range projectile sizes, launch speeds, and discharge distances, from microscopic mushroom ballistospores discharged at <1 m s(-1) over a distance of <0.1mm (Re<1.0), to macroscopic sporangia of Pilobolus that are launched at >10 m s(-1) and travel as far as 2.5m (Re>100).

The cation diffusion facilitator gene cdf-2 mediates zinc metabolism in Caenorhabditis elegans.

Zinc is essential for many cellular processes. To use Caenorhabditis elegans to study zinc metabolism, we developed culture conditions allowing full control of dietary zinc and methods to measure zinc content of animals. Dietary zinc dramatically affected growth and zinc content; wild-type worms survived from 7 microm to 1.3 mm dietary zinc, and zinc content varied 27-fold. We investigated cdf-2, which encodes a predicted zinc transporter in the cation diffusion facilitator family. cdf-2 mRNA levels were increased by high dietary zinc, suggesting cdf-2 promotes zinc homeostasis. CDF-2 protein was expressed in intestinal cells and localized to cytosolic vesicles. A cdf-2 loss-of-function mutant displayed impaired growth and reduced zinc content, indicating that CDF-2 stores zinc by transport into the lumen of vesicles. The relationships between three cdf genes, cdf-1, cdf-2, and sur-7, were analyzed in double and triple mutant animals. A cdf-1 mutant displayed increased zinc content, whereas a cdf-1 cdf-2 double mutant had intermediate zinc content, suggesting cdf-1 and cdf-2 have antagonistic functions. These studies advance C. elegans as a model of zinc metabolism and identify cdf-2 as a new gene that has a critical role in zinc storage.

Biomechanics of invasive growth by Armillaria rhizomorphs.

Rhizomorphs of wood-decay basidiomycetes are root-like structures produced by the coordinated growth of thousands of hyphae. Very little is known about their development nor the way that they penetrate soils and rotting wood. In this study, we applied techniques used in previous studies on hyphae to explore the mechanics of the invasive growth process in Armillaria gallica. Growth rate measurements were made in media with different gel strengths. The osmolyte composition of rhizomorph sap was determined spectroscopically and the forces exerted by growing tips were measured using a force transducer. Cultured rhizomorphs extended at much faster rates than unbundled hyphae (3.5mmd(-1) versus 1.5mmd(-1)) and their growth accelerated in response to increased medium gel strength (to 7.4mmd(-1)). Measurements of rhizomorph osmolality provided a turgor pressure estimate of 760kPa (7.5atm.), and spectroscopic analysis showed that this pressure was generated by the accumulation of erythritol, mannitol, and KCl. Forces exerted by growing tips ranged from 1 to 6mN, corresponding to pressures of 40-300kPa (0.4-3.0atm.). Pressures exerted by extending rhizomorphs are comparable to those produced by individual vegetative hyphae. This suggests that the mechanical behavior of hyphae is similar whether they grow as unbundled cells or aggregate to form macroscopic rhizomorphs.

TRICARE Management Activity Healthcare Facility Evidence-Based Design Survey.

UNLABELLED: This report summarizes findings from the TRICARE Management Activity (TMA) Healthcare Facility Evidence-Based Design Survey. TMA conducted 382 telephone interviews with active duty (AD) personnel and 36 interviews with AD spouses to solicit their opinions regarding 10 proposed healthcare facility design features that could improve the comfort and convenience of a hospital stay. The survey was composed of 10 multiple-choice questions that were based on recent findings in evidence-based healthcare facility design features. RESULTS: The 4 most important features for all respondents include having space in the patient room for overnight visitors, privacy features, and individual control of lighting and temperature. CONCLUSION: Developing specific hospital design plans will likely require continuing to work with patients and their loved ones to develop well-defined requirements. Potential study techniques include interviewing in facilities, holding focus groups, and observing patient and family behavior in the facility.

Adaptation of the spore discharge mechanism in the basidiomycota.

BACKGROUND: Spore discharge in the majority of the 30,000 described species of Basidiomycota is powered by the rapid motion of a fluid droplet, called Buller's drop, over the spore surface. In basidiomycete yeasts, and phytopathogenic rusts and smuts, spores are discharged directly into the airflow around the fungal colony. Maximum discharge distances of 1-2 mm have been reported for these fungi. In mushroom-forming species, however, spores are propelled over much shorter ranges. In gilled mushrooms, for example, discharge distances of <0.1 mm ensure that spores do not collide with opposing gill surfaces. The way in which the range of the mechanism is controlled has not been studied previously. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we report high-speed video analysis of spore discharge in selected basidiomycetes ranging from yeasts to wood-decay fungi with poroid fruiting bodies. Analysis of these video data and mathematical modeling show that discharge distance is determined by both spore size and the size of the Buller's drop. Furthermore, because the size of Buller's drop is controlled by spore shape, these experiments suggest that seemingly minor changes in spore morphology exert major effects upon discharge distance. CONCLUSIONS/SIGNIFICANCE: This biomechanical analysis of spore discharge mechanisms in mushroom-forming fungi and their relatives is the first of its kind and provides a novel view of the incredible variety of spore morphology that has been catalogued by traditional taxonomists for more than 200 years. Rather than representing non-selected variations in micromorphology, the new experiments show that changes in spore architecture have adaptive significance because they control the distance that the spores are shot through air. For this reason, evolutionary modifications to fruiting body architecture, including changes in gill separation and tube diameter in mushrooms, must be tightly linked to alterations in spore morphology.