The fission yeast cell size control system integrates pathways measuring cell surface area, volume, and time.

Eukaryotic cells tightly control their size, but the relevant aspect of size is unknown in most cases. Fission yeast divide at a threshold cell surface area (SA) due, in part, to the protein kinase Cdr2. We find that fission yeast cells only divide by SA under a size threshold. Mutants that divide at a larger size shift to volume-based divisions. Diploid cells divide at a larger size than haploid cells do, but they maintain SA-based divisions, and this indicates that the size threshold for changing from surface-area-based to volume-based control is set by ploidy. Within this size control system, we found that the mitotic activator Cdc25 accumulates like a volume-based sizer molecule, whereas the mitotic cyclin Cdc13 accumulates in the nucleus as a timer. We propose an integrated model for cell size control based on multiple signaling pathways that report on distinct aspects of cell size and growth, including cell SA (Cdr2), cell volume (Cdc25), and time (Cdc13). Combined modeling and experiments show how this system can generate both sizer- and adder-like properties.

Developing a Diversity, Equity, and Civility Council to Advance Health Equity in Nursing Academia and Practice.

The National Academy of Medicine (NAM) recently released the Future of Nursing 2020-2030 focused on charting a path to achieve health equity. This article focuses on the critical role of nursing education in this call for action. Most specifically, we provide an overview of the process of developing a diversity, equity, and civility council in a school of nursing to promote equity, inclusivity, and diversity grounded in social justice within the culture of the school for faculty, staff, and students. In addition, we describe the council's work to date highlighting goals and the council's plans for future work based on data-driven processes.

Arf6 anchors Cdr2 nodes at the cell cortex to control cell size at division.

Fission yeast cells prevent mitotic entry until a threshold cell surface area is reached. The protein kinase Cdr2 contributes to this size control system by forming multiprotein nodes that inhibit Wee1 at the medial cell cortex. Cdr2 node anchoring at the cell cortex is not fully understood. Through a genomic screen, we identified the conserved GTPase Arf6 as a component of Cdr2 signaling. Cells lacking Arf6 failed to divide at a threshold surface area and instead shifted to volume-based divisions at increased overall size. Arf6 stably localized to Cdr2 nodes in its GTP-bound but not GDP-bound state, and its guanine nucleotide exchange factor (GEF), Syt22, was required for both Arf6 node localization and proper size at division. In arf6Δ mutants, Cdr2 nodes detached from the membrane and exhibited increased dynamics. These defects were enhanced when arf6Δ was combined with other node mutants. Our work identifies a regulated anchor for Cdr2 nodes that is required for cells to sense surface area.

Comparing the Effects of Traditional Education and Root-Cause Analysis on Nursing Students' Attitudes About Safety Culture and Knowledge of Safe Medication Administration Practices: An Experimental Study.

BACKGROUND: Root-cause analysis (RCA) has been used for decades to support a culture of safety in health care institutions. Although RCA has been recommended for inclusion in a nursing curriculum, little research has been conducted on educational strategies or outcomes. PURPOSE: The study aims were to compare differences in attitudes about safety culture and knowledge of safe medication administration after education about RCA (intervention) versus traditional safe medication administration education (control) and to provide psychometric data for the Safety Attitudes Questionnaire (SAQ) with nursing students. METHODS: An experimental pretesfy/posttest study was conducted in 3 schools of nursing (N = 117). RESULTS: Although there was no significant difference in outcomes between the control and intervention groups, increases in SAQ scores were observed for the intervention group. The Cronbach's α for the SAQ was .93. CONCLUSIONS: The SAQ is a reliable instrument for measuring safety culture in schools of nursing.

Sequestration of the exocytic SNARE Psy1 into multiprotein nodes reinforces polarized morphogenesis in fission yeast.

