Point Of Interruption Research Articles

Biphasic clinical course of a ruptured right gastric artery aneurysm caused by segmental arterial mediolysis: a case report

BackgroundGastric artery aneurysms are rarely caused by segmental arterial mediolysis (SAM), a condition that often involves multiple vessels. The clinical course of SAM after vessel rupture may vary depending on the involved vessels. For example, the “double-rupture phenomenon” observed following the rupture of the splenic artery aneurysm manifests as a biphasic and relatively slow clinical course. Even in cases of rupture of gastric artery aneurysm, the double-rupture phenomenon has only been reported in two cases so far. However, the rupture was not caused by SAM in either case. Herein, we present the apparent first case of a right gastric artery (RGA) aneurysm rupture caused by SAM that presented with a biphasic clinical course, possibly due to the double-rupture phenomenon.Case presentationA 54-year-old woman was transferred to the emergency department with severe abdominal pain and a cold sweat for a duration of 3 h. She had developed mild abdominal pain and nausea 3 days earlier. Her vital signs were stable. Physical examination revealed tenderness in the epigastric area. Abdominal contrast-enhanced computed tomography revealed an RGA aneurysm with contrast media extravasation. A diagnosis of hemoperitoneum following a ruptured RGA aneurysm was made, and the patient underwent angiography. However, this modality did not reveal any extravasation from the RGA due to an interruption in the peripheral branch of the artery. Nevertheless, to prevent major bleeding, we performed coil embolization at the point of interruption in the RGA, which we suspected to be a ruptured aneurysm. A distal gastrectomy with Roux-en-Y reconstruction for aneurysm resection was performed the following day. There were no postoperative complications, and the patient was discharged 17 days after surgery. Histologically, the RGA demonstrated multiple vacuoles in the medial muscle layer, which were characteristic of SAM.ConclusionsAn RGA aneurysm rupture should be considered a differential diagnosis in patients presenting with hemoperitoneum with a slow or biphasic clinical course.

Intermittent warming as an efficient postharvest treatment affects the enzymatic and non-enzymatic responses of pomegranate during cold storage

Limited shelf life of pomegranate makes its cold storage necessary. On the other hand, it encounters chilling injury (CI) incidence at temperatures below 5 oC. Intermittent warming (IW), known as one or more warming periods during cold storage, is a beneficial postharvest treatment for keeping fruit quality. Pomegranate ‘Rabab-e-Neyriz’ fruit were stored at 2 ± 0.5 °C (chilling temperature) and 90 ± 5% relative humidity (RH) for 70 days. IW was performed as one warming period by transferring the fruit to a warm room (1 day at 20 °C with 70% RH). The experimental design was factorial based on a complete randomized design. Experimental factors included 4 temporal points of interruption in storage, i.e., 15th, 25th, 35th or 45th days of storage; 2 levels of warming regime for each interruption date, i.e., warming and control; and 2 levels of sampling time, i.e., immediately after treatment or postponed until the end of the storage period. Treated fruit were compared to controls twice, immediately after treatment and at the end of the storage period. Warming on the 15th day of storage led to higher enzymatic antioxidant activity and phenolic content coincided with lower polyphenol oxidase (PPO) activity in the peel and, as a result, lower chilling injury (CI) damage to the treated fruit compared to control. It was concluded that a successful and commercially applicable method for postharvest cold storage of pomegranate could be the only one warming period prior to the incidence of irreversible damage.

Self-initiated error-repairs in cluttering

ABSTRACT The aim of the study is the analysis of the error-repairs of people with cluttering (PWC), whether they repair their speech errors similarly to control speakers or not. Error-repairs were analysed in spontaneous speech samples of 13 PWC and 13 age- and sex-matched control speakers. Error-to-cutoff time, duration of the editing phase, and error-to-repair time were measured. Strategies of repairs (point of interruption, proportion of delays, and types of editing terms and phases) were also examined. Results of the two groups were compared. Results show that there are no differences between the two groups in the total duration of error-repairs. However, there might be differences between the two groups in the self-repair strategies. Results suggest that control speakers might try to plan the error-repairs in parallel with the speech production and they interrupt the speech when the repair is available. In contrast, PWC interrupt speaking earlier perhaps to focus on planning self-repairs.

