Hours Of Darkness Research Articles

Modelling warfare between vampires and humans: who wins?

We adapt the Lanchester combat model to represent conflict between vampires and humans. It is assumed that vampires attack humans during the hours of darkness whilst humans attack vampires during the hours of light. The right-hand side of the differential equation model therefore depends upon the hour of the day. A key insight is that to answer the question ‘who wins’ it is not required to ‘stitch together’ the solutions to the differential equation over many days. Rather, the number of combatants surviving at the end of each day can be cast as a difference equation in terms of the numbers surviving at the end of the previous day. Two models are investigated and from the solutions the boundary delimiting the parameter regions of victory and defeat is found. Where appropriate we introduce discussion points, both mathematical and modelling. The mathematical techniques used include finding the eigenvalues and eigenvectors of a matrix, solving linear differential and discrete systems, and considering the physical meaning of the model and questioning its assumptions. Thus a variety of problem-solving skills are developed within the context of a model where students can question the underlying assumptions and propose, and investigate, models of their own.

The power of "it will be okay".

As caregivers for critically ill children and their families, there are moments when we find ourselves unsure of how best to offer support. The magnitude of the medical experience can cloud our communication with patients and their families. With years of counseling families through some of their most challenging and darkest hours, I aim to emphasize the profound impact of thoughtful and well-informed reassurance; how we can provide hope in hopeless situations.

Role of Melatonin in Viral, Bacterial and Parasitic Infections.

In all mammals, the circulating pool of MLTs is synthesized in the pineal gland during the night's darkness hours. Its main function is synchronizing the organism in the photoperiod. In contrast, extra-pineal MLT is synthesized in peripheral organs, does not follow any circadian rhythm or circulate, and plays a detoxifying and cytoprotective role. Circulating MLT may stimulate both innate and acquired immune responses through its circadian action and by activating high-affinity receptors on immunocompetent cells. Extra-pineal MLT may have antioxidant and anti-inflammatory effects that dampen the innate immune response. These two seemingly divergent roles may be considered to be two sides of the same coin. In fact, the integration of both circulating and extra-pineal MLT functions might generate a balanced and effective immune response against microbial pathogens. The studies described in this review investigated the effects of exogenous MLT in various models of infectious diseases using extremely different doses and treatment schedules. None of them evaluated the possibility of integrating the non-circadian anti-inflammatory effect with the circadian immunoenhancing action of MLT. As a consequence, in spite of the fact that most studies agree that MLT has a beneficial effect against infections, it seems difficult to draw any definite conclusion about its possible therapeutic use.

Spatial planning for dark hours in Sweden – conditions and proposal for action

The purpose of this study was to investigate how the absence of daylight are handled within spatial planning in Sweden, and to propose measures for action. The study includes a review of spatial planning documents, interviews with planning officers, and an overview of how outdoor lighting is included within the Swedish Planning and Building Act (PBL). The result shows that planning documents according to the PBL generally present few specific analyses and proposals linking to the design and the use of outdoor environments during dark hours, such as lighting. Instead, outdoor lighting is often managed within lighting masterplans, that lack a common methodology and a formal planning status. Possible consequences include that spatial planning provides limited support for how different public interests should be weighed against each other in a nocturnal context, and that citizens have little formal influence over strategic decisions on outdoor lighting. As a proposal, we suggest developing spatial planning for dark hours (‘nattstadsplanering’ in Swedish), that integrates the use, the design, and the outdoor lighting within the same planning process, using the PBL as a framework. The proposal includes clarification of lighting regulations, methodology development, and knowledge dissemination, which requires further research and investigations.

Coping with darkness: residents’ experience of reduced outdoor lighting in neighbourhoods

