Investigations of host feeding behaviour in haematophagous insects are critical to assess transmission routes of vector-borne diseases. Understanding if a certain species has ornithophilic or mammalophilic feeding behaviour can facilitate future studies focused on pathogens transmission to and from certain host species. Culicoides Latreille (Diptera: Ceratopogonidae) are vectors of several pathogens, which include arboviruses, bacteria and parasites to a considerable diversity of vertebrate hosts. However, most of the studies focused on feeding habits target Culicoides species that could transmit the Bluetongue virus, consequently with a mammalophilic feeding behaviour, leaving aside the Culicoides species that are involved in the transmission of vector-borne parasites to birds, such as Haemoproteus Kruse (Haemosporida: Haemoproteidae). This study aimed to investigate the source of blood meals of wild-caught Culicoides using molecular-based methods and to correlate our findings with the reports of Haemoproteus parasites in Culicoides species. Engorged Culicoides females were collected using ultraviolet (UV)-light traps at seven different localities in Lithuania in 2021-2023. Biting midges were dissected, and the abdomens of engorged females were used for molecular investigation of the blood meal source. A polymerase chain reaction (PCR) protocol that amplifies a fragment of the Cytochrome B gene of vertebrates was used. Obtained sequences were compared to available information in GenBank database to confirm the source of the blood meal. In total, 258 engorged Culicoides females, representing nine different species, were analysed. The source of blood meal was identified in 29.1% of them with most of the insects having fed on birds (74.7%) and the remaining on mammals (25.3%). Culicoides segnis Campbell, Pelham-Clinton was the only species to feed exclusively on birds; Culicoides from the Obsoletus group, C. pallidicornis Kieffer and C. punctatus Latreille were found to feed exclusively on mammals; C. festivipennis Kieffer, C. kibunensis Tokunaga and C. pictipennis Staeger had an opportunistic feeding behaviour, with the first two preferably feeding on birds. Due to their feeding behaviour and the presence of Haemoproteus parasites reported in the literature, C. festivipennis, C. kibunensis, C. pictipennis, and C. segnis play an important role in the transmission of those avian vector-borne parasite in the wild. These Culicoides species were already confirmed as being able to support the development of several Haemoproteus species and lineages. Future studies focused on understanding the epidemiology of avian pathogens transmitted by Culicoides should target these species.

OBJECTIVE: Liver-expressed antimicrobial peptide 2 (LEAP2) dynamics in human plasma and its association with feeding behaviour remain poorly understood. Therefore, this study aims: (a) to investigate fasting LEAP2 in participants with normal weight or with overweight or mild obesity (OW/OB); (b) to study the association between fasting LEAP2 and anthropometric and metabolic traits, feeding behaviour, LEAP2 genetic variants and blood cell DNA methylation status; and (c) to ascertain postprandial changes in LEAP2 after high protein intake and the association with feeding behaviour and food intake.
METHODS: Anthropometric and behavioural measures, genotyping, methylation profiling, plasma glucose and LEAP2 concentrations were assessed in 327 females and males. A subgroup of 123 participants received an ad libitum high-protein meal, and postprandial LEAP2 concentration and behavioural measures were assessed.
RESULTS: LEAP2 concentration was higher in participants with OW/OB (p < 0.001) and in females (p < 0.001), and was associated with LEAP2 single nucleotide polymorphisms rs765760 (p = 0.012) and rs803223 (p = 0.019), but not with LEAP2 methylation status. LEAP2 concentration was directly related to glycaemia (p = 0.001) and fullness (p = 0.003) in participants with normal weight, whereas it was associated with body mass index (p = 0.018), waist circumference (p = 0.014) and motor impulsivity in participants with OW/OB (p = 0.005). A negative association with reward responsiveness was observed in participants with OW/OB (p = 0.023). LEAP2 concentration was inversely associated with food intake (p = 0.034) and decreased after a high-protein meal (p < 0.001), particularly in women (p = 0.002).
CONCLUSIONS: Increased LEAP2 in participants with OW/OB is associated with behavioural characteristics of obesity. Our results show sexual dimorphism in LEAP2 concentration before and after food intake and highlight the role of LEAP2 in feeding regulation.

