Alarm Response Research Articles

Experimental Pain Is Alleviated by Manual Traction Itself Rather than Subjective Bias in the Knee: A Signal Detection Analysis.

Manual traction is used for pain relief, but it is not clear whether the pain relief effect of manual traction is due to sensitivity or to subjective bias. The differences between manual traction and touch have also been unclear. We used signal detection theory to investigate whether manual traction and touch were effective for pain relief, and we compared the pain relief effect between manual traction and touch. Repeated measures and single blinding. Twenty healthy adult volunteers performed an intensity judgment task immediately before and after each intervention. The intervention was either manual traction or touch for 10 minutes. We measured the intensity judgment task's signal detection measures of hit rates, false alarm rates, sensitivity (d'), and response bias (C) in an Aδ fiber-mediated pain condition and C fiber-mediated pain condition. Manual traction did not provide a significant level of change, but its effect sizes differed. In our comparison of the effect sizes, manual traction tended to reduce the hit rate and altered the sensitivity value rather than the response bias in Aδ fiber-mediated pain. There was no significant difference in the amount of change in the hit rate between touch and manual traction regarding Aδ fiber-mediated pain and C fiber-mediated pain. In terms of effect sizes, manual traction was effective for the pain relief of the first pain by producing a change in pain sensitivity rather than by subjective bias. Manual traction reduced the first pain, whereas touch reduced the first pain and second pain.

Impact, recovery and carryover effect of Roundup® on predator recognition in common spiny loach, Lepidocephalichthys thermalis.

Understanding the negative impact of a variety of environmental contaminants on aquatic animals is essential to curb biodiversity loss and stop degradation of ecological functions. Excessive and unrestricted use of pesticides is the most serious threat to aquatic animals including amphibians and fishes. Among the known pesticides, glyphosate based formulations have been shown to have lethal effects on many aquatic organisms. However, negative effects of pesticides on crucial ecological interactions such as prey-predator interactions are relatively unknown from tropics. In many aquatic organisms, recognition of predators is based on odor signatures; and therefore any anthropogenic alteration in water chemistry has the potential to impair recognition and learning of predators. Through a series of behavioral experiments we evaluated the effect of glyphosate based herbicide (Roundup®) on the antipredator behavior of common spiny loach, Lepidocephalichthys thermalis to understand the effects of pesticide-exposure on recognition of conspecific alarm cues, and associative learning to avoid predation. We exposed common spiny loach (for 3 h or 15 days) to sub-lethal concentration (0.5 mg a.e./L) of Roundup® and subsequently with conspecific alarm cues, signaling the proximity of a predator. Unexposed prey fish showed a significant reduction in activity level in response to conspecific alarm cues. Whereas such alarm response was not observed in prey fish that were exposed to Roundup® either for 3 h or 15 days. Such lack of response could be associated with alteration of olfactory function in prey individuals. However, this inability to detect the conspecific alarm cues was found to be transient and exposed fish recovered within 2 days. In subsequent experiments, we showed that Roundup® deactivates the conspecific alarm cues thus making them unavailable for prey to evoke the response. Furthermore, Roundup® mediated degradation of conspecific alarm cues and diminished the associative learning necessary for detection of the invasive/unknown/novel predators. Overall, due to the worldwide occurrence of glyphosate in water bodies, glyphosate mediated behavioral suppression exposes the prey animals to a considerable risk of predation, both by native and non-native predators.

Fire Management Preparedness at PT X Sleman Regency

The implementation of Occupational Safety and Health (OSH)is one of the efforts to create a workplace that is safe, healthy, and freefrom environmental pollution, to minimize work accidents andoccupational diseases, and to finally improve work efficiency andproductivity. The mortality rate caused by fire cases in the industrial sectorare high. Therefore, fire management is needed as the implementation ofOccupational Safety and Health. This study aims to determine managementpreparedness in dealing with fire emergencies to prevent fire and minimizethe potential hazard risk of PT X. The method in this study uses qualitativemethods with triangulation approach through in-depth interview, observation, checklist form and documentation. The research resultsthrough in-depth interviews show that fire management is still not optimal, i.e. there are no hydrants, automatic alarms and emergency doors. Inaddition, the fire prevention unit has been established but not specifically. From the observation of using the checklist form, it showed that firemanagement has 3 Good (G) categories, includes fire extiguisher (82%), standard operating procedures (100%), and evacuation routes (100%). Theothers are 5 Less (L) categories, includes hydrant (0%), alarm (0%), emergency door (0%), education and emergency response training (33%), fire management unit (25%).

