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Navigation requires integrating sensory information with a stable schema to create a dynamic map of an animal’s position using egocentric and allocentric coordinate systems. In the hippocampus, place cells encode allocentric space, but their firing rates may also exhibit directional tuning within egocentric or allocentric reference frames. We compared experimental and simulated data to assess the prevalence of tuning to egocentric bearing (EB) among hippocampal cells in rats foraging in an open field. Using established procedures, we confirmed egocentric modulation of place cell activity in recorded data; however, simulated data revealed a high false-positive rate (FPR). When we accounted for false positives by comparing with shuffled data that retain correlations between the animal’s direction and position, only a very low number of hippocampal neurons appeared modulated by EB. Our study highlights biases affecting FPRs and provides insights into the challenges of identifying egocentric modulation in hippocampal neurons. [ABSTRACT FROM AUTHOR]

Sport is often harnessed to serve broader societal objectives. In Flanders (Belgium) – the region of interest in this research – sport is instrumentalised to promote social integration and inclusion, particularly among communities with a migration background. However, this Sport for Development and Peace (SDP) policy and programming is not straightforward. Scholars have pointed to the lingering imperial residue within SDP, prompting a need for critical examination. Therefore, this research aims to gain an understanding of how contemporary SDP discourse in Flanders is socially and culturally constructed and what its performative implications are for communities with a migration background. To this end, online documents from the sport administration and organisations involved in SDP were subjected to critical discourse analysis informed by the theoretical and cultural understanding of post-colonial theory and decoloniality. The findings indicate that SDP discourse reflects a complex interplay of imperial legacies and neoliberal influences, simultaneously projecting an image of inclusivity and perpetuating inequalities. Consequently, decolonising the SDP discourse in Flanders is an imperative transformative process and requires a comprehensive approach rooted in historical awareness, contextual sensitivity, and challenging existing power structures. This decolonisation may pave the way for a more equitable and inclusive SDP framework, genuinely reflecting the diverse realities of communities with a migration background while acknowledging and rectifying its colonial legacy. [ABSTRACT FROM AUTHOR]

The navigational mechanisms of homing pigeons, Columba livia , have been extensively studied and represent a useful model for the navigation of birds and other animals. Pigeons navigate with an olfactory map and sun compass from unfamiliar areas and, in familiar areas, are largely guided by visual landscape cues, following stereotyped and idiosyncratic routes. However, the mechanisms by which they gain familiarity, improve their navigation and transition between navigational strategies during learning are not fully understood. Addressing these outstanding questions in this navigational model will help to improve our understanding of navigational ontogeny. We sought to investigate whether passive exposure to the cues at a site, without release, was sufficient for navigational learning, given that pigeons can determine the home direction before taking off. We exposed pigeons to cues at a novel site before returning them to the site the next day and releasing them alongside controls. We found no differences in the directional distributions, mean vector lengths, virtual vanishing times, efficiency indices or homing efficiency indices between birds that had and had not previously visited the site. We therefore found no evidence to suggest that passive exposure to the cues at a novel site was sufficient to facilitate a detectable improvement in navigational performance. There are three possible explanations for this result: first, a larger sample size would have detected a weak effect of learning; second, passive exposure to a release site is insufficient to generate navigational learning; and third, pigeons learn from passive exposure but do not rely upon this information, showing no difference in performance, despite learning. We discuss these three explanations with reference to previous findings on navigational learning in homing pigeons. We suggest that experiments should continue to examine navigational ontogeny in homing pigeons to help address this major problem for the field of navigation. • The ways navigational learning proceeds in homing pigeons are not fully understood. • We investigated whether exposure at a novel site is sufficient for learning. • We found no evidence that exposure to a novel site improved homing performance. [ABSTRACT FROM AUTHOR]

Migration is generally considered to be a driver of enhancing the subjective well-being of immigrants; however, personal characteristics such as educational attainment, migration channel, and country of origin may moderate the impact of immigrant life on expected well-being. Therefore, the present study aimed to explore the intersections between the lived experiences of post-secondary Indian immigrant students in the United Kingdom (UK), the challenges they encounter as immigrants, and how these experiences could impact their subjective well-being. A qualitative research design was employed, which included a focus group discussion and 24 in-depth interviews with postgraduate students who had migrated from India to the United Kingdom. Four themes generated from the thematic analysis, which overall indicated that individuals who came to the United Kingdom as international students to study, work, and settle over time often found themselves unable to leverage their educational credentials to establish expected subjective well-being. This was primarily due to the systematic denial of their agency (capability) to overcome challenges in the host society. Reasons include becoming involuntarily immobile in the host country, incongruency between past expectations and present experiences and prospects, socio-emotional and financial costs associated with immigrant life that hinder the freedom of agency, and bureaucratic burdens. All these reasons can generate an unconducive environment for those immigrants who took part in the study, ultimately decreasing their life satisfaction and positive feelings while increasing negative feelings. In conclusion, the findings question the widely held belief that migration can increase subjective well-being and describe how migration comes at a cost, along with several other challenges, particularly for those who have moved first to learn, secondly to earn, and then to settle in. The channel of migration (migration for education and then to settle in) thus plays a crucial role in determining the outcomes of migration while influencing the anticipated subjective well-being of migrants. [ABSTRACT FROM AUTHOR]

This article reviews the current knowledge and recent advancements in computational modeling of the cell cycle. It offers a comparative analysis of various modeling paradigms, highlighting their unique strengths, limitations, and applications. Specifically, the article compares deterministic and stochastic models, single-cell versus population models, and mechanistic versus abstract models. This detailed analysis helps determine the most suitable modeling framework for various research needs. Additionally, the discussion extends to the utilization of these computational models to illuminate cell cycle dynamics, with a particular focus on cell cycle viability, crosstalk with signaling pathways, tumor microenvironment, DNA replication, and repair mechanisms, underscoring their critical roles in tumor progression and the optimization of cancer therapies. By applying these models to crucial aspects of cancer therapy planning for better outcomes, including drug efficacy quantification, drug discovery, drug resistance analysis, and dose optimization, the review highlights the significant potential of computational insights in enhancing the precision and effectiveness of cancer treatments. This emphasis on the intricate relationship between computational modeling and therapeutic strategy development underscores the pivotal role of advanced modeling techniques in navigating the complexities of cell cycle dynamics and their implications for cancer therapy. [ABSTRACT FROM AUTHOR]