Despite ongoing replacement of old lighting installations with new energy-efficient light emitting diodes, the energy crisis has led to the implementation of strategies for reducing energy use for public outdoor lighting in neighbourhood environments. This would save money and reduce light pollution; however, the situations should be evaluated from the residents’ perspective. This paper presents a pilot study, which aimed to explore how residents experience and respond to reduced outdoor lighting in their neighbourhoods during dark hours, by applying the adapted Human-Environment Interaction model to understand the relation between outdoor lighting quality, neighbourhood quality and local independent mobility from the residents’ perspective. The pilot study was based on a short questionnaire (N =76, 29 males, 47 females, Mage = 66.66 years) and telephone or online interviews (N = 13, 5 males, 8 females, Mage = 68.08 years) with the residents living in the neighbourhood areas, in Southern Sweden, where strategies were employed for reducing the use of public outdoor lighting. Data were collected between February and March 2023. Overall, the results affirmed the important role of outdoor lighting quality in residents’ experience of neighbourhood environments and local independent mobility (i.e. the ability of residents to walk or move around on their own in their neighbourhood area), whereas the effect of reduced outdoor lighting was rather insignificant. The interviews further showed different experiences of the reduced outdoor lighting and how the residents coped with the lighting conditions by using solutions (i.e. headlamps, flashlights, bike lamps and reflectors), and that high-level perceived safety from crime in the neighbourhoods was found to play an important role in local independent mobility during dark hours. The adapted conceptual model allowed for the evaluation of outdoor lighting conditions considering both internal and external factors from the residents’ perspective, and could provide a basis for discussion about potential changes in public outdoor lighting.

Darker Cities due to the Energy Crisis and the need for context-specific urban lighting

Outdoor lighting has been dimmed or turned off in European municipalities due to the energy crisis. Dimming of outdoor lighting levels led to energy savings, advantages for biodiversity and less light pollution. But the dimming also triggers the basic human assumption that bright light is connected to safety and darkness is connected to fear. To discuss this basic assumption, human experience of dimmed lighting and perceived safety is explored through three case studies. One study explores human experiences of dimmed street lighting during energy crises, the second study investigates dimmed lighting levels around public transportation, and the third study is an example of a context-specific adaptation of street lighting in a residential area. The case studies reveal that dimmed lighting levels, minimized contrasts, and context-specific lighting can lead to an increased connectedness to the spatial and social urban context and an increased feeling of perceived safety. Thus, more light doesn’t always lead to more perceived safety. With a dimmed general lighting level, it is possible to introduce additional subtle lighting layers, structured in a lighting hierarchy to further enhance spatial and social qualities in outdoor contexts in the dark hours. in constructing both.

It is Not Too Late for Reconciliation Between Israel and Palestine, Even in the Darkest Hour

The conflict in Gaza and Israel that ignited on October 7, 2023 signals a catastrophic breakdown in the possibility of ethical dialogue in the region. The actions on both sides have revealed a dissolution of ethical restraints, with unimaginably cruel attacks on civilians, murder of children, destruction of health facilities, and denial of basic needs such as water, food, and shelter. There is a need both to understand the nature of the ethical singularity represented by this conflict and what, if any, options are available to allow the reconstruction of communication between the warring parties. This article seeks to address these tasks by analysing the conflict as inherently an ethical one, in the sense that it exposes a rupture in the fabric of communicative relationships that has evolved systematically out of the deep cultural structures from which all protagonists have emerged. Drawing on the work of Levinas, Habermas, Arendt, and others, and referring to the specific circumstances in the region, it examines the ethical sources of the crisis and tries to identify conditions for its resolution. The possibility of reconciliation—that is, of refiguring relationships to open up a space for dialogue to create pathways to heal the ruptures—is examined. The dark legacy of the Holocaust is identified as an abiding cultural vulnerability for both societies. It is concluded, however, that the rich history of partnerships and collaborations between Jews and Palestinians provides a robust infrastructure on the basis of which a sustainable peace might be built, providing a much-needed source of hope.

Biogenic Synthesis of Zinc Oxide Nanoparticles with Leaves and Cones Concentrate of Cupressus Arizonica and Assessment of Photocatalytic and Antibacterial Efficiency

Among the metal oxide nanoparticles, zinc oxide (ZnO) has recently been cited as the new material of the future due to its unique properties and wide application areas. In this study, we offer a simple technique for the production of extremely stable ZnO nanoparticles (CA-ZnO NPs) using the aqueous and ethyl alcohol (1/1, v/v) extract of Cupressus arizonica (CA, Blue cypress) leaves and cones and zinc acetate (Zn-Ac) salt. The structure of the produced CA-ZnO NPs was elucidated and nanoparticles were used as a photocatalyst for the removal of textile dyestuffs. The particle sizes of CA-ZnO NPs calcined at different temperatures (60ºC, 150ºC, and 400ºC) increased from 20 nm to 50 nm. Produced CA-ZnO NPs were used to investigate photocatalytic degradation of Basic Yellow (BY28), Basic Violet 39 (BV39), Methylene blue (MB), Brilliant Blue (BB3) and Basic Red 46 (BR46) in aqueous solution under UV- light and daylight irradiation. After stirring dye solutions containing CA-ZnO NP for one hour in darkness and 7 hours under UV- light, decolorization rates varied from 53% to 100%. Decolorization of the dyestuff molecules follows the pseudo first-order kinetics. Produced CA-ZnO NPs showed antibacterial efficiency against Escherichia coli and Staphylococcus aureus. CA-ZnO NPs formed zones ranging from 10 mm to 11 mm against gram+ and gram- bacteria. Green production of ZnO NPs utilizing Cupressus arizonica plant extract can replace chemical methods, and the resulting CA-ZnO NPs can be used in industries like water purification. This eco-friendly biogenic synthesis method is a new, inexpensive and useful technique suitable for large scale.

