Nocturnal Behavior Research Articles

A novel binary greater cane rat algorithm for feature selection

There is a surge in the application of population-based metaheuristic algorithms to find the optimal feature subset from high dimensional datasets. Many of these approaches cannot properly scale especially as they are expected to maintain two opposing goals: maximizing the accuracy of classification while at the same time minimizing the number of feature subsets selected. In this study, a novel binary greater cane rat algorithm (GCRA), inspired by intelligent nocturnal behavior of the GCR which significantly affects their foraging and mating activities. They leave trails to food sources, shelters, and water as they forage, and this information is kept by the dominant. Also, they split into male and female groups during mating season is during abundant food supply and near water source. This information is modeled into and effective method for selecting the optimal feature subset from high-dimensional datasets using two different approaches. Firstly, five variants of binary GCRA are developed using one each from the family of S-shaped, V-shaped, U-shaped, Z-shaped, and quadratic transfer functions to binarize the GCRA. Secondly, the threshold which maps a variable to 0 or 1 is used to develop a variant of GCRA. The performance of the six (6) variants were evaluated using 12 datasets with different dimensionalities. The experimental results show the stability of all the proposed methods as they generally performed competitively. However, the threshold version known as BGCRA showed better performance in yielding the highest accuracy of classification on 9 of the 12 datasets utilized in the study and performed second in selecting the least number of important feature sets. It also showed superiority over other variants in yielding the least average fitness values in 11 of 12 (91.6%) of the datasets used. Hence, the BGCRA was utilized for further comparative analysis against 5 other popular feature selection (FS) algorithms with outstanding performance in terms of producing the highest mean accuracy of classification on 91.6% (11 of 12) of the datasets, 100% least average fitness values, and 91.6% in selecting the least average number of significant features. The results were also validated by statistical tests which showed that the BGCRA is significantly superior compared to other methods.

Reducing scratching behavior in atopic dermatitis patients using the EMDR treatment protocol for urge: A pilot study.

Itch, and thereby the scratching behavior, is a common complaint in atopic dermatitis. Scratching damages the skin, which in turn worsens the itch. This itch-scratch cycle perpetuates the skin condition and has a major impact on the patient's quality of life. In addition to pharmacological treatment, psychological interventions show promising results in reducing scratching behavior. To investigate the effect of treatment according the EMDR treatment protocol for urge on scratching behavior of atopic dermatitis patients in a controlled study. This study applies a multiple baseline across subjects design. Six patients were randomly allocated to different baseline lengths and all of them started registration of scratching behavior at the same day, using a mobile phone application. Nocturnal scratching was registered by a smart watch application. The total study duration was 46 days and was equal for all patients. Treatment consisted of two sessions using the EMDR treatment protocol for urge. Furthermore, standardized measures were used to assess disease activity, quality of life, and self-control. The nonoverlap of all pairs effect size was calculated for the daily measure data. One patient dropped out. Visual inspection suggests that the scratching behavior decreased over time in all patients. Furthermore, a moderate effect size of the treatment is found. During the baseline phase, scratching behavior fluctuated considerably and showed a slight negative trend. Outcomes of disease activity decreased over time and patients' self-control and quality of life improved after treatment. Nocturnal scratching behavior did not change after the intervention. The results of the visual analysis of day time scratching behavior, disease activity, quality of life, and self-control seem promising. These findings pave the way for future research into the effect of the new intervention on other skin conditions suffering from scratching behavior, such as prurigo nodularis.

Seasonal, environmental and anthropogenic influences on nocturnal basking in turtles and crocodiles from North‐Eastern Australia