Environmental temperature strongly influences the adaptation dynamics of amphibians, whose limited regulation capabilities render them susceptible to thermal oscillations. A central element of the adaptive strategies is the transcription factors (TFs), which act as master regulators that orchestrate stress responses, enabling species to navigate the fluctuations of their environment skillfully. Our study delves into the intricate relationship between TF expression and thermal adaptation mechanisms in the Rhinella spinulosa populations. We sought to elucidate the dynamic modulations of TF expression in prometamorphic and metamorphic tadpoles that inhabit two thermally contrasting environments (Catarpe and El Tatio Geyser, Chile) and which were exposed to two thermal treatments (25 °C vs. 20 °C). Our findings unravel an intriguing dichotomy in response strategies between these populations. First, results evidence the expression of 1374 transcription factors. Regarding the temperature shift, the Catarpe tadpoles show a multifaceted approach by up-regulating crucial TFs, including fosB, atf7, and the androgen receptor. These dynamic regulatory responses likely underpin the population's ability to navigate thermal fluctuations effectively. In stark contrast, the El Tatio tadpoles exhibit a more targeted response, primarily up-regulating foxc1. This differential expression suggests a distinct focus on specific TFs to mitigate the effects of temperature variations. Our study contributes to understanding the molecular mechanisms governing thermal adaptation responses and highlights the resilience and adaptability of amphibians in the face of ever-changing environmental conditions. [ABSTRACT FROM AUTHOR]

Microbiomes, comprised of diverse microbial species and viruses, play pivotal roles in human health, environmental processes, and biotechnological applications and interact with each other, their environment, and hosts via ecological interactions. Our understanding of microbiomes is still limited and hampered by their complexity. A concept improving this understanding is systems biology, which focuses on the holistic description of biological systems utilizing experimental and computational methods. An important set of such experimental methods are metaomics methods which analyze microbiomes and output lists of molecular features. These lists of data are integrated, interpreted, and compiled into computational microbiome models, to predict, optimize, and control microbiome behavior. There exists a gap in understanding betweenmicrobiologists andmodelers/bioinformaticians, stemming froma lack of interdisciplinary knowledge. This knowledge gap hinders the establishment of computational models in microbiome analysis. This review aims to bridge this gap and is tailored formicrobiologists, researchers newtomicrobiomemodeling, and bioinformaticians. To achieve this goal, it provides an interdisciplinary overview of microbiome modeling, starting with fundamental knowledge of microbiomes, metaomics methods, common modeling formalisms, and how models facilitate microbiome control. It concludes with guidelines and repositories for modeling. Each section provides entry-level information, example applications, and important references, serving as a valuable resource for comprehending and navigating the complex landscape of microbiome research and modeling. [ABSTRACT FROM AUTHOR]

Magnetic sense, or termed magnetoreception, has evolved in a broad range of taxa within the animal kingdom to facilitate orientation and navigation. MagRs, highly conserved A-type iron-sulfur proteins, are widely distributed across all phyla and play essential roles in both magnetoreception and iron-sulfur cluster biogenesis. However, the evolutionary origins and functional diversification of MagRs from their prokaryotic ancestor remain unclear. In this study, MagR sequences from 131 species, ranging from bacteria to humans, were selected for analysis, with 23 representative sequences covering species from prokaryotes to Mollusca, Arthropoda, Osteichthyes, Reptilia, Aves, and mammals chosen for protein expression and purification. Biochemical studies revealed a gradual increase in total iron content in MagRs during evolution. Three types of MagRs were identified, each with distinct iron and/or iron-sulfur cluster binding capacity and protein stability, indicating continuous expansion of the functional roles of MagRs during speciation and evolution. This evolutionary biochemical study provides valuable insights into how evolution shapes the physical and chemical properties of biological molecules such as MagRs and how these properties influence the evolutionary trajectories of MagRs. [ABSTRACT FROM AUTHOR]

Stem cells can be coaxed to self-organize into dynamic models of human development and early embryo formation. Despite their scientific promise, might widespread use of these technologies alter people's beliefs about what it means to be a human individual? Attention to some important philosophical distinctions may help navigate our thinking. [ABSTRACT FROM AUTHOR]

Chromium contamination in soil, primarily originating from anthropogenic activities has always been a significant threat to plant and ecosystem health. Key factors influencing Cr-induced stress responses including oxidative stress, altered nutrient uptake and disruption of cellular processes are elucidated. The alterations in the signalling pathways & molecular reactions due to Chromium stress, leads to an abnormal production of certain harmful compounds like ROS and other secondary metabolites in the plant cells. These compounds must either be removed or detoxified for the plant to function normally and survive. This review provides an overview of the different signalling pathways, role of genes and proteins, hormesis effect of Cr, alterations in enzymatic activities and the physiological response of the plants. The role of biochar & microbes in bioremediation, hyper-accumulator plants in phytoremediation emerges as a natural yet effective solution in detoxifying the pollutants. The impacts and potential mitigation strategies to minimize and restore the contamination caused in the ecosystem is emphasized. This review provides valuable insights into the multifaceted interactions between plants and Cr stress. It also focuses on mitigating it by bioremediation mechanisms for sustainable environmental management. [ABSTRACT FROM AUTHOR]

Experiments since the classic studies of Niko Tinbergen have provided evidence that animals use visual landmarks to navigate. We tested whether birds use visual landmarks to relocate their nest sites by presenting two species of cavity nesting birds with a dyad of nest boxes with different white markings around the entrance, a circle or a triangle. When the two boxes were erected in close proximity on the same tree, pied flycatchers Ficedula hypoleuca and blue tits Cyanistes caeruleus confused the entrance of their nest both when the boxes had different external markings and when they were unmarked. Most females added nest material to both boxes of a dyad and one third of the flycatchers laid eggs in both boxes although a female can only incubate the eggs in one nest at a time. Thus, the birds did not use external markings around cavity entrances for orientation. We also tried to replicate a previous study purporting to show that migratory birds use social learning of the external appearance of nests from other species. However, pied flycatchers did not choose boxes with the same painted markings as those applied to nests of resident great tits Parus major which were judged to be high quality "demonstrators" from their large clutch sizes. We argue that conclusions from previous studies on social learning based on external markings as landmarks on nest cavities in birds need to be reconsidered. Significance: Animals may try to hide their nest site on the landscape to avoid the attention of predators and competitors. However, this may make it difficult in the beginning of the breeding season for the parents to relocate the nest site quickly, particularly in a habitat with a complex three-dimensional structure of bushes and trees. To test whether birds might use conspicuous markings around the entrance of their nest as landmarks, we presented prospecting pied flycatchers Ficedula hypoleuca and blue tits Cyanistes caeruleus with a dyad of nest boxes painted with a white circle or a white triangle affixed to different trees or the same tree. However, we found no evidence that the birds used the external markings to identify the entrance to their nest site, or that such markings on nest cavities were learned from resident great tits Parus major. [ABSTRACT FROM AUTHOR]

