Standardization of Emergency Department Clinical Note Templates: A Retrospective Analysis Across an Integrated Health System

Background / Objective: Clinical documentation is essential for conveying medical decision-making, communication between providers and patients, and capturing quality, billing, and regulatory measures during emergency department (ED) visits. Growing evidence suggests the benefits of note template standardization, however, variations in documentation practices are common. The primary objective of this study is to measure the utilization and coding performance of a standardized ED note template implemented across a nine-hospital health system.

METHODS

This was a retrospective study before and after the implementation of a standardized ED note template. A multi-disciplinary group consensus was built around standardized note elements, provider note workflows within the electronic health record (EHR), and how to incorporate newly required medical decision-making elements. The primary outcomes measured included the proportion of ED visits using standardized note templates, and the distribution of billing codes in the six months before and after implementation.

RESULTS

In the pre-implementation period, a total of six legacy ED note templates were being used across nine emergency departments, with the most used template accounting for approximately 36% of ED visits. Marked variations in documentation elements were noted across six legacy templates. After the implementation, 82% of ED visits system-wide used a single standardized note template. Following implementation, we observed a 1% increase in the proportion of ED visits coded as highest acuity and an unchanged proportion coded as second highest acuity.

CONCLUSIONS

We observed a greater than two-fold increase in the use of a standardized ED note template across a 9-hospital health system in anticipation of the new 2023 coding guidelines. The development and utilization of a standardized note template format relied heavily on multi-disciplinary stakeholder engagement to inform design that worked for varied documentation practices within the EHR. After the implementation of a standardized note template, we observed better-than-anticipated coding performance.

Patient sex, racial and ethnic disparities in emergency department triage: A multi-site retrospective study

OBJECTIVES

There is limited evidence on sex, racial, and ethnic disparities in Emergency Department (ED) triage across diverse settings. We evaluated differences in the assignment of Emergency Severity Index (ESI) by patient sex and race/ethnicity, accounting for age, clinical factors, and ED operating conditions.

METHODS

We conducted a multi-site retrospective study of adult patients presenting to high-volume EDs from January 2019-February 2020. Patient-level data were obtained and analyzed from three EDs (academic, metropolitan community, and rural community) affiliated with a large health system in the Southeastern United States. For the study outcome, ESI levels were grouped into three categories: 1-2 (highest acuity), 3, and 4-5 (lowest acuity). Multinomial logistic regression was used to compare ESI categories by patient race/ethnicity and sex jointly (referent = White males), adjusted for patient age, insurance status, ED arrival mode, chief complaint category, comorbidity score, time of day, day of week, and average ED wait time.

RESULTS

We identified 186,840 eligible ED visits with 56,417 from the academic ED, 69,698 from the metropolitan community ED, and 60,725 from the rural community ED. Patient cohorts between EDs varied by patient age, race/ethnicity, and insurance status. The majority of patients were assigned ESI 3 in the academic and metropolitan community EDs (61% and 62%, respectively) whereas 47% were assigned ESI 3 in the rural community ED. In adjusted analyses, White females were less likely to be assigned ESI 1-2 compared to White males although both groups were roughly comparable in the assignment of ESI 4-5. Non-White and Hispanic females were generally least likely to be assigned ESI 1-2 in all EDs. Interactions between ED wait time and race/ethnicity-sex were not statistically significant.

CONCLUSIONS

This retrospective study of adult ED patients revealed sex and race/ethnicity-based differences in ESI assignment, after accounting for age, clinical factors, and ED operating conditions. These disparities persisted across three different large EDs, highlighting the need for ongoing research to address inequities in ED triage decision-making and associated patient-centered outcomes.

A Natural Language Processing and Machine Learning Approach to Identification of Incidental Radiology Findings in Trauma Patients Discharged from the Emergency Department

STUDY OBJECTIVE

Patients undergoing diagnostic imaging studies in the emergency department (ED) commonly have incidental findings, which may represent unrecognized serious medical conditions, including cancer. Recognition of incidental findings frequently relies on manual review of textual radiology reports and can be overlooked in a busy clinical environment. Our study aimed to develop and validate a supervised machine learning model using natural language processing to automate the recognition of incidental findings in radiology reports of patients discharged from the ED.

METHODS

We performed a retrospective analysis of computed tomography (CT) reports from trauma patients discharged home across an integrated health system in 2019. Two independent annotators manually labeled CT reports for the presence of an incidental finding as a reference standard. We used regular expressions to derive and validate a random forest model using open-source and machine learning software. Final model performance was assessed across different ED types.

RESULTS

The study CT reports were divided into derivation (690 reports) and validation (282 reports) sets, with a prevalence of incidental findings of 22.3%, and 22.7%, respectively. The random forest model had an area under the curve of 0.88 (95% confidence interval [CI], 0.84 to 0.92) on the derivation set and 0.92 (95% CI, 0.88 to 0.96) on the validation set. The final model was found to have a sensitivity of 92.2%, a specificity of 79.4%, and a negative predictive value of 97.2%. Similarly, strong model performance was found when stratified to a dedicated trauma center, high-volume, and low-volume community EDs.

CONCLUSION

Machine learning and natural language processing can classify incidental findings in CT reports of ED patients with high sensitivity and high negative predictive value across a broad range of ED settings. These findings suggest the utility of natural language processing in automating the review of free-text reports to identify incidental findings and may facilitate interventions to improve timely follow-up.

