bluuebunny/crossref_metadata_2025 huggingface dataset:
The Evolution of a Peer Assistance Network for Nurse Anesthetists’ Substance Use Disorder
Authors: Stone Linda , Quinlan Diana , Rice Julie A. , Wright Elizabeth Laura
Published: August 2016

The American Association of Nurse Anesthetists has a long history of providing peer support for its members with substance use disorder (SUD). The American Association of Nurse Anesthetists’ Peer Assistance Advisors Committee (PAAC) is a group of certified registered nurse anesthetist volunteers who strive to promote the awareness of SUD through education and research and provide support to certified registered nurse anesthetists and students with this disease. During the committee’s 33-year history, educational outreach to nurse anesthesia educational programs and anesthesia workplaces has expanded, the peer support network has been strengthened, resources and guidelines have been developed, and research related to SUD has been conducted in an effort to accomplish these goals. Although faced with challenges along the way, the PAAC’s dedication and commitment to the association and members have helped overcome these challenges as well as strengthen the program. Through its generous catalog of online resources, peer support network, and helpline, the PAAC continues to provide help to those in need.
Endoscopic and pharmacological treatment for prophylaxis against postendoscopic retrograde cholangiopancreatography pancreatitis: a meta-analysis and systematic review
Authors: Vadalà di Prampero Salvatore F. , Faleschini Giacomo , Panic Nikola , Bulajic Milutin
Published: August 2016

Background and aim

Postendoscopic retrograde cholangiopancreatography (post-ERCP) pancreatitis (PEP) is the most common complication following ERCP. We carried out a systematic review and meta-analysis of the global literature on PEP prevention to provide clinical guidance and a framework for future research in this important field.

Methods

PubMed, Embase, Science Citation Index, Ovid, and the Cochrane Controlled Trials Register were searched by two independent reviewers to identify full-length, prospective, randomized controlled trials (RCTs) published up until March 2016 investigating the use of pancreatic duct stents and pharmacological agents to prevent PEP.

Results

Twelve RCTs comparing the risk of PEP after pancreatic duct stent placement (1369 patients) and 30 RCTs comparing pharmacological agents over placebo (10251 patients) fulfilled the inclusion criteria and were selected for final review and analysis. Meta-analysis showed that prophylactic pancreatic stents significantly decreased the odds of post-ERCP pancreatitis [odds ratio (OR), 0.28; 95% confidence interval (CI), 0.18–0.42]. Significant OR reduction of PEP was also observed in relation to rectal administration of diclofenac (OR, 0.24; 95% CI, 0.12–0.48) and rectal administration of indometacin (OR, 0.59; 95% CI, 0.44–0.79) compared with placebo. Subgroup analysis showed a significant reduction with bolus-administered somatostatin (OR, 0.23; 95% CI, 0.11–0.49). Subgroup analysis showed a significant reduction with bolus-administered somatostatin (OR, 0.23; 95% CI, 0.11–0.49).

Conclusion

Pancreatic stent placement, rectal diclofenac, and bolus administration of somatostatin appear to be most effective in preventing post-ERCP pancreatitis.
Physical and virtual modelling of the head and neck for surgical simulation and training
Authors: Dirven Steven , Allen Jacqui E.
Published: August 2016

Purpose of review

Investigation and surgical manipulation of the larynx, pharynx, and oesophagus suffer from inherent challenges with access to the sites of interest. To reduce trauma and external scarring, visualization and minimally invasive interventions by the transnasal or transoral routes have become more prevalent. This article discusses engineering methods used to understand and overcome the mechanical constraints inside the airway and upper gastrointestinal tract, and examines the role that robotics and engineering are beginning to play in modelling of surgical interventions in this region.

Recent findings

Although robotic solutions to minimally invasive surgery of the airway and upper gastrointestinal tract already exist, there is still scope for increasing the breadth of their use. Physical and virtual models of these organs are used to investigate the capability and limitations of manual and robotic surgical interventions in this region. Understanding the tissue mechanics and tool capabilities is central to improving outcomes in the clinical setting. Both physical and virtual modelling modalities are used in training surgeons for both manual-assisted and robot-assisted surgeries.

Minimally invasive surgical interventions via the transnasal and the transoral route are strong candidates for overcoming access issues to the airway. They are likely to become more robotically driven as the demand for higher dexterity and accuracy increases for fine manipulation. Physical and virtual organ models are required to enable surgical training for these procedures.
Cricopharyngeal function or dysfunction: what's the deal?
Authors: Allen Jacqui E.
Published: August 2016

Purpose of review

The purpose of the review is to examine current research focused on upper oesophageal sphincter (UES) and cricopharyngeus muscle function, and how better understanding UES physiology will translate to improved management.

Recent findings

Although much is known about UES function, new information describing the dynamics of the UES and cricopharyngeus is being identified through manometry, combined fluoromanometry, and anatomic study. Response of the UES to injury, reflux, and surgical interventions is reported. Direct surgical treatment of cricopharyngeus noncompliance with or without diverticuli continues to show benefit and long-term results support a sustained improvement in three-quarters of patients.