Polarized morphogenesis is achieved by targeting or inhibiting growth in distinct regions. Rod-shaped fission yeast cells grow exclusively at their ends by restricting exocytosis and secretion to these sites. This growth pattern implies the existence of mechanisms that prevent exocytosis and growth along nongrowing cell sides. We previously identified a set of 50-100 megadalton-sized node structures along the sides of fission yeast cells that contained the interacting proteins Skb1 and Slf1. Here, we show that Skb1-Slf1 nodes contain the syntaxin-like soluble N-ethylmaleimide-sensitive factor attachment protein receptor Psy1, which mediates exocytosis in fission yeast. Psy1 localizes in a diffuse pattern at cell tips, where it likely promotes exocytosis and growth, but is sequestered in Skb1-Slf1 nodes at cell sides where growth does not occur. Mutations that prevent node assembly or inhibit Psy1 localization to nodes lead to aberrant exocytosis at cell sides and increased cell width. Genetic results indicate that this Psy1 node mechanism acts in parallel to actin cables and Cdc42 regulation. Our work suggests that sequestration of syntaxin-like Psy1 at nongrowing regions of the cell cortex reinforces cell morphology by restricting exocytosis to proper sites of polarized growth.

Infected juvenile salmon can experience increased predation during freshwater migration.

Predation risk for animal migrants can be impacted by physical condition. Although size- or condition-based selection is often observed, observing infection-based predation is rare due to the difficulties in assessing infectious agents in predated samples. We examined predation of outmigrating sockeye salmon (Oncorhynchus nerka) smolts by bull trout (Salvelinus confluentus) in south-central British Columbia, Canada. We used a high-throughput quantitative polymerase chain reaction (qPCR) platform to screen for the presence of 17 infectious agents found in salmon and assess 14 host genes associated with viral responses. In one (2014) of the two years assessed (2014 and 2015), the presence of infectious haematopoietic necrosis virus (IHNv) resulted in 15-26 times greater chance of predation; in 2015 IHNv was absent among all samples, predated or not. Thus, we provide further evidence that infection can impact predation risk in migrants. Some smolts with high IHNv loads also exhibited gene expression profiles consistent with a virus-induced disease state. Nine other infectious agents were observed between the two years, none of which were associated with increased selection by bull trout. In 2014, richness of infectious agents was also associated with greater predation risk. This is a rare demonstration of predator consumption resulting in selection for prey that carry infectious agents. The mechanism by which this selection occurs is not yet determined. By culling infectious agents from migrant populations, fish predators could provide an ecological benefit to prey.

Regulation of Cdc42 for polarized growth in budding yeast.

The Rho GTPase Cdc42 is a central regulator of cell polarity in diverse cell types. The activity of Cdc42 is dynamically controlled in time and space to enable distinct polarization events, which generally occur along a single axis in response to spatial cues. Our understanding of the mechanisms underlying Cdc42 polarization has benefited largely from studies of the budding yeast Saccharomyces cerevisiae, a genetically tractable model organism. In budding yeast, Cdc42 activation occurs in two temporal steps in the G1 phase of the cell cycle to establish a proper growth site. Here, we review findings in budding yeast that reveal an intricate crosstalk among polarity proteins for biphasic Cdc42 regulation. The first step of Cdc42 activation may determine the axis of cell polarity, while the second step ensures robust Cdc42 polarization for growth. Biphasic Cdc42 polarization is likely to ensure the proper timing of events including the assembly and recognition of spatial landmarks and stepwise assembly of a new ring of septins, cytoskeletal GTP-binding proteins, at the incipient bud site. Biphasic activation of GTPases has also been observed in mammalian cells, suggesting that biphasic activation could be a general mechanism for signal-responsive cell polarization. Cdc42 activity is necessary for polarity establishment during normal cell division and development, but its activity has also been implicated in the promotion of aging. We also discuss negative polarity signaling and emerging concepts of Cdc42 signaling in cellular aging.

How pathogens affect the marine habitat use and migration of sea trout (Salmo trutta) in two Norwegian fjord systems.