AbstractMany ectotherms bask in the sun as a behavioural mechanism to increase body temperature and facilitate metabolism, digestion or gamete production, among other functions. Such behaviours are common during the day, but some nocturnal species are also known to thermoregulate at night, in the absence of solar radiation, through shifts in body posture or microhabitat selection. Additionally, recent work has documented nocturnal basking in freshwater turtles in tropical Australia, though the purpose of the behaviour remains unknown. Here, we have built upon that work to test: 1. seasonal differences, 2. the influence of environmental factors and 3. the influence of anthropogenic development (e.g. river‐front houses) on nocturnal basking behaviour. We visually surveyed transects repeatedly at night on the Ross River, Townsville, QLD, Australia from March to November 2020 and documented nocturnal basking in both freshwater turtles (Emydura macquarii krefftii) and freshwater crocodiles (Crocodylus johnstoni). For both taxa, we found significantly more nocturnal basking activity during the hotter months. Likewise, water surface temperature significantly influenced nocturnal basking in both taxa, especially when water temperatures were both high and warmer than air temperatures. We propose that nocturnal basking provides a mechanism for thermoregulatory cooling when water temperatures are high (e.g. 30°C) and above‐preferred temperatures. After accounting for availability in basking habitat, both turtles and crocodiles basked more frequently on the undeveloped side of the river, suggesting avoidance of human activity or disturbance. This study is the first to document nocturnal basking activity temporally throughout the year as well as the first to identify the influences of environmental factors. Nocturnal thermoregulation has been documented in many reptiles, however, thermoregulatory cooling in tropical systems is less well‐known.

Sleep impairments in refugees diagnosed with post-traumatic stress disorder: a polysomnographic and self-report study

ABSTRACT Background: Post-traumatic stress disorder (PTSD) is the clinical manifestation of traumatic events and is associated with sleep disturbances. Sleep disturbances, if left untreated, may perpetuate or even worsen symptoms of PTSD. Previous studies of other PTSD populations show a higher incidence of sleep impairments and sleep disorders compared to healthy controls (HCs); however, this has never been investigated in trauma-affected refugees diagnosed with PTSD. Objectives: To examine subjective sleep quality, measure sleep architecture, and identify latent sleep disorders in refugees diagnosed with PTSD compared to HCs. Method: This comparative study included 20 trauma-affected refugees diagnosed with PTSD and 20 HC matched on age, sex, and body mass index. All participants completed self-report questionnaires assessing sleep quality, insomnia severity, and disturbing nocturnal behaviour, and all took part in a one-night polysomnography (PSG) assessment. Results: Patients reported significantly poorer subjective sleep quality, sleep latency, sleep duration, and sleep efficiency compared to HCs. Subjective reports on hours spent in bed were not significantly different between patients and HCs. Patients reported significantly higher nightmare frequency and severity compared to HCs. PSG measures showed that patients had significantly reduced sleep efficiency, more awakenings, and longer REM sleep latency, and spent more time awake, whereas there was no significant differences regarding total time in bed, total sleep time, or sleep latency. The prevalence of sleep disorders was equal between groups. Conclusions: The study identified significant impairments in several sleep domains, with a preponderance of disturbed regulation of sleep resulting in awakenings. These results indicate a need for more focus on hyperarousal and nightmares as key elements of disturbed sleep in PTSD. Furthermore, the study identified a discrepancy between subjective and objective measures concerning total sleep time, raising questions regarding the causes of ‘sleep state misperception’. Trial registration: ClinicalTrials.gov identifier: NCT03535636.. Trial registration: Sleep Impairments in Refugees Diagnosed with PTSD (PSG-PTSD). URL: https://clinicaltrials.gov/ct2/show/NCT03535636. ClinicalTrials.gov NCT03535636. Date of registration: 24/05/2018.

Alterations in Brain Neural Network and Stress System in Atopic Dermatitis: Novel Therapeutic Interventions.