Disparities in emergency department prioritization and rooming of patients with similar triage acuity score

BACKGROUND

We identify patient demographic and emergency department (ED) characteristics associated with rooming prioritization decisions among ED patients who are assigned the same triage acuity score.

METHODS

We performed a retrospective analysis of adult ED patients with similar triage acuity, as defined as an Emergency Severity Index (ESI) of 3, at a large academic medical center, during 2019. Violations of a first-come-first-served (FCFS) policy for rooming are identified and used to create weighted multiple logistic regression models and 1:M matched case-control conditional logistic regression models to determine how rooming prioritization is affected by individual patient age, sex, race, and ethnicity after adjusting for patient clinical and time-varying ED operational characteristics.

RESULTS

A total of 15,781 ED encounters were analyzed, with 1612 (10.2%) ED encounters having a rooming prioritization in violation of a FCFS policy. Patient age and race were found to be significantly associated with being prioritized in violation of FCFS in both logistic regression models. The 1:M matched model showed a statistically significant relationship between violation of rooming prioritization with increasing age in years (adjusted odds ratio [aOR] 1.009, 95% confidence interval [CI] 1.005-1.013) and among African American patients compared to Caucasians (aOR 0.636, 95% CI 0.545-0.743).

CONCLUSIONS

Among ED patients with a similar triage acuity (ESI 3), we identified patient age and patient race as characteristics that were associated with deviation from a FCFS prioritization in ED rooming decisions. These findings suggest that there may be patient demographic disparities in ED rooming decisions after adjusting for clinical and ED operational characteristics.

Burn related injuries: a nationwide analysis of adult inter-facility transfers over a six-year period in the United States

Background

US emergency department (ED) visits for burns and factors associated with inter-facility transfer are unknown and described in this manuscript.

Methods

We conducted a retrospective analysis of burn-related injuries from 2009–2014 using the Nationwide Emergency Department Sample (NEDS), the largest sample of all-payer datasets. We included all ED visits by adults with a burn related ICD-9 code and used a weighted multivariable logistic regression model to predict transfer adjusting for covariates.

Results

Between 2009–2014, 3,047,701 (0.4%) ED visits were for burn related injuries. A total of 108,583 (3.6%) burn visits resulted in inter-facility transfers occurred during the study period, representing approximately 18,097 inter-facility transfers per year. Burns with greater than 10% total body surface area (TBSA) resulted in a 10-fold increase in the probability of transfer, compared to burn visits with less than 10% TBSA burns. In the multivariable model, male sex (adjusted odds ratio [aOR] 2.4, 95% CI 2.3–2.6) was associated with increased odds of transfer. Older adults were more likely to be transferred compared to all other age groups. Odds of transfer were increased for Medicare and self-pay patients (vs. private pay) but there was a significant interaction of sex and payer and the effect of insurance varied by sex.

Conclusions

In a national sample of ED visits, burn visits were more than twice as likely to have an inter-facility transfer compared to the general ED patient population. Substantial sex differences exist in U.S. EDs that impact the location of care for patients with burn injuries and warrants further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-022-00705-6.

Incidental Radiology Findings on Computed Tomography Studies in Emergency Department Patients: A Systematic Review and Meta-Analysis

STUDY OBJECTIVE

An incidental finding is defined as a newly discovered mass or lesion detected on imaging performed for an unrelated reason. The identification of an incidental finding may be an opportunity for the early detection of a serious medical condition, including a malignancy. However, little is known about the prevalence of incidental findings in the emergency department (ED) setting and the strategies that can be used to mitigate the risk associated with them in the ED. This study aimed to estimate the overall prevalence of incidental findings and to summarize the currently described measures to mitigate the risks associated with incidental findings.

METHODS

On November 22, 2020, a systematic literature search of PubMed, EMBASE, and Scopus was performed for studies that were published in peer-reviewed journals and reported the prevalence of incidental findings in computed tomography (CT) scans in patients in the ED. Patients who received CT scans that included the head, neck, chest, or abdomen/pelvis were included. The study characteristics, overall prevalence of incidental findings, prevalence of incidental findings by body region, and prespecified subgroups were extracted. The criteria used for risk stratification within individual studies were also extracted. Pooled estimates were calculated using a random-effects meta-analysis.

RESULTS

A total of 1,385 studies were identified, and 69 studies met the inclusion criteria. The included studies represented 147,763 ED encounters or radiology reports across 16 countries, and 83% of studies were observational, cross-sectional studies. A total of 35 studies (50.7%) were in trauma patients. A large degree of heterogeneity was observed across the included studies. The overall pooled prevalence estimate for any incidental finding was 31.3% (95% confidence interval 24.4% to 39.1%). We found great variation in the methods described to mitigate the risk associated with incidental findings, including a lack of standardized risk stratification, inconsistent documentation practices, and only a small subset of studies describing prospective interventions aimed at improving the recognition and management of incidental findings from the ED.

CONCLUSION

In patients in the ED receiving CT scans, incidental findings are commonly encountered across a broad range of ED chief complaints. This review highlights the existence of great heterogeneity in the definitions used to classify incidental findings. Future studies are needed to determine a clinically feasible categorization standard or terminology for commonly encountered incidental findings in the ED setting to standardize classification and documentation.

Clinical Effects of Balanced Crystalloids vs Saline in Adults With Diabetic Ketoacidosis: A Subgroup Analysis of Cluster Randomized Clinical Trials

IMPORTANCE

Saline (0.9% sodium chloride), the fluid most commonly used to treat diabetic ketoacidosis (DKA), can cause hyperchloremic metabolic acidosis. Balanced crystalloids, an alternative class of fluids for volume expansion, do not cause acidosis and, therefore, may lead to faster resolution of DKA than saline.

