Project description:When we are fatigued, we feel that our performance is worse than when we are fresh. Yet, for over 100 years, researchers have been unable to identify an objective, behavioral measure that covaries with the subjective experience of fatigue. Previous work suggests that the metrics of signal detection theory (SDT)-response bias (criterion) and perceptual certainty (d')-may change as a function of fatigue, but no work has yet been done to examine whether these metrics covary with fatigue. Here, we investigated cognitive fatigue using SDT. We induced fatigue through repetitive performance of the n-back working memory task, while functional magnetic resonance imaging (fMRI) data was acquired. We also assessed cognitive fatigue at intervals throughout. This enabled us to assess not only whether criterion and d' covary with cognitive fatigue but also whether similar patterns of brain activation underlie cognitive fatigue and SDT measures. Our results show that both criterion and d' were correlated with changes in cognitive fatigue: as fatigue increased, subjects became more conservative in their response bias and their perceptual certainty declined. Furthermore, activation in the striatum of the basal ganglia was also related to cognitive fatigue, criterion, and d'. These results suggest that SDT measures represent an objective measure of cognitive fatigue. Additionally, the overlap and difference in the fMRI results between cognitive fatigue and SDT measures indicate that these measures are related while also separate. In sum, we show the relevance of SDT measures in the understanding of fatigue, thus providing researchers with a new set of tools with which to better understand the nature and consequences of cognitive fatigue.
Project description:Transitive inference (TI) is a disjunctive syllogism that allows an individual to indirectly infer a relationship between two components, by knowing their respective relationship to a third component (if A > B and B > C, then A > C). The common procedure is the 5-term series task, in which individuals are tested on indirect, unlearned relations. Few bird species have been tested for TI to date, which limits our knowledge of the phylogenetic spread of such reasoning ability. Here we tested TI in adult laying hens using a more solid methodology, the 6-term series task, which has not been tested in poultry so far. Six hens were trained to learn direct relationships in a sequence of six arbitrary items (A > B > C > D > E > F) in a hybrid training procedure. Then, 12 testing sessions were run, comprising 3 non-rewarded inference trials each: BD, BE, and CE. All subjects showed TI within 12 inference trials and were capable of TI whatever the relative distance between the items in the series. We found that TI performance was not impacted by the reinforcement ratios of the items for most individuals, making it harder to support a purely associative-based resolution of the task. We suggest that TI is based on the same cognitive processes in poultry (Galloanserae) than in modern flying birds (Neoaves), and that the cognitive strategy to solve the task might be driven mainly by individual parameters within species. These results contribute to a better understanding of transitive inference processes in birds.
Project description:Proteomics-based biological research is greatly expanded by high-quality mass spectrometry studies, which are themselves enabled by access to quality mass spectrometry resources, such as high-quality curated proteome data repositories. We present a PeptideAtlas for the domestic chicken, containing an extensive and robust collection of chicken tissue and plasma samples with substantial value for the chicken proteomics community for protein validation and design of downstream targeted proteome quantitation. The chicken PeptideAtlas contains 6646 canonical proteins at a protein FDR of 1.3%, derived from ∼100 000 peptides at a peptide level FDR of 0.1%. The rich collection of readily accessible data is easily mined for the purposes of data validation and experimental planning, particularly in the realm of developing proteome quantitation workflows. Herein we demonstrate the use of the atlas to mine information on common chicken acute-phase proteins and biomarkers for cancer detection research, as well as their localization and polymorphisms. This wealth of information will support future proteome-based research using this highly important agricultural organism in pursuit of both chicken and human health outcomes.
Project description:IntroductionDespite being a natural feline behavior, scratching can become undesirable from a human perspective when directed at household items. This complex behavior can stem from various motivations, ranging from individual cat characteristics to environmental factors. This study investigates the factors influencing the increased level of undesirable scratching behavior in domestic cats, considering both cat-related and environmental aspects.MethodsData from 1,211 cats were collected for this study. An online questionnaire comprising three sections was utilized. The first section gathered caregiver demographics, while the subsequent section examined aspects of cats' daily routines, social interactions, environments, behaviours, and temperaments. The final section assessed the frequency and intensity of undesirable scratching behavior in cats. Scratching behavior was evaluated based on a combined scratching index.ResultsThe study suggests that the presence of a child may be associated with scratching episodes in the home environment. Additionally, factors such as play duration, playfulness, and nocturnal activity were identified as significant contributors to heightened scratching levels (p ≤ 0.05). Aggressiveness and disruptiveness also played significant roles in increased scratching behavior (p ≤ 0.05). The location of scratching posts emerged as a significant factor, with posts placed in areas frequented by the cat being more effective in redirecting scratching behavior (p ≤ 0.05).DiscussionThis study reveals several significant associations between cat characteristics, nocturnal activity and play, as well as the environment. It underscores the multifaceted nature of undesirable scratching behavior and emphasizes the importance of comprehensively understanding both the individual characteristics of the cat and its environment to effectively address this behavior.