Since the COVID-19 outbreak, raccoon dogs have been suggested as a potential intermediary in transmitting SARS-CoV-2 to humans. To understand their role in the COVID-19 pandemic and the species barrier for SARS-CoV-2 transmission to humans, we analyzed how their ACE2 protein interacts with SARS-CoV-2 spike protein. Biochemical data showed that raccoon dog ACE2 is an effective receptor for SARS-CoV-2 spike protein, though not as effective as human ACE2. Structural comparisons highlighted differences in the virus-binding residues of raccoon dog ACE2 compared to human ACE2 (L24Q, Y34H, E38D, T82M, R353K), explaining their varied effectiveness as receptors for SARS-CoV-2. These variations contribute to the species barrier that exists between raccoon dogs and humans regarding SARS-CoV-2 transmission. Identifying these barriers can help assess the susceptibility of other mammals to SARS-CoV-2. Our research underscores the potential of raccoon dogs as SARS-CoV-2 carriers and identifies molecular barriers that affect the virus's ability to jump between species. Author summary: Raccoon dogs are thought to have been a crucial link in the chain that led to the spread of the COVID-19 virus to humans. The key to a coronavirus moving from one species to another is its spike protein's ability to bind to receptors on the cells of the new host. In our research, we investigated the interaction between the spike protein of the COVID-19 virus and the ACE2 receptor in raccoon dogs, using both structural and biochemical techniques. We found that the ACE2 receptor in raccoon dogs does indeed work as an effective receptor for the virus, but there are critical differences when compared to the human ACE2 receptor, which may act as barriers to the virus making the jump between raccoon dogs and humans. To our knowledge, this study is the first in-depth examination of these cross-species transmission barriers for the COVID-19 virus, shedding light on how other mammals might be impacted by the virus. Our findings indicate that raccoon dogs could potentially carry and pass the COVID-19 virus on to humans, providing foundational knowledge for how the virus can navigate between different species. [ABSTRACT FROM AUTHOR]

Alzheimer's Disease (AD) is characterized by a range of behavioral alterations, including memory loss and psychiatric symptoms. While there is evidence that molecular pathologies, such as amyloid beta (Aβ), contribute to AD, it remains unclear how this histopathology gives rise to such disparate behavioral deficits. One hypothesis is that Aβ exerts differential effects on neuronal circuits across brain regions, depending on the neurophysiology and connectivity of different areas. To test this, we recorded from large neuronal populations in dorsal CA1 (dCA1) and ventral CA1 (vCA1), two hippocampal areas known to be structurally and functionally diverse, in the APP/PS1 mouse model of amyloidosis. Despite similar levels of Aβ pathology, dCA1 and vCA1 showed distinct disruptions in neuronal population activity as animals navigated a virtual reality environment. In dCA1, pairwise correlations and entropy, a measure of the diversity of activity patterns, were decreased in APP/PS1 mice relative to age-matched C57BL/6 controls. However, in vCA1, APP/PS1 mice had increased pair-wise correlations and entropy as compared to age matched controls. Finally, using maximum entropy models, we connected the microscopic features of population activity (correlations) to the macroscopic features of the population code (entropy). We found that the models' performance increased in predicting dCA1 activity, but decreased in predicting vCA1 activity, in APP/PS1 mice relative to the controls. Taken together, we found that Aβ exerts distinct effects across different hippocampal regions, suggesting that the various behavioral deficits of AD may reflect underlying heterogeneities in neuronal circuits and the different disruptions that Aβ pathology causes in those circuits. Author summary: Patients with Alzheimer's disease (AD) experience an array of cognitive deficits, such as memory loss and executive dysfunction, as well as behavioral symptoms, such as agitation and anxiety. However, it is unclear how these myriad deficits arise from the molecular and cellular hallmarks of AD, such as amyloid beta (Aβ) plaques. In the current study, we sought to bridge this gap by studying how neural activity is disrupted in the context of Aβ pathology. We recorded the activity of large populations of neurons in two different brain regions, the dorsal and ventral CA1 subfields of the hippocampus, in a mouse model of Aβ pathology as animals navigated a virtual reality environment. Using statistical approaches to quantify the features of the population code, we showed that the disruptions to neuronal activity in the Aβ model were different across these two regions. These results suggest that Aβ exerts diverse effects across different brain regions that likely reflect underlying heterogeneities in the circuits of the brain. [ABSTRACT FROM AUTHOR]

The Editors' and Readers' Choice Awards were established in 2022 to celebrate some of the outstanding articles published every year in the Journal of Comparative Physiology A. The recipients of the 2024 Editors' Choice Awards were selected based on votes cast by the Editorial Board on articles published in 2023. In the category Original Paper, this distinction goes to 'Views from 'crabworld': the spatial distribution of light in a tropical mudflat' by Jochen Zeil (J Comp Physiol A 209:859–876, 2023); and in the category Review Article to 'Olfactory navigation in arthropods' by Theresa J. Steele and colleagues (J Comp Physiol A 209:467–488, 2023). The winners of the 2024 Readers' Choice Awards were determined by the number of online accesses of articles published in 2022. In the category Original Paper, the winner is 'Broadband 75–85 MHz radiofrequency fields disrupt magnetic compass orientation in night‑migratory songbirds consistent with a flavin‑based radical pair magnetoreceptor' by Bo Leberecht and colleagues (J Comp Physiol A 208:97–106, 2022). In the category Review Article, the winner is 'Magnetic maps in animal navigation' by Kenneth J. Lohmann and colleagues (J Comp Physiol A 208:41–67, 2022), which already won the Editors' Choice Award in 2023. [ABSTRACT FROM AUTHOR]