OBJECTIVE

To compare the clinical effects of balanced crystalloids with the clinical effects of saline for the acute treatment of adults with DKA.

DESIGN, SETTING, AND PARTICIPANTS

This study was a subgroup analysis of adults with DKA in 2 previously reported companion trials-Saline Against Lactated Ringer's or Plasma-Lyte in the Emergency Department (SALT-ED) and the Isotonic Solutions and Major Adverse Renal Events Trial (SMART). These trials, conducted between January 2016 and March 2017 in an academic medical center in the US, were pragmatic, multiple-crossover, cluster, randomized clinical trials comparing balanced crystalloids vs saline in emergency department (ED) and intensive care unit (ICU) patients. This study included adults who presented to the ED with DKA, defined as a clinical diagnosis of DKA, plasma glucose greater than 250 mg/dL, plasma bicarbonate less than or equal to 18 mmol/L, and anion gap greater than 10 mmol/L. Data analysis was performed from January to April 2020.

INTERVENTIONS

Balanced crystalloids (clinician's choice of Ringer lactate solution or Plasma-Lyte A solution) vs saline for fluid administration in the ED and ICU according to the same cluster-randomized multiple-crossover schedule.

MAIN OUTCOMES AND MEASURES

The primary outcome was time between ED presentation and DKA resolution, as defined by American Diabetes Association criteria. The secondary outcome was time between initiation and discontinuation of continuous insulin infusion.

RESULTS

Among 172 adults included in this secondary analysis of cluster trials, 94 were assigned to balanced crystalloids and 78 to saline. The median (interquartile range [IQR]) age was 29 (24-45) years, and 90 (52.3%) were women. The median (IQR) volume of isotonic fluid administered in the ED and ICU was 4478 (3000-6372) mL. Cumulative incidence analysis revealed shorter time to DKA resolution in the balanced crystalloids group (median time to resolution: 13.0 hours; IQR: 9.5-18.8 hours) than the saline group (median: 16.9 hours; IQR: 11.9-34.5 hours) (adjusted hazard ratio [aHR] = 1.68; 95% CI, 1.18-2.38; P = .004). Cumulative incidence analysis also revealed shorter time to insulin infusion discontinuation in the balanced crystalloids group (median: 9.8 hours; IQR: 5.1-17.0 hours) than the saline group (median: 13.4 hours; IQR: 11.0-17.9 hours) (aHR = 1.45; 95% CI, 1.03-2.03; P = .03).

CONCLUSIONS AND RELEVANCE

In this secondary analysis of 2 cluster randomized clinical trials, compared with saline, treatment with balanced crystalloids resulted in more rapid resolution of DKA, suggesting that balanced crystalloids may be preferred over saline for acute management of adults with DKA.

TRIAL REGISTRATION

ClinicalTrials.gov Identifiers: NCT02614040; NCT02444988.

Managing sedation in the mechanically ventilated emergency department patient: a clinical review

Managing sedation in the ventilated emergency department (ED) patient is increasingly important as critical care unit admissions from EDs increase and hospital crowding results in intubated patients boarding for longer periods. The objectives of this review are 3-fold; (1) describe the historical perspective of how sedation of the ventilated patient has changed, (2) summarize the most commonly used sedation and analgesic agents, and (3) provide a practical approach to sedation and analgesia in mechanically ventilated ED patients. We searched PubMed using keywords "emergency department post-intubation sedation," "emergency department critical care length of stay," and "sedation in mechanically ventilated patient." The search results were limited to English language and reviewed for relevance to the subject of interest. Our search resulted in 723 articles that met the criteria for managing sedation in the ventilated ED patient, of which 19 articles were selected and reviewed. Our review of the literature found that the level of sedation and practices of sedation and analgesia in the ED environment have downstream consequences on patient care including overall patient centered outcomes even after the patient has left the ED. It is reasonable to begin with analgesia in isolation, although sedating medications should be used when patients remain uncomfortable and agitated after initial interventions are performed.

Vitamin D Deficiency and Long-Term Cognitive Impairment Among Older Adult Emergency Department Patients

INTRODUCTION

Approximately 16% of acutely ill older adults develop new, long-term cognitive impairment (LTCI), many of whom initially seek care in the emergency department (ED). Currently, no effective interventions exist to prevent LTCI after an acute illness. Identifying early and modifiable risk factors for LTCI is the first step toward effective therapy. We hypothesized that Vitamin D deficiency at ED presentation was associated with LTCI in older adults.

METHODS

This was an observational analysis of a prospective cohort study that enrolled ED patients ≥ 65 years old who were admitted to the hospital for an acute illness. All patients were enrolled within four hours of ED presentation. Serum Vitamin D was measured at enrollment and Vitamin D deficiency was defined as serum concentrations <20 mg/dL. We measured pre-illness and six-month cognition using the short form Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), which ranges from 1 to 5 (severe cognitive impairment). Multiple linear regression was performed to determine whether Vitamin D deficiency was associated with poorer six-month cognition adjusted for pre-illness IQCODE and other confounders. We incorporated a two-factor interaction into the regression model to determine whether the relationship between Vitamin D deficiency and six-month cognition was modified by pre-illness cognition.