Atopic dermatitis is a common chronic inflammatory skin disease, with most cases experiencing skin barrier dysfunction and enhanced allergen entry, accompanied by cytokine production which evokes predominantly type-2-skewed immune responses, itch, and scratching behavior. Although intense itch and excessive scratching behavior affect progression of skin lesions, it is unclear what causes them. Data suggest that scratching behavior stimulates brain dopaminergic reward and habit learning systems, strengthening habitual scratching behavior, while nocturnal scratching behavior presumably increases locus coeruleus-noradrenergic system activity, prompting sleep disturbances. At the early stage of atopic dermatitis, increased cortisol levels, due to hypothalamic-pituitary-adrenal axis overactivation caused by such system stimulation, can induce dorsolateral prefrontal cortex disturbance with reinforcement of habitual scratching behavior and may aggravate type-2-skewed immune responses in the skin. During the later phases, whereas blunted hypothalamic-pituitary-adrenal axis function and the shift of type-2-dominated to type-1-co-dominated inflammation are induced, noradrenergic system overactivation-associated dorsolateral prefrontal cortex disruption is ongoing and responsible for itch cognitive distortion to catastrophize about itch, which leads to a vicious spiral along with habitual scratching behavior and skin lesions. Data are presented in this review indicating that while skin immune system dysfunction initiates pathologic changes in atopic dermatitis, brain neural network and stress system alterations can promote the progression of this condition. It is also suggested that cognitive distortion contributes to pathology in atopic dermatitis as with some psychiatric disorders and chronic pain. The proposed mechanistic model could lead to development of novel medications for slowing or terminating the relentless progression of this disorder. SIGNIFICANCE STATEMENT: Although conventional pharmacological interventions focusing on skin homeostasis and itch occurrence significantly attenuate clinical signs in atopic dermatitis patients, achievement of 100% improvement is less than 40% in several double-blind, randomized, placebo-controlled trials. Our model predicts that itch cognitive distortion, due to dorsolateral prefrontal cortex disturbance, can significantly contribute to the progression of atopic dermatitis and that agents capable of improving brain neural network, stress system, and skin homeostasis may be effective as interventions in the treatment of this condition.

Sphenophorus levis Behavior Studies: Evaluating Insect Attractiveness or Repellency to One Insecticide Treatment and Assessing Nocturnal Insect Activity and Location Pattern

Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae). is a difficult to control pest in sugarcane that causes great damage to the subterranean part of the plant. Low insect control is the result of the pesticide application technology adopted but also a consequence of the lack of studies regarding the pest's behavior. This research aimed to examine the attractiveness and repellency of one labelled insecticide dose to S. levis adults and to evaluate the activity and location behavior of S. levis adults under hourly observations over 24 h. Repellency and attractiveness studies were conducted in free-choice tests with treated soil with an insecticide product composed of lambda-cyhalothrin + thiamethoxam active ingredients and untreated soil. Insect activity and location behavior studies were assessed by conducting hourly observations of S. levis adults in containers with soil and sugarcane plant. The results indicate that S. levis adults are not repelled nor attracted to soil treated with the labelled dose of lambda-cyhalothrin + thiamethoxam in sugarcane. Additionally, insects presented nocturnal behavior for most activities (walking, digging and mating) starting at 6:00 p.m. until 2:00 a.m. An average of 21% of insects were out of the soil at night while the majority, 79%, remained inside the soil. During the day, most insects, 95%, remained hidden in the soil. Exposed insects were primarily located on the soil surface. According to these results, nocturnal insecticide applications may improve S. levis adult control due to greater insect activity and exposure at night.

Temperament traits and glucocorticoid metabolites in tropical screech owl (Megascops choliba)

Animals constantly respond to stimuli from their surroundings, showing individual behavioral and endocrine differences upon perceived challenging and/or threatening stimuli. The temperament of 13 captive tropical screech owls (Megascops choliba) was defined by performing three challenge tests (novel space, taxidermist predator and trapping) to identify inter-individual differences and their possible relationship with the production of glucocorticoid metabolites (GCM). Feces samples of each bird were taken pre-and-post predator challenge to quantify GCM concentration by means of enzymatic immunoassay (EIA). The intensity of 13 adjectives selected to describe the owls' temperament was determined by three judges during behavioral testing. Only 3 adjectives (passive, vulnerable, and attentive) that showed strong inter-test and intra-individual correlation coefficients were considered. These adjectives were later grouped in a single dimension named “shyness”, enabling establishment of individual scores. The temperament of the owls showed correlation to post-predator challenge GCM levels (ρ = 0.79; p < 0.001). However, no significant differences were found in GCM levels before and after predator challenge. Our results both confirm that nocturnal behavior raptorial birds show positive relation between shy temper and adrenal response, and offer the non-invasive herein implemented methods for establishment of new hypotheses that will assess welfare of species kept under human care.

Feeding behaviour, locomotion rhythms and blood biochemistry of the neotropical red-tailcatfish (Phractocephalus hemioliopterus).