UES and cricopharyngeus function is complex and dynamic. It is affected by internal signals such as posture and constitution of refluxate, aging, and interventions particularly radiation and surgery. Clear understanding of the triggers and responses of the UES will enable clinicians to choose the correct therapy for their dysphagic patients.
SOARing Into Strategic Planning
Authors: Wadsworth Barbara , Felton Fiona , Linus Rita
Published: August 2016

In 2013, a new system chief nursing officer engaged the nursing leaders and staff in an Appreciative Inquiry process utilizing strengths, opportunities, aspirations, and results (SOAR), and a Journey of Excellence to assess and understand the current environment. The ultimate goal was to engage all nurses in strategic planning and goal setting to connect their patient care to the system strategic initiatives. This work led to the creation of a nursing vision, a revised professional practice model and greater council alignment, resulting in significant positive change and ongoing advancement throughout the system. The shared decision-making structure was key to the process with a direct connection of each council's goals, leading to the successful achievement of 34 of the 36 goals in 2 years. This article outlines the process, tools, and staff engagement strategies used to achieve system-wide success. This methodology has improved the outcomes across the organization in both small and system-wide work groups. This work can easily be replicated and adapted to help disparate staffs brought together through mergers or acquisitions to become aligned as a new team. This process, model, and framework, provides structure and results in significant outcomes that recognizes and celebrates the work of individual entities while aligning future strategies and goals.
Design and Implementation of a Centralized Model of Clinical Education Within a Statewide Health System
Authors: Elzy Pamela Smith
Published: August 2016

Today's dynamic health care environment is exceedingly complex, and health care facilities across the United States are struggling to respond to changes in technology, health care reimbursement, the Affordable Care Act, and the much-anticipated nursing shortage. Mergers, acquisitions, and integrations are the current health care reality. These are proposed to increase efficiency, efficacy, quality, satisfaction, and safety while effectively reducing cost to the consumer and stabilizing the economy of the health care system. Many of these projects fail to achieve objectives, even years after the formal change in status. Clinical education departments in merged organizations are often operated in the single-facility mindset, or contain an element of the shared services model. They are not truly integrated. Development of skills in complex analysis of current state, identification of desired scope of service and expectations of performance, and articulation of the benefits of the desired future state are all essential to nursing executive practice. This article describes an experience integrating 3 legacy education departments across 21 facilities into a centralized education system. The complexity of integration activities is illustrated and outcome measures of success are discussed. Barriers, facilitators, and risks of the project are identified and evaluated.
Risk Taking
Authors: Trepanier Sylvain , Crenshaw Jeannette T. , Yoder-Wise Patricia S.
Published: August 2016

Today's nurse executive is likely to find himself or herself in the middle of a merger, acquisition, and/or partnership (MAP). This is the result of health care agencies vying for market share in the midst of stiff competition, as well as decreased reimbursement in a rapidly changing payment system. The phenomenon of MAPs is fueled by the focus on care coordination and population health management. To be prepared for the ongoing and increasing MAP activity, nurse executives need to develop the skill of risk taking as an essential competency for leading change. This article emphasizes the need to maintain and improve health care quality and patient safety.
NAQ's 40th Birthday Nursing: Predictions From the Past; Predictions for the Future, Parts I & II
Authors: McClure Margaret L. , Batcheller Joyce
Published: August 2016

The following two articles relate to Nursing's past and future, described through a series of predictions made by one of Nursing's great leaders Margaret L. McClure (Maggie McClure). It is reprinted from NAQ Fall 2000, Volume 25, Issue 1. The second article, by another great leader, Joyce Batcheller, DNP, RN, NEA-BC, FAAN, is a follow up on those predictions, reflecting on Nursing today and tommorow.
Palliative Care and Moral Distress in the Intensive Care Unit
Authors: Wolf Alexander T.
Published: August 2016

Moral distress is a harmful emotional experience that often afflicts health care providers who care for dying patients. First described among nurses, morally distressing situations are particularly common in critical care, where nurses and other providers can feel forced to prolong their patients’ death and suffering in pursuit of curative treatment. Meanwhile, the role of palliative care in the intensive care unit (ICU) continues to evolve, necessitating inquiry about how access to palliative care might affect the moral distress of ICU clinicians. The purpose of this review was to examine the relationship between palliative care and moral distress among health care providers in the adult ICU. An integrative review methodology was used to examine theoretical and empirical literature from 6 databases. Four studies—2 qualitative and 2 quantitative descriptive studies—met the final criteria for inclusion. Overall, inadequate palliative care seems to contribute to moral distress in ICU clinicians, and palliative care education alone is not sufficient to prevent moral distress in nurses and other providers. Further research is needed to examine how specific palliative interventions impact health care provider moral distress and to determine the effects of clinician moral distress on ICU patient outcomes and satisfaction.
The Transition From Palliation With Anticancer Treatment to Palliation Without Anticancer Treatment
Authors: Combrink Margaretha Johanna W. , Maree Johanna Elizabeth
Published: August 2016