RESULTS

We included a total of 134 older ED patients; the median (interquartile range [IQR]) age was 74 (69, 81) years old, 61 (46%) were female, and 14 (10%) were nonwhite race. The median (IQR) vitamin D level at enrollment was 25 (18, 33) milligrams per deciliter and 41 (31%) of enrolled patients met criteria for vitamin D deficiency. Seventy-seven patients survived and had a six-month IQCODE. In patients with intact pre-illness cognition (IQCODE of 3.13), Vitamin D deficiency was significantly associated with worsening six-month cognition (β-coefficient: 0.43, 95% CI, 0.07 to 0.78, p = 0.02) after adjusting for pre-illness IQCODE and other confounders. Among patients with pre-illness dementia (IQCODE of 4.31), no association with Vitamin D deficiency was observed (β-coefficient: -0.1;, 95% CI, [-0.50-0.27], p = 0.56).

CONCLUSION

Vitamin D deficiency was associated with poorer six-month cognition in acutely ill older adult ED patients who were cognitively intact at baseline. Future studies should determine whether early Vitamin D repletion in the ED improves cognitive outcomes in acutely ill older patients.

Repeated Emergency Medical Services Use by Older Adults: Analysis of a Comprehensive Statewide Database

STUDY OBJECTIVE

The objective of this study is to characterize repeated emergency medical services (EMS) transports among older adults across a large and socioeconomically diverse region.

METHODS

Using the North Carolina Prehospital Medical Information System, we analyzed the frequency of repeated EMS transports within 30 days of an index EMS transport among adults aged 65 years and older from 2010 to 2015. We used multivariable logistic regressions to determine characteristics associated with repeated EMS transport.

RESULTS

During the 6-year period, EMS performed 1,711,669 transports for 689,664 unique older adults in North Carolina. Of these, 303,099 transports (17.7%) were followed by another transport of the same patient within 30 days. The key characteristics associated with an increased adjusted odds ratio of repeated transport within 30 days include transport from an institutionalized setting (odds ratio [OR] 1.42; 95% confidence interval [CI] 1.38 to 1.47), blacks compared with whites (OR 1.29; 95% CI 1.24 to 1.33), a dispatch complaint of psychiatric problems (OR 1.38; 95% CI 1.25 to 1.52), back pain (OR 1.35; 95% CI 1.26 to 1.45), breathing problems (OR 1.21; 95% CI 1.15 to 1.30), and diabetic problems (OR 1.14; 95% CI 1.06 to 1.22). Falls accounted for 15.6% of all transports and had a modest association with repeated transports (OR 1.07; 95% CI 1.00 to 1.14).

CONCLUSION

More than 1 in 6 EMS transports of older adults in North Carolina are followed by a repeated transport of the same patient within 30 days. Patient characteristics and chief complaints may identify increased risk for repeated transport and suggest the potential for targeted interventions to improve outcomes and manage EMS use.

The Effect of Community Health Center (CHC) Density on Preventable Hospital Admissions in Medicaid and Uninsured Patients

Community health centers (CHCs) are expected to play a major role in expanding primary care access under the Affordable Care Act (ACA). Although benefits of such health centers among Medicaid populations have been documented, little is known about their impact on the uninsured. Additionally, the effect of health center density on preventable hospitalizations is unknown. This study calculated health center density within five miles of California hospitals using geocoding and Haversine distance formula. Using the 2010 California inpatient dataset, rates of preventable hospitalizations were classified by Prevention Quality Indicators (PQIs). After adjusting for patient and community covariates, we found that as health center density increased, the odds ratio of preventable hospitalizations decreased in both Medicaid and uninsured patients. (OR 0.79 and 0.86 for Medicaid and uninsured respectively p<.001,.044) These findings suggest health centers are contributing to lowering preventable hospitalizations and supports plans to expand such health centers.

Diagnosis of Elder Abuse in U.S. Emergency Departments

OBJECTIVES

To estimate the proportion of visits to U.S. emergency departments (EDs) in which a diagnosis of elder abuse is reached using two nationally representative datasets.

DESIGN

Retrospective cross-sectional analysis.

SETTING

U.S. ED visits recorded in the 2012 Nationwide Emergency Department Sample (NEDS) or the 2011 National Hospital Ambulatory Medical Care Survey (NHAMCS).

PARTICIPANTS

All ED visits of individuals aged 60 and older.

MEASUREMENTS

The primary outcome was elder abuse defined according to International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. The proportion of visits with elder abuse was estimated using survey weights. Odds ratios (ORs) were calculated to identify demographic characteristics and common ED diagnoses associated with elder abuse.

RESULTS

In 2012, NEDS contained information on 6,723,667 ED visits of older adults, representing an estimated 29,056,673 ED visits. Elder abuse was diagnosed in an estimated 3,846 visits, corresponding to a weighted diagnosis period prevalence of elder abuse in U.S. EDs of 0.013% (95% confidence interval (CI) = 0.012-0.015%). Neglect and physical abuse were the most common types diagnosed, accounting for 32.9% and 32.2% of cases, respectively. Multivariable analysis showed greater weighted odds of elder abuse diagnosis in women (odds ratio (OR) = 1.95, 95% CI = 1.68-2.26) and individuals with contusions (OR = 2.91, 95% CI = 2.36-3.57), urinary tract infection (OR = 2.21, 95% CI = 1.84-2.65), and septicemia (OR = 1.92, 95% CI = 1.44-2.55). In the 2011 NHAMCS dataset, no cases of elder abuse were recorded for the 5,965 older adult ED visits.