The study evaluated the feeding behaviour of Phractocephalus hemioliopterus through the animals' ability to adapt to the self-feeding system, their preferred feeding times and locomotor activity, as well as the blood biochemistry of juveniles fed in a light/dark cycle. The study was carried out through two experiments, the first of which contained two phases. In experiment 1 - phase I, 24 juveniles (35.28 ± 0.62 g) were distributed in eight 48 l tanks. The tanks were equipped with a self-feeding system and the experiment consisted of evaluating whether the animals were able to adapt to the self-feeding system, as well as evaluating the preferred feeding times and locomotor activity of these animals. A feeding challenge to the animals was introduced in phase II, based on the results of phase I. The results of the first phase evidenced a nocturnal feeding preference. Thus, the feeding challenge consisted of measuring whether the animal would feed during the day and how long it would take to adapt. When the animals consumed 100% of the amount of feed provided daily, phase II was ended. In experiment 2, 24 juveniles of P. hemioliopterus (182.00 ± 14.03 g) were distributed in eight 96 l tanks. This experiment consisted of two treatments with four repetitions, one with exclusive feeding during the middle of the light cycle and another with exclusive feeding in the middle of the dark cycle. At the end, blood samples were collected from the animals for blood biochemistry evaluations. In experiment 1 - phase I, the results showed that the fish adapted very well to the self-feeding system and had a strictly nocturnal feeding behaviour and locomotor rhythm. When they were submitted to the feeding challenge in phase II, the feed intake was stabilized from the 17th day onwards, proportionally to the nocturnal consumption observed in the first phase, thus demonstrating feeding plasticity. In experiment 2, the feeding times influenced the animals' biochemical parameters. Animals fed during the night had higher values of cholesterol and triglycerides than animals fed during the day. It is concluded that P. hemioliopterus has fast adaptability to a self-feeding system, with strictly nocturnal feeding and locomotor behaviours. However, it has feeding plasticity, adapting its behaviour according to food availability. Blood biochemical parameters are influenced by the light/dark feeding cycle.

285 Performance metrics of a soft wearable acousto-mechanic sensor for measuring itch in children and adults with atopic dermatitis

Abstract Pruritus is a prominent symptom in many systemic (e.g. renal failure, cholestasis) and dermatologic (e.g. urticaria, xerosis) conditions. Atopic dermatitis (AD) is characterized by the itch-scratch cycle, whereby the reflexive scratching leads to greater skin inflammation and worsens pruritus. Itch in AD has also been associated with certain stages of the circadian rhythm. Therefore, an objective method of measuring nocturnal scratching behaviour as a proxy for itch symptom severity would prove useful and insightful in the management of a patient’s AD. The purpose of this study is to validate the performance of a novel wearable sensor, the advanced acousto-mechanic (ADAM) device, in regard to the detection of nocturnal scratching behaviour in paediatric and adult populations with AD. The sensor is able to detect both the accelerometer data (movement in space) and acoustic data generated by finger and wrist movements in scratching. Performance metrics used to evaluate the sensor include sensitivity, specificity, positive predictive value (PPV) and F1 score (combination of precision and recall). The sensor’s performance was compared to video recordings, the gold standard for objectively measuring scratch. A total of 60 healthy adult subjects (22 males and 38 females) were recruited and asked to perform a series of scratching behaviours and non-scratching behaviours while wearing the ADAM sensor on their dorsal hand using a one-use adhesive in a controlled environment. The data were used to create a machine-learning algorithm for scratch detection and validation in both a paediatric and adult AD cohort. Individuals with mild-to-severe AD were recruited to monitor their nocturnal scratching behaviour in the home environment. An infrared camera was provided for each subject to record the patient’s scratching and compared it to data collected by the ADAM sensor worn on the subject’s dominant dorsal hand. Video recordings were graded for scratching activity by at least two graders; scratch was defined as lasting at least 4.5 s. The scratch algorithm’s classification of scratch and non-scratch was then compared to the gold standard video recording and generated performance metrics. The initial scratch algorithm yielded sensitivity of 88%, specificity of 88% and F1 score of 90% when cross-validated with data from 10 healthy adult subjects. When cross-validated with data from all 60 healthy adult subjects, the algorithm yielded a sensitivity of 92%, specificity of 98% and F1 score of 95%. A total of 11 paediatric AD subjects (1 : 3 male-to-female ratio, ages 10.5 ± 9.1) and 46 nights of data were collected in the home setting, yielding a total of 378.4 h of video. The scratch algorithm was able to detect scratching behaviour with sensitivity of 84%, specificity of 99% and F1 score of 83% in the paediatric cohort. In the adult cohort, a total of 11 adults with atopic dermatitis (two males and nine females, ages 29 ± 13) and 73 nights of data were collected, resulting in a total of 457.7 h of video. When the data was applied to the scratch algorithm, the algorithm yielded a sensitivity of 93%, specificity of 100% and F1 score of 91%. The use of a flexible wearable sensor on the dorsal hand for detection of nocturnal scratching behaviour in both paediatric and adult subjects with atopic dermatitis can provide valuable information regarding the degree of scratching and severity of pruritus the wearer is experiencing when compared to video recording. Its ability to serve as an accurate objective measure of itch may be helpful in drug development and can help serve as a tool to guide the clinical management of symptoms.