P-340 Regorafenib dose-strategy in patients with metastatic colorectal cancer who progressed on standard treatment: A retrospective study

Regorafenib is recommended in patients with metastatic colorectal cancer (mCRC) after failure of at least two lines of treatment regardless of the RAS and BRAF mutation status. It significantly increased progression-free survival and overall survival in two phase III studies (CONCUR and CORRECT). The side effects such as fatigue and hand-foot skin reaction (HFSR) has limited its use with a standard dose, especially in fragile patients. However, the maximum effect of therapy can be achieved only with regard to the profile of adverse events, correct time points of starting, interruption and effectiveness control.

Predictors of Bleeding in the Perioperative Anticoagulant Use for Surgery Evaluation (PAUSE) Study

Introduction In the Perioperative Anticoagulant Use for Surgery Evaluation (PAUSE) Study a simplified, standardized, pharmacokinetic based perioperative interruption scheme was stablished for patients with non-valvular atrial fibrillation taking direct oral anticoagulants (DOACs). The rate of bleeding and thromboembolic outcomes was low, yet better awareness of bleeding predictors will aid the informed decision making for both clinicians and patients. Thus, we aimed to define the factors associated with perioperative bleeding events in the PAUSE cohorts. Methods The standardized interruption scheme is depicted in figure 1. We analyzed bleeding as the composite of major and clinically relevant non-major bleeding (MB/CRNM) according to the ISTH criteria. Putative predictors of bleeding were prospectively collected during the PAUSE recruitment. For patients taking dabigatran the dilute thrombin time was measured from a pre-operative blood sample. A DOAC-calibrated anti-factor Xa level was assessed preoperatively for patients taking factor Xa inhibitors. Continuous numeric variables were reported as means with SD; frequencies were reported when appropriate. We used stratified logistic regression models for analysis. All statistical analyses were performed in R version 3.6.0. Results There were 3007 patients requiring perioperative DOAC interruption, distributed in the apixaban (A) (N = 1,257), dabigatran (D) (N = 668), and rivaroxaban (R) (N = 1,082) cohorts. Characteristics of the patients who developed MB/CRNM are reported in table 1. More than one third of included patients underwent a high bleeding risk procedure. The rates of MB/CRNM were 3.02% in group A, 2.84% in group D, and 4.16% of group R patients from the point of DOAC interruption to 30 days after the procedure. In the univariate analysis, surgery bleeding risk was significantly associated with MB/CRNM (low vs high, OR 0.56, 95% CI 0.36-0.86; p=0.008). Multivariate analysis stratified by region found hypertension (OR 1.81, 95%CI 1.07-3.07; p=0.027), prior bleed or bleed predisposition (OR 1.62, 95% CI 1.02-2.58; p=0.043) were significantly associated with MB/CRNM (table 2); whereas surgery bleeding risk was not significant after adjusting other covariates. Female gender was associated with lower MB/CRNM risk (This result seems to be mainly driven by the rate of CRNM, 2.21% male had CRNM and 1.57% female had CRNM, and the signal disappeared in the model for MB). [Hypertension (OR 3.93, 95%CI 1.40-11.07; p=0.010), active cancer (OR 2.30, 95% CI 1.10-4.81; p=0.026) were significantly associated with MB (table 3)] Aspirin use was more prevalent among males (13.78%) than females (7.75%), but this did not fully explain the gender effect. The model for MB/CRNM had an area under the curve (AUC) of 0.65 (standard error 0.03). Drug level analysis was available for 2541 (84.5%) patients. In the stratified analysis with the DOAC level (>50ng/dL vs £50ng/dL) as a single predictor, there was no significant association with MB/CRNM observed (OR 1.07, 95% CI 0.38-2.96; p=0.902). In the multivariate model, adding DOAC level to the model did not improve the AUC. Discussion A standardized interruption scheme results in low risk of bleeding for patients with atrial fibrillation interrupting DOACs for surgery/invasive procedures. The protocol-defined surgical bleed risk in PAUSE was valid, and selected to numerically higher bleeding rates, but it was not independent predictor of bleeding when the interruption scheme and covariates are accounted for. Hypertension was the only potentially modifiable predictor of perioperative MB/CRNM bleeding. Likely selecting for a frail population, active cancer and hypertension were predictors of MB events. In the exploratory analyses, residual levels did not improve the predictive model. The multivariate model had a low performance and we do not advocate modification of the PAUSE-proposed interruption schema based on these results. The PAUSE trial is the first large scale study enabled to investigate the factors governing perioperative bleed among DOAC-Anticoagulated patients. Nonetheless, we did not have power to analyze DOAC cohorts independently due to the paucity outcomes. Overall, the results strengthen the validity of the PAUSE-proposed DOAC interruption scheme for atrial fibrillation patients who need surgery. Disclosures Tafur: Recovery Force: Consultancy; Janssen: Other: Educational Grants, Research Funding; BMS: Research Funding; Idorsia: Research Funding; Daichi Sanyo: Research Funding; Stago: Research Funding; Doasense: Research Funding. Spyropoulos:Bayer: Consultancy; Ingelheim: Consultancy; Portola: Consultancy; Janssen: Research Funding; Boehringer INgelheim: Research Funding; Janssen: Consultancy. Douketis:Pfizer: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Leo Pharma: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Portola: Other: Consultant ; Janssen: Other: Consultant ; The Merck Manual: Patents & Royalties; Up-to-Date: Patents & Royalties.