Rationale: Animal studies suggest that the so-called "female" hormone estrogen enhances spatial navigation and memory. This contradicts the observation that males generally out-perform females in spatial navigation and tasks involving spatial memory. A closer look at the vast number of studies actually reveals that performance differences are not so clear. Objectives: To help clarify the unclear performance differences between men and women and the role of estrogen, we attempted to isolate organizational from activational effects of estrogen on spatial navigation and memory. Methods: In a double-blind, placebo-controlled study, we tested the effects of orally administered estradiol valerate (E2V) in healthy, young women in their low-hormone menstrual cycle phase, compared to healthy, young men. Participants performed several first-person, environmentally rich, 3-D computer games inspired by spatial navigation and memory paradigms in animal research. Results: We found navigation behavior suggesting that sex effects dominated any E2 effects with men performing better with allocentric strategies and women with egocentric strategies. Increased E2 levels did not lead to general improvements in spatial ability in either sex but to behavioral changes reflecting navigation flexibility. Conclusion: Estrogen-driven differences in spatial cognition might be better characterized on a spectrum of navigation flexibility rather than by categorical performance measures or skills. [ABSTRACT FROM AUTHOR]

This qualitative study explored the perceived relationships between outdoor built environments and sensory sensitivities, focusing on autism, ADHD, and dyslexia. Thirty-one semi-structured interviews were conducted with participants who had lived experience with these focal groups. Through thematic analysis of their narratives, the study uncovered patterns highlighting the perceived relationships between designed landscapes and sensory sensitivities in neurodivergent individuals, encompassing both heightened sensitivity (hypersensitivity) and reduced sensitivity (hyposensitivity). Emergent themes included individual and personal factors, sensory affordances, the benefits of outdoor environments, ambient environmental factors, materiality, spatial design, navigating environments, pedestrian-centric transportation, sensorimotor movement, safety, refuge, human settlement types, social environments, and accessibility plus inclusion. Subthematic patterns within these larger thematic categories were also identified. Study participants revealed significant sensory barriers and sensorially supportive elements of designed outdoor environments, along with promising design interventions. The findings unveil the advantages of designing multi-sensory landscapes tailored to atypical sensory needs, emphasizing the importance of fostering inclusion by designing landscapes that reflect the communities they serve. This concept is encapsulated in the development of the Sensory Responsive Environments Framework (SREF), the emergent theoretical framework of this study. [ABSTRACT FROM AUTHOR]

Iron-sulfur clusters are essential cofactors for proteins involved in various biological processes, such as electron transport, biosynthetic reactions, DNA repair, and gene expression regulation. Iron-sulfur cluster assembly protein IscA1 (or MagR) is found within the mitochondria of most eukaryotes. Magnetoreceptor (MagR) is a highly conserved A-type iron and iron-sulfur cluster-binding protein, characterized by two distinct types of iron-sulfur clusters, [2Fe-2S] and [3Fe-4S], each conferring unique magnetic properties. MagR forms a rod-like polymer structure in complex with photoreceptive cryptochrome (Cry) and serves as a putative magnetoreceptor for retrieving geomagnetic information in animal navigation. Although the N-terminal sequences of MagR vary among species, their specific function remains unknown. In the present study, we found that the N-terminal sequences of pigeon MagR, previously thought to serve as a mitochondrial targeting signal (MTS), were not cleaved following mitochondrial entry but instead modulated the efficiency with which iron-sulfur clusters and irons are bound. Moreover, the N-terminal region of MagR was required for the formation of a stable MagR/Cry complex. Thus, the N-terminal sequences in pigeon MagR fulfil more important functional roles than just mitochondrial targeting. These results further extend our understanding of the function of MagR and provide new insights into the origin of magnetoreception from an evolutionary perspective. [ABSTRACT FROM AUTHOR]

Sex differences in navigation have been a topic of investigation for decades and has been subjected to various contradictory findings and debates. The aim of this work was to compare the spatial memory of men and women tested in various different types of spatial tasks, while controlling for navigation strategies and aging. It is generally thought thatmen outperformwomen in navigation and that women have higher scores on object location tasks. However, many studies fail to control for different factors that may bias one sex or the other. We aggregated the data of 465 participants (349 young adults, 127 older adults) who took part in various studies conducted in our laboratory, which include both published and original unpublished data, in order to investigate sex differences. In these studies, we used a number of different paradigms: virtual radial arm mazes, a virtual wayfinding task, an object location task, a virtual Morris Water Maze, and the invisible sensor task which is a real-life model of the Morris Water Maze. While our results may seem discordant at first glance, they demonstrate that several factors can impact the performance of men and women on spatial tasks, including spontaneous navigation strategies, environmental characteristics, and age. Wereplicated findings showing thatwomen favor proximal landmarks compared to men who favor distal landmarks, women have better memory than men for the position of objects in the absence of reference frames, but they will have poorer scores when navigation requires specific angles, distances and polar coordinates. Moreover, we found that in aging, women who avoid the use of landmarks when navigating a radial maze show stronger reliance on these non-spatial strategies than men. On the other hand, women who rely on landmarks, do so to the same extent asmen. Our findings highlight the need to carefully take into consideration these factors in order to produce amore harmonious understanding of sex differences in navigation. Finally, the interaction between spontaneous navigation strategies, sex, and age is discussed in terms of its implications for risk of Alzheimer's disease. [ABSTRACT FROM AUTHOR]

The germline provides the genetic and non-genetic information that passes from one generation to the next. Given this important role in species propagation, egg and sperm precursors, called primordial germ cells (PGCs), are one of the first cell types specified during embryogenesis. In fact, PGCs form well before the bipotential somatic gonad is specified. This common feature of germline development necessitates that PGCs migrate through many tissues to reach the somatic gonad. During their journey, PGCs must respond to select environmental cues while ignoring others in a dynamically developing embryo. The complex multi-tissue, combinatorial nature of PGC migration is an excellent model for understanding how cells navigate complex environments in vivo. Here, we discuss recent findings on the migratory path, the somatic cells that shepherd PGCs, the guidance cues somatic cells provide, and the PGC response to these cues to reach the gonad and establish the germline pool for future generations.We end by discussing the fate of wayward PGCs that fail to reach the gonad in diverse species. Collectively, this field is poised to yield important insights into emerging reproductive technologies. [ABSTRACT FROM AUTHOR]

Insect navigation has become a fascinating and ever expanding field of neuroethological research. From sphecid wasps, honey bees, and desert ants to monarch butterflies and bogong moths, and even to drosophilid flies, several species are now intensively studied by several research groups using various experimental approaches and formulating various hypotheses about how insects find their way. Some species like the hymenopterans mentioned above are central place foragers performing round-trip journeys from and to their home base. Others like the lepidopterans are migrants embarking on long-distance journeys to-and-fro, with individuals either journeying one-way (and the next generations travelling back) or both ways. Given this diversity of navigational challenges for the animals it is important to understand the ecological setting within which each navigator operates, the tasks it actually must accomplish, and the various modes of behavior that evolved for tackling these tasks. Hence, conceptual approaches and experimental design should be firmly rooted in detailed studies of the navigator's natural history. Here, I let the reader join us in our approaches of studying desert ant navigation by illustrating, as an example, the design of our varied channel paradigms. I tell my story in a personal as well as an essayistic and narrative style, not least because the formal scheme of scientific papers may run the risk of hiding or even misrepresenting the historical and idiosyncratic ways of how the described research has actually been done. [ABSTRACT FROM AUTHOR]