Night-time and strategies for regeneration in two medium-sized town centres

ABSTRACT This paper examines the regeneration proposals for two town centres in medium-sized towns in the north of England through the lens of urban design and nocturnal activities. Drawing from the field of night studies, it questions whether the hours of darkness have been included in the proposals and compares the extent to which findings and practical guidance from this emergent cross-disciplinary area of interest have been interpreted and incorporated. The paper argues that towns would benefit from addressing the specific characters and qualities of night time activities, including nightlife, in their policies and masterplans for revitalizing town centres.

Attuned visibility and the ambiguity of demanding public spaces in Copenhagen

ABSTRACT Based on ethnographic data and mapping exercises, this article explores North West Park in Copenhagen, Denmark and asks how lighting forms perceptions of urban space. The park was inaugurated in the late 2000s and has been praised for its bold landscape and lighting design. However, it was received in more ambiguous ways by users, explaining their experience of it in words such as “magical” and “kitsch.” This ambiguity highlights how current urban design may entail a reconfiguration of how visibility unfolds. Urban spaces have largely been lit to be seen. However, current trends in lighting design increasingly aim for spaces to be felt. Beyond visibility as the ability to see and be seen, we argue that the park design also evinces a more fundamental attuned visibility, conceptualized through the notion of ways of feeling. In a broader sense, we suggest that the increasingly atmosphere-oriented design of urban spaces facilitates a pressure to feel something. That is, this type of design is not solely functional but demands emotional responses – although undeterminable and open-ended. For the users, the atmospheric design raises questions about how lighting shapes urban life during dark hours in the field of tension between usage and architectural imaginations.

Controlling the photoperiod to raise the melatonin content of sheep milk. Photoperiod control and milk melatonin content

The aim of this study was to determine the effect of changing photoperiod time on the melatonin content of sheep milk. The animal material of the study consisted of 40 heads of Awassi sheep that gave birth in May 2021. The sheep were given roughage containing dry matter with 2.5% of their body weight and concentrated feed (2400-2600 kcal ME and 15-16% Crude Protein) as the 40% of their milk yield each day during the lactation period. The experimental ewes were randomly assigned into two groups with 20 animals in each. While the control group sheep were managed with normal day-time length during the lactation, the photoperiod restriction group were kept in the shed with 16 hours of darkness and 8 hours of daylight for 2 months. At the end of the two months, ewes of the both groups were managed in normal daylight until the end of lactation period. During the photoperiod restriction term, milk samples were taken at an interval of 15 days, while the milk composition was determined by a milk analyser and melatonin contents were determined by using LC MS/MS. In addition, lactation milk yield and lactation periods were estimated for all sheep. Statistical evaluation of the obtained data was done by using the SPSS package program. At the end of the study, the application of the extended dark period was found to be affected milk yield (P<0.05) as well as melatonin amount in the milk (P<0.001). Significantly higher melatonin amount was observed in the milk of sheep kept in a long-term dark environment compared to those exposed to normal photoperiod (11.1±7.24 pg/ml vs 6.1±4.55 pg/ml; P<0.001). As a result, it was determined that the prolonged dark period during a day increases the milk melatonin content. It can be also stated that the sheep's milk to be produced with this application could be a product that could take place in the functional food market.