The purpose of our exploratory qualitative study was to study the experiences of patients and their families when transitioning from palliative care with anticancer treatment to palliative care without anticancer treatment. A total of 22 qualitative interviews were conducted, 11 with patients and 11 with their families, and analyzed using Tesch’s approach. Four themes arose from the patient data, and 3 themes from the family data. Our study highlights the shock and severe suffering of the patients and their families. Both the patients and families experienced various losses, such as the care they received from the health care professionals, while they were receiving treatment. They also had to cope with high symptom burdens, including uncontrolled pain. Some patients and family members were able to accept their own or their family member’s impending death, whereas others hoped for the miracle of cure.
Difficulties Felt by Intensive Care Unit Nurses in Providing End-of-Life Care in Southeast Iran
Authors: Tirgari Batool , Azizzadeh Forouzi Mansooreh , Razban Farideh , Alimirzaei Rezvan
Published: August 2016

Introduction: Critical care deaths represent most hospital deaths. The difficulties felt by intensive care unit (ICU) nurses providing end-of-life care may cause nurses to experience negative attitudes toward caring for dying patients. This study was conducted to examine the difficulties felt by ICU nurses providing end-of-life care in Southeast Iran. Method: The study used a cross-sectional descriptive design and was conducted in 3 hospitals supervised by Kerman Medical University. Using DFINE (difficulties felt by ICU nurses providing end-of-life care), difficulties felt by critical care nurses providing end-of-life care were assessed. Results: The results indicated that the difficulties that were felt by critical care nurses were moderate (2.64 ± 0.65). Among the categories and items, the most difficulties felt by critical care nurses belonged to the category of “converting from curative care to end-of-life care” (3.12 ± 0.93) and the item “life-sustaining treatment is often given excessively” (3.49 ± 1.14). Conclusions: The study suggests that health care managers should organize systematic and dynamic policies and procedures in dealing with end-of-life care to assist ICU nurses.
What Does the Staff Think?
Authors: Bennett Rebecca , Proudfoot James
Published: August 2016

In an effort to improve the care of a dying child in the hospital, research was conducted to identify factors associated with the staff's perception of high-quality dying and death. The research used a unique electronic survey that was administered to clinical staff caring for children within the final 3 days of their life in the hospital. Positive death experiences were associated with absence of patient pain, dyspnea, anxiety, or agitation and the presence of spiritual, psychological, and culturally appropriate care for the patient and family. A positive correlation with quality was noted if there was clarity about goals of care and appropriate directives were in place to alleviate suffering. When clinicians felt their needs were met and they had more end-of-life education, they also perceived the quality of the experience as higher and had less distress from the event. Variability in perceived quality of the death experience was noted between different units of the hospital. Providing a supportive environment for pediatric deaths is enhanced by ensuring certain processes are in place and clinicians have the education and support to deliver high-quality care at the end of life.
Analysis of Cutmarks on Bone
Authors: Cerutti Elisa , Spagnoli Laura , Araujo Nadezhda , Gibelli Daniele , Mazzarelli Debora , Cattaneo Cristina
Published: August 2016

One of the main issues in forensic anthropology consists of the identification of signs of trauma in skeletal remains, including sharp-force injuries. So far, several studies have been performed to assess differences between injuries caused by different instruments, not, however, through light microscopy.

In this study, 152 sharp-force injuries were performed by 5 different tools through 2 different orientations on 2 humeral diaphyses and were analyzed by stereo and light microscopy to assess possible morphological differences.

This study showed that although W-shaped injuries are frequently reported in cases of wood-cutting saws, other shapes are often observed; lesions due to metal-cutting saws are almost always U shaped, whereas injuries caused by knives are V shaped. Although cut marks may represent a variable range of features, the present study was able to highlight typical profiles that may be of some help for the diagnosis of weapon and the intentionality of the action.
Development of a Model to Measure Emergency Department Staffing Limitations
Authors: Michelson Kenneth A. , Stack Anne M. , Bachur Richard G.
Published: August 2016

Background

The optimal staffing model for emergency departments (EDs) is not known. Improving staffing could lead to more timely, efficient, and effective care. We created a model of staffing to identify times of staffing limitation by provider type.

Methods

We analyzed data from an academic pediatric ED with 60,000 visits per year. Each 10-minute interval from January 1, 2011, through December 31, 2012, was categorized as nonlimited (no staffing limitation), space limited (≥2 patients in the waiting room with wait times > 30 minutes and ≥ 80% ED bed occupancy), nurse limited (≥2 patients in the waiting room with wait times > 30 min and < 80% ED bed occupancy), or physician limited (≥2 patients in examination rooms who have waited > 30 minutes for a physician) using computer modeling. We calculated the percentage of time each type of limitation was in effect and the median lengths of stay for patients presenting during times of each category of limitation.