The Relation of Emergency Duties to Cardiac Death Among US Firefighters

Sudden cardiac death accounted for 42% of all firefighter duty-related fatalities over the last decade. This retrospective study analyzed available medical examiner records for duty-related firefighter fatalities among male firefighters 18 to 65 years of age that occurred between 1999 and 2014 and reported the pathoanatomic substrate for cardiac-related fatalities. Odds of duty-related cardiac death during specific duties compared with fire station duties were calculated by pathoanatomic substrate. There were 285 cardiac fatalities. Of fatalities, 80% had evidence at autopsy of coronary heart disease (CHD) and increased heart size (cardiomegaly and/or left ventricular hypertrophy). CHD alone, cardiomegaly or left ventricular hypertrophy, and causes other than CHD or increased heart size were identified in 7.7%, 6.0%, and 6.7% of fatalities, respectively. The largest proportion of deaths occurred during fire suppression (33%), although only 1% of annual occupational time was estimated to be spent performing this duty. For deaths attributed to CHD and increased heart size, fire suppression, alarm response, and physical training were associated with approximately a 112-fold, eightfold, and sevenfold increased risk of cardiac death, respectively, compared with station duties. In conclusion, the majority of firefighters who suffered a duty-related cardiac death had CHD and increased heart size, which was associated with a markedly increased risk of death during fire suppression compared with station duties. Targeted occupational medical screening for CHD and increased heart size may reduce duty-related cardiac deaths among firefighters.

Alarm-Related Workload in Default and Modified Alarm Settings and the Relationship Between Alarm Workload, Alarm Response Rate, and Care Provider Experience: Quantification and Comparison Study.

BackgroundDelayed or no response to impending patient safety–related calls, poor care provider experience, low job satisfaction, and adverse events are all unwanted outcomes of alarm fatigue. Nurses often cite increases in alarm-related workload as a reason for alarm fatigue, which is a major contributor to the aforementioned unwanted outcomes. Increased workload affects both the care provider and the patient. No studies to date have evaluated the workload while caring for patients and managing alarms simultaneously and related it to the primary measures of alarm fatigue—alarm response rate and care provider experience. Many studies have assessed the effect of modifying the default alarm setting; however, studies on the perceived workload under different alarm settings are limited.ObjectiveThis study aimed to assess nurses’ or assistants’ perceived workload index of providing care under different clinical alarm settings and establish the relationship between perceived workload, alarm response rate, and care provider experience.MethodsIn a clinical simulator, 30 participants responded to alarms that occurred on a physiological monitor under 2 conditions (default and modified) for a given clinical condition. Participants completed a National Aeronautics and Space Administration-Task Load Index questionnaire and rated the demand experienced on a 20-point visual analog scale with low and high ratings. A correlational analysis was performed to assess the relationships between the perceived workload score, alarm response rate, and care provider experience.ResultsParticipants experienced lower workloads when the clinical alarm threshold limits were modified according to patients’ clinical conditions. The workload index was higher for the default alarm setting (57.60 [SD 2.59]) than for the modified alarm setting (52.39 [SD 2.29]), with a statistically significant difference of 5.21 (95% CI 3.38-7.04), t28=5.838, P<.05. Significant correlations were found between the workload index and alarm response rate. There was a strong negative correlation between alarm response rate and perceived workload, ρ28=−.54, P<.001 with workload explaining 29% of the variation in alarm response rate. There was a moderate negative correlation between the experience reported during patient care and the perceived workload, ρ28=−.49, P<.05.ConclusionsThe perceived workload index was comparatively lower with alarm settings modified for individual patient care than in an unmodified default clinical alarm setting. These findings demonstrate that the modification of clinical alarm limits positively affects the number of alarms accurately addressed, care providers’ experience, and overall satisfaction. The findings support the removal of nonessential alarms based on patient conditions, which can help care providers address the remaining alarms accurately and provide better patient care.