Biologging as an important tool to uncover behaviors of cryptic species: an analysis of giant armadillos (Priodontes maximus).

Advances in biologging have increased the understanding of how animals interact with their environment, especially for cryptic species. For example, giant armadillos (Priodontes maximus) are the largest extant species of armadillo but are rarely encountered due to their fossorial and nocturnal behavior. Through the analysis of speed, turning angles, and accelerometer activity counts, we estimated behavioral states, characterized activity budgets, and investigated the state-habitat associations exhibited by individuals monitored with GPS telemetry in the Brazilian Pantanal from 2019 to 2020. This methodology is proposed as a useful framework for the identification of priority habitat. Using the non-parametric Bayesian mixture model for movement (M3), we estimated four latent behavioral states that were named 'vigilance-excavation', 'local search', 'exploratory', and 'transit'. These states appeared to correspond with behavior near burrows or termite mounds, foraging, ranging, and rapid movements, respectively. The first and last hours of activity presented relatively high proportions of the vigilance-excavation state, while most of the activity period was dominated by local search and exploratory states. The vigilance-excavation state occurred more frequently in regions between forest and closed savannas, whereas local search was more likely in high proportions of closed savanna. Exploratory behavior probability increased in areas with high proportions of both forest and closed savanna. Our results establish a baseline for behavioral complexity, activity budgets, and habitat associations in a relatively pristine environment that can be used for future work to investigate anthropogenic impacts on giant armadillo behavior and fitness. The integration of accelerometer and GPS-derived movement data through our mixture model has the potential to become a powerful methodological approach for the conservation of other cryptic species.

Nocturnal activity and behaviour of the elusive bushy-tailed opossum (Glironia Venusta)

Abstract The bushy-tailed opossum (Glironia venusta) is a small arboreal marsupial found in the Amazon basin. G. venusta is rarely seen and has few published sightings throughout its range. Videos (N = 79) were obtained from arboreal camera traps located in the Las Piedras Amazon Center near the Las Piedras River (SE Peru) from April 2017 until November 2017. Our new records, the first for the Las Piedras River, demonstrate that the species is nocturnal with activity peaks at 3:00 h and 20:00 h in the hours of complete darkness. The abundance of camera trap footage of such a rarely observed species further demonstrates the effectiveness of arboreal camera trapping to conduct species assessments.

Nocturnal surveys of lined seahorses reveal increased densities and seasonal recruitment patterns.

Although the nighttime ecology of organisms remains understudied, nocturnal surveys play an integral part in assessing fish assemblages and the selective forces shaping them. Eleuthera (Bahamas) contains an unusual population of lined seahorses (Hippocampus erectus) in an anchialine lake, possessing morphological characteristics distinct from those found in the ocean. Population surveys for seahorses and their potential predators were conducted at midnight and midday during wet and dry seasons, with belt transects perpendicular to the shoreline that increased in depth away from shore. Nocturnal surveys uncovered seahorse densities 259% higher than daytime transects on average. Sex ratios were consistently male-biased, and the frequency of animals from different reproductive categories varied significantly by time of day, with gravid males observed around the clock but females and nongravid males observed more often at night. Spatial and seasonal recruitment was detected for the first time in this species, with an increase in juveniles detected in the shallow ends of transects during dry season surveys. Juvenile recruitment is poorly understood across syngnathid fishes, so the detection of early recruits at night has broad implications for this fish family. Seahorses from all reproductive categories were perched significantly higher in the water column during the night regardless of their depth or season. Predator densities followed a similar pattern with higher densities observed at night, indicating that elevated nocturnal perch height may be a response to predator presence. However, the selective agents driving these nocturnal behaviors have yet to be identified. Considering H.erectus is listed on the IUCN Red List as "Vulnerable," the increase in nocturnal population size and the detection of juveniles has crucial implications for understanding their ecology, recruitment, and conservation.