The Gross domestic expenditure on R&D (GERD) is one of the most important indicators of the Research and Development area, part of Science and Technology and Digital Society branch on the data navigation tree of the EUROSTAT Database. In this paper we analyzed the evolution of GERD in Romania and EU countries on the last ten years with the available data (2013-2022). [ABSTRACT FROM AUTHOR]

At around age 60, people are approaching late adulthood and are typically going through or anticipating life transitions such as grandparenthood, retirement, or changes in health and functioning. The timing and perception of transitions are individual and based on current circumstances and earlier life history and may link to well-being. The TRAILS (Developmental Psychological Perspectives on Transitions at Age 60: Individuals Navigating Across the Lifespan) study, which is presented in the current article, examines the diversity and underlying factors of different transitions at around age 60 and how they associate with mental well-being. It also investigates whether these transitions link to personality characteristics, contextual resources, and/or societal challenges. The role of earlier life history in the studied associations requires a prospective multiwave design where the same participants are followed over time. Only a few longitudinal studies have examined the developmental pathways from childhood to the beginning of late adulthood. The TRAILS study continues the Jyväskylä Longitudinal Study of Personality and Social Development (JYLS). The JYLS was initiated in 1968 and includes earlier data collected from ages 8 to 50. At age 61, in 2020-21, 206 of the JYLS participants (of the initial 369 children) took part in TRAILS. The data collection included a Life Situation Questionnaire, a psychological interview, self-report inventories, a health examination and physical activity surveillance covering major areas of adult life. TRAILS extends the JYLS study to over 52 years of follow-up time and provides unique opportunities for studying individual development throughout the lifespan. [ABSTRACT FROM AUTHOR]

The International Association for the Study of Pain (IASP) revised its definition of pain to "an unpleasant sensory and emotional experience." Three recent recommendations for understanding pain if there are no clear brain correlates include eliminativism, multiple realizability, and affordance-based approaches. I adumbrate a different path forward. Underlying each of the proposed approaches and the new IASP definition is the suspicion that there are no specific correlates for pain. I suggest that this basic assumption is misguided. As we learn more about brain function, it is becoming clear that many areas process many different types of information at the same time. In this study, I analogize how animal brains navigate in three-dimensional space with how the brain creates pain. Underlying both cases is a large-scale combinatorial system that feeds back on itself through a diversity of convergent and divergent bi-directional connections. Brains are not like combustion engines, with energy driving outputs via the structure of the machine, but are instead more like whirlpools, which are essentially dynamic patterns in some substrates. We should understand pain experiences as context-dependent, spatiotemporal trajectories that reflect heterogeneous, multiplex, and dynamically adaptive brain cells. [ABSTRACT FROM AUTHOR]

Spatial navigation is more difficult and effortful for older than younger individuals, a shift which occurs for a variety of neurological, physical, and cognitive reasons associated with aging. Despite a large body of evidence documenting age-related deficits in spatial navigation, comparatively less research addresses how to facilitate more effective navigation behavior for older adults. Since navigation challenges arise for a variety of reasons in old age, a one-size-fits-all solution is unlikely to work. Here, we introduce a framework for the variety of spatial navigation challenges faced in aging, which we call LOST-Location, Orientation, Spatial mapping, and Transit. The LOST framework builds on evidence from the cognitive neuroscience of spatial navigation, which reveals distinct components underpinning human wayfinding. We evaluate research on navigational aids--devices and depictions--which help people find their way around; and we reflect on how navigation aids solve (or fail to solve) specific wayfinding difficulties faced by older adults. In summary, we emphasize a bespoke approach to improving spatial navigation in aging, which focuses on tailoring navigation solutions to specific navigation challenges. Our hope is that by providing precise support to older navigators, navigation opportunities can facilitate independence and exploration, while minimizing the danger of becoming lost. We conclude by delineating critical knowledge gaps in how to improve older adults' spatial navigation capacities that the novel LOST framework could guide to address. [ABSTRACT FROM AUTHOR]

The cognitive map, proposed by Tolman in the 1940s, is a hypothetical internal representation of space constructed by the brain to enable an animal to undertake flexible spatial behaviors such as navigation. The subsequent discovery of place cells in the hippocampus of rats suggested that such a map-like representation does exist, and also provided a tool with which to explore its properties. Single-neuron studies in rodents conducted in small singular spaces have suggested that the map is founded on a metric framework, preserving distances and directions in an abstract representational format. An open question is whether this metric structure pertains over extended, often complexly structured real-world space. The data reviewed here suggest that this is not the case. The emerging picture is that instead of being a single, unified construct, the map is a mosaic of fragments that are heterogeneous, variably metric, multiply scaled, and sometimes laid on top of each other. Important organizing factors within and between fragments include boundaries, context, compass direction, and gravity. The map functions not to provide a comprehensive and precise rendering of the environment but rather to support adaptive behavior, tailored to the species and situation. [ABSTRACT FROM AUTHOR]

This document is a special issue of the journal "Learning & Behavior" that honors the contributions of Dr. Ken Cheng to the field of comparative cognition. Dr. Cheng received the Comparative Cognition Society Research Award in 2023 and gave a master lecture at the Comparative Cognition Society Conference. The issue includes articles that highlight Dr. Cheng's work on the geometric module in rats, as well as his research on ant navigation and his recent interests in cognition and oscillations across different life forms. The articles demonstrate Dr. Cheng's impact on the field and his dedication to integrating ideas from various disciplines. [Extracted from the article]