Multiomics analyses of the effects of LED white light on the ripening of apricot fruits

IntroductionApricot (Prunus armeniaca L.) fruits are highly perishable and prone to quality deterioration during storage and transportation. ObjectivesTo investigate the effects of LED white light treatment on postharvest ripening of fruits using metabolomics, transcriptomics, and ATAC-Seq analysis. MethodsFruits were exposed to 5 μmol m−2 s−1 LED white light for 12 h followed by 12 h of darkness at 20 °C daily for 12 days. The effects of the treatments on the physiological and nutritional quality of the fruits were evaluated. These data were combined with transcriptomic, metabolomic, and ATAC-Seq data from fruits taken on 8 d of treatment to provide insight into the potential mechanism by which LED treatment delays ripening. ResultsLED treatment activated pathways involved in ascorbate and aldarate metabolism and flavonoid and phenylpropanoid biosynthesis. Specifically, LED treatment increased the expression of UDP-sugar pyrophosphorylase (USP), L-ascorbate peroxidase (AO), dihydroflavonol 4-reductase (DFR), chalcone synthase (CHS), and caffeoyl-CoA O-methyltransferase (CCOAOMT1), leading to the accumulation of caffeoyl quinic acid, epigallocatechin, and dihydroquercetin and the activation of anthocyanin biosynthesis. LED treatment also affected the expression of genes associated with plant hormone signal transduction, fruit texture and color transformation, and antioxidant activity. The notable genes affected by LED treatment included 1-aminocyclopropane-1-carboxylate synthase (ACS), 1-aminocyclopropane-1-carboxylate oxidase (ACO), hexokinase (HK), lipoxygenase (LOX), malate dehydrogenase (MDH), endoglucanase (CEL), various transcription factors (TCP, MYB, EFR), and peroxidase (POD). ATAC-Seq analysis further revealed that LED treatment primarily regulated phenylpropanoid biosynthesis. ConclusionThe results obtained in this study provide insights into the effects of LED light exposure on apricot fruits ripening. LEDs offer a promising approach for extending the shelf life of other fruits and vegetables.

Fatores que estimulam a eclosão de ovos de resistência e a sua contribuição para a composição das assembleias de cladóceros em lagoas temporárias tropicais

Abstract: Aim We aimed to verify the contribution of cladocerans’ resting eggs to the active communities of temporary lagoons and, through an experiment, identify which conditions induce high hatching rates. Methods Cladocera assemblages were sampled in four temporary lagoons in the Turvo River floodplain (20° 22’S and 49° 16’W), in the northwest region of São Paulo State, Brazil. Sediment samples were taken during the dry season from a depth of 5 cm, using a 4.5 cm diameter corer. Plankton samples were taken from the water column before and after the dry season. For the hatching test, two treatments were performed 1. Natural condition – without light and temperature control; 2. Controlled condition – with controlled photoperiod and temperature. Temperature, pH, conductivity, dissolved oxygen and hatching of resting eggs were monitored for two weeks. The influence of the parameters on hatching in both treatments was evaluated using Hierarchical Partition Analysis. Results Hatching of resting eggs was higher in the Controlled condition than in the Natural one. Thirty percent of species observed in the active community after flooding hatched in the laboratory test. Conductivity, pH, and dissolved oxygen were positively correlated to the hatching of some species, e.g., Ephemeroporus hybridus, Leydigiops ornata, Notoalona sculpta and Ilyocryptus spinifer. The first species to hatch were those living associated with macrophytes and at low depths. Conclusions Our results show that stable temperature and photoperiod with similar light and dark hours stimulate greater hatching of Cladocera resting eggs. Variables such as pH, conductivity and dissolved oxygen were also correlated with the hatching of some species. We observed that the first contributions to activating the community after drought came from hatching of species usually associated with macrophytes and low depth conditions.

Histomorphological Changes in the Ovary of African giant rat (Cricetomys gambianus, WATERHOUSE – 1840) subjected to Different light/dark cycles

The present study was undertaken to investigate the effect of photoperiod on the ovary of African giant rats (AGR), Cricetomys gambianus. A total of 15 captive African giant rats from the wild served as subjects. The rats were randomized into three photoperiodic treatment groups of five rats each. Groups I, II and III were the control (12 hours of darkness (12D), 12 hours of light (12L); total darkness (24D: 0L) and total light (0D: 24L), respectively. The rats were humanely euthanized, and ovaries collected at 4 weeks and 8 weeks of sacrifice for routine histological examination and histomorphometry. Cystic follicles were observed in the ovaries of AGR exposed to constant light. Again, continuous lighting exposure significantly increased (p < 0.05) the ovarian follicular diameter when compared with the control. In conclusion, the findings of this study indicate that continuous light exposure could have significant effect in follicular cyst formation in AGR.