Results

The ED was space limited 5.0% of the time, nurse limited 16.1% of the time, and physician limited 0.1% of the time. In nonlimited times, length of stay was 201 minutes (interquartile range, 128–301), whereas patients presenting during space-limited, nurse-limited, and physician-limited times had statistically significantly higher LOS of 265 (187-360), 244 (169-337), and 247 (174-334) minutes, respectively.

Conclusions

Times identified as space and staffing limited were associated with longer LOS. This computer model could be used to rapidly identify targeted staffing needs and then measure the effect of modifying staffing.
Essentials of PEM Fellowship
Authors: Reynolds Stacy , Chang Todd , Iyer Sujit , Mann Courtney , Wilkinson Matthew , Yen Ken , Schnadower David
Published: August 2016

Objective

The aim of this article was to discuss the current landscape in pediatric emergency medicine fellowship training for scholarship training and provide an overview of the resources and general strategies required to prepare fellows for their careers.

Overview

This article is the fifth in a 7-part series that aims to comprehensively describe the current state and future directions of pediatric emergency medicine fellowship training from the essential requirements to considerations for successfully administering and managing a program to the careers that may be anticipated upon program completion. This article focuses on scholarship training.
Low Control and High Demands at Work as Risk Factors for Suicide: An Australian National Population-Level Case-Control Study
Authors: Milner Allison , Spittal Matthew J. , Pirkis Jane , Chastang Jean-François , Niedhammer Isabelle , LaMontagne Anthony D.
Published: August 2016

Objective

Previous research suggests that psychosocial job stressors may be plausible risk factors for suicide. This study assessed the relationship between psychosocial job stressors and suicide mortality across the Australian population.

Methods

We developed a job exposure matrix to objectively measure job stressors across the working population. Suicide data came from a nationwide coronial register. Living controls were selected from a nationally representative cohort study. Incidence density sampling was used to ensure that controls were sampled at the time of death of each case. The period of observation for both cases and controls was 2001 to 2012. We used multilevel logistic regression to assess the odds of suicide in relation to 2 psychosocial job stressors (job control and job demands), after matching for age, sex, and year of death/survey and adjusting for socioeconomic status.

Results

Across 9,010 cases and 14,007 matched controls, our results suggest that low job control (odds ratio [OR], 1.35; 95% confidence interval [CI], 1.26–1.44; p < .001) and high job demands (OR, 1.36; 95% CI, 1.26–1.46; p < .001) were associated with increased odds of male suicide after adjusting for socioeconomic status. High demands were associated with lower odds of female suicide (OR, 0.81; 95% CI, 0.72–0.92; p = .002).

Conclusions

It seems that adverse experiences at work are a risk factor for male suicide while not being associated with an elevated risk among females. Future studies on job stressors and suicide are needed, both to further understand the biobehavioral mechanisms explaining the link between job stress and suicide, and to inform targeted prevention initiatives.
Advances in prevention and treatment of vancomycin-resistant Enterococcus infection
Authors: Isenman Heather , Fisher Dale
Published: August 2016

Purpose of review

This article reviews data, particularly from the last 2 years, addressing the prevention and treatment of vancomycin-resistant Enterococcus (VRE). We focus on infection control, particularly active screening, use of contact precautions as well as pharmacologic options for therapy. This is timely given the evolving priorities in efforts towards the prevention and treatment of multidrug-resistant organisms globally.

Recent findings

Key findings include new data regarding the impact of contact precautions on the incidence of VRE colonization and bloodstream infection, new laboratory screening methods, and novel decolonization strategies and treatments.

Additional and specific measures beyond standard precautions for infection prevention of VRE remain controversial. Horizontal measures such as chlorhexidine bathing appear beneficial, as are nontouch environmental cleaning methods. Treatment options for invasive disease have improved considerably in the last decade. Decolonization strategies require further research. Overall, the threat of VRE seems exaggerated.
Reducing the impact of carbapenem-resistant Enterobacteriaceae on vulnerable patient groups: what can be done?
Authors: Metan Gökhan , Akova Murat
Published: August 2016

Purpose of review

Carbapenem-resistant Enterobacteriaceae (CRE) is a worldwide challenge and associated with a high mortality rate in critically ill patients. This review focused on rapid diagnosis, optimization of antimicrobial therapy, and implication of effective infection control precautions to reduce impact of CRE on vulnerable patients.

Recent findings

Several new diagnostic assays have recently been described for the early diagnosis of CRE. Retrospective studies are supportive for colistin plus meropenem combination for the treatment of CRE infections; however, solid evidence is still lacking. Ceftazidime–avibactam may be an effective therapeutic agent for infections caused by carbapenem-hydrolyzing oxacillinase-48 and Klebsiella pneumoniae carbapenamase-producing Enterobacteriaceae, but not for New Delhi metallo-β-lactamase producers. Gastrointestinal screening may permit early identification of patients with CRE infections. There is not enough evidence to recommend selective digestive decontamination for CRE carriers.