The behavioral and neural mechanisms that support spatial cognition have been an enduring interest of psychologists, and much of that enduring interest is attributable to the groundbreaking research of Ken Cheng. One manifestation of this interest, inspired by the idea of studying spatial cognition under natural field conditions, has been research carried out to understand the role of the avian hippocampal formation (HF) in supporting homing pigeon navigation. Emerging from that research has been the conclusion that the role of HF in homing pigeon navigation aligns well with the canonical narrative of a hippocampus important for spatial memory and the implementation of such memories to support navigation. However, recently an accumulation of disparate observations has prompted a rethinking of the avian HF as a structure also important in shaping visual-spatial perception or attention antecedent to any memory processing. In this perspective paper, we summarize field observations contrasting the behavior of intact and HF-lesioned homing pigeons from several studies, based primarily on GPS-recorded flight paths, that support a recharacterization of HF's functional profile to include visual-spatial perception. Although admittedly still speculative, we hope the offered perspective will motivate controlled, experimental-laboratory studies to further test the hypothesis of a HF important for visual-perceptual integration, or scene construction, of landscape elements in support of navigation. [ABSTRACT FROM AUTHOR]

A behavioral strategy crucial to survival is directed navigation to a goal, such as a food or home location. One potential neural substrate for supporting goal-directed navigation is the parahippocampus, which contains neurons that represent an animal's position, orientation, and movement through the world, and that change their firing activity to encode behaviorally relevant variables such as reward. However, little prior work on the parahippocampus has considered how neurons encode variables during goal-directed navigation in environments that dynamically change. Here, we recorded single units from rat parahippocampal cortex while subjects performed a goal-directed task. The maze dynamically changed goal-locations via a visual cue on a trial-to-trial basis, requiring subjects to use cue-location associations to receive reward. We observed a mismatch-like signal, with elevated neural activity on incorrect trials, leading to rate-remapping. The strength of this remapping correlated with task performance. Recordings during open-field foraging allowed us to functionally define navigational coding for a subset of the neurons recorded in the maze. This approach revealed that head-direction coding units remapped more than other functional-defined units. Taken together, this work thus raises the possibility that during goal-directed navigation, parahippocampal neurons encode error information reflective of an animal's behavioral performance. [ABSTRACT FROM AUTHOR]

Behavioral neuroscience has successfully and in great detail deconstructed circuit mechanisms underlying fear behaviors using reductionist approaches. Recent research in more naturalistic settings now reveals additional higher-level organization, where hypothalamic circuits multiplex threat detection and fear memory updating to safely navigate complex environments. Behavioral neuroscience has successfully and in great detail deconstructed circuit mechanisms underlying fear behaviors using reductionist approaches. Recent research in more naturalistic settings now reveals additional higher-level organization, where hypothalamic circuits multiplex threat detection and fear memory updating to safely navigate complex environments. [ABSTRACT FROM AUTHOR]

Scientific research is an exploration of the unknown. The process is full of uncertainty, missteps, delightful surprises, painful lessons, and ultimately a measure of insight into nature. In this Science and Society article I suggest a few practical strategies that helped me navigate these challenges at the earliest stages of becoming a cell biologist. [ABSTRACT FROM AUTHOR]

The Anthropocene is characterized by accelerating change and global challenges of increasing complexity. Inspired by what some have called a polycrisis, we explore whether the human trajectory of increasing complexity and influence on the Earth system could become a form of trap for humanity. Based on an adaptation of the evolutionary traps concept to a global human context, we present results from a participatory mapping. We identify 14 traps and categorize them as either global, technology or structural traps. An assessment reveals that 12 traps (86%) could be in an advanced phase of trapping with high risk of hard-to-reverse lock-ins and growing risks of negative impacts on human well-being. Ten traps (71%) currently see growing trends in their indicators. Revealing the systemic nature of the polycrisis, we assess that Anthropocene traps often interact reinforcingly (45% of pairwise interactions), and rarely in a dampening fashion (3%). We end by discussing capacities that will be important for navigating these systemic challenges in pursuit of global sustainability. Doing so, we introduce evolvability as a unifying concept for such research between the sustainability and evolutionary sciences. This article is part of the theme issue 'Evolution and sustainability: gathering the strands for an Anthropocene synthesis'. [ABSTRACT FROM AUTHOR]

In many organisms, sensory abilities develop and evolve according to the changing demands of navigating, foraging, and communication across different environments and life stages. Teleost fish inhabit heterogeneous light environments and exhibit a large diversity in visual system properties among species. Cichlids are a classic example of this diversity; visual system variation is generated by different tuning mechanisms that involve both genetic factors and phenotypic plasticity. Here, we document the developmental progression of visual pigment gene expression in Lake Victoria cichlids and test if these patterns are influenced by variation in light conditions. We reared two sister species of Pundamilia to adulthood in two distinct visual conditions that resemble the light environments that they naturally inhabit in Lake Victoria. We also included interspecific first‐generation hybrids. We focused on the four opsins that are expressed in Pundamilia adults (using real‐time quantitative polymerase chain reaction (RT‐qPCR)) (SWS2B, SWS2A, RH2A, and LWS) at 17 time points. We find that opsin expression profiles progress from shorter‐wavelength sensitive opsins to longer‐wavelength sensitive opsins with increasing age, in both species and their hybrids. The developmental trajectories of opsin expression also responded plastically to the visual conditions. Developmental and environmental plasticity in opsin expression may provide an important stepping stone in the evolution of cichlid visual system diversity. Research highlights: In Lake Victoria cichlid fish, expression levels of opsin genes (encoding visual pigments) differ between developmental stages and between experimental light treatments. This plasticity may contribute to the evolution of cichlid visual system diversity. [ABSTRACT FROM AUTHOR]

Birds exhibit extraordinary mobility and remarkable navigational skills, obtaining guidance cues from the Earth’s magnetic field for orientation and long-distance movement. Bird species also show tremendous diversity in navigation strategies, with considerable differences even within the same taxa and among individuals from the same population. The highly conserved iron and iron-sulfur cluster binding magnetoreceptor (MagR) protein is suggested to enable animals, including birds, to detect the geomagnetic field and navigate accordingly. Notably, MagR is also implicated in other functions, such as electron transfer and biogenesis of iron-sulfur clusters, raising the question of whether variability exists in its biochemical and biophysical features among species, particularly birds. In the current study, we conducted a comparative analysis of MagR from two different bird species, including the migratory European robin and the homing pigeon. Sequence alignment revealed an extremely high degree of similarity between the MagRs of these species, with only three sequence variations. Nevertheless, two of these variations underpinned significant differences in metal binding capacity, oligomeric state, and magnetic properties. These findings offer compelling evidence for the marked differences in MagR between the two avian species, potentially explaining how a highly conserved protein can mediate such diverse functions. [ABSTRACT FROM AUTHOR]