Automated acoustic monitoring of fish for near-real-time resource management

Abstract Freshwater fisheries in developing regions provide livelihoods and nutrition for millions of people worldwide. These fisheries are frequently data poor, which limits fisheries management. The seasonal Cambodian dai platform fishery on the Tonle Sap River is one of the best monitored inland fisheries in Southeast Asia, yet catch sampling is limited and there is no fishery-independent monitoring. A monitoring system is needed to characterize fish migration and mortality, be cost effective, and be deployable in areas with minimal infrastructure. We integrated a Simrad wide-band transceiver mini echosounder (200 kHz), solar power, and an Internet of Things communications module as an autonomous, automated monitoring package for the deployment on upstream and downstream commercial fishing platforms. The solar panel and controller supply direct current power to the echosounder, communications module, and battery for power during dark hours. Echosounders are programmed to sample at 1 Hz for 15 min every hour. The communications module is a built cellular endpoint that accesses a local wireless network to transmit raw data files to a data server. Data are downloaded from the server for processing and analysis. This expandable system provides a flexible management tool that can be deployed at any location with wireless communication capability.

Effects of LED Light Colors on the Growth Performance, Intestinal Morphology, Cecal Short-Chain Fatty Acid Concentrations and Microbiota in Broilers

This study aimed to explore the effects of light-emitting diode (LED) light colors on growth, intestinal morphology, and cecal microbiota in broilers. A total of 360 healthy male Arbor Acres (AA) broilers with similar weights were selected and divided into four groups with six replicates in each group and 15 broilers in each replicate: LED white light (W), LED green light (G), LED blue light (B), and LED blue–green composite light (BG). The experimental period was 42 d, the light cycle of each treatment group was 23L:1D (23 h of light, one hour of darkness) from 1 to 3 d, and the light cycle from 4 to 42 d was 16L:8D; light intensity was 20 Lux. The results showed that the average daily feed intake and final weight of broilers receiving the B group were the highest in 21 d and 42 d compared with other groups. The average daily feed intake of the BG group was lower than that of the B group. In the same light color, small intestine villus height grows with age. On days 21 and 42, compared with other groups, the ileal villus height was higher, the crypt depth was lower, and the V/C ratio (villus to crypt ratio) was higher in the BG group. The combination of blue–green composite light was beneficial to increase the content of propionate, isobutyrate, butyrate, isovalerate, and valerate in the cecum of 21-day-old broilers and the content of isobutyrate in the cecum of 42-day-old broilers, and a decrease in cecal short-chain fatty acid concentrations with age. The B group and the BG group had higher abundances of Bacteroidetes at day 21 of age and lower abundances of Phascolarctobacterium at day 42. However, no cecal microbiota differences were detected by the Bonferroni-corrected test. In general, our research results showed that light color could promote the growth of broilers by affecting intestinal morphology, microbiota abundance (needs to be validated by further experiments), and cecal short-chain fatty acid concentrations. And blue and blue–green composite lights are more suitable for broiler growth.

Abstract 13568: Proteomic Analysis Reveals Protein Alterations in Drp1 Cardiac Knockout Mice With Circadian Rhythm Disruption

Introduction: Mitochondria dynamics are altered in circadian rhythm disruption, and dynamin-related protein 1 (Drp1) may be an important target. Methods: Wild-type and Drp1 cardiac-specific knockout mice were divided into normal circadian group and circadian disorder group, respectively. Normal circadian group mice were housed in a standard environment (12 hours of light/12 hours of darkness), while dark group mice were housed in a 24-hour dark environment. After 4 weeks, the cardiac tissues were analysed using Tandem Mass Tag proteomics. Differentially expressed proteins (DEPs) was identified. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed. Gene set enrichment analysis (GSEA) was performed to find enriched biological processes. Results: Compared with the WT/N group, the Drp1-/N group possessed a total of 176 DEPs. These proteins are widely involved in mitochondrial membrane and metabolism process. We identified several differentially expressed mitochondrial dynamics-related genes, including Drp1, using Western blotting. Compared with the WT/D group, the Drp1-/D group exhibited a total of 126 DEPs. GO and KEGG showed that the DEPs were mainly involved in response to stress, metabolic pathways. For Drp1 cKO mice, the protein changes caused by the circadian rhythm disorder were mainly concentrated in vitamin transport, complement coagulation cascades. Conclusions: This study may provide an insight into the myocardial protein changes caused by Drp1 cKO with circadian rhythm disruption, which may involve in terms such as metabolic pathways, complement coagulation, and vitamin transport.