CONCLUSION

The proportion of U.S. ED visits by older adults receiving a diagnosis of elder abuse is at least two orders of magnitude lower than the estimated prevalence in the population. Efforts to improve the identification of elder abuse in EDs may be warranted.

Influence of less than full-time or full-time on totality of training and subsequent consultant appointment in anaesthesia

Changes in medical training have increased the popularity of less than full-time training. However, there are no data on the impact on training time or consultant workforce. We reviewed a three-year cohort of trainees via the Royal College of Anaesthetist's training and recruitment databases. Eighty-eight (96%) less than full-time trainees and 677 (95%) full-time trainees were appointed to a substantive consultant post (p = 0.82). Three (3%) less than full-time trainees and 12 (2%) full-time trainees gained part-time consultant posts (p < 0.001). Average length of training (years, months, days) was 8 y, 5 m, 6 d (median (IQR [range]) 5 y, 0 m, 14 d (4 y, 11 m, 29 d - 9 y, 8 m, 3 d [4 y, 2 m, 18 d - 12 y, 0 m, 0 d]) for full-time and 10 y, 8 m, 23 d (median (IQR [range]) 7 y, 3 m, 28 d (6 y, 7 m, 24 d - 11 y, 1 m, 23 d [4 y, 11 m, 29 d - 11 y, 9 m, 10 d]) for less than full-time trainees. The average length of training for both groups is significantly longer than the seven years used in workforce planning.

The role of the anterior lateral eyes in the vision-based behaviour of jumping spiders

Jumping spiders, or salticids, sample their environment using a combination of two types of eyes. The forward-facing pair of 'principal' eyes have narrow fields of view, but exceptional spatial resolution, while the two or three pairs of 'secondary' eyes have wide fields of view and function especially well as motion analysers. Motion detected by the secondary eyes may elicit an orienting response, whereupon the object of interest is examined further using the high-acuity principal eyes. The anterior lateral (AL) eyes are particularly interesting, as they are the only forward-facing pair of secondary eyes. In this study, we aimed to determine characteristics of stimuli that elicit orienting responses mediated by the AL eyes. After covering all eyes except the AL eyes, we measured orienting responses to dot stimuli that varied in size and contrast, and moved at different speeds. We found that all stimulus parameters had significant effects on orientation propensity. When tethered flies were used as prey, we found that visual information from the AL eyes alone was sufficient to elicit stalking behaviour. These results suggest that, in terms of overall visual processing, the relevance of spatial vision in the AL eyes has been underestimated in the literature. Our results also show that female spiders are significantly more responsive than males. We found that hunger caused similar increases in orientation propensity in the two sexes, but females responded more often than males both when sated and when hungry. A higher propensity by females to orient toward moving objects may be related to females tending to experience higher nutritional demands than males.

Anisaldehyde and Veratraldehyde Acting as Redox Cycling Agents for H(2)O(2) Production by Pleurotus eryngii

The existence of a redox cycle leading to the production of hydrogen peroxide (H(2)O(2)) in the white rot fungus Pleurotus eryngii has been confirmed by incubations of 10-day-old mycelium with veratryl (3,4-dimethoxybenzyl) and anisyl (4-methoxybenzyl) compounds (alcohols, aldehydes, and acids). Veratraldehyde and anisaldehyde were reduced by aryl-alcohol dehydrogenase to their corresponding alcohols, which were oxidized by aryl-alcohol oxidase, producing H(2)O(2). Veratric and anisic acids were incorporated into the cycle after their reduction, which was catalyzed by aryl-aldehyde dehydrogenase. With the use of different initial concentrations of either veratryl alcohol, veratraldehyde, or veratric acid (0.5 to 4.0 mM), around 94% of veratraldehyde and 3% of veratryl alcohol (compared with initial concentrations) and trace amounts of veratric acid were found when equilibrium between reductive and oxidative activities had been reached, regardless of the initial compound used. At concentrations higher than 1 mM, veratric acid was not transformed, and at 1.0 mM, it produced a negative effect on the activities of aryl-alcohol oxidase and both dehydrogenases. H(2)O(2) levels were proportional to the initial concentrations of veratryl compounds (around 0.5%), and an equilibrium between aryl-alcohol oxidase and an unknown H(2)O(2)-reducing system kept these levels steady. On the other hand, the concomitant production of the three above-mentioned enzymes during the active growth phase of the fungus was demonstrated. Finally, the possibility that anisaldehyde is the metabolite produced by P. eryngii for the maintenance of this redox cycle is discussed.

Silent tidbitting in male fowl, Gallus gallus: a referential visual signal with multiple functions

With the notable exception of bee dances, there are no established examples of multimodal referential signals. The food calls of male fowl, Gallus gallus, are functionally referential and the acoustic component of a multimodal display. However, the specificity of the receiver's response to the visual component (tidbitting) has never been tested. Here we provide the first detailed analysis of tidbitting, and test the hypothesis that these characteristic movements are functionally referential. We conducted a playback experiment with five high-definition video stimuli: Silent tidbit,Matched-frequency motion in the opposite direction, Silent crows, Inactive male and Empty cage. Females searched for food more during Silent tidbitting than under any other condition, suggesting that this visual display specifically predicts the presence of food and hence has similar functional properties to food calls. Silent tidbitting was also singularly effective at evoking approach and close inspection, which may enhance signal memorability. These social responses suggest that the visual component of the display has the unique function of triggering assessment of signaler identity and quality as a potential mate. The acoustic and visual components are hence redundant as a food signal, but synergistic when additional functions are considered. These findings emphasize the perceptual complexity of multimodal displays and provide the first demonstration of multimodal referential signaling in a vertebrate.