Temperature-triggered sensitive resistance transition of graphene oxide wide-ribbons wrapped sponge for fire ultrafast detecting and early warning.

Fire prevention and safety of combustible materials is a global challenge. To reduce their high fire risk, traditional smoke detectors are widely used indoor via detecting smoke product after combustion; however, they usually show a long response time and limitation for outdoor use. Herein, we report a temperature-induced electrical resistance transition of graphene oxide wide-ribbon (GOWR) wrapped sponges to reliably monitor fire safety of the combustible materials. Novel rectangle-like GOWR sheets are synthesized from unzipping carbon nanofibers and used to fabricate GOWR wrapped melamine formaldehyde sponges with multi-functionalities, e.g. lightweight, good hydrophobicity, reversible compressibility, excellent acidic/alkaline tolerance and flame resistance. The GOWR sheets on the sponge skeleton can be in-situ thermally reduced once encountering a flame attack or abnormal high temperature, inducing a distinct transition in electrical resistance. Consequently, an ultrafast alarm response of ∼2 s to flame attack is triggered, and rapid fire early warning signals to abnormal high temperatures, e.g. ∼33 s at 300 °C, are achieved below ignition temperature of most combustible materials. This method drives substantial motivation and opportunity to develop advanced fire detection and early warning sensors for reducing the high fire risk of various combustible materials in outdoor applications.

Assessing impacts of offshore pile driving noise on the antipredator defense and shoaling behaviors of squid (Doryteuthis pealeii)

Impulsive pile driving occurs during construction of marine platforms, producing intense sounds that may adversely impact animals’ physiology and behavior. Little is known regarding how this noise impacts sound-sensitive invertebrates such as squid, which is surprising given squids’ relative abundance and key ecological role. We quantified how a commercially important squid species (Doryteuthis pealeii) behaviorally responded (in a controlled environment) to pile driving sounds recorded from an offshore windfarm installation within this species' habitat. Both sound pressure and particle motion components of the sound were quantified. Fifteen-minute portions of the recordings were played to individual squid. Body pattern changes, inking, jetting, and startle responses were observed during sound exposure and all squid exhibited at least one response. These responses occurred primarily during the first few noise impulses and diminished quickly over the first minute of playback, indicating short-term habituation. Responses returned after a 24-hr rest, indicating re-sensitization. Separate experiments investigated changes in shoaling behaviors by quantifying shoal cohesion and polarity in groups of squid during ten-minute noise exposures. Rapid habituation of antipredator alarm responses and changes in shoaling dynamics may alter squids’ susceptibility to predation. Noise exposure may also disrupt normal intraspecific communication and ecologically relevant behavioral responses to sounds.Impulsive pile driving occurs during construction of marine platforms, producing intense sounds that may adversely impact animals’ physiology and behavior. Little is known regarding how this noise impacts sound-sensitive invertebrates such as squid, which is surprising given squids’ relative abundance and key ecological role. We quantified how a commercially important squid species (Doryteuthis pealeii) behaviorally responded (in a controlled environment) to pile driving sounds recorded from an offshore windfarm installation within this species' habitat. Both sound pressure and particle motion components of the sound were quantified. Fifteen-minute portions of the recordings were played to individual squid. Body pattern changes, inking, jetting, and startle responses were observed during sound exposure and all squid exhibited at least one response. These responses occurred primarily during the first few noise impulses and diminished quickly over the first minute of playback, indicating short-term habituat...