Project description:The hen is an attractive animal model for in vivo testing of agents that thwart ovarian carcinogenesis because ovarian cancer in the domestic hen features clinical and molecular alterations that are similar to ovarian cancer in humans, including a high incidence of p53 mutations. The objective of the study was to test the potential ovarian cancer chemopreventive effect of the p53 stabilizing compound CP-31398 on hens that spontaneously present the ovarian cancer phenotype. Beginning at 79 wk of age, 576 egg-laying hens (Gallus domesticus) were randomized to diets containing different amounts of CP-31398 for 94 wk, 5 d, comprising a control group (C) (n = 144), which was fed a diet containing 0 ppm (mg/kg) of CP-31398; a low-dose treatment (LDT) group (n = 144), which was fed a diet containing 100 ppm of CP-31398; a moderate-dose treatment (MDT) group (n = 144) which was fed a diet containing 200 ppm of CP-31398; and a high-dose treatment (HDT) group (n = 144), which was fed a diet containing 300 ppm of CP-31398. Hens were killed at 174 wk of age to determine the incidence of ovarian and oviductal adenocarcinomas. Whereas the incidence of localized and metastatic ovarian cancers in the MDT and HDT groups was significantly lower (up to 77%) compared to levels in the C and LDT groups (P < 0.05), the incidence of oviductal cancer was unaffected by CP-31398. CP-31398 appears to be an effective tool for chemoprevention against ovarian malignancies, but does not appear to affect oviductal malignancies.
Project description:Plants have evolved diverse strategies for foraging, e.g., mycorrhizae, modification of root system architecture, and secretion of phosphatase. Despite extensive molecular/physiological studies on individual strategies under laboratory/greenhouse conditions, there is little information about how plants orchestrate these strategies in the field. We hypothesized that individual strategies are independently driven by corresponding genetic modules in response to deficiency/unbalance in nutrients. Roots colonized by mycorrhizal fungi, leaves, and root-zone soils were collected from 251 maize plants grown across the United States Corn Belt and Japan, which provided a large gradient of soil characteristics/agricultural practice and thus gene expression for foraging. RNA was extracted from the roots, sequenced, and subjected to gene coexpression network analysis. Nineteen genetic modules were defined and functionally characterized, from which three genetic modules, mycorrhiza formation, phosphate starvation response (PSR), and root development, were selected as those directly involved in foraging. The mycorrhizal module consists of genes responsible for mycorrhiza formation and was upregulated by both phosphorus and nitrogen deficiencies. The PSR module that consists of genes encoding phosphate transporter, secreted acid phosphatase, and enzymes involved in internal-phosphate recycling was regulated independent of the mycorrhizal module and strongly upregulated by phosphorus deficiency relative to nitrogen. The root development module that consists of regulatory genes for root development and cellulose biogenesis was upregulated by phosphorus and nitrogen enrichment. The expression of this module was negatively correlated with that of the mycorrhizal module, suggesting that root development is intrinsically an opposite strategy of mycorrhizae. Our approach provides new insights into understanding plant foraging strategies in complex environments at the molecular level.
Project description:The venom and transcriptome profile of the captive Chinese cobra (Naja atra) is not characterized until now. Here, LC-MS/MS and illumine technology were used to unveil the venom and trascriptome of neonates and adults N. atra specimens. In captive Chinese cobra, 98 co-existing transcripts for venom-related proteins was contained. A total of 127 proteins belong to 21 protein families were found in the profile of venom. The main components of snake venom were three finger toxins (3-FTx), snake venom metalloproteinase (SVMP), cysteine-rich secretory protein (CRISP), cobra venom factor (CVF), and phosphodiesterase (PDE). During the ontogenesis of captive Chinese cobra, the rearrangement of snake venom composition occurred and with obscure gender difference. CVF, 3-FTx, PDE, phospholipase A2 (PLA2) in adults were more abundant than neonates, while SVMP and CRISP in the neonates was richer than the adults. Ontogenetic changes in the proteome of Chinese cobra venom reveals different strategies for handling prey. The levels of different types of toxin families were dramatically altered in the wild and captive specimens. Therefore, we speculate that the captive process could reshape the snake venom composition vigorously. The clear comprehension of the composition of Chinese cobra venom facilitates the understanding of the mechanism of snakebite intoxication and guides the preparation and administration of traditional antivenom and next-generation drugs for snakebite.