An Adiabatic Coaxial Line for Microcalorimeter Power Measurements in Wireless Communication for Smart Grid

This paper presents the extended results and prototype of the adiabatic copper conductor constructed with two interruption points in the external conductor layer, for use as a microcalorimeter power standard in wireless communication for a smart grid frequency range. Gaps are intended to drive down the thermal transfer from the outer environment into microcalorimeter and to reduce measurement inaccuracies in the microcalorimeter. The proposed design method is based on the combination of thermal and electromagnetic finite-element method simulations by which the desired line performance has been tailored. A prototype of the proposed adiabatic line has been manufactured and measurements on the prototype are presented along with the design procedure. Measured results are in line with the ones predicted by numerical calculations.

Impact evaluation of Zika epidemic on congenital anomalies registration in Brazil: An interrupted time series analysis

This study aimed to assess the impact of the Zika epidemic on the registration of birth defects in Brazil. We used an interrupted time series analysis design to identify changes in the trends in the registration of congenital anomalies. We obtained monthly data from Brazilian Live Birth Information System and used two outcome definitions: 1) rate of congenital malformation of the brain and eye (likely to be affected by Zika and its complications) 2) rate of congenital malformation not related to the brain or eye unlikely to be causally affected by Zika. The period between maternal infection with Zika and diagnosis of congenital abnormality attributable to the infection is around six months. We therefore used September 2015 as the interruption point in the time series, six months following March 2015 when cases of Zika started to increase. For the purposes of this analysis, we considered the period from January 2010 to September 2015 to be “pre-Zika event,” and the period from just after September 2015 to December 2017 to be “post-Zika event.” We found that immediately after the interruption point, there was a great increase in the notification rate of congenital anomalies of 14.9/10,000 live births in the brain and eye group and of 5.2/10,000 live births in the group not related with brain or eye malformations. This increase in reporting was in all regions of the country (except in the South) and especially in the Northeast. In the period “post-Zika event”, unlike the brain and eye group which showed a monthly decrease, the group without brain or eye malformations showed a slow but significant increase (relative to the pre-Zika trend) of 0.2/10,000 live births. These findings suggest an overall improvement in the registration of birth malformations, including malformations that were not attributed to Zika, during and after the Zika epidemic.

Failure Monitoring and Recovery System During Manufacturing Process

Originally designed for industrial use, numerical control (CNC) machines have been increasingly present incommercial and residential environments, especially due to the popularization of low-cost 3D printers and machines with a similar control system, such as small laser cutting machines. Most of such machines are controlled by G-codes, however, open, simple and generic tools for remote control, monitoring and open management of G-codes sent to them are rare. In the context of Industry 4.0, including remote operation and monitoring of such machines, their use has become fundamental. This article introduces an open and generic CNC device control software platform that manages and controls the machine via remote web, from anywhere, with any device (computer or smartphone). The system involves failure detection during the manufacturing process and remote monitoring of sensors and enables the pausing or continuation of manufacturing or restarting processes from the point of interruption. The article addresses the systems characteristics, its implementation and the experimental results from its use with two 3D printers.