The information for rapid diagnosis of CRE is accumulating. There are new agents with high in-vitro activity against CRE, but clinical experience is limited to case reports. Active surveillance with a high rate of compliance to basic infection control precautions seems to be the best approach to reduce the impact of CRE on vulnerable patients.
The management of multidrug-resistant Enterobacteriaceae
Authors: Bassetti Matteo , Peghin Maddalena , Pecori Davide
Published: August 2016

Purpose of review

Multidrug-resistant (MDR) Enterobacteriaceae are often related to the production of extended-spectrum b-lactamases (ESBLs) and carbapenemase-producing Enterobacteriaceae (CRE), and represent an increasing global threat. Recommendations for the therapeutic management of MDR-related infections, however, are mainly derived from retrospective and nonrandomized prospective studies. The aim of this review is to discuss the challenges in the treatment of patients with infections because of MDR Enterobacteriaceae and provide an expert opinion while awaiting for more definitive data.

Recent findings

To avoid the selection of carbapenemase-producing Enterobacteriaceae, carbapenem-sparing strategies should be considered. B-lactams/b-lactamase inhibitors, mainly piperacillin–tazobactam, minimum inhibitory concentration (MIC) 16/4mg/ml or less represents the best alternative to carbapenems for the treatment of ESBL-producing strains. Overall, combination therapy may be preferred over monotherapy for CRE. The combination of a carbapenem-containing regimen with colistin or high-dose tigecycline or aminoglycoside can be administered at high-dose prolonged infusion with therapeutic drug monitoring for the treatment of CRE with MIC for meropenem 8–16 mg/l or less. For MIC higher than 8–16 mg/l, the use of meropenem should be avoided and various combination therapies based on the in-vitro susceptibility of antimicrobials (e.g., colistin, high-dose tigecycline, fosfomycin, and aminoglycosides) should be selected.

Carbapenem-sparing strategies should be used, when feasible, for ESBL infections. The majority of available nonrandomized studies highlight that combination for CRE seem to offer some therapeutic advantage over monotherapy. Strict infection control measures toward MDR Gram-negative pathogens remain necessary while awaiting for new treatment options.
Recent advances in the genetic neuropathies
Authors: Rossor Alexander M. , Tomaselli Pedro J. , Reilly Mary M.
Published: August 2016

Purpose of review

Charcot–Marie–Tooth disease (CMT) is one of the commonest inherited neuromuscular diseases with a population prevalence of 1 in 2500. This review will cover recent advances in the genetics and pathomechanisms of CMT and how these are leading to the development of rational therapies.

Recent findings

Pathomechanistic and therapeutic target advances in CMT include the identification of the ErbB receptor signalling pathway as a therapeutic target in CMT1A and pharmacological modification of the unfolded protein response in CMT1B. In CMT2D, due to mutations in glycyl-tRNA synthetase, vascular endothelial growth factor-mediated stimulation of the Nrp1 receptor has been identified as a therapeutic target. Preclinical advances have been accompanied by the publication of large natural history cohorts and the identification of a sensitive biomarker of disease (muscle MRI) that is able to detect disease progression in CMT1A over 1 year.

Advances in next-generation sequencing technology, cell biology and animal models of CMT are paving the way for rational treatments. The combination of robust natural history data and the identification of sensitive biomarkers mean that we are now entering an exciting therapeutic era in the field of the genetic neuropathies.
Correlation Between the Revised Brain Symmetry Index, an EEG Feature Index, and Short-term Prognosis in Acute Ischemic Stroke
Authors: Xin Xiyan , Chang Jingling , Gao Ying , Shi Yongmei
Published: August 2016

Purpose:

The present study aims to investigate the correlation between EEG features and short-term prognosis in patients who have experienced an acute ischemic stroke.

Methods:

The present study included 29 patients who had experienced an acute ischemic stroke and were treated at the Beijing Dongzhimen Hospital affiliated with Beijing University of Chinese Medicine between January 2010 and January 2012. Patients were evaluated using the revised Brain Symmetry Index (r-BSI), National Institutes of Health Stroke Scale, and Glasgow Coma Scale. Functional outcomes were assessed 21 days after admission using the Barthel Index and modified Rankin Scale. Two groups were created based on the Barthel Index (<60 vs. ≥60) and modified Rankin Scale (<3 vs. ≥3).

Results:

Significant differences were observed in r-BSI, National Institutes of Health Stroke Scale, and Glasgow Coma Scale scores between the two groups. Poor functional outcomes were associated with higher r-BSI and National Institutes of Health Stroke Scale scores as well as lower Glasgow Coma Scale scores in comparison with those obtained for patients with good prognosis. Logistic regression analysis revealed that r-BSI scores at admission exhibited significant negative correlation with Barthel Index scores (−2.070, P = 0.049) and significant positive correlation with modified Rankin Scale scores (2.256, P = 0.033).

Conclusions:

The r-BSI may be a valuable prognostic tool in the prediction of short-term outcomes for patients who have experienced acute ischemic stroke.