Using computer vision, image analysis and UAVs for the automatic recognition and counting of common cranes (Grus grus)

Long-term monitoring of wildlife numbers traditionally uses observers, which are frequently inefficient and inaccurate due to their variable experience/training, are costly and difficult to sustain over time. Furthermore, there are other inhibiting factors for wildlife counting, such as: inhabiting inaccessible areas, fear of humans, and nocturnal behavior. There is a need to develop new technologies that will automatically identify and count wild animals in order to determine the appropriate management protocol. In this study, an advanced and accurate method for automatically calculating the number of cranes (Grus grus), using thermal cameras at night and visible light (RGB) cameras during the day onboard unmanned aerial vehicles (UAVs), based on image analysis and computer vision, was developed. The cranes congregate at night in a large communal roost, making it possible to count the birds while they are relatively static and all together. Each bird was counted individually by creating a standardized tool to determine population numbers for management, using image analysis and automatic processing. A dedicated algorithm was developed that aimed to identify the cranes based on their spectral characteristics (typical temperature, shape, size) and to effectively separate the cranes from the typical background. The automatic segmentation and counting of roosting common cranes using UAV nighttime thermal images had an Overall Accuracy (OA) of 91.47%, User's Accuracy (UA) of 99.68%, and Producer's Accuracy (PA) of 91.74%. The computer vision and machine learning algorithm based on the YOLO v3 platform of daytime RGB UAV images of common cranes at the feeding station yielded an overall loss accuracy level of 2.25%, with a mean square error of 1.87, OA of 94.51%, UA of 99.91%, PA of 94.59%. These results are highly encouraging, and although the algorithms were developed for the purpose of counting cranes, they could be adapted for other counting purposes for wildlife management.

Monitoring of the habitat usage of Tembadau (Bos javanicus lowi) around salt lick in a forest plantation of Sabah, Malaysia

Abstract. Enn HS, Musta B, Sarjadi MS, Maid M, Muning M, Kodoh J, Goh C, Jonalius M, Sompud J. 2022. Monitoring of the habitat usage of Tembadau (Bos javanicus lowi) around salt lick in a forest plantation of Sabah, Malaysia. Biodiversitas 23: 6062-6069. Tembadau (Bos javanicus lowi) is a wild cattle endemic to Borneo Island, especially in Sabah, Malaysia. Their population is declining due to habitat loss and illegal hunting. Previous researchers have reported that hunting pressure and forest fragmentation due to the conversion of natural forests into oil palm plantations are driving the species into the looming extinction of this species. Tembadau is well known for using the salt lick in its habitat. Salt licks are rich in minerals, or feeding sites are important as critical temporal use for wildlife, including Tembadau. The lack of data on the ecological behavior of Tembadau in salt lick areas caused difficulties in monitoring their population in the forest. It may undermine their conservation, especially in the forest plantations. The habitat usage of the Tembadau in this study was expressed in the detection rate and activity pattern. This study aimed to compare Tembadau’s detection rate at salt and non-salt lick areas in a forest plantation situated at the Segaliud Lokan Forest Reserve, Sandakan, Sabah. The activity pattern of Tembadau between a salt lick and non-salt lick areas was also determined. A camera trap survey was carried out from 2 November 2019 to 6 September 2020 to collect the presence, absence and activity pattern of Tembadau. The results show that the detection rate of Tembadau was higher in salt licks, especially salt lick C59SL (n: 171, U: 3187.5, p: 0.003). Tembadau at the salt licks expressed all diurnal, nocturnal and crepuscular behavior but was primarily active at night (n: 12, 43% of nocturnal behavior). Salt licks are beneficial for wildlife to provide the essential elements of intake, health and reproductive success. These findings are helpful information for the monitoring and further conservation work for the species, especially in forest plantation areas. It also provides essential baseline data for lawmakers to make policies for the total protection of salt licks in forest plantations.

Monitoring abnormal nocturnal behaviour in the homes of patients living with dementia.

