Inhibitory control, exploration behaviour and manipulated ecological context are associated with foraging flexibility in the great tit.

Organisms are constantly under selection to respond effectively to diverse, sometimes rapid, changes in their environment, but not all individuals are equally plastic in their behaviour. Although cognitive processes and personality are expected to influence individual behavioural plasticity, the effects reported are highly inconsistent, which we hypothesise is because ecological context is usually not considered. We explored how one type of behavioural plasticity, foraging flexibility, was associated with inhibitory control (assayed using a detour-reaching task) and exploration behaviour in a novel environment (a trait closely linked to the fast-slow personality axis). We investigated how these effects varied across two experimentally manipulated ecological contexts-food value and predation risk. In the first phase of the experiment, we trained great tits Parus major to retrieve high value (preferred) food that was hidden in sand so that this became the familiar food source. In the second phase, we offered them the same familiar hidden food at the same time as a new alternative option that was visible on the surface, which was either high or low value, and under either high or low perceived predation risk. Foraging flexibility was defined as the proportion of choices made during 4-min trials that were for the new alternative food source. Our assays captured consistent differences among individuals in foraging flexibility. Inhibitory control was associated with foraging flexibility-birds with high inhibitory control were more flexible when the alternative food was of high value, suggesting they inhibited the urge to select the familiar food and instead selected the new food option. Exploration behaviour also predicted flexibility-fast explorers were more flexible, supporting the information-gathering hypothesis. This tendency was especially strong under high predation risk, suggesting risk aversion also influenced the observed flexibility because fast explorers are risk prone and the new unfamiliar food was perceived to be the risky option. Thus, both behaviours predicted flexibility, and these links were at least partly dependent on ecological conditions. Our results demonstrate that an executive cognitive function (inhibitory control) and a behavioural assay of a well-known personality axis are both associated with individual variation in the plasticity of a key functional behaviour. That their effects on foraging flexibility were primarily observed as interactions with food value or predation risk treatments also suggest that the population-level consequences of some behavioural mechanisms may only be revealed across key ecological conditions.

Cognition and covariance in the producer-scrounger game.

The producer-scrounger game is a key element of foraging ecology in many systems. Producing and scrounging typically covary negatively, but partitioning this covariance into contributions of individual plasticity and consistent between individual differences is key to understanding population-level consequences of foraging strategies. Furthermore, little is known about the role cognition plays in the producer-scrounger game. We investigated the role of cognition in these alternative foraging tactics in wild mixed-species flocks of great tits and blue tits, using a production learning task in which we measured individuals' speed of learning to visit the single feeder in an array that would provide them with a food reward. We also quantified the proportion of individuals' feeds that were scrounges ('proportion scrounged'); scrounging was possible if individuals visited immediately after a previous rewarded visitor. Three learning experiments-initial and two reversal learning-enabled us to estimate the repeatability and covariance of each foraging behaviour. First, we examined whether individuals learned to improve their scrounging success (i.e. whether they obtained food by scrounging when there was an opportunity to do so). Second, we quantified the repeatability of proportion scrounged, and asked whether proportion scrounged affected production learning speed among individuals. Third, we used multivariate analyses to partition within- and among-individual components of covariance between proportion scrounged and production learning speed. Individuals improved their scrounging success over time. Birds with a greater proportion scrounged took longer to learn their own rewarding feeder. Although multivariate analyses showed that covariance between proportion scrounged and learning speed was driven primarily by within-individual variation, that is, by behavioural plasticity, among-individual differences also played a role for blue tits. This is the first demonstration of a cognitive trait influencing producing and scrounging in the same wild system, highlighting the importance of cognition in the use of alternative resource acquisition tactics. The results of our covariance analyses suggest the potential for genetic differences in allocation to alternative foraging tactics, which are likely species- and system-dependent. They also point to the need to control for different foraging tactics when studying individual cognition in the wild.

Individual recognition through olfactory-auditory matching in lemurs.

Individual recognition can be facilitated by creating representations of familiar individuals, whereby information from signals in multiple sensory modalities become linked. Many vertebrate species use auditory-visual matching to recognize familiar conspecifics and heterospecifics, but we currently do not know whether representations of familiar individuals incorporate information from other modalities. Ring-tailed lemurs (Lemur catta) are highly visual, but also communicate via scents and vocalizations. To investigate the role of olfactory signals in multisensory recognition, we tested whether lemurs can recognize familiar individuals through matching scents and vocalizations. We presented lemurs with female scents that were paired with the contact call either of the female whose scent was presented or of another familiar female from the same social group. When the scent and the vocalization came from the same individual versus from different individuals, females showed greater interest in the scents, and males showed greater interest in both the scents and the vocalizations, suggesting that lemurs can recognize familiar females via olfactory-auditory matching. Because identity signals in lemur scents and vocalizations are produced by different effectors and often encountered at different times (uncoupled in space and time), this matching suggests lemurs form multisensory representations through a newly recognized sensory integration underlying individual recognition.