Motile cells encounter microenvironments with locally heterogeneous mechanochemical composition. Individual compositional parameters, such as chemokines and extracellular matrix pore sizes, are well known to provide guidance cues for pathfinding. However, motile cells face diverse cues at the same time, raising the question of how they respond to multiple and potentially competing signals on their paths. Here, we reveal that amoeboid cells require nuclear repositioning, termed nucleokinesis, for adaptive pathfinding in heterogeneous mechanochemical micro‐environments. Using mammalian immune cells and the amoeba Dictyostelium discoideum, we discover that frequent, rapid and long‐distance nucleokinesis is a basic component of amoeboid pathfinding, enabling cells to reorientate quickly between locally competing cues. Amoeboid nucleokinesis comprises a two‐step polarity switch and is driven by myosin‐II forces that readjust the nuclear to the cellular path. Impaired nucleokinesis distorts path adaptions and causes cellular arrest in the microenvironment. Our findings establish that nucleokinesis is required for amoeboid cell navigation. Given that many immune cells, amoebae, and some cancer cells utilize an amoeboid migration strategy, these results suggest that nucleokinesis underlies cellular navigation during unicellular biology, immunity, and disease. Synopsis: How migrating cells prioritize chemical and mechanical guidance cues during their pathfinding in the local microenvironment is largely unknown. This study shows that amoeboid cell migration towards dominant chemotactic and mechanical pore size cues involves long‐distance nuclear repositioning that is driven by actomyosin contractility. Immune cell migration towards dominant chemotactic guidance cues into narrow microenvironmental pores requires fast and long‐distance intracellular repositioning of the nucleus (nucleokinesis) towards the cellular path.Nucleokinesis in amoeboid migrating cells requires a two‐step polarity switch in the nucleus‐MTOC axis configuration.Nucleokinesis during amoeboid migration is driven by myosin‐II forces and is regulated by the RhoA guanine nucleotide exchange factor GEF‐H1/Lfc.Major principles of amoeboid nucleokinesis are conserved between mammalian immune cells (dendritic cells, T cells) and the amoeba Dictyostelium discoideum. [ABSTRACT FROM AUTHOR]

Ants store and recall views associated with foraging success, facilitating future foraging journeys. Negative views are also learned, but instead prompt avoidance behaviors such as turning away. However, little is known about the aversive view's role in navigation, the effect of cue conflict, or the contextual relationship between learning and recalling. In this study, we tested Myrmecia midas' capacity for aversive learning of views either independently of or in conflict with appetitive events. We either captured and released foragers when reaching a location or let them pass unhindered. After a few journeys, captured foragers exhibited aversive learning by circumventing the capture location and increasing both meandering and scanning. Ants that experienced foraging-appetitive and homing-aversive events on their journeys exhibited lower rates of avoidance behavior and scans than those experiencing aversive events in both outbound and homebound journeys. The foraging-aversive and homing-aversive ants exhibited similar levels of avoidance and scanning as those that experienced the foraging-aversive and homing-appetitive. We found that foragers showed evidence of context specificity in their scanning behavior, but not in other measures of aversive learning. The foragers did not increase their meandering and scans while approaching the views associated with aversive events. In addition to shedding light on the role of aversive views in navigation, our finding has important implications for understanding the learning mechanisms triggered by handling animals. [ABSTRACT FROM AUTHOR]

Glia and neurons are intimately associated throughout bilaterian nervous systems, and were early proposed to interact for patterning circuit assembly. The investigations of circuit formation progressed from early hypotheses of intermediate guideposts and a "glia blueprint", to recent genetic and cell manipulations, and visualizations in vivo. An array of molecular factors are implicated in axon pathfinding but their number appears small relatively to circuit complexity. Comprehending this circuit complexity requires to identify unknown factors and dissect molecular topographies. Glia contribute to both aspects and certain studies provide molecular and functional insights into these contributions. Here, I survey glial roles in guiding axon navigation in vivo, emphasizing analogies, differences and open questions across major genetic models. I highlight studies pioneering the topic, and dissect recent findings that further advance our current molecular understanding. Circuits of the vertebrate forebrain, visual system and neural tube in zebrafish, mouse and chick, the Drosophila ventral cord and the C. elegans brain-like neuropil emerge as major contexts to study glial cell functions in axon navigation. I present astroglial cell types in these models, and their molecular and cellular interactions that drive axon guidance. I underline shared principles across models, conceptual or technical complications, and open questions that await investigation. Glia of the radial-astrocyte lineage, emerge as regulators of axon pathfinding, often employing common molecular factors across models. Yet this survey also highlights different involvements of glia in embryonic navigation or pioneer axon pathfinding, and unknowns in the molecular underpinnings of glial cell functions. Future cellular and molecular investigations should complete the comprehensive view of glial roles in circuit assembly. [ABSTRACT FROM AUTHOR]

Living organisms routinely navigate their surroundings in search of better conditions, more food, or to avoid predators. Typically, animals do so by integrating sensory cues from the environment with their locomotor apparatuses. For single cells or small organisms that possess motility, fundamental physical constraints imposed by their small size have led to alternative navigation strategies that are specific to the microscopic world. Intriguingly, underlying these myriad exploratory behaviours or sensory functions is the onset of periodic activity at multiple scales, such as the undulations of cilia and flagella, the vibrations of hair cells, or the oscillatory shape modes of migrating neutrophils. Here, I explore oscillatory dynamics in basal microeukaryotes and hypothesize that these active oscillations play a critical role in enhancing the fidelity of adaptive sensorimotor integration. [ABSTRACT FROM AUTHOR]

The ways in which seabirds navigate over very large spatial scales remain poorly understood. While olfactory and visual information can provide guidance over short distances, their range is often limited to 100s km, far below the navigational capacity of wide-ranging animals such as albatrosses. Infrasound is a form of low-frequency sound that propagates for 1,000s km in the atmosphere. In marine habitats, its association with storms and ocean surface waves could in effect make it a useful cue for anticipating environmental conditions that favor or hinder flight or be associated with profitable foraging patches. However, behavioral responses of wild birds to infrasound remain untested. Here, we explored whether wandering albatrosses, Diomedea exulans, respond to microbarom infrasound at sea. We used Global Positioning System tracks of 89 free-ranging albatrosses in combination with acoustic modeling to investigate whether albatrosses preferentially orientate toward areas of 'loud' microbarom infrasound on their foraging trips. We found that in addition to responding to winds encountered in situ, albatrosses moved toward source regions associated with higher sound pressure levels. These findings suggest that albatrosses may be responding to long-range infrasonic cues. As albatrosses depend on winds and waves for soaring flight, infrasonic cues may help albatrosses to identify environmental conditions that allow them to energetically optimize flight over long distances. Our results shed light on one of the great unresolved mysteries in nature, navigation in seemingly featureless ocean environments. [ABSTRACT FROM AUTHOR]