Wild fish are confronting changing pathogen dynamics arising from anthropogenic disturbance and climate change. Pathogens can influence animal behaviour and life histories, yet there are little such data from fish in the high north where pathogen dynamics may differ from comparatively southern regions. We aimed to compare the pathogen communities of 160 wild anadromous brown trout in two fjords in northern Norway and to determine whether pathogens influenced area use or return to spawn. Application of high-throughput qPCR detected 11 of the 46 pathogens screened for; most frequently encountered were Ichthyobodo spp., Flavobacterium psychrophilum and Candidatus Branchiomonas cysticola. The rate of returning to freshwater during the spawning season was significantly lower for the Skjerstadfjord fish. Piscichlamydia salmonis and F. psychrophilum were indicator species for the Skjerstadfjord and pathogen communities in the two fjords differed according to perMANOVA. Individual length, Fulton's condition factor and the time between first and last detection of the fish were not related to the presence of pathogens ordinated using non-metric multidimensional scaling (NMDS). However, there was evidence that pathogen load was correlated with the expression of smoltification genes, which are upregulated by salmonids in freshwater. Correspondingly, percentage of time in freshwater after release was longer for fish with greater pathogen burdens.

A rapid intrinsic heart rate resetting response with thermal acclimation in rainbow trout, Oncorhynchus mykiss.

We examined cardiac pacemaker rate resetting in rainbow trout following a reciprocal temperature transfer. In the original experiment, performed in winter, 4°C-acclimated fish transferred to 12°C reset intrinsic heart rate after just 1 h (from 56.8±1.2 to 50.8±1.5 beats min-1); 12°C-acclimated fish transferred to 4°C reset intrinsic heart rate after 8 h (from 33.4±0.7 to 37.7±1.2 beats min-1). However, in a replicate experiment, performed in the summer using a different brood year, intrinsic heart rate was not reset, even after 10 weeks at a new temperature. Using this serendipitous opportunity, we compared mRNA expression changes of a suite of proteins in sinoatrial node (SAN), atrial and ventricular tissues after both 1 h and longer than 3 weeks for both experimental acclimation groups to identify those changes only associated with pacemaker rate resetting. Of the changes in mRNA expression occurring after more than 3 weeks of warm acclimation and associated with pacemaker rate resetting, we observed downregulation of NKA α1c in the atrium and ventricle, and upregulation of HCN1 in the ventricle. However, in the SAN there were no mRNA expression changes unique to the fish with pacemaker rate resetting after either 1 h or 3 weeks of warm acclimation. Thus, despite identifying changes in mRNA expression of contractile cardiac tissues, there was an absence of changes in mRNA expression directly involved with the initial, rapid pacemaker rate resetting with warm acclimation. Importantly, pacemaker rate resetting with thermal acclimation does not always occur in rainbow trout.

Temporal regulation of cell polarity via the interaction of the Ras GTPase Rsr1 and the scaffold protein Bem1.

The Cdc42 guanosine triphosphatase (GTPase) plays a central role in polarity development in species ranging from yeast to humans. In budding yeast, a specific growth site is selected in the G1 phase. Rsr1, a Ras GTPase, interacts with Cdc42 and its associated proteins to promote polarized growth at the proper bud site. Yet how Rsr1 regulates cell polarization is not fully understood. Here, we show that Rsr1-GDP interacts with the scaffold protein Bem1 in early G1, likely hindering the role of Bem1 in Cdc42 polarization and polarized secretion. Consistent with these in vivo observations, mathematical modeling predicts that Bem1 is unable to promote Cdc42 polarization in early G1 in the presence of Rsr1-GDP. We find that a part of the Bem1 Phox homology domain, which overlaps with a region interacting with the exocyst component Exo70, is necessary for the association of Bem1 with Rsr1-GDP. Overexpression of the GDP-locked Rsr1 interferes with Bem1-dependent Exo70 polarization. We thus propose that Rsr1 functions in spatial and temporal regulation of polarity establishment by associating with distinct polarity factors in its GTP- and GDP-bound states.

Impact of the Agency for Healthcare Research and Quality's Safety Program for Perinatal Care.