Significance:

The early prediction of functional outcomes after stroke may enhance clinical management and minimize short-term mortality.
Strong phylogenetic inertia on genome size and transposable element content among 26 species of flies
Authors: Sessegolo Camille , Burlet Nelly , Haudry Annabelle
Published: August 2016

While the evolutionary mechanisms driving eukaryote genome size evolution are still debated, repeated element content appears to be crucial. Here, we reconstructed the phylogeny and identified repeats in the genome of 26
Drosophila
exhibiting a twofold variation in genome size
.
The content in transposable elements (TEs) is highly correlated to genome size evolution among these closely related species. We detected a strong phylogenetic signal on the evolution of both genome size and TE content, and a genome contraction in the
Drosophila melanogaster
subgroup.
How cognitive heuristics can explain social interactions in spatial movement
Authors: Seitz Michael J. , Bode Nikolai W. F. , Köster Gerta
Published: August 2016

The movement of pedestrian crowds is a paradigmatic example of collective motion. The precise nature of individual-level behaviours underlying crowd movements has been subject to a lively debate. Here, we propose that pedestrians follow simple heuristics rooted in cognitive psychology, such as ‘stop if another step would lead to a collision’ or ‘follow the person in front’. In other words, our paradigm explicitly models individual-level behaviour as a series of discrete decisions. We show that our cognitive heuristics produce realistic emergent crowd phenomena, such as lane formation and queuing behaviour. Based on our results, we suggest that pedestrians follow different cognitive heuristics that are selected depending on the context. This differs from the widely used approach of capturing changes in behaviour via model parameters and leads to testable hypotheses on changes in crowd behaviour for different motivation levels. For example, we expect that rushed individuals more often evade to the side and thus display distinct emergent queue formations in front of a bottleneck. Our heuristics can be ranked according to the cognitive effort that is required to follow them. Therefore, our model establishes a direct link between behavioural responses and cognitive effort and thus facilitates a novel perspective on collective behaviour.
Hierarchical compression ofCaenorhabditis eleganslocomotion reveals phenotypic differences in the organization of behaviour
Authors: Gomez-Marin Alex , Stephens Greg J. , Brown André E. X.
Published: August 2016

Regularities in animal behaviour offer insights into the underlying organizational and functional principles of nervous systems and automated tracking provides the opportunity to extract features of behaviour directly from large-scale video data. Yet how to effectively analyse such behavioural data remains an open question. Here, we explore whether a minimum description length principle can be exploited to identify meaningful behaviours and phenotypes. We apply a dictionary compression algorithm to behavioural sequences from the nematode wormCaenorhabditis elegansfreely crawling on an agar plate both with and without food and during chemotaxis. We find that the motifs identified by the compression algorithm are rare but relevant for comparisons between worms in different environments, suggesting that hierarchical compression can be a useful step in behaviour analysis. We also use compressibility as a new quantitative phenotype and find that the behaviour of wild-isolated strains ofC. elegansis more compressible than that of the laboratory strain N2 as well as the majority of mutant strains examined. Importantly, in distinction to more conventional phenotypes such as overall motor activity or aggregation behaviour, the increased compressibility of wild isolates is not explained by the loss of function of the genenpr-1, which suggests that erratic locomotion is a laboratory-derived trait with a novel genetic basis. Because hierarchical compression can be applied to any sequence, we anticipate that compressibility can offer insights into the organization of behaviour in other animals including humans.
High-throughput recombinant protein expression in
Escherichia coli
: current status and future perspectives
Authors: Jia Baolei , Jeon Che Ok
Published: August 2016

The ease of genetic manipulation, low cost, rapid growth and number of previous studies have made
Escherichia coli
one of the most widely used microorganism species for producing recombinant proteins. In this post-genomic era, challenges remain to rapidly express and purify large numbers of proteins for academic and commercial purposes in a high-throughput manner. In this review, we describe several state-of-the-art approaches that are suitable for the cloning, expression and purification, conducted in parallel, of numerous molecules, and we discuss recent progress related to soluble protein expression, mRNA folding, fusion tags, post-translational modification and production of membrane proteins. Moreover, we address the ongoing efforts to overcome various challenges faced in protein expression in
E. coli
, which could lead to an improvement of the current system from trial and error to a predictable and rational design.
The social structure of Golfo Dulce bottlenose dolphins (Tursiops truncatus) and the influence of behavioural state
Authors: Moreno Kelsey , Acevedo-Gutiérrez Alejandro
Published: August 2016