Multimodal signaling in fowl,Gallus gallus

Many social birds produce food-associated calls. In galliforms, these vocalizations are typically accompanied by a distinctive visual display,creating a multimodal signal known as tidbitting. This system is ideal for experimental analysis of the way in which signal components interact to determine overall efficacy. We used high-definition video playback to explore perception of male tidbitting by female fowl, Gallus gallus. Hens experienced four treatments consisting of multimodal tidbitting, visual tidbitting without sound, audible tidbitting without a male present, and a silent empty cage control. Hens took longer to begin food search when the display was silent, but the overall rate of this response did not differ among the multimodal, visual only or audio only playback treatments. These results suggest that the visual and vocal components of tidbitting are redundant, but they also highlight the importance of a temporal dimension for any categorization scheme. Visual displays also evoked inspection behavior,characterized by close binocular fixation on the head of the playback male,which is known to facilitate individual recognition. This may also allow hens to assess male quality. Such social responses reveal that tidbitting probably has multiple functions and provide a new insight into the selective factors responsible for the evolution of this complex multimodal signal.

Assessment of repeated displays: a test of possible mechanisms

Many animals signal their resource holding potential (RHP) to deter competitors from engaging them in potentially costly fights. Studies of this opponent assessment function have generated important insights into signal design and evolution. In the case of sounds, rate of production is often a salient feature. We used digital video playback to conduct analogous experiments exploring the importance of temporal variation in visual signals. Our study focused on the push-up display of male Jacky dragons Amphibolurus muricatus, an Australian agamid lizard. This stereotyped movement-based signal is commonly performed during male–male contests. A previous study has shown that Jacky dragons responses are influenced by the overall display rate of a video conspecific. We built upon this finding by investigating the effect of short-term variation in display rate. Each playback sequence varied systematically across a different combination of display parameters, while keeping the total number of push-ups constant. Other potential cues, such as morphology and the characteristics of individual motor patterns, were precisely controlled. The aggressive signalling and locomotor behaviour of subject males varied significantly between sequences. Most notably, performance of throat expansions, a typical agamid threat posture,was suppressed by video sequences with temporal clumping of displays. These results show that lizards are sensitive to differences in the temporal fine structure of display sequences and suggest that display concentration is an important assessment cue.

Representational signalling in birds

Some animals give specific calls when they discover food or detect a particular type of predator. Companions respond with food-searching behaviour or by adopting appropriate escape responses. These signals thus seem to denote objects in the environment, but this specific mechanism has only been demonstrated for monkey alarm calls. We manipulated whether fowl (Gallus gallus) had recently found a small quantity of preferred food and then tested for a specific interaction between this event and their subsequent response to playback of food calls. In one treatment, food calls thus potentially provided information about the immediate environment, while in the other the putative message was redundant with individual experience. Food calls evoked substrate searching, but only if the hens had not recently discovered food. An identical manipulation had no effect on responses to an acoustically matched control call. These results show that chicken food calls are representational signals: they stimulate retrieval of information about a class of external events. This is the first such demonstration for any non-primate species. Representational signalling is hence more taxonomically widespread than has previously been thought, suggesting that it may be the product of common social factors, rather than an attribute of a particular phylogenetic lineage.

Active space of a movement-based signal: response to the Jacky dragon(Amphibolurus muricatus) display is sensitive to distance, but independent of orientation

The efficacy of any animal signal is constrained by the range over which it remains above the sensory threshold of potential receivers. The spatial area in which reliable detection occurs defines active space; this is influenced by signal structure, the signalling environment and the sensory characteristics of receivers. Identification of the factors influencing active space has provided valuable insights into signal design, particularly in bioacoustics,in which signal distortion and degradation can be easily quantified. In the present study, we consider whether active space can similarly help to explain the design of a movement-based visual signal. The Jacky dragon(Amphibolurus muricatus) threat display is composed of five distinct motor patterns delivered in an obligatory sequence: tail-flicks, backward and forward foreleg waves, a push-up and a `body-rock'. In contrast to other communication systems, the introductory element is characterized by reduced intensity (average speed) but greater duration than subsequent motor patterns. Furthermore, the tail-flick sweeps a three-dimensional (3D) space around the lizard, whereas the motor patterns that follow are largely restricted to a single plane. Structural properties thus suggest that the active space of the tail-flick might be greater than that of the other motor patterns in the display, which would provide a parsimonious explanation for its use as an alerting component. We tested this prediction in a playback experiment incorporating 3D animations of lizard displays, comparing response probabilities to the factorial combination of three motor patterns, three viewing angles and three distances. Results suggest that the tail-flick does not have a greater active space than other display motor patterns, but that each degrades predictably with distance, thereby providing potential ranging cues. In addition, display components are remarkably robust to variation in receiver orientation, so that efficacy should be maximized in most potential signalling situations. These findings are consistent with the hypothesis that duration is the principal determinant of signal efficacy in this system.