Intravenous Drug Abuser Treated for Chronic Infected Open Forearm Fracture with Shortening and Primary Wound Closure.

Neglected and open forearm fracture wounds accompanied by shortening are complex injuries that are seldom reported in the known literature. We describe a patient with a history of chronic intravenous drug abuse (IVDA) and a neglected forearm wound with radius and ulna fractures with chronic osteomyelitis managed by limb salvage. The patient had a history of IVDA and a neglected forearm wound with fractures in both the radius and ulna, along with chronic osteomyelitis. The approach taken to manage this complex injury involved limb salvage. The case emphasizes the treatment challenges associated with patients who had IVDA and neglected their wounds. Thorough evaluation combining clinical and radiological assessments, followed by appropriate surgical planning and intervention, played a crucial role in restoring the functional status of the limb. Neglected open fracture wounds in the forearm are uncommon and have limited documentation in the existing literature. The described patient's chronic history of IVDA and the disregarded open forearm osteomyelitis exemplify the severe consequences that can arise from injectable drug abuse in the upper extremity. In such cases, limb preservation and optimization of functional outcomes become paramount. To the best of our knowledge, this is one among the few reported cases of this nature, highlighting the significance of sharing such experiences to enhance medical understanding and inform future treatment approaches.

Hemolysis at different vacuum levels during vacuum-assisted venous drainage: a prospective randomized clinical trial.

BACKGROUND: There are several reports on the application of variable degrees of vacuum pressure to hardshell venous reservoirs. The aim of the current study was to compare the hemolytic effects of vacuum-assisted venous drainage (VAVD) at two different vacuum levels with the classical gravity siphon method. METHODS: A prospective, equally randomized (1: 1: 1), parallel group study was performed in elective coronary artery bypass grafting (CABG) operations. PATIENTS: (n = 162) were divided into three groups: gravity siphon (group 1, n = 55), VAVD at -40 mmHg (group 2, n = 55) and VAVD at -80 mmHg (group 3, n = 52). Hemolysis tests were performed at 2, 24 and 48 h following the operations. RESULTS: There were no deaths in this study. Plasma-free hemoglobin (PfHb) levels showed a difference at 2 h (p < 0.001) compared to 24 h (p = 0.02) between the groups. Haptoglobin (Hp) levels also revealed hemolysis in groups 2 and 3 at all sampling times. CONCLUSIONS: Constant negative suction at -80 mmHg during elective coronary bypass operations caused more hemolysis. We do not recommend a constant suction of -80 mmHg for VAVD.

Multiple factors affect discrimination learning performance, but not between-individual variation, in wild mixed-species flocks of birds.

Cognition arguably drives most behaviours in animals, but whether and why individuals in the wild vary consistently in their cognitive performance is scarcely known, especially under mixed-species scenarios. One reason for this is that quantifying the relative importance of individual, contextual, ecological and social factors remains a major challenge. We examined how many of these factors, and sources of bias, affected participation and performance, in an initial discrimination learning experiment and two reversal learning experiments during self-administered trials in a population of great tits and blue tits. Individuals were randomly allocated to different rewarding feeders within an array. Participation was high and only weakly affected by age and species. In the initial learning experiment, great tits learned faster than blue tits. Great tits also showed greater consistency in performance across two reversal learning experiments. Individuals assigned to the feeders on the edge of the array learned faster. More errors were made on feeders neighbouring the rewarded feeder and on feeders that had been rewarded in the previous experiment. Our estimates of learning consistency were unaffected by multiple factors, suggesting that, even though there was some influence of these factors on performance, we obtained a robust measure of discrimination learning in the wild.

Diet induces parallel changes to the gut microbiota and problem solving performance in a wild bird.

The microbial community in the gut is influenced by environmental factors, especially diet, which can moderate host behaviour through the microbiome-gut-brain axis. However, the ecological relevance of microbiome-mediated behavioural plasticity in wild animals is unknown. We presented wild-caught great tits (Parus major) with a problem-solving task and showed that performance was weakly associated with variation in the gut microbiome. We then manipulated the gut microbiome by feeding birds one of two diets that differed in their relative levels of fat, protein and fibre content: an insect diet (low content), or a seed diet (high content). Microbial communities were less diverse among individuals given the insect compared to those on the seed diet. Individuals were less likely to problem-solve after being given the insect diet, and the same microbiota metrics that were altered as a consequence of diet were also those that correlated with variation in problem solving performance. Although the effect on problem-solving behaviour could have been caused by motivational or nutritional differences between our treatments, our results nevertheless raise the possibility that dietary induced changes in the gut microbiota could be an important mechanism underlying individual behavioural plasticity in wild populations.