Novel sonification and haptic displays of physiologic variables to improve patient safety

Auditory medical alarms in healthcare are uninformative, poorly localizable, have a low positive predictive value, and are set at thresholds forcing practitioners to be reactive instead of proactive. Sonifying patient physiology as it transitions from normal to abnormal will allow practitioners to respond before the patient status devolves into an emergency. Multimodal interactions have the potential to enhance future sonification tools by reducing alarm fatigue—the addition of haptic cuing to novel physiologic sonification may improve patient safety. To increase the overall efficiency of alarm design in healthcare, we propose reducing alarm fatigue by integrating multisensory streams. We present an experiment that characterizes how the integration of tactile and auditory signals affects the speed and accuracy of alarm responses. Participants received multisensory auditory and haptic input while performing a task designed to tax attentional resources mimicking working in the ICU. Our results indicate there is a trend towards increased perception of change of physiologic variables with concordant haptic stimuli and participants are significantly better at determining the direction of change versus the physiologic variable of change. Future directions include simplification of the sonification schemata and increasing information complexity in the haptic modality to utilize multisensory integration.

Comparative chemical analysis of army ant mandibular gland volatiles (Formicidae: Dorylinae).

Army ants are keystone species in many tropical ecosystems. Yet, little is known about the chemical compounds involved in army ant communication. In the present study, we analyzed the volatile mandibular gland secretions—triggers of ant alarm responses—of six Neotropical army ant species of the genus Eciton (outgroup: Nomamyrmex esenbeckii). Using solid-phase microextraction, we identified 12 chemical compounds, primarily ketones with associated alcohols, one ester and skatole. Most compounds were shared among species, but their relative composition was significantly different. By comparing chemical distances of mandibular gland secretions to species divergence times, we showed that the secretions’ compositions are not strictly determined by phylogeny. By identifying chemical bouquets of seven army ant species, our study provides a valuable comparative resource for future studies aiming to unveil the chemicals’ precise role in army ant alarm communication.

HPLC Separation of 2-Ethyl-5(6)-methylpyrazine and Its Electroantennogram and Alarm Activities on Fire Ants (Solenopsis invicta Buren).

2-Ethyl-3,6-dimethylpyrazine (EDMP) was an alarm pheromone component isolated from the mandibular gland of the red imported fire ant, Solenopsis invicta Buren. Several pyrazine analogues have been previously found to elicit significant alarm responses in S. invicta workers. This study aimed to separate the commercially available 2-ethyl-5(6)-methylpyrazine (EMP), i.e., a mixture of 2-ethyl-6-methylpyrazine (2E6MP) and 2-ethyl-5-methylpyrazine (2E5MP), and to examine both electroantennogram (EAG) and behavioral responses of S. invicta workers to EMP and the purified isomers. HPLC separations were achieved using a polysaccharide chiral stationary phase (Chiralpak AD-H) column with both mobile phases: Cyclohexane/isopropanol, and hexane/isopropanol. A ratio of 99:1 was selected for the separation of EMP at semipreparative level. The structures of the isomers obtained through the cyclohexane/isopropanol mobile phase were confirmed by detailed analyses of 2D-HSQC- and -HMBC-NMR data. The two isomers showed differential methine C–H correlations evidenced by 2D-HMBC-NMR spectra. The two concentrated fractions obtained through hexane/isopropanol mobile phase were subjected to EAG test and behavioral bioassay on S. invicta workers. The two HPLC−purified isomers, 2E6MP and 2E5MP, and their mixture (1:1) at same dose elicited similar EAG and alarm responses, indicating that these two isomers are equally active. The 2D-NMR−spectroscopic characterization, and electrophysiological and alarm activities of 2E6MP and 2E5MP were reported here for the first time.

Multiple adaptive and non-adaptive processes determine responsiveness to heterospecific alarm calls in African savannah herbivores.

Heterospecific alarm calls may provide crucial survival benefits shaping animal behaviour. Multispecies studies can disentangle the relative importance of the various processes determining these benefits, but previous studies have included too few species for alternative hypotheses to be tested quantitatively in a comprehensive analysis. In a community-wide study of African savannah herbivores, we here, for the first time to our knowledge, partition alarm responses according to distinct aspects of the signaller–receiver relationship and thereby uncover the impact of several concurrent adaptive and non-adaptive processes. Stronger responses were found to callers who were vulnerable to similar predators and who were more consistent in denoting the presence of predators of the receiver. Moreover, alarm calls resembling those of conspecifics elicited stronger responses, pointing to sensory constraints, and increased responsiveness to more abundant callers indicated a role of learning. Finally, responses were stronger in risky environments. Our findings suggest that mammals can respond adaptively to variation in the information provided by heterospecific callers but within the constraints imposed by a sensory bias towards conspecific calls and reduced learning of less familiar calls. The study thereby provides new insights central to understanding the ecological consequences of interspecific communication networks in natural communities.