Project description:IntroductionCharacteristics of electronic nicotine delivery systems (ENDS) make assessment of their use a challenge for researchers. Cognitive interviews are a way of gaining insight into participants' interpretations of survey questions and the methods they use in answering them, to improve survey tools.MethodsWe used cognitive interviews to modify a young adult survey and improve assessment of quantity and frequency of ENDS use, as well as reasons for initiation and use of ENDS products. Twenty-five college students between the ages of 18 and 32 participated in individual cognitive interviews, which assessed question comprehension, answer estimation, retrieval processes, and answer response processes.ResultsComprehension issues arose discerning between ENDS device types (eg, cigalikes vs. vape pens), and answer estimation issues arose regarding ENDS use as drug delivery systems. These issues appeared to improve when pictures were added specifying the device in question, as well as when specific language naming nicotine as the ENDS product content was added to survey questions. Regarding answer retrieval, this sample of users had problems reporting their frequency of ENDS use, as well as quantifying the amount of ENDS products consumed (eg, volume of e-juice, number of cartridges, nicotine concentration).ConclusionsAccurate assessment of ENDS products proved challenging, but cognitive interviews provided valuable insight into survey interpretation that was otherwise inaccessible to researchers. Future research that explores how to assess the wide array of ENDS devices, as well as possible population differences among specific device-type users would be valuable to public health researchers and professionals.ImplicationsThis study extends the current literature by using cognitive interviews to test ENDS assessment questions in a sample of young adults, a population at elevated risk for ENDS use. Problems encountered when answering ENDS use questions underscore the need to develop easily understood ENDS questions that allow for quantification of ENDS use. Future research examining the nature of ENDS product types and different levels of user experience will yield valuable assessment tools for researchers and tobacco control professionals.
Project description:Foraging strategies are of great ecological interest, as they have a strong impact on the fitness of an individual and can affect its ability to cope with a changing environment. Recent studies on foraging strategies show a higher complexity than previously thought due to intraspecific variability. To reliably identify foraging strategies and describe the different foraging niches they allow individual animals to realize, high-resolution multivariate approaches which consider individual variation are required. Here we dive into the foraging strategies of Galápagos sea lions (Zalophus wollebaeki), a tropical predator confronted with substantial annual variation in sea surface temperature. This affects prey abundance, and El Niño events, expected to become more frequent and severe with climate change, are known to have dramatic effects on sea lions. This study used high-resolution measures of depth, GPS position and acceleration collected from 39 lactating sea lion females to analyze their foraging strategies at an unprecedented level of detail using a novel combination of automated broken stick algorithm, hierarchical cluster analysis and individually fitted multivariate hidden Markov models. We found three distinct foraging strategies (pelagic, benthic, and night divers), which differed in their horizontal, vertical and temporal distribution, most likely corresponding to different prey species, and allowed us to formulate hypotheses with regard to adaptive values under different environmental scenarios. We demonstrate the advantages of our multivariate approach and inclusion of individual variation to reliably gain a deeper understanding of the adaptive value and ecological relevance of foraging strategies of marine predators in dynamic environments.
Project description:Balancing foraging gain and predation risk is a fundamental trade-off in the life of animals. Individual strategies to acquire, process, store and use information to solve cognitive tasks are likely to affect speed and flexibility of learning, and ecologically relevant decisions regarding foraging and predation risk. Theory suggests a functional link between individual variation in cognitive style and behaviour (animal personality) via speed-accuracy and risk-reward trade-offs. We tested whether cognitive style and personality affect risk-reward trade-off decisions posed by foraging and predation risk. We exposed 21 bank voles (Myodes glareolus) that were bold, fast learning and inflexible and 18 voles that were shy, slow learning and flexible to outdoor enclosures with different risk levels at two food patches. We quantified individual food patch exploitation, foraging and vigilance behaviour. Although both types responded to risk, fast animals increasingly exploited both food patches, gaining access to more food and spending less time searching and exercising vigilance. Slow animals progressively avoided high-risk areas, concentrating foraging effort in the low-risk one, and devoting >50% of visit to vigilance. These patterns indicate that individual differences in cognitive style/personality are reflected in foraging and anti-predator decisions that underlie the individual risk-reward bias.