525. The Impact of Switching to Molecular Testing on Clostridium difficile Infection Rates: Large-Scale Assessment Using an Interrupted Time Series Poisson Regression Approach

Background Clostridium difficile is the most common cause of hospital-acquired infections in the United States, affecting over 500,000 patients per year at a cost of nearly $5 billion. The reported incidence of C. difficile infections (CDIs) has increased in recent years, partly due to broad adoption of polymerase chain reaction (PCR) testing replacing enzyme-linked immunosorbent assay (ELISA) methods. Our aim was to assess the contribution of this change on reported CDI incidence using a large-scale empirical data set.MethodsWe retrospectively analyzed 8 years of CDI surveillance data (2009–2016) collected from 47 hospitals in the Duke Infection Control Outreach Network. During this period, 24 hospitals switched to PCR testing, 10 used ELISA throughout, and 13 used PCR throughout. We used interrupted time series analysis to quantify the relative change in incidence rate (IRR) of CDIs due to the switch from nonmolecular (ELISA) to molecular (PCR) testing. Data were aligned across hospitals at their interruption point, set at the reported test change date or nearest available measurement. Individual hospital and network-wide estimates of the PCR-over-ELISA IRR were determined through Poisson regression, controlling for total patient days, proportion of intensive care unit patient-days as a proxy for acuity, background trends, and previously detected clusters.ResultsAverage monthly CDI rates significantly increased after the test change from 11.7 to 26.8 per 10,000 patient-days in hospitals that switched to PCR testing. A similar difference was observed between ELISA-only and PCR-only hospitals, which averaged 12.7 and 21.0 CDIs per 10,000 patient-days, respectively. Regression analysis yielded hospital-specific test change IRRs ranging from 0.70 (95% confidence interval [CI]: 0.48–1.02) to 3.64 (CI: 2.77–8.46) (Figure 1) and a network-wide IRR of 1.79 (CI: 1.73–1.90). Results also found an increasing background trend of 0.9 CDIs per 10,000 patient-days per year (CI: 0.7–1.2) (Figure 2), as well as a significant effect of known clusters (IRR of 1.56, CI: 1.48–1.65).ConclusionHospitals that switched to molecular testing experienced an average post-change increase of 80% in reported CDI rates, similar to that observed during known cluster periods. Disclosures All authors: No reported disclosures.

Interruption points in the wing gene regulatory network underlying wing polyphenism evolved independently in male and female morphs in Cardiocondyla ants.

Wing polyphenism in ants, which produces a winged female queen caste and a wingless female worker caste, evolved approximately 150 million years ago and has been key to the remarkable success of ants. Approximately 20 million years ago, the myrmicine ant genus Cardiocondyla evolved an additional wing polyphenism among males producing two male morphs: wingless males that fight to enhance mating success and winged males that disperse. Here we show that interruption of rudimentary wing-disc development in larvae of the ant Cardiocondyla obscurior occurs further downstream in the network in wingless males as compared with wingless female workers. This pattern is corroborated in C. kagutsuchi, a species from a different clade within the genus, indicating that late interruption of wing development in males is conserved across Cardiocondyla. Therefore, our results show that the novel male wing polyphenism was not developmentally constrained by the pre-existing female wing polyphenism and evolved through independent alteration of interruption points in the wing gene network. Furthermore, a comparison of adult morphological characters in C. obscurior reveals that developmental trajectories lead to similar morphological trait integration between winged and wingless females, but dramatically different integration between winged and wingless males. This suggests that the alternative sex-specific developmental routes to achieve winglessness in the genus Cardiocondyla may have evolved through different selection regimes acting on wingless males and females.

Optimization of ISP Service Maintenance Router Using Dijkstra and Flyod-Warshall Algorithm

In this paper, Dijkstra algorithm and Floyd-Warshall algorithm are proposed to reduce the number of repetitive operations and read the shortest path and the fastest time from the starting point to all other nodes to arrive at the destination. The Dijkstra algorithm is used to sort location data by distance and sort location data based on the travel time using the Floyd-Warshall algorithm. This application is expected to provide benefits as an example to facilitate ISP personnel in obtaining the shortest path information or route to the point of service interruption. This will optimize disruption handling time and vehicle fuel. Operational costs are more efficient. For ISP Consumers, handling disruptions will be more quickly resolved. Test result indicate that the application can show steps to find the route to the ISP service disruption and advise which node is passed for the shortest distance and the fastest time. A numerical example was used to illustrate the efficiency of the proposed technique. The propose technique can be applied to real application transportation system and many other network optimization problem that can be formulated as shortest path problem.

Which criteria do naïve people use for identifying and evaluating different kinds of interruptions?