Sensilla Morphology and Complex Expression Pattern of Odorant Binding Proteins in the Vetch Aphid Megoura viciae (Hemiptera: Aphididae).

Chemoreception in insects is mediated by several components interacting at different levels and including odorant-binding proteins (OBPs). Although recent studies demonstrate that the function of OBPs cannot be restricted to an exclusively olfactory role, and that OBPs have been found also in organs generally not related to chemoreception, their feature of binding molecules remains undisputed. Studying the vetch aphid Megoura viciae (Buckton), we used a transcriptomic approach to identify ten OBPs in the antennae and we examined the ultrastructural morphology of sensilla and their distribution on the antennae, legs, mouthparts and cauda of wingless and winged adults by scanning electron microscopy (SEM). Three types of sensilla, trichoid, coeloconic and placoid, differently localized and distributed on antennae, mouthparts, legs and cauda, were described. The expression analysis of the ten OBPs was performed by RT-qPCR in the antennae and other body parts of the wingless adults and at different developmental stages and morphs. Five of the ten OBPs (MvicOBP1, MvicOBP3, MvicOBP6, MvicOBP7, and MvicOBP8), whose antibodies were already available, were selected for experiments of whole-mount immunolocalization on antennae, mouthparts, cornicles and cauda of adult aphids. Most of the ten OBPs were more expressed in antennae than in other body parts; MvicOBP1, MvicOBP3, MvicOBP6, MvicOBP7 were also immunolocalized in the sensilla on the antennae, suggesting a possible involvement of these proteins in chemoreception. MvicOBP6, MvicOBP7, MvicOBP8, MvicOBP9 were highly expressed in the heads and three of them (MvicOBP6, MvicOBP7, MvicOBP8) were immunolocalized in the sensilla on the mouthparts, supporting the hypothesis that also mouthparts may be involved in chemoreception. MvicOBP2, MvicOBP3, MvicOBP5, MvicOBP8 were highly expressed in the cornicles-cauda and two of them (MvicOBP3, MvicOBP8) were immunolocalized in cornicles and in cauda, suggesting a possible new function not related to chemoreception. Moreover, the response of M. viciae to different components of the alarm pheromone was assessed by behavioral assays on wingless adult morph; (-)-α-pinene and (+)-limonene were found to be the components mainly eliciting an alarm response. Taken together, our results represent a road map for subsequent in-depth analyses of the OBPs involved in several physiological functions in M. viciae, including chemoreception.

Stop the Noise! A Framework for Improving Alarm Response Time on a Pediatric Inpatient Unit

Alarm fatigue is an ongoing problem that has received increasing attention as a patient safety concern. Recently the Joint Commission issued a Sentinel Event Alert that named frequent exposure to nonactionable alarms “the most common contributing factor to alarm related sentinel events.” This quality problem affects all institutions, but pediatrics in particular. Not only are high number of children placed on monitors, but their differing vital signs by age and smaller body size can create a high volume of alarms needing assessment. QI initiatives tailored to this population are needed to address this workforce and safety concern. The primary aim …

Stop the Noise! A Framework for Improving Alarm Response Time on a Pediatric Inpatient Unit

Stop the Noise! A Framework for Improving Alarm Response Time on a Pediatric Inpatient Unit

Diagnostic Utility of Intraoperative Neurophysiological Monitoring for Intramedullary Spinal Cord Tumors: Systematic Review and Meta-Analysis.