BACKGROUND: The Safety Program for Perinatal Care (SPPC) seeks to improve safety on labor and delivery (L&D) units through three mutually reinforcing components: (1) fostering a culture of teamwork and communication, (2) applying safety science principles to care processes; and (3) in situ simulation. The objective of this study was to describe the SPPC implementation experience and evaluate the short-term impact on unit patient safety culture, processes, and adverse events. METHODS: We supported SPPC implementation by L&D units with a program toolkit, trainings, and technical assistance. We evaluated the program using a pre-post, mixed-methods design. Implementing units reported uptake of program components, submitted hospital discharge data on maternal and neonatal adverse events, and participated in semi-structured interviews. We measured changes in safety and quality using the Modified Adverse Outcome Index (MAOI) and other perinatal care indicators. RESULTS: Forty-three L&D units submitted data representing 97,740 deliveries over 10 months of follow-up. Twenty-six units implemented all three program components. L&D staff reported improvements in teamwork, communication, and unit safety culture that facilitated applying safety science principles to clinical care. The MAOI decreased from 5.03% to 4.65% (absolute change -0.38% [95% CI, -0.88% to 0.12%]). Statistically significant decreases in indicators for obstetric trauma without instruments and primary cesarean delivery were observed. A statistically significant increase in neonatal birth trauma was observed, but the overall rate of unexpected newborn complications was unchanged. CONCLUSIONS: The SPPC had a favorable impact on unit patient safety culture and processes, but short-term impact on maternal and neonatal adverse events was mixed.

The shared role of the Rsr1 GTPase and Gic1/Gic2 in Cdc42 polarization.

The Cdc42 GTPase plays a central role in polarity development in many species. In budding yeast, Cdc42 is essential for polarized growth at the proper site and also for spontaneous cell polarization in the absence of spatial cues. Cdc42 polarization is critical for multiple events in the G1 phase prior to bud emergence, including bud-site assembly, polarization of the actin cytoskeleton, and septin filament assembly to form a ring at the new bud site. Yet the mechanism by which Cdc42 polarizes is not fully understood. Here we report that biphasic Cdc42 polarization in the G1 phase is coupled to stepwise assembly of the septin ring for bud emergence. We show that the Rsr1 GTPase shares a partially redundant role with Gic1 and Gic2, two related Cdc42 effectors, in the first phase of Cdc42 polarization in haploid cells. We propose that the first phase of Cdc42 polarization is mediated by positive feedback loops that function in parallel-one involving Rsr1 via local activation of Cdc42 in response to spatial cues and another involving Gic1 or Gic2 via reduction of diffusion of active Cdc42.

Thiamine Levels in Muscle and Eggs of Adult Pacific Salmon from the Fraser River, British Columbia.

Multiple species and stocks of Pacific salmon Oncorhynchus spp. have experienced large declines in the number of returning adults over a wide region of the Pacific Northwest due to poor marine survival (low smolt-to-adult survival rates). One possible explanation for reduced survival is thiamine deficiency. Thiamine (vitamin B1 ) is an essential vitamin with an integral role in many metabolic processes, and thiamine deficiency is an important cause of salmonid mortality in the Baltic Sea and in the Laurentian Great Lakes. To assess this possibility, we (1) compared muscle thiamine content over time in a holding experiment using Fraser River (British Columbia) Sockeye Salmon O. nerka to establish whether adults that died during the holding period had lower thiamine levels than survivors, (2) measured infectious loads of multiple pathogens in held fish, and (3) measured egg thiamine content from four species of Pacific salmon collected on Fraser River spawning grounds. Chinook Salmon O. tshawytscha had the lowest egg thiamine, followed by Sockeye Salmon; however, egg thiamine concentrations were above levels known to cause overt fry mortality. Thiamine vitamers in the muscle of Fraser River adult Sockeye Salmon shifted over a 13-d holding period, with a precipitous decline in thiamine pyrophosphate (the active form of thiamine used in enzyme reactions) in surviving fish. Survivors also carried lower loads of Flavobacterium psychrophilum than fish that died during in the holding period. Although there is no evidence of thiamine deficiency in the adults studied, questions remain about possible thiamine metabolism-fish pathogen relationships that influence survival.