Dynamic Relationships between Information Transmission and Social Connections.

Understanding the drivers of sociality is a major goal in biology. Individual differences in social connections determine the overall group structure and have consequences for a variety of processes, including if and when individuals acquire information from conspecifics. Effects in the opposite direction, where information acquisition and transmission have consequences for social connections, are also likely to be widespread. However, these effects are typically overlooked. We propose that individuals who successfully learn about their environment become valuable social partners and become highly connected, leading to feedback-based dynamic relationships between social connections and information transmission. These dynamics have the potential to change our understanding of social evolution, including how selection acts on behavior and how sociality influences population-level processes.

Multimodal signals enhance decision making in foraging bumble-bees.

Multimodal signals are common in nature and have recently attracted considerable attention. Despite this interest, their function is not well understood. We test the hypothesis that multimodal signals improve decision making in receivers by influencing the speed and the accuracy of their decisions. We trained bumble-bees (Bombus impatiens) to discriminate between artificial flowers that differed either in one modality, visual (specifically, shape) or olfactory, or in two modalities, visual plus olfactory. Bees trained on multimodal flowers learned the rewarding flowers faster than those trained on flowers that differed only in the visual modality and, in extinction trials, visited the previously rewarded flowers at a higher rate than bees trained on unimodal flowers. Overall, bees showed a speed-accuracy trade-off; bees that made slower decisions achieved higher accuracy levels. Foraging on multimodal flowers did not affect the slope of the speed-accuracy relationship, but resulted in a higher intercept, indicating that multimodal signals were associated with consistently higher accuracy across range of decision speeds. Our results suggest that bees make more effective decisions when flowers signal in more than one modality, and confirm the importance of studying signal components together rather than separately.

Evaluation of the Quality of Beef Patties Formulated with Dried Pumpkin Pulp and Seed.

The objective of this study was to investigate quality attributes of beef patties formulated with dried pumpkin pulp and seed mixture (PM). Four different meatball formulations were prepared where lean was replaced with PM as C (0% PM), P2 (2% PM), P3 (3% PM) and P5 (5% PM). Utilization of PM decreased moisture and increased ash content of the patties. Incorporation of 5% PM (P5) increased the pH value of both uncooked and cooked patties compared to C group. Increasing levels of PM increased water-holding capacity. No significant differences were found in cooking yield and diameter change with the addition of PM. Incorporation of PM increased fat and decreased moisture retention of the samples. a* values were decreased with PM addition, where L* values did not differ among treatments and b* values were similar in C, P3 and P5 samples. Textural properties were mostly equivalent to control samples with the incorporation of PM even at higher concentrations. The addition of PM did not significantly affect any of the sensory scores tested. These results indicated that utilization of PM presents the opportunity to decrease the amount of meat besides to improve healthier profile without causing negative changes in physical, chemical and technological quality of beef patties.

Knowledgeable Lemurs Become More Central in Social Networks.

Strong relationships exist between social connections and information transmission [1-9], where individuals' network position plays a key role in whether or not they acquire novel information [2, 3, 5, 6]. The relationships between social connections and information acquisition may be bidirectional if learning novel information, in addition to being influenced by it, influences network position. Individuals who acquire information quickly and use it frequently may receive more affiliative behaviors [10, 11] and may thus have a central network position. However, the potential influence of learning on network centrality has not been theoretically or empirically addressed. To bridge this epistemic gap, we investigated whether ring-tailed lemurs' (Lemur catta) centrality in affiliation networks changed after they learned how to solve a novel foraging task. Lemurs who had frequently initiated interactions and approached conspecifics before the learning experiment were more likely to observe and learn the task solution. Comparing social networks before and after the learning experiment revealed that the frequently observed lemurs received more affiliative behaviors than they did before-they became more central after the experiment. This change persisted even after the task was removed and was not caused by the observed lemurs initiating more affiliative behaviors. Consequently, quantifying received and initiated interactions separately provides unique insights into the relationships between learning and centrality. While the factors that influence network position are not fully understood, our results suggest that individual differences in learning and becoming successful can play a major role in social centrality, especially when learning from others is advantageous.

How does cognition shape social relationships?