Systematic review and meta-analysis. The aim of this study was to systematically evaluate the diagnostic utility of intraoperative neurophysiological monitoring (IONM) for detecting postoperative injury in resection of intramedullary spinal cord tumors (IMSCT). Surgical management of IMSCT can involve key neurological and vascular structures. IONM aims to assess the functional integrity of susceptible elements in real time. The diagnostic value of IONM for ISMCT has not been systematically evaluated. We performed a systematic review of the PubMed and MEDLINE databases for studies investigating the use of IONM for IMSCT and conducted a meta-analysis of diagnostic capability. Our search produced 257 citations. After application of exclusion criteria, 21 studies remained, 10 American Academy of Neurology grade III and 11 American Academy of Neurology grade IV. We found that a strong pooled mean sensitivity of 90% [95% confidence interval (CI), 84-94] and a weaker pooled mean specificity of 82% (95% CI, 70-90) for motor-evoked potential (MEP) recording changes. Somatosensory-evoked potential (SSEP) recording changes yielded pooled sensitivity of 85% (95% CI, 75-91) and pooled specificity of 72% (95% CI, 57-83). The pooled diagnostic odds ratio for MEP was 55.7 (95% CI, 26.3-119.1) and 14.3 (95% CI, 5.47-37.3) for SSEP. Bivariate analysis yielded summary receiver operative characteristic curves with area under the curve of 91.8% for MEPs and 86.3% for SSEPs. MEPs and SSEPs appear to be more sensitive than specific for detection of postoperative injury. Patients with perioperative neurological deficits are 56 times more likely to have had changes in MEPs during the procedure. We observed considerable variability in alarm criteria and interventions in response to IONM changes, indicating the need for prospective studies capable of defining standardized alarm criteria and responses.

Temporal Response of Foragers and Guards of Two Stingless Bee Species to Cephalic Compounds of the Robber Bee Lestrimelitta niitkib (Ayala) (Hymenoptera, Apidae).

Lestrimelitta spp. are stingless bees that steal food and nesting materials from other highly social bees to survive. Though most of their victim species respond, either aggressively or submissively, to cephalic components of Lestrimelitta, little is known about if such response changes at some point during extended periods of exposure. Moreover, potential synergistic effects due to a mixture of victim's alarm/defense pheromones and Lestrimelitta mandibular pheromones, like in an actual attack, have not been examined so far. In this paper, we investigated the response of two species of non-robber stingless bees, Scaptotrigona mexicana (Guérin) and Tetragonisca angustula (Latreille), to (a) cephalic compounds from crushed heads of nestmates, (b) cephalic compounds of Lestrimelitta niitkib (Ayala), and (c) a mixture of (a) and (b). We found that even though T. angustula did not react to nestmates' crushed head, its response towards L. niitkib cephalic compounds was stronger and lasted longer than that of S. mexicana. Interestingly, the addition of crushed heads of the non-robber species to L. niitkib crushed heads caused no significant increase in the alarm response of both species. It may be that the absence of an alarm pheromone in T. angustula made this species more receptive to extraneous odors, which is not the case for S. mexicana; however, more species must be studied to elucidate any pattern regarding the absence/presence of alarm pheromones and the corresponding response to intruders' pheromones.

Colony-level non-associative plasticity of alarm responses in the stingless honey bee, Tetragonisca angustula.

In ants, bees, and other social Hymenoptera alarm pheromones are widely employed to coordinate colony nest defense. In that context, alarm pheromones elicit innate species-specific defensive behaviors. Therefore, in terms of classical conditioning, an alarm pheromone could act as an unconditioned stimulus (US). Here we test this hypothesis by establishing whether repeated exposure to alarm pheromone in different testing contexts modifies the alarm response. We evaluate colony level alarm responses in the stingless bee, Tetragonisca angustula, which has a morphologically distinct guard caste. First, we describe the overall topology of defense behaviors in the presence of an alarm pheromone. Second, we show that repeated, regular exposure to synthetic alarm pheromone reduces different components of the alarm response, and memory of that exposure decays over time. This observed decrease followed by recovery occurs over different time frames and is consistent with behavioral habituation. We further tested whether the alarm pheromone can act as a US to classically condition guards to modify their defense behaviors in the presence of a novel (conditioned) stimulus (CS). We found no consistent changes in the response to the CS. Our study demonstrates the possibility that colony-level alarm responses can be adaptively modified by experience in response to changing environmental threats. Further studies are now needed to reveal the extent of these habituation-like responses in regard to other pheromones, the potential mechanisms that underlie this phenomenon, and the range of adaptive contexts in which they function at the colony level.