Urban configuration and food availability influence birds\' foraging behaviour and constitute key factors for understanding how they exploit cities. Here, we conducted a field survey in the city of Madrid (Spain) from winter 2021 to autumn 2022 to understand how the common wood pigeon (Columba palumbus) exploits the food resources provided by urban parks and streets across different seasons. The proportion of observations away from parks increased during winter and spring, and the proportion of observations of wood pigeons eating on the ground was the greatest in summer. The common wood pigeon fed from 45 tree species, 60% of which were exotic ornamental species. Most tree species used as food sources coincided with those widely planted in parks, streets and avenues. The preferred trees varied throughout the year, with a greater incidence of exotic species in winter and spring. Our results show that the diversity of trees available in cities and the use of non-native plants with contrasting phenological patterns compared with the local flora are crucial elements in explaining the successful establishment of the common wood pigeon in the city.

Neuropeptide Y (NPY) plays a crucial role in controlling energy homeostasis and feeding behaviour. The role of NPY neurons located in the arcuate nucleus of the hypothalamus (Arc) in responding to homeostatic signals has been the focus of much investigation, but most studies have used AgRP promoter-driven models, which do not fully encompass Arc NPY neurons. To directly investigate NPY-expressing versus AgRP-expressing Arc neurons function, we utilised chemogenetic techniques in NPY-Cre and AgRP-Cre animals to activate Arc NPY or AgRP neurons in the presence of food and food-related stimuli. Our findings suggest that chemogenetic activation of the broader population of Arc NPY neurons, including AgRP-positive and AgRP-negative NPY neurons, has equivalent effects on feeding behaviour as activation of Arc AgRP neurons. Our results demonstrate that these Arc NPY neurons respond specifically to caloric signals and do not respond to non-caloric signals, in line with what has been observed in AgRP neurons. Activating Arc NPY neurons significantly increases food consumption and influences macronutrient selection to prefer fat intake.

Nutritional exposure is considered the main environmental influence that contributes to gallstone disease (GD).
The aim of this study was to determine food intakes patters and estimate risk of GD.
A nested case-control study was carried out within the framework of a previous screening study conducted on a representative sample in Rosario, Argentina. Participants underwent a personal interview. Average amount of each food intake and quantity nutrients were estimated applying a food-frequency questionnaire. Food consumption patterns were identified by principal component analysis, and logistic regression analysis was used to estimate risks.
The sample was conformed by 51 cases and 69 controls. Two dietary patterns were identified. Cases were characterised by the unhealthy intake pattern (high intakes of animal fats, sugar, cereals, grains, cold cuts, processed meats, chicken with skin, fat beef and low intake of red vegetables and yellows, cabbages, fruits and fish).
Controls were characterised by the healthy intake pattern (high intake of skinless chicken, nuts, lean beef, vitamin A and C rich fruits, and low consumption of chicken with skin, green leaves vegetables and sprouts). The unhealthy pattern showed an increased risk of developing GD while healthy patter behaved as a protective factor.
La exposición nutricional se considera la principal exposición ambiental que contribuye a la formación de cálculos biliares.
El objetivo de este trabajo fue determinar el patrón de consumo alimentario de casos y controles de EC y estimar el riesgo de desarrollar la enfermedad según los distintos patrones constituidos.
Se llevó a cabo un estudio analítico retrospectivo transversal de casos y controles, anidado a un estudio de prevalencia realizado en Rosario. Todos los participantes fueron entrevistados personalmente. El consumo de alimentos se consignó a través de un cuestionario semi-cuantitativo de frecuencia de consumo. Para determinar patrones de consumo alimentario se realizó un análisis de componentes principales, y análisis de regresión logística múltiple para evaluar riesgos.
La muestra quedó conformada por 51 casos y 69 controles. Se determinaron dos componentes que permitían diferenciar los casos de los controles, a través de las cuales se establecieron 2 patrones de consumo. Los casos se caracterizaron por un consumo determinado por el Patrón Poco saludable (altas ingestas de grasas animales, azúcar, cereales, granos, fiambres y embutidos) y los controles por el consumo del patrón Saludable (altas ingestas de pollo sin piel, frutas secas, carne vacuna magra, frutas, lácteos enteros). El patrón Poco saludable, aumentó el riesgo de desarrollar EC mientras que el patrón Saludable, se comportó como protector.
Los patrones constituidos diferencian los casos de los controles, y la ingesta propia de los casos se correlaciona con un perfil de consumo que caracteriza a las culturas occidentales modernas y urbanas.