In June 2022, a group of Animal Behaviour and Welfare researchers from around the world organised a workshop (https://www.asab.org/conferences-events/2022/6/20/ethics-of-animal-behaviour-and-welfare-research-for-the-21st-century-and-beyond) designed to prompt discussion about the future of ethics in animal behaviour and welfare research. In the Collection, we have tried to capture some of the current debates and discussions that are emerging in Animal Behaviour and Welfare research across several fields, including wild animal biology, companion animals, zoo animals and farm animals. [Extracted from the article]

In 2007, Cheng and colleagues published their influential review wherein they analyzed the literature on spatial cue interaction during navigation through a Bayesian lens, and concluded that models of optimal cue integration often applied in psychophysical studies could explain cue interaction during navigation. Since then, numerous empirical investigations have been conducted to assess the degree to which human navigators are optimal when integrating multiple spatial cues during a variety of navigation-related tasks. In the current review, we discuss the literature on human cue integration during navigation that has been published since Cheng et al.'s original review. Evidence from most studies demonstrate optimal navigation behavior when humans are presented with multiple spatial cues. However, applications of optimal cue integration models vary in their underlying assumptions (e.g., uninformative priors and decision rules). Furthermore, cue integration behavior depends in part on the nature of the cues being integrated and the navigational task (e.g., homing versus non-home goal localization). We discuss the implications of these models and suggest directions for future research. [ABSTRACT FROM AUTHOR]

Boundary and landmark as visual spatial cues exert different effects in human spatial navigation. However, it is unclear that how different contributions between boundary and landmark are during human spatial navigation, and how their learning processes occur. In this study, we addressed these issues by using boundary-based and landmark-based spatial navigation tasks in a large sample of participants. During the task, participants were instructed to learn an object's location based on boundary or landmark in the learning phase, and then retrieve the object's location in the testing phase. Firstly, we found significantly lower distance and angular errors, and smaller variability during the boundary-based task than that in the landmark-based task, which suggested that boundary cue might guide more effectively and stably than landmark cue during spatial navigation. Secondly, our results showed that individual's distance and angular errors declined less across the time in the boundary-based navigation than that in the landmark-based navigation, suggested that the boundary-based learning effect was weaker than the landmark-based learning effect. Finally, we found that boundary-influenced individuals were more proficient in the boundary-based navigation, while landmark-influenced individuals were more proficient in the landmark-based navigation. Together, these findings indicate that boundary has higher effectiveness for guiding but less enhancement for learning than landmark in spatial navigation. [ABSTRACT FROM AUTHOR]

Craters on the lunar surface are the most direct method for the study of geological processes and are of great significance to the study of lunar evolution. In order to fill the research gap on small craters (diameter less than 3 m), we focus on the small craters around the moving path of the Yutu-2 lunar rover and carry out a 3D reconstruction and geometrical morphology analysis on them. First, a self-calibration model with multiple feature constraints is used to calibrate the navigation camera and obtain the internal and external parameters. Then, the sequence images with overlapping regions from neighboring stations are used to obtain the precise position of the rover through the bundle adjustment (BA) method. After that, a cross-scale cost aggregation for a stereo matching network is proposed to obtain a parallax map, which can further obtain 3D point clouds of the lunar surface. Finally, the indexes of the craters are extracted (diameter D, depth d, and depth–diameter ratio dr), and the different indicators are fitted and analyzed. The results suggest that CscaNet has an anomaly percentage value of 1.73% in the KITTI2015 dataset, and an EPE of 0.74 px in the SceneFlow dataset, both of which are superior to GC-Net, DispNet, and PSMnet, and have higher reconstruction accuracy. The correlation between D and d is high and exhibits a positive correlation, while the correlation between D and dr is low. The geometric morphology expressions of small craters fitted by using D and d are significantly different from the expressions proposed by other scholars for large craters. This study provides a priori knowledge for the subsequent Von Karmen crater survey mission in the SPA Basin. [ABSTRACT FROM AUTHOR]

The fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera, Noctuidae), has emerged as a highly invasive pest globally in the past decade due to its remarkable migratory capabilities. Magnetic receptors play an important role in the migration and navigation of the animal, but little is known about the molecular mechanism of the magnetic receptors of S. frugiperda (SfMagR). In this study, we successfully cloned the cDNA encoding SfMagR, which has a 396 bp of open reading frame (ORF) encoding 132 amino acids. Phylogenetic analysis revealed a high conservation of magnetic receptors among various animal species, notably demonstrating a 98.4% sequence identity between S. frugiperda and Spodoptera litura, and a 70.3% identity with Homo sapiens, a vertebrate species. Expression analysis conducted across different developmental stages demonstrated SfMagR expression in the egg, larval, and pupal stages of the moth, but exhibited predominate expression in the adult stage, particularly in male adults. Moreover, the tissue expression profile indicated that SfMagR expression primarily occurred within the thorax of the moth, specifically in the thorax excluding the legs and wings. These findings not only provide fundamental data and a molecular foundation for future investigations into the function of SfMagR, but also offer valuable insights for the future management of invasive species. [ABSTRACT FROM AUTHOR]

Olfactory navigation is observed across species and plays a crucial role in locating resources for survival. In the laboratory, understanding the behavioral strategies and neural circuits underlying odor-taxis requires a detailed understanding of the animal's sensory environment. For small model organisms like Caenorhabditis elegans and larval Drosophila melanogaster, controlling and measuring the odor environment experienced by the animal can be challenging, especially for airborne odors, which are subject to subtle effects from airflow, temperature variation, and from the odor's adhesion, adsorption, or reemission. Here, we present a method to control and measure airborne odor concentration in an arena compatible with an agar substrate. Our method allows continuous controlling and monitoring of the odor profile while imaging animal behavior. We construct stationary chemical landscapes in an odor flow chamber through spatially patterned odorized air. The odor concentration is measured with a spatially distributed array of digital gas sensors. Careful placement of the sensors allows the odor concentration across the arena to be continuously inferred in space and monitored through time. We use this approach to measure the odor concentration that each animal experiences as it undergoes chemotaxis behavior and report chemotaxis strategies for C. elegans and D. melanogaster larvae populations as they navigate spatial odor landscapes. [ABSTRACT FROM AUTHOR]