People living with dementia (PLWD) often exhibit marked sleep disturbances. These cause substantial care challenges and may be causally related to dementia progression. Collecting ecologically valid data on sleep disturbance in naturalistic settings has been difficult. As a result, sleep assessments in PLWD are generally limited to short studies in sleep laboratories or data collection from wearables, where compliance is problematic. Here, we demonstrate how passive internet of things (IoT) sensors can be used to monitor the effects of dementia on nocturnal behaviour and physiology. Using the Withings under-mattress pressure sensor, we validated bed occupancy and physiological measures in 35 older adults tested both at home and in the laboratory. We then examined data collected between 2019 and 2021 from the general population (N=13,663) and from a cohort of PLWD taking part in the UK DRI study of home monitoring for PLWD (N=46). More than 4 million unique bed mat observations were analysed. Arise time across all subjects was negatively correlated with time to bed (Fig.1a, r(13,617) =-0.5, p<.0001). Bed occupancy increased with age, but PLWD spent more time in bed than age-matched controls (Fig.1b) and had more nocturnal awakenings (Fig.1c). Explainable gradient boosting machine learning was successfully used to classify data from individual nights (PLWD vs. general population). PLWD probability was related to specific changes, such as increased awakenings, high or low time spent in bed, high heart rate and low breathing rate (Fig.2). We also explored variations in night-time behaviour and physiology over time for individual PLWD (Fig.3a). High within-subject variability was present, which related to disease progression, intercurrent illness and changes in medication. Data from each night was transformed into a risk score for each metric (Fig.3b) and a compound risk score. These quantify the risk of abnormal night-time behaviour and physiology produced by dementia (Fig.3c) and reflect clinically relevant changes in PLWD. Taken together our work demonstrates how digital biomarkers collected passively using under mattress technology can be used to automatically monitor the nocturnal effects of dementia across large populations. The approach is also potentially applicable for preclinical screening and the evaluation of treatments effects.

Monitoring abnormal nocturnal behaviour in the homes of patients living with dementia ¶

AbstractBackgroundPeople living with dementia (PLWD) often exhibit marked sleep disturbances. These cause substantial care challenges and may be causally related to dementia progression. Collecting ecologically valid data on sleep disturbance in naturalistic settings has been difficult. As a result, sleep assessments in PLWD are generally limited to short studies in sleep laboratories or data collection from wearables, where compliance is problematic. Here, we demonstrate how passive internet of things (IoT) sensors can be used to monitor the effects of dementia on nocturnal behaviour and physiology.MethodUsing the Withings under‐mattress pressure sensor, we validated bed occupancy and physiological measures in 35 older adults tested both at home and in the laboratory. We then examined data collected between 2019 and 2021 from the general population (N=13,663) and from a cohort of PLWD taking part in the UK DRI study of home monitoring for PLWD (N=46). More than 4 million unique bed mat observations were analysed.ResultArise time across all subjects was negatively correlated with time to bed (Fig.1a, r(13,617)=‐0.5, p&lt;.0001). Bed occupancy increased with age, but PLWD spent more time in bed than age‐matched controls (Fig.1b) and had more nocturnal awakenings (Fig.1c). Explainable gradient boosting machine learning was successfully used to classify data from individual nights (PLWD vs. general population). PLWD probability was related to specific changes, such as increased awakenings, high or low time spent in bed, high heart rate and low breathing rate (Fig.2). We also explored variations in night‐time behaviour and physiology over time for individual PLWD (Fig.3a). High within‐subject variability was present, which related to disease progression, intercurrent illness and changes in medication. Data from each night was transformed into a risk score for each metric (Fig.3b) and a compound risk score. These quantify the risk of abnormal night‐time behaviour and physiology produced by dementia (Fig.3c) and reflect clinically relevant changes in PLWD.ConclusionTaken together our work demonstrates how digital biomarkers collected passively using under mattress technology can be used to automatically monitor the nocturnal effects of dementia across large populations. The approach is also potentially applicable for preclinical screening and the evaluation of treatments effects.