The relation between aphids and Sclerotinia stem rot (SSR) in oilseed rape is rarely examined because they are often studied alone. We have observed a significant correlation between the number of aphids and the occurrence of SSR in our field studies. Electropenetrography (EPG) was used to evaluate the effects of Brevicoryne brassicae (Linnaeus) on two oilseed rape cultivars while acquiring, vectoring and inoculating of Sclerotinia sclerotiorum Lib. (de Bary) ascospores. The results demonstrated that aphid feeding followed by the application of an ascospore suspension significantly increased S. sclerotiorum incidence. Aphids were capable of adhering to ascospores and carrying them to healthy plants, thereby causing diseases. The results of the EPG analysis indicated that aphid feeding behaviour was significantly altered in all leaf tissue levels following infection with S. sclerotiorum. Aphids initiated their first puncture significantly sooner than the control group, began probing mesophyll cells earlier, significantly increased the frequency of both short probes and intracellular punctures and had a significantly shorter pathway duration. On infected aphid-susceptible cultivars, aphids secreted more saliva but had reduced ingestion compared with aphids feeding on non-infected oilseed rape. In addition, ascospores can affect aphid feeding behaviour by adhering to aphids. Aphids carrying ascospores punctured cells earlier, with a significant increase in the frequency and duration of short probes and cell punctures, shortened pathway durations, increased salivation and reduced ingestion compared with aphids not carrying ascospores. On aphid-susceptible cultivars, aphids carrying ascospores delayed puncture onset, but on resistant cultivars, puncture onset was shortened. There is a correlation between aphids and S. sclerotiorum. The impact of S. sclerotiorum on aphid feeding behaviour is directional, favouring the spread of the fungus. This promotion does not appear to be altered by the aphid resistance of the cultivar.

Artificial light at night (ALAN) negatively impacts organisms in many ways, from their feeding behaviors to their response and ability to deal with disease. Our knowledge of ALAN is focused on hosts, but we must also consider their parasites, which constitute half of all described animal species. Here, we assessed the impact of light exposure on a model host-parasite system (Poecilia reticulata and the ectoparasitic monogenean Gyrodactylus turnbulli). First, parasite-free fish were exposed to 12:12 h light:dark (control) or 24:0 h light:dark (ALAN) for 21 days followed by experimental infection. Second, naturally acquired G. turnbulli infections were monitored for 28 days during exposure of their hosts to a specified light regime (6:18 h, 12:12 h, or 24:0 h light:dark). Experimentally infected fish exposed to constant light had, on average, a greater maximum parasite burden than controls, but no other measured parasite metrics were impacted. Host feeding behavior was also significantly affected: fish under ALAN fed faster and took more bites than controls, whilst fish exposed to reduced light fed slower. Thus, ALAN can impact parasite burdens, even in the short term, and altering light conditions will impact fish feeding behavior. Such responses could initiate disease outbreaks or perturb food-webs with wider ecological impacts.

Measuring feed intake accurately is crucial to determine feed efficiency and for genetic selection. A system using three-dimensional (3D) cameras and deep learning algorithms can measure the volume of feed intake in dairy cows, but for now, the system has not been validated for feed intake expressed as weight of feed. The aim of this study was to validate the weight of feed intake predicted from the 3D cameras with the actual measured weight. It was hypothesised that diet-specific coefficients are necessary for predicting changes in weight, that the relationship between weight and volume is curvilinear throughout the day, and that manually pushing the feed affects this relationship. Twenty-four lactating Danish Holstein cows were used in a cross-over design with four dietary treatments, 2 × 2 factorial arranged with either grass-clover silage or maize silage as silage factor, and barley or dried beet pulp as concentrate factor. Cows were adapted to the diets for 11 d, and for 3 d to tie-stall housing before camera measurements. Six cameras were used for recording, each mounted over an individual feeding platform equipped with a weight scale. When building the predictive models, four cameras were used for training, and the remaining two for testing the prediction of the models. The most accurate predictions were found for the average feed intake over a period when using the starting density of the feed pile, which resulted in the lowest errors, 6% when expressed as RMSE and 5% expressed as mean absolute error. A model including curvilinear effects of feed volume and the impact of manual feed pushing was used on a dataset including daily time points. When cross-validating, the inclusion of a curvilinear effect and a feed push effect did not improve the accuracy of the model for neither the feed pile nor the feed removed by the cow between consecutive time points. In conclusion, measuring daily feed intake from this 3D camera system in the present experimental setup could be accomplished with an acceptable error (below 8%), but the system should be improved for individual meal intake measurements if these measures were to be implemented.