Ecological factors such as habitat and food availability affect the social structure of bottlenose dolphins (Tursiopsspp.). Here, we describe the social structure of bottlenose dolphins (T. truncatus) in Golfo Dulce, Costa Rica, a semi-enclosed, fjord-like tropical embayment resembling a pelagic system. We also examine behaviour-linked social strategies by comparing social structure relative to behavioural state: feeding versus non-feeding. We analysed 333 sightings over 210 days from boat-based surveys. Despite the uniqueness of the area, the 47 analysed adults had a social structure similar to other populations: a well-differentiated fission–fusion society with sex-specific patterns of associations and aggression. These results indicate that differences in social structure relative to other populations were a matter of degree. Association strength of dyads was highly correlated across behavioural states, indicating constraints on social fluidity. Males displayed a marked difference in lagged association rate and females displayed a small difference in association homogeneity between states. We suggest this difference in population-wide social connections between behavioural states, particularly for males, was due to mating strategies, a pressure which is strongest during non-feeding behaviour and relaxed during feeding. This finding highlights the importance of considering behavioural state when examining individual bonds and the behavioural plasticity for which the bottlenose dolphin is well known.
A newly identified left–right asymmetry in larval sea urchins
Authors: Hodin Jason , Lutek Keegan , Heyland Andreas
Published: August 2016

Directional asymmetry (DA) in body form is a widespread phenomenon in animals and plants alike, and a functional understanding of such asymmetries can offer insights into the ways in which ecology and development interface to drive evolution. Echinoids (sea urchins, sand dollars and their kin) with planktotrophic development have a bilaterally symmetrical feeding pluteus larva that undergoes a dramatic metamorphosis into a pentameral juvenile that enters the benthos at settlement. The earliest stage of this transformation involves a DA: a left-side invagination in mid-stage larvae leads to the formation of the oral field of the juvenile via a directionally asymmetric structure called the echinus rudiment. Here, we show for the first time in two echinoid species that there is a corresponding DA in the overall shape of the larva: late-stage plutei have consistently shorter arms specifically on the rudiment (left) side. We then demonstrate a mechanistic connection between the rudiment and arm length asymmetries by examining rare, anomalous purple urchin larvae that have rudiments on both the left and the right side. Our data suggest that this asymmetry is probably a broadly shared feature characterizing ontogeny in the class Echinoidea. We propose several functional hypotheses—including developmental constraints and water column stability—to account for this newly identified asymmetry.
Asynchronous partial contact motion due to internal resonance in multiple degree-of-freedom rotordynamics
Authors: Shaw A. D. , Champneys A. R. , Friswell M. I.
Published: August 2016

Sudden onset of violent chattering or whirling rotor–stator contact motion in rotational machines can cause significant damage in many industrial applications. It is shown that internal resonance can lead to the onset of bouncing-type partial contact motion away from primary resonances. These partial contact limit cycles can involve any two modes of an arbitrarily high degree-of-freedom system, and can be seen as an extension of a synchronization condition previously reported for a single disc system. The synchronization formula predicts multiple drivespeeds, corresponding to different forms of mode-locked bouncing orbits. These results are backed up by a brute-force bifurcation analysis which reveals numerical existence of the corresponding family of bouncing orbits at supercritical drivespeeds, provided the damping is sufficiently low. The numerics reveal many overlapping families of solutions, which leads to significant multi-stability of the response at given drive speeds. Further, secondary bifurcations can also occur within each family, altering the nature of the response and ultimately leading to chaos. It is illustrated how stiffness and damping of the stator have a large effect on the number and nature of the partial contact solutions, illustrating the extreme sensitivity that would be observed in practice.
Interspecific interactions through 2 million years: are competitive outcomes predictable?
Authors: Liow Lee Hsiang , Di Martino Emanuela , Voje Kjetil Lysne , Rust Seabourne , Taylor Paul D.
Published: August 2016

Ecological interactions affect the survival and reproduction of individuals. However, ecological interactions are notoriously difficult to measure in extinct populations, hindering our understanding of how the outcomes of interactions such as competition vary in time and influence long-term evolutionary changes. Here, the outcomes of spatial competition in a temporally continuous community over evolutionary timescales are presented for the first time. Our research domain is encrusting cheilostome bryozoans from the Wanganui Basin of New Zealand over a
ca
2 Myr time period (Pleistocene to Recent). We find that a subset of species can be identified as consistent winners, and others as consistent losers, in the sense that they win or lose interspecific competitive encounters statistically more often than the null hypothesis of 50%. Most species do not improve or worsen in their competitive abilities through the 2 Myr period, but a minority of species are winners in some intervals and losers in others. We found that conspecifics tend to cluster spatially and interact more often than expected under a null hypothesis: most of these are stand-off interactions where the two colonies involved stopped growing at edges of encounter. Counterintuitively, competitive ability has no bearing on ecological dominance.
Using viromes to predict novel immune proteins in non-model organisms
Authors: Quistad Steven D. , Lim Yan Wei , Silva Genivaldo Gueiros Z. , Nelson Craig E. , Haas Andreas F. , Kelly Linda Wegley , Edwards Robert A. , Rohwer Forest L.
Published: August 2016