Differential Diagnosis of Complex Nocturnal Behaviors

Differential Diagnosis of Complex Nocturnal Behaviors

Using camera trap bycatch data to assess habitat use and the influence of human activity on African elephants (Loxodonta africana) in Kasungu National Park, Malawi

African elephants (Loxodonta africana) are increasingly exposed to high levels of human disturbance and are threatened by poaching and human–elephant conflict. As anthropogenic pressures continue to increase, both inside and outside protected areas, understanding elephant behavioural responses to human activity is required for future conservation management. Here, we use bycatch data from camera trap surveys to provide inferences on elephant habitat use and temporal activity in Kasungu National Park (KNP), Malawi. The KNP elephant population has declined by ~ 95% since the late 1970s, primarily because of intensive poaching, and information on elephant ecology and behaviour can assist in the species’ recovery. Using occupancy modelling, we show that proximity to water is the primary driver of elephant habitat use in KNP, with sites closer to water having a positive effect on elephant site use. Our occupancy results suggest that elephants do not avoid sites of higher human activity, while results from temporal activity models show that elephants avoid peak times of human activity and exhibit primarily nocturnal behaviour when using the KNP road network. As key park infrastructure is located near permanent water sources, elephant spatiotemporal behaviour may represent a trade-off between resource utilisation and anthropogenic-risk factors, with temporal partitioning used to reduce encounter rates. Increased law enforcement activity around permanent water sources could help to protect the KNP elephant population during the dry season. Our findings highlight that camera trap bycatch data can be a useful tool for the conservation management of threatened species beyond the initial scope of research.

What’s Black and White and Pink All Over? Lesser Flamingo Nocturnal Behaviour Captured by Remote Cameras

The study of animal behaviour is important for the development of husbandry and management practices for zoo-housed species. Yet, data are typically only collected during daylight hours, aligning with human work schedules rather than animal activity patterns. To remedy this, 24 h data collection is needed. This study investigated the behaviour of a captive flock of lesser flamingos to understand temporal changes in their time-activity patterns. Two remote camera traps were placed around the birds’ outdoor enclosure and one within the indoor house. Counts of birds visible within specific enclosure zones were recorded from photographic data. Behaviour was defined as active or inactive, and modified Spread of Participation Index (SPI) was used to calculate enclosure zone occupancy. Results indicated that lesser flamingos are active overnight, and to a similar amount as in the daytime. Proportions of birds observed as active were significantly higher at later times of the day (i.e., dusk) when compared to the number of active birds in the morning. Enclosure usage was diverse and indoor and outdoor zones could be used by different numbers of birds at different times of the day. Variation in enclosure usage may indicate the changing needs of the flamingos when housed indoors overnight and when they have night-time access to an outdoor enclosure. This research has identified the need for further research into the nocturnal behaviour and space use of lesser flamingos and suggests the need for 24 h research in captive birds, and other zoo-held species, especially when species are locked indoors or face behavioural restriction overnight due to biosecurity measures surrounding zoonoses outbreaks, e.g., Avian Influenza.

Latitudinal variations in the nocturnal behaviour of OI 630 nm airglow emissions and their relationship with equatorial electrodynamics

Airglow emissions from the thermosphere act as tracers of the behaviour of the upper atmosphere. OI 630 nm nightglow emissions that originate from an altitude of around 250 km in the thermosphere have been investigated using a large field-of-view ground-based optical spectrograph from Mt. Abu (24.6°N, 72.7°E, 19°N Mag.), a low-latitudinal location in India. The latitudinal movement of the crest of the equatorial ionization anomaly (EIA) in both poleward in the evening and equatorward in the night has been reported using the OI 630 nm nightglow emissions. The EIA crest is found to shift away from the equator after the sunset, which has been shown to be directly related to the strength of the twilighttime equatorial electrodynamics. Later in the night, after 20 LT, a clear movement of the crest back towards the equator, known as the reversal of EIA, has been observed. The speeds of the EIA reversals for forty nights in the years 2014 and 2015 have been obtained and are found to be in the range of 10–55 ms−1. As the global equatorial electric fields (E) are irrotational in nature (∇×E=0), simultaneous variations in the daytime electrojet strength over Jicamarca in the American sector have been compared with the nighttime reversal speeds of the EIA over the Indian sector, which show a remarkable relationship with each other. Thus, it is hereby demonstrated that the reversal in EIA as inferred by the OI 630 nm nightglow emissions in our measurements is due to the westward equatorial electric field. It is hereby proposed that the reversal speed derived from optical nightglow measurements can serve as a proxy for the determination of westward electric field over equator for that longitude sector.