Fine-tuning the orientation of the polarity axis by Rga1, a Cdc42 GTPase-activating protein.

In yeast and animal cells, signaling pathways involving small guanosine triphosphatases (GTPases) regulate cell polarization. In budding yeast, selection of a bud site directs polarity establishment and subsequently determines the plane of cell division. Rga1, a Cdc42 GTPase-activating protein, prevents budding within the division site by inhibiting Cdc42 repolarization. A protein complex including Nba1 and Nis1 is involved in preventing rebudding at old division sites, yet how these proteins and Rga1 might function in negative polarity signaling has been elusive. Here we show that Rga1 transiently localizes to the immediately preceding and older division sites by interacting with Nba1 and Nis1. The LIM domains of Rga1 are necessary for its interaction with Nba1, and loss of this interaction results in premature delocalization of Rga1 from the immediately preceding division site and, consequently, abnormal bud-site selection in daughter cells. However, such defects are minor in mother cells of these mutants, likely because the G1 phase is shorter and a new bud site is established prior to delocalization of Rga1. Indeed, our biphasic mathematical model of Cdc42 polarization predicts that premature delocalization of Rga1 leads to more frequent Cdc42 repolarization within the division site when the first temporal step in G1 is assumed to last longer. Spatial distribution of a Cdc42 GAP in coordination with G1 progression may thus be critical for fine-tuning the orientation of the polarity axis in yeast.

Capture severity, infectious disease processes and sex influence post-release mortality of sockeye salmon bycatch.

Bycatch is a common occurrence in heavily fished areas such as the Fraser River, British Columbia, where fisheries target returning adult Pacific salmon (Oncorhynchus spp.) en route to spawning grounds. The extent to which these encounters reduce fish survival through injury and physiological impairment depends on multiple factors including capture severity, river temperature and infectious agents. In an effort to characterize the mechanisms of post-release mortality and address fishery and managerial concerns regarding specific regulations, wild-caught Early Stuart sockeye salmon (Oncorhynchus nerka) were exposed to either mild (20 s) or severe (20 min) gillnet entanglement and then held at ecologically relevant temperatures throughout their period of river migration (mid-late July) and spawning (early August). Individuals were biopsy sampled immediately after entanglement and at death to measure indicators of stress and immunity, and the infection intensity of 44 potential pathogens. Biopsy alone increased mortality (males: 33%, females: 60%) when compared with non-biopsied controls (males: 7%, females: 15%), indicating high sensitivity to any handling during river migration, especially among females. Mortality did not occur until 5-10 days after entanglement, with severe entanglement resulting in the greatest mortality (males: 62%, females: 90%), followed by mild entanglement (males: 44%, females: 70%). Infection intensities of Flavobacterium psychrophilum and Ceratonova shasta measured at death were greater in fish that died sooner. Physiological indicators of host stress and immunity also differed depending on longevity, and indicated anaerobic metabolism, osmoregulatory failure and altered immune gene regulation in premature mortalities. Together, these results implicate latent effects of entanglement, especially among females, resulting in mortality days or weeks after release. Although any entanglement is potentially detrimental, reducing entanglement durations can improve post-release survival.

The Perinatal Birth Environment: Communication Strategies and Processes for Adherence to a Standardized Guideline in Women Undergoing Second-Stage Labor With Epidural Anesthesia.