Accessory chemosignaling mechanisms in primates

Accessory olfaction is defined as the chemoreceptive system that employs the vomeronasal complex (VNC) and its distinct central projections to the accessory olfactory bulb (AOB) and limbic/cortical systems. Comparisons of the structural and functional features of primate accessory olfaction can now be made at many levels. Advances in the understanding of molecular mechanisms of odorant transfer and detection, physiological analyses of signal processing, and appreciation of ontogenetic timetables have clarified the contribution of accessory chemoreception to the sensory map. Two principal functions dominate: the decoding of social information through the uptake of signals (often fluid-borne), and the provision of an essential pathway for the "migration" of presumptive neurocrine (GnRH) cells from the olfactory placode to the hypothalamus. VN "smelling" (vomerolfaction) is now seen to overlap with primary olfaction. Both systems detect signal compounds along the spectrum of volatility/molecular weight, and neither is an exclusive sensor. Both main and accessory chemoreception seem to require collaborative molecular devices to assist in odorant transfer (binding proteins) and (for the VNO) signal recognition (MHC1 proteins). Most adaptive-selective features of primate chemocommunication variously resemble those of other terrestrial mammals. VN function, along with its genome, has been maintained within the Strepsirrhines and tarsiers, reduced in Platyrrhines, and nearly extinguished at the Catarrhine up to hominin levels. It persists as an intriguing ancient sense that retains key features of past evolutionary events.

Measuring social structure: a comparison of eight dominance indices

Measurement of social status is an important component of many behavioural studies. A variety of techniques have been developed and adopted, but while there have been some analyses of index properties using simulated data, the rationale for selecting a method remains poorly documented. As a first step in exploring the implications of index choice, we compared the characteristics of eight popular indices by applying each to the same data set from interactions between male fowl Gallus gallus, the system in which social hierarchies were first described. Data from eight social groups, observed over four successive breeding seasons, were analysed to determine whether different indices produced consistent dominance scores. These scores were then used in tests of the relation between social status and crowing to explore whether index choice affected the results obtained. We also examined the pattern of dominance index use over the last decade to infer whether this has likely been influenced by tradition, or by taxa of study animal. Overall agreement among methods was good when groups of birds had perfectly linear hierarchies, but results diverged when social structure was more complex, with either intransitive triads or reversals. While all regression analyses revealed a positive relationship between dominance and vocal behaviour, there were substantial differences in the amount of variance accounted for, even though the original data were identical in every case. Index selection can hence perturb estimates of the importance of dominance, relative to other factors. We also found that several methods have been adopted only by particular research teams, while the use of others has been taxonomically constrained, patterns implying that indices have not always been chosen solely upon their merits. Taken together, our results read as a cautionary tale. We suggest that selection of a dominance index requires careful consideration both of algorithm properties and of the factors affecting social status in the system of interest.

Life History and Social Learning: Megapode Chicks Fail to Acquire Feeding Preferences From Conspecifics

Australian brush-turkeys, Alectura lathami, are birds with an unusual life history: The young receive no parental care and first encounter conspecifics at an unpredictable age. Brush-turkey chicks that were 3-4 days old were presented with a robot model that appeared to feed from a distinctively colored dish. In control training trials, chicks saw a robot standing next to a different dish and scanning from side to side. Chicks expressed a strong tendency to feed from dishes of the type indicated by the pecking robot, but this effect proved ephemeral. Brush-turkeys hence appear to show no social learning under conditions that inculcate stable preferences in other galliforms such as chickens, suggesting that life history plays an important role in the evolution of learning.

Social responses without early experience: Australian brush-turkey chicks use specific visual cues to aggregate with conspecifics

Almost all birds depend upon early experience with adults and siblings to learn recognition cues. Megapodes, such as the Australian brush-turkey(Alectura lathami), have evolved a very different life history. Eggs are incubated in mounds of decaying organic material. Chicks hatch asynchronously and receive no parental care, so imprinting cannot occur. Nevertheless, chicks subsequently form groups with similar-aged conspecifics. We explored the perceptual basis of this aggregation response, focussing on likely visual cues, such as pecking movements and body colour. Experiments were conducted under naturalistic conditions in a large aviary, using realistic robot models and colour filters. The robots successfully evoked a range of social responses resembling those of a live companion. Aggregation depended upon both behaviour and morphology. Simultaneous choice tests revealed that brush-turkey chicks preferred a pecking robot over either a static model or a scanning robot, suggesting that responsiveness depends upon particular movement patterns. In addition, chicks were sensitive to changes in appearance but only those that affected radiance at short wavelengths. The mechanism underlying social aggregation after hatching hence involves relatively specific cues. This perceptual bias seems to be largely experience independent and may exploit attributes to which potential predators are insensitive.

Egg size predicts motor performance and postnatal weight gain of Australian Brush-turkey (Alectura lathami) hatchlings

Birds usually influence offspring survival through the amount of parental care they provide. Megapodes have evolved a different life history. Eggs are incubated by external heat sources, and chicks dig themselves out of their underground nest and live independently of their parents. Egg size is one of the few means by which females can influence chick survival. We found that in the Australian Brush-turkey, Alectura lathami Gray, 1831, eggs and hatchlings varied considerably in size, with a ratio of 1.62 between the largest and the smallest egg. Egg size was positively correlated with hatchling body mass and tarsus length. It also significantly predicted the chicks' motor performance: chicks from larger eggs dug their way out of their underground nest faster and were more active when kept in a resting box and monitored by motion detection software. The main advantage of reaching the surface more quickly is likely that such chicks will have more time to find suitable food, refuge, and a tree for roosting at night while still feeding on their internal yolk reserves. Egg size also interacted significantly with body mass during the first 10 months of life. A size advantage at hatching thus seems to have an immediate effect on motor performance and a longer term effect on the ability to gain mass.