In two experiments, we played an audio recording of a conversational exchange for N = 224 and N = 144 participants, manipulating the point of interruption (early, late or no interruption = control) and types of interruption (change of subject, disagreement, clarification and agreement) in order to understand their effects on naïve observers' perception (Study 1) and evaluation of interruptions (Study 2). Results show that: early rather than late interruptions, changing the subject rather than disagreement, disagreement rather than clarification, and clarification rather than agreement were regarded more as interruptions and were evaluated more negatively; although both criteria—type and point of interruption—showed significant effects, naïve observers used the point of interruption more than the type of interruption for identifying and evaluating the interruptions. Valence and perception of a conversational transition were correlated: in the interruption condition and even in non-interruption conditions, the more a turn taking was evaluated as negative, the more it was perceived to be an interruption. Finally, the results did not support the gender hypothesis. Results were interpreted in terms of politeness theory and considering cultural and contextual factors.

Equilibrium and optimal balking strategies for low-priority customers in the M/G/1 queue with two classes of customers and preemptive priority

This paper investigates the low-priority customers' strategic behavior in the single-server queueing system with general service time and two customer types. The priority system is preemptive resume, which means that if a high-priority customer enters the system that are serving a low-priority customer, the arriving customer preempts the service facility and the preempted customer returns to the head of the queue for his own class. The customer who is preempted resumes service at the point of interruption upon reentering the system. The low-priority customer's dilemma is whether to join or balk based on a linear reward-cost structure. Two cases are distinguished based on the different levels of information that the low-priority customers acquire before joining the system. The equilibrium threshold strategy in the observable case and the equilibrium balking strategy as well as the socially optimal balking strategy in the unobservable case for the low-priority customers are derived finally.

Lack of interruption of the gene network underlying wing polyphenism in an early-branching ant genus.

Ants evolved about 140 million years ago and have diversified into more than 15,000 species with tremendous ecological and morphological diversity, yet evolution of the gene regulatory networks (GRNs) underlying this diversification remains poorly understood. Wing polyphenism, the ability of a single genome to produce either winged or wingless castes during development in response to environmental cues, is a nearly universal feature of ants. The underlying wing GRN is evolutionarily labile in worker castes of phylogenetically derived species: it is conserved in winged castes but interrupted at different points in wingless castes of different species. However, it remains unknown whether the wing GRN is interrupted in wingless castes of species from early branching lineages, and if so, whether it is interrupted at similar locations in worker castes of derived species. We therefore used in situ hybridization to assay the expression of nine genes in the wing GRN in wing imaginal discs of larvae from two species from the early branching ('basal') genus Mystrium. These species possess two castes each: Mystrium rogeri has winged queens and wingless workers, and M. oberthueri has wingless queens and wingless workers. In contrast to derived species, we found no evidence of interruption points in the wing GRN kernel of wingless castes. Our finding supports: (1) a "phylogenetic ladder model" of wing GRN evolution, where interruption points move further upstream in the wing GRN as ant lineages become more derived; and (2) that evolutionary lability of the GRN underlying wing polyphenism originated later during ant evolution.

Adolescent to Adult HIV Health Care Transition From the Perspective of Adult Providers in the United States

PurposeThe HIV Care Continuum highlights the need for HIV-infected youth to be tested, linked, and maintained in lifelong care. Care engagement is important for HIV-infected youth in order for them to stay healthy, maintain a low viral load, and reduce further transmission. One point of potential interruption in the care continuum is during health care transition from adolescent- to adult-centered HIV care. HIV-related health care transition research focuses mainly on youth and on adolescent clinic providers; missing is adult clinic providers' perspectives. MethodsWe examined health care transition processes through semi-structured interviews with 28 adult clinic staff across Adolescent Trials Network sites. We also collected quantitative data related to clinical characteristics and transition-specific strategies. ResultsOverall, participants described health care transition as a “warm handoff” and a collaborative effort across adolescent and adult clinics. Emergent transition themes included adult clinical care culture (e.g., patient responsibility), strategies for connecting youth to adult care (e.g., adolescent clinic staff attending youth's first appointment at adult clinic), and approaches to evaluating transition outcomes (e.g., data sharing). Participants provided transition improvement recommendations (e.g., formalized protocols). ConclusionsUsing evidence-based research and a quality improvement framework to inform comprehensive and streamlined transition protocols can help enhance the capacity of adult clinics to collaborate with adolescent clinics to provide coordinated and uninterrupted HIV-related care and to improve continuum of care outcomes.