Key to any perinatal safety initiative is buy-in and strong leadership from obstetric and pediatric providers, advanced practice nurses, and labor and delivery nurses in collaboration with ancillary staff. In the fall of 2007, executives of a large Midwestern hospital system created the Zero Birth Injury Initiative. This multidisciplinary group sought to eliminate birth injury using the Institute of Healthcare Improvement Perinatal Bundles. Concurrently, the team implemented a standardized second-stage labor guideline for women who choose epidural analgesia for pain management to continue the work of eliminating birth injuries in second-stage labor. The purpose of this article was to describe the process of the modification and adaptation of a standardized second-stage labor guideline, as well as adherence rates of these guidelines into clinical practice. Prior to implementation, a Web-based needs assessment survey of providers was conducted. Most (77% of 180 respondents) believed there was a need for an evidence-based guideline to manage the second stage of labor. The guideline was implemented at 5 community hospitals and 1 academic health center. Data were prospectively collected during a 3-month period for adherence assessment at 1 community hospital and 1 academic health center. Providers adhered to the guideline in about 57% of births. Of patients whose provider followed the guideline, 75% of women were encouraged to delay pushing compared with only 28% of patients delayed pushing when the provider did not follow the guideline.

Integrated Approach to Reduce Perinatal Adverse Events: Standardized Processes, Interdisciplinary Teamwork Training, and Performance Feedback.

OBJECTIVE: To improve safety practices and reduce adverse events in perinatal units of acute care hospitals. DATA SOURCES: Primary data collected from perinatal units of 14 hospitals participating in the intervention between 2008 and 2012. Baseline secondary data collected from the same hospitals between 2006 and 2007. STUDY DESIGN: A prospective study involving 342,754 deliveries was conducted using a quality improvement collaborative that supported three primary interventions. Primary measures include adoption of three standardized care processes and four measures of outcomes. DATA COLLECTION METHODS: Chart audits were conducted to measure the implementation of standardized care processes. Outcome measures were collected and validated by the National Perinatal Information Center. PRINCIPAL FINDINGS: The hospital perinatal units increased use of all three care processes, raising consolidated overall use from 38 to 81 percent between 2008 and 2012. The harms measured by the Adverse Outcome Index decreased 14 percent, and a run chart analysis revealed two special causes associated with the interventions. CONCLUSIONS: This study demonstrates the ability of hospital perinatal staff to implement efforts to reduce perinatal harm using a quality improvement collaborative. Findings help inform the relationship between the use of standardized care processes, teamwork training, and improved perinatal outcomes, and suggest that a multiplicity of integrated strategies, rather than a single intervention, may be essential to achieve high reliability.

Decreasing Malpractice Claims by Reducing Preventable Perinatal Harm.

OBJECTIVE: To evaluate the association of improved patient safety practices with medical malpractice claims and costs in the perinatal units of acute care hospitals. DATA SOURCES: Malpractice and harm data from participating hospitals; litigation records and medical malpractice claims data from American Excess Insurance Exchange, RRG, whose data are managed by Premier Insurance Management Services, Inc. (owned by Premier Inc., a health care improvement company). STUDY DESIGN: A quasi-experimental prospective design to compare baseline and postintervention data. Statistical significance tests for differences were performed using chi-square, Wilcoxon signed-rank test, and t-test. DATA COLLECTION: Claims data were collected and evaluated by experienced senior claims managers through on-site claim audits to evaluate claim frequency, severity, and financial information. Data were provided to the analyzing institution through confidentiality contracts. PRINCIPAL FINDINGS: There is a significant reduction in the number of perinatal malpractice claims paid, losses paid, and indemnity payments (43.9 percent, 77.6 percent, and 84.6 percent, respectively) following interventions to improve perinatal patient safety and reduce perinatal harm. This compares with no significant reductions in the nonperinatal claims in the same hospitals during the same time period. CONCLUSIONS: The number of perinatal malpractice claims and dollar amount of claims payments decreased significantly in the participating hospitals, while there was no significant decrease in nonperinatal malpractice claims activity in the same hospitals.

Training for teamwork through in situ simulations.

In situ simulations allow healthcare teams to practice teamwork and communication as well as clinical management skills in a team's usual work setting with typically available resources and equipment. The purpose of this video is to demonstrate how to plan and conduct in situ simulation training sessions, with particular emphasis on how such training can be used to improve communication and teamwork. The video features an in situ simulation conducted at a labour and delivery unit in response to postpartum hemorrhage.