Introductory tail-flick of the Jacky dragon visual display: signal efficacy depends upon duration

Many animal signals have introductory components that alert receivers. Examples from the acoustic and visual domains show that this effect is often achieved with high intensity, a simple structure and a short duration. Quantitative analyses of the Jacky dragon Amphibolurus muricatusvisual display reveal a different design: the introductory tail-flick has a lower velocity than subsequent components of the signal, but a longer duration. Here, using a series of video playback experiments with a digitally animated tail, we identify the properties responsible for signal efficacy. We began by validating the use of the computer-generated tail, comparing the responses to digital video footage of a lizard tail-flick with those to a precisely matched 3-D animation (Experiment 1). We then examined the effects of variation in stimulus speed, acceleration, duration and period by expanding and compressing the time scale of the sequence (Experiment 2). The results identified several variables that might mediate recognition. Two follow-up studies assessed the importance of tail-flick amplitude (Experiment 3),movement speed and signal duration (Experiment 4). Lizard responses to this array of stimuli reveal that duration is the most important characteristic of the tail-flick, and that intermittent signalling has the same effect as continuous movement. We suggest that signal design may reflect a trade-off between efficacy and cost.

Design of the Jacky dragon visual display: signal and noise characteristics in a complex moving environment

Visual systems are typically selective in their response to movement. This attribute facilitates the identification of functionally important motion events. Here we show that the complex push-up display produced by male Jacky dragons ( Amphibolurus muricatus) is likely to have been shaped by an interaction between typical signalling conditions and the sensory properties of receivers. We use novel techniques to define the structure of the signal and of a range of typical moving backgrounds in terms of direction, speed, acceleration and sweep area. Results allow us to estimate the relative conspicuousness of each motor pattern in the stereotyped sequence of which displays are composed. The introductory tail-flick sweeps a large region of the visual field, is sustained for much longer than other components, and has velocity characteristics that ensure it will not be filtered in the same way as wind-blown vegetation. These findings are consistent with the idea that the tail-flick has an alerting function. Quantitative analyses of movement-based signals can hence provide insights into sensory processes, which should facilitate identification of the selective forces responsible for structure. Results will complement the detailed models now available to account for the design of static visual signals.

The role of differential reinforcement in predator avoidance learning

Little is known about how predator recognition develops under natural conditions. Predispositions to respond to some stimuli preferentially are likely to interact with the effects of experience. Convergent evidence from several studies suggests that predator-nai;ve tammar wallabies (Macropus eugenii) have some ability to respond to vertebrate predators differently from non-predators and that antipredator responses can be selectively enhanced by experience. Here, we examined the effects of differential reinforcement on responses to a model fox (Vulpes vulpes), cat (Felis catus) and conspecific wallaby. During training, tammars experienced paired presentations of a model fox and a simulated capture, as well as presentations of a wallaby and a cat alone. Training enhanced responses to the fox, relative to the conspecific wallaby, but acquired responses to the two predators did not differ, despite repeated, non-reinforced presentations of the cat. Results suggest that experience interacts with the wallabies' ability to perceive predators as a natural category.

Adaptation of the white-rot basidiomycete Panus tigrinus for transformation of high concentrations of chlorophenols

During feed-batch cultivation of the white-rot fungus Panus tigrinus in a 5-l bioreactor on N-limited medium, 100, 200, 500, 1,000 and 2,000 mg 2,4,6-trichlorophenol (2,4,6-TCP) l(-1) were added sequentially after 90% removal of the previous portion of the toxicant. The addition of 500 mg 2,4,6-TCP l(-1) without preliminary adaptation killed the culture. The addition of 300 mg 2,4,6-TCP l(-1) without prior adaptation resulted in its slower removal than removal of 2,000 mg 2,4,6-TCP l(-1) by this adapted culture. After adaptation of P. tigrinus to 2,4,6-TCP in a 72-l bioreactor, the mixture of 2,4-dichlorophenol, 2,4,6-TCP, and pentachlorophenol, each at 500 mg x l(-1), was totally removed over 3 weeks. No lignin peroxidase activity was found in the course of cultivation of the fungus. Laccase activity was suppressed by addition of 2,4,6-TCP. Mn-peroxidase was found to be responsible for transformation of the chlorophenols. As final products of the process, several newly formed aromatic polymers, both chlorinated and non-chlorinated, were found in the culture liquid.

A rapid and efficient mass spectrometric method for the analysis of explosives

The high explosives trinitrotoluene, nitroglycerine, pentaerythritol tetranitrate and hexahydro-1,3,5-trinitro-1,3,5-triazine are efficiently ionised under negative ion atmospheric pressure chemical ionisation (APCI) conditions. The limit of detection is improved, in some cases by several orders of magnitude, by complexation with chlorine demonstrating this to be a highly suitable method for enhancing the detection capabilities for explosives. The spectra produced from introduction of the analytes in a liquid matrix, with and without chlorine present, contain a number of ions that arise through secondary processes including breakdown and adduct formation. Sample introduction into an APCI source in air, via a heated-plate inlet with a supplementary feed of dichloromethane, produces improved response for the chloride adducts of the analytes and minimises their decomposition during analysis. The tandem mass spectra produced from the chloride adducts are simple. Optimisation of the trapping parameters of the ion trap detector enhances selected transitions, yields highly reproducible spectra and improves the limits of detection for MS/MS analysis.