Temporal structure of repetition disfluencies in American English

A repetition disfluency involves an interruption in the flow of speech followed by a restart, leading to repetition of one or more words. We analyzed the temporal structure of one-word, two-word, and three-word repetition disfluencies in the Switchboard Corpus (none-word = 30546, ntwo-word = 8102, nthree-word = 1606). Comparing durations of words preceding an interruption point to their repeated counterparts, we find that repetition is typically accompanied by prolongation, which mainly influences the last word preceding the interruption point. When prolongation does not provide enough time for planning upcoming speech—as there seems to be a temporal limit to prolongation—the speaker repeats parts of the utterance just produced. Our results demonstrate that the number of words repeated is determined both by word duration and by co-occurrence relations between words. Mixed effects logistic regression analysis revealed that longer words are less likely to be repeated (z=-24.45, p<.0001). However, the number...

Australian LGBTQ teachers, exclusionary spaces and points of interruption

Lesbian, gay, bisexual, transgender and queer (LGBTQ) teachers are a marginalised group that historically have been absent from research on sexuality and schooling. Rather, much research in the field has focused upon the experiences of same sex attracted and increasingly, gender diverse young people in schools, as well as the delivery of sexuality education. Up until recently, very little research has been carried out that explicitly addresses the experiences of LGBTQ teachers, particularly within the Australian context. This article focuses upon key issues arising from the semi-structured interviews that the Out/In Front team carried out as part of a pilot study that took place between April and July 2013 in the state of Victoria, Australia. We interviewed nine current or former teachers working within primary and secondary education across the public, Catholic and private sectors. This paper focuses upon the notion that LGBTQ teachers exist within a ‘space of exclusion’ that is dominated by discursive mechanisms that (re)produce heteronormativity. We also argue that the Victorian policy context – as well as increasing socio-political tolerance for LGBTQ people within Australia – enables LGBT teachers to interrupt the discursive frameworks within which their professional lives are situated.

Modelling Aggregation on the Large Scale and Regularity on the Small Scale in Spatial Point Pattern Datasets

AbstractWe consider a dependent thinning of a regular point process with the aim of obtaining aggregation on the large scale and regularity on the small scale in the resulting target point process of retained points. Various parametric models for the underlying processes are suggested and the properties of the target point process are studied. Simulation and inference procedures are discussed when a realization of the target point process is observed, depending on whether the thinned points are observed or not. The paper extends previous work by Dietrich Stoyan on interrupted point processes.

Life history of the most complete fossil primate skeleton: exploring growth models for Darwinius.

Darwinius is an adapoid primate from the Eocene of Germany, and its only known specimen represents the most complete fossil primate ever found. Its describers hypothesized a close relationship to Anthropoidea, and using a Saimiri model estimated its age at death. This study reconstructs the ancestral permanent dental eruption sequences for basal Euprimates, Haplorhini, Anthropoidea, and stem and crown Strepsirrhini. The results show that the ancestral sequences for the basal euprimate, haplorhine and stem strepsirrhine are identical, and similar to that of Darwinius. However, Darwinius differs from anthropoids by exhibiting early development of the lower third molars relative to the lower third and fourth premolars. The eruption of the lower second premolar marks the point of interruption of the sequence in Darwinius. The anthropoid Saimiri as a model is therefore problematic because it exhibits a delayed eruption of P2. Here, an alternative strepsirrhine model based on Eulemur and Varecia is presented. Our proposed model shows an older age at death than previously suggested (1.05–1.14 years), while the range for adult weight is entirely below the range proposed previously. This alternative model is more consistent with hypotheses supporting a stronger relationship between adapoids and strepsirrhines.

Follower ants in a tandem pair are not always naïve.

In addition to foraging individually several species of ants guide nestmates to a goal by tandem running. We found that the Australian ant, Camponotus consobrinus, forages both individually and by tandem running to head to the same goal, nest-specific native Australian trees on which they forage. While paths of solitary foragers and initial paths of tandem followers showed no differences in heading directions or straightness, tandem followers moved at about half the speed of solitary runs. When leaders were experimentally removed, follower ants initially engaged in a systematic search around the point of interruption, following which they either (a) headed directly towards and successfully reached the foraging trees, or (b) continued searching or (c) returned to the nest. The high incidence of followers that successfully navigated towards the foraging trees on their own provides strong evidence that many tandem followers are in fact experienced foragers. Detailed analysis of the searching behaviour revealed that even seemingly lost followers displayed a directional bias towards the foraging trees in their search path. Our results show that in a foraging context follower ants in a tandem pair are not always naïve.