Immunity is mostly studied in a few model organisms, leaving the majority of immune systems on the planet unexplored. To characterize the immune systems of non-model organisms alternative approaches are required. Viruses manipulate host cell biology through the expression of proteins that modulate the immune response. We hypothesized that metagenomic sequencing of viral communities would be useful to identify both known and unknown host immune proteins. To test this hypothesis, a mock human virome was generated and compared to the human proteome using tBLASTn, resulting in 36 proteins known to be involved in immunity. This same pipeline was then applied to reef-building coral, a non-model organism that currently lacks traditional molecular tools like transgenic animals, gene-editing capabilities, and
in vitro
cell cultures. Viromes isolated from corals and compared with the predicted coral proteome resulted in 2503 coral proteins, including many proteins involved with pathogen sensing and apoptosis. There were also 159 coral proteins predicted to be involved with coral immunity but currently lacking any functional annotation. The pipeline described here provides a novel method to rapidly predict host immune components that can be applied to virtually any system with the potential to discover novel immune proteins.
Deadly competition and life-saving predation: the potential for alternative stable states in a stage-structured predator–prey system
Authors: Toscano Benjamin J. , Rombado Bianca R. , Rudolf Volker H. W.
Published: August 2016

Predators often undergo complete ontogenetic diet shifts, engaging in resource competition with species that become their prey during later developmental stages. Theory posits that this mix of stage-specific competition and predation, termed life-history intraguild predation (LHIGP), can lead to alternative stable states. In one state, prey exclude predators through competition (i.e. juvenile competitive bottleneck), while in the alternative, adult predators control prey density to limit competition and foster coexistence. Nevertheless, the interactions leading to these states have not been demonstrated in an empirical LHIGP system. To address this gap, we manipulated densities of cannibalistic adult cyclopoid copepods (Mesocyclops edax) and their cladoceran prey (Daphnia pulex) in a response-surface design and measured the maturation and survival of juvenile copepods (nauplii). We found thatDaphniareduced and even precluded both nauplii maturation and survival through depletion of a shared food resource. As predicted, adult copepods enhanced nauplii maturation and survival throughDaphniaconsumption, yet this positive effect was dependent on the relative abundance ofDaphniaas well as the absolute density of adult copepods. Adult copepods reduced nauplii survival through cannibalism at lowDaphniadensities and at the highest copepod density. This work demonstrates that predation can relax a strong juvenile competitive bottleneck in freshwater zooplankton, though cannibalism can reduce predator recruitment. Thus, our results highlight a key role for cannibalism in LHIGP dynamics and provide evidence for the interactions that drive alternative stable states in such systems.
Repetition suppression: a means to index neural representations using BOLD?
Authors: Barron Helen C. , Garvert Mona M. , Behrens Timothy E. J.
Published: August 2016

Understanding how the human brain gives rise to complex cognitive processes remains one of the biggest challenges of contemporary neuroscience. While invasive recording in animal models can provide insight into neural processes that are conserved across species, our understanding of cognition more broadly relies upon investigation of the human brain itself. There is therefore an imperative to establish non-invasive tools that allow human brain activity to be measured at high spatial and temporal resolution. In recent years, various attempts have been made to refine the coarse signal available in functional magnetic resonance imaging (fMRI), providing a means to investigate neural activity at the meso-scale, i.e. at the level of neural populations. The most widely used techniques include repetition suppression and multivariate pattern analysis. Human neuroscience can now use these techniques to investigate how representations are encoded across neural populations and transformed by relevant computations. Here, we review the physiological basis, applications and limitations of fMRI repetition suppression with a brief comparison to multivariate techniques. By doing so, we show how fMRI repetition suppression holds promise as a tool to reveal complex neural mechanisms that underlie human cognitive function.

This article is part of the themed issue ‘Interpreting BOLD: a dialogue between cognitive and cellular neuroscience’.
Wide-field optical mapping of neural activity and brain haemodynamics: considerations and novel approaches
Authors: Ma Ying , Shaik Mohammed A. , Kim Sharon H. , Kozberg Mariel G. , Thibodeaux David N. , Zhao Hanzhi T. , Yu Hang , Hillman Elizabeth M. C.
Published: August 2016

Although modern techniques such as two-photon microscopy can now provide cellular-level three-dimensional imaging of the intact living brain, the speed and fields of view of these techniques remain limited. Conversely, two-dimensional wide-field optical mapping (WFOM), a simpler technique that uses a camera to observe large areas of the exposed cortex under visible light, can detect changes in both neural activity and haemodynamics at very high speeds. Although WFOM may not provide single-neuron or capillary-level resolution, it is an attractive and accessible approach to imaging large areas of the brain in awake, behaving mammals at speeds fast enough to observe widespread neural firing events, as well as their dynamic coupling to haemodynamics. Although such wide-field optical imaging techniques have a long history, the advent of genetically encoded fluorophores that can report neural activity with high sensitivity, as well as modern technologies such as light emitting diodes and sensitive and high-speed digital cameras have driven renewed interest in WFOM. To facilitate the wider adoption and standardization of WFOM approaches for neuroscience and neurovascular coupling research, we provide here an overview of the basic principles of WFOM, considerations for implementation of wide-field fluorescence imaging of neural activity, spectroscopic analysis and interpretation of results.

This article is part of the themed issue ‘Interpreting BOLD: a dialogue between cognitive and cellular neuroscience’.