Chemical Sensor Systems and Associated Algorithms for Fire Detection: A Review.

Indoor fire detection using gas chemical sensing has been a subject of investigation since the early nineties. This approach leverages the fact that, for certain types of fire, chemical volatiles appear before smoke particles do. Hence, systems based on chemical sensing can provide faster fire alarm responses than conventional smoke-based fire detectors. Moreover, since it is known that most casualties in fires are produced from toxic emissions rather than actual burns, gas-based fire detection could provide an additional level of safety to building occupants. In this line, since the 2000s, electrochemical cells for carbon monoxide sensing have been incorporated into fire detectors. Even systems relying exclusively on gas sensors have been explored as fire detectors. However, gas sensors respond to a large variety of volatiles beyond combustion products. As a result, chemical-based fire detectors require multivariate data processing techniques to ensure high sensitivity to fires and false alarm immunity. In this paper, we the survey toxic emissions produced in fires and defined standards for fire detection systems. We also review the state of the art of chemical sensor systems for fire detection and the associated signal and data processing algorithms. We also examine the experimental protocols used for the validation of the different approaches, as the complexity of the test measurements also impacts on reported sensitivity and specificity measures. All in all, further research and extensive test under different fire and nuisance scenarios are still required before gas-based fire detectors penetrate largely into the market. Nevertheless, the use of dynamic features and multivariate models that exploit sensor correlations seems imperative.

Extending the analysis of zebrafish behavioral endophenotypes for modeling psychiatric disorders: Fear conditioning to conspecific alarm response

Anxiety, trauma- and stressor-related disorders are severe psychiatric conditions that affect human population worldwide. Given their genetic tractability, evolutionarily conserved neurotransmitter systems, and extensive behavioral repertoire, zebrafish have become an emergent model organism in translational neuroscience. Here, we investigate whether a single exposure to conspecific alarm substance (CAS) produces fear conditioning in zebrafish using a conditioned place aversion (CPA) paradigm, as well as the persistence of aversive responses at different time intervals. While CAS elicited freezing and erratic movements at conditioning phase, zebrafish showed a robust avoidance for the CAS-paired compartment and increased risk assessment up to 7 days postconditioning. Additionally, we observed the existence of two behavioral phenotypes (high- and low-avoider fish) that present different fear-like responses at conditioning phase and evasion of the conditioning side at postconditioning trials. Collectively, we show a prolonged conditioned place aversion in zebrafish after a single CAS conditioning session, reinforcing the use of fear conditioning protocols as valuable strategies for modeling psychiatric disorders-related phenotypes in zebrafish.

The sea urchin Diadema africanum uses low resolution vision to find shelter and deter enemies.

Many sea urchins can detect light on their body surface and some species are reported to possess image-resolving vision. Here, we measure the spatial resolution of vision in the long-spined sea urchin Diadema africanum, using two different visual responses: a taxis towards dark objects and an alarm response of spine-pointing towards looming stimuli. For the taxis response we used visual stimuli, which were isoluminant to the background, to discriminate spatial vision from phototaxis. Individual animals were placed in the centre of a cylindrical arena under bright down-welling light, with stimuli of varying angular width placed on the arena wall at alternating directions from the centre. We tracked the direction of movement of individual animals in relation to the stimuli to determine whether the animals oriented towards the stimulus. We found that D. africanum responds by taxis towards isoluminant stimuli with a spatial resolution in the range of 29-69 deg. This corresponds to a theoretical acceptance angle of 38-89 deg, assuming a contrast threshold of 10%. The visual acuity of the alarm response of D. africanum was tested by exposing animals to different sized dark looming and appearing stimuli on a monitor. We found that D. africanum displays a spine-pointing response to appearing black circles of 13-25 deg angular width, corresponding to an acceptance angle of 60-116 deg, assuming the same contrast threshold as above.