Seasonal roost selection of wild turkeys at their northern range edge

Wild turkeys Meleagris gallopavo are diurnally active birds that spend the dark hours roosting in trees. We tested the hypothesis that multiple benefits exist for roost tree selection by wild turkeys, including thermoregulation, resource acquisition, and protection from predators. We compared 48 roost trees used by eastern wild turkeys M. g. silvestris in Ontario, Canada to 48 non‐roost trees sampled contemporaneously during 2017–2019 to determine roost site selection between seasons. Mean (± SE) roost tree height (21.4 ± 0.8 m) was taller than non‐roost trees (18.2 ± 0.8 m), and roost trees were also larger in diameter at breast height (58.1 ± 5.5 vs 38.7 ± 3.1 cm). Using ibuttons to collect microclimate temperatures at the tree, we found that mean temperature (± SE) of a deciduous roost (14.5 ± 0.1°C) was higher than temperature at either a coniferous roost (13.9 ± 0.1°C) or ambient temperature (13.2 ± 0.1°C) during the summer months. In winter however, we did not find any relationship between temperature and tree type. Roosts were closer to buildings (150.8 ± 26.0 m) in the winter compared to summer and year‐round roosts, and winter roosts were also farther away from crops (395.2 ± 63.7 m) compared to roost sites used year‐round. Summer roosts were closer to roads (143 ± 36.3 m) than the roosts in the winter and roosts used year‐round. Our data suggest that thermoregulation is not the driving force behind roost selection; instead, predator avoidance appears to play the most important role, with some weaker evidence in support of proximity to resources.

Tissue Propagation of Marjoram Plant (in vitro)

The experiment was conducted in the plant tissue culture laboratory of the Department of Horticulture and Landscape Engineering, College of Agriculture, University of Kirkuk for the season 2022. to study the propagation of the marjoram plant tissue from tips of branches outside the body. plant parts were sterilized for a period of 10-15 min, water was used to remove dust, and they were sterilized inside the cultivation table in Naocl sodium hypochlorite solution (commercial minor solution) at a concentration of 6% for 8 minutes in order to remove suspended microscopic parts. plant parts were washed 3 times each for 5 minutes. plant parts were cut, and tips of branches were taken, with (1) cm. with kinetin at, 2, 4, 6, 8) mg. L-1. plants were vaccinated at a temperature of 25 + 2 m 0 with an intensity of illumination was 3000 lux, with a light sequence of 16 hours, followed by 8 hours of darkness, for 4 weeks of cultivation. data were taken for the experiment (length of the longest branch) (number of branches) (number of leaves). after replanting the tips of the branches for another 4 weeks of the multiplication process, data were taken at (length of the longest branch cm) number of leaves/plant part). tips of branches. Regarding the root experience, data were taken (percentage of rooting %) (average number of roots/vegetative part) (average root length/cm) (branch length/cm) (number of leaves/vegetative part) full and half concentration of salt from the same soil were added to cultivated on a medium with different concentrations of IBA.

Cathemerality: a key temporal niche.

Given the marked variation in abiotic and biotic conditions between day and night, many species specialise their physical activity to being diurnal or nocturnal, and it was long thought that these strategies were commonly fairly fixed and invariant. The term 'cathemeral', was coined in 1987, when Tattersall noted activity in a Madagascan primate during the hours of both daylight and darkness. Initially thought to be rare, cathemerality is now known to be a quite widespread form of time partitioning amongst arthropods, fish, birds, and mammals. Herein we provide a synthesis of present understanding of cathemeral behaviour, arguing that it should routinely be included alongside diurnal and nocturnal strategies in schemes that distinguish and categorise species across taxa according to temporal niche. This synthesis is particularly timely because (i) the study of animal activity patterns is being revolutionised by new and improved technologies; (ii) it is becoming apparent that cathemerality covers a diverse range of obligate to facultative forms, each with their own common sets of functional traits, geographic ranges and evolutionary history; (iii) daytime and nighttime activity likely plays an important but currently neglected role in temporal niche partitioning and ecosystem functioning; and (iv) cathemerality may have an important role in the ability of species to adapt to human-mediated pressures.