Sleep may influence appetite regulation through physiological and neurocognitive pathways. However, the association between sleep and appetite in childhood has been scarcely reported, particularly using a prospective design. We aimed to test associations between sleep duration at 7 years of age (y) and appetitive traits at both 7 and 10 y. Participants are from the population-based birth cohort Generation XXI (Porto, Portugal), at 7 (n = 2437) and 10 y (n = 1938) follow-ups. Data on sleep was gathered at 7 y and, considering bedtime and get-up time, total mean sleep duration was calculated and further categorized according to the 10th and 90th percentiles. Appetitive traits were assessed at 7 and 10 y using the parent-reported Children\'s Eating Behaviour Questionnaire. Associations were tested through Generalized Linear Models (co-variates: child\'s sex; maternal age, education and pre-pregnancy body mass index at 7 y). At 10 y, associations were further adjusted for the respective appetitive trait at 7 y. Children slept a mean of 10.2 h/night, and 13% and 9% slept ≤9.5 and ≥ 11.0 h/night at 7 y, respectively. For each additional hour in sleep duration, children scored 0.078 (99%CI: -0.145; -0.011) lower on Food Responsiveness, 0.065 (99%CI: -0.129; -0.002) lower on Emotional Undereating and 0.096 (99%CI: -0.161; -0.032) lower on Food Fussiness. Lastly, children sleeping ≤9.5 h/night scored higher on Food Responsiveness (β = 0.145 99%CI: 0.020; 0.271); while those sleeping ≥11.0 h/night scored lower on Food Fussiness (β = -0.255 99%CI: -0.370; -0.079). No significant prospective associations were found. In conclusion, in 7 y children, sleep duration was cross-sectionally associated with lower scores on food approach (Food Responsiveness) and avoidant traits (Emotional Undereating and Food Fussiness). However, the magnitude of the associations was small and further studies are warranted.

OBJECTIVE: Glucose dependent insulinotropic polypeptide (GIP) is well established as an incretin hormone, boosting glucose-dependent insulin secretion. However, whilst anorectic actions of its sister-incretin glucagon-like peptide-1 (GLP-1) are well established, a physiological role for GIP in appetite regulation is controversial, despite the superior weight loss seen in preclinical models and humans with GLP-1/GIP dual receptor agonists compared with GLP-1R agonism alone.
METHODS: We generated a mouse model in which GIP expressing K-cells can be activated through hM3Dq Designer Receptor Activated by Designer Drugs (DREADD, GIP-Dq) to explore physiological actions of intestinally-released GIP.
RESULTS: In lean mice, Dq-stimulation of GIP expressing cells increased plasma GIP to levels similar to those found postprandially. The increase in GIP was associated with improved glucose tolerance, as expected, but also triggered an unexpected robust inhibition of food intake. Validating that this represented a response to intestinally-released GIP, the suppression of food intake was prevented by injecting mice peripherally or centrally with antagonistic GIPR-antibodies, and was reproduced in an intersectional model utilising Gip-Cre/Villin-Flp to limit Dq transgene expression to K-cells in the intestinal epithelium. The effects of GIP cell activation were maintained in diet induced obese mice, in which chronic K-cell activation reduced food intake and attenuated body weight gain.
CONCLUSIONS: These studies establish a physiological gut-brain GIP-axis regulating food intake in mice, adding to the multi-faceted metabolic effects of GIP which need to be taken into account when developing GIPR-targeted therapies for obesity and diabetes.