The requirements of living in social groups, and forming and maintaining social relationships are hypothesized to be one of the major drivers behind the evolution of cognitive abilities. Most empirical studies investigating the relationships between sociality and cognition compare cognitive performance between species living in systems that differ in social complexity. In this review, we ask whether and how individuals benefit from cognitive skills in their social interactions. Cognitive abilities, such as perception, attention, learning, memory, and inhibitory control, aid in forming and maintaining social relationships. We investigate whether there is evidence that individual variation in these abilities influences individual variation in social relationships. We then consider the evolutionary consequences of the interaction between sociality and cognitive ability to address whether bi-directional relationships exist between the two, such that cognition can both shape and be shaped by social interactions and the social environment. In doing so, we suggest that social network analysis is emerging as a powerful tool that can be used to test for directional causal relationships between sociality and cognition. Overall, our review highlights the importance of investigating individual variation in cognition to understand how it shapes the patterns of social relationships.This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.

Social networks predict selective observation and information spread in ravens.

Animals are predicted to selectively observe and learn from the conspecifics with whom they share social connections. Yet, hardly anything is known about the role of different connections in observation and learning. To address the relationships between social connections, observation and learning, we investigated transmission of information in two raven (Corvus corax) groups. First, we quantified social connections in each group by constructing networks on affiliative interactions, aggressive interactions and proximity. We then seeded novel information by training one group member on a novel task and allowing others to observe. In each group, an observation network based on who observed whose task-solving behaviour was strongly correlated with networks based on affiliative interactions and proximity. Ravens with high social centrality (strength, eigenvector, information centrality) in the affiliative interaction network were also central in the observation network, possibly as a result of solving the task sooner. Network-based diffusion analysis revealed that the order that ravens first solved the task was best predicted by connections in the affiliative interaction network in a group of subadult ravens, and by social rank and kinship (which influenced affiliative interactions) in a group of juvenile ravens. Our results demonstrate that not all social connections are equally effective at predicting the patterns of selective observation and information transmission.

Fifteen-year clinical experience with the biocor porcine bioprostheses in the mitral position.

BACKGROUND: Bioprosthetic valve use represents a crucial improvement in surgical treatment of mitral valve disease. The aim of this study is to determine the long-term durability of the Biocor porcine bioprosthetic mitral valve. METHODS: Between 1985 and 1989, a total of 158 Biocor porcine bioprosthetic valves were placed in the mitral position, and long-term results of these patients were investigated retrospectively in 1999. RESULTS: Thirty-day mortality was 4.4% (7 patients). Total follow-up was 1,499 patient-years. Actuarial survival was 83.66% +/- 3% at 5 years, 77.78% +/- 3.36% at 13 years (1.8% patient-year). Multivariate analysis demonstrated younger age, duration of implantation, congestive heart failure, and functional class to be significant predictors of late mortality. Actuarial freedom from valve-related mortality was 98.58% +/- 1% at 15 years (0.13% patient-year). Actuarial freedom from structural valve deterioration was 95.49% +/- 1.8% at 5 years, 70.2% +/- 4.12% at 10 years, and 64.82% +/- 5.34% at 13 years (2.6% patient-year). Actuarial freedom from structural valve deterioration-related reoperation was 98.43% +/- 1.1% at 5 years, 89.15% +/- 2.85% at 10 years, and 76.82% +/- 7.91% at 14 years. Multivariate analysis showed younger age and duration of implantation to be significant predictors of structural valve deterioration and its related reoperation. CONCLUSIONS: By studying a 15-year time period, it is seen that this new generation porcine bioprosthetic valve should be considered an alternative for mechanical valves in selected patients.

Midterm angiographic assessment of coronary artery bypass grafting without cardiopulmonary bypass.

BACKGROUND: Coronary bypass surgery that provides good long-term graft patency can be performed on the beating heart as a viable alternative to conventional coronary artery bypass grafting (CABG). METHODS: From September 1993 to December 1996, 696 patients underwent CABG on the beating heart at the Kosuyolu Heart and Research Hospital in Istanbul. Among them, 70 patients were chosen randomly for angiographic assessment of off-pump coronary artery bypass grafting. RESULTS: The interval from operation to angiography varied from 24 to 61 months (mean, 36.1+/-10.9 months). The patency rate of left internal mammary-left anterior descending artery anastomoses was 95.59% (patency achieved in 65 of 68 patients) and of vein grafts was 47.06% (patency achieved in 16 of 34 patients) (p < 0.0001). The patency rates of grafts anastomosed to the left anterior descending artery were significantly higher than the rates of the grafts anastomosed to the other coronary arteries (95.71% versus 45.45%, p < 0.0001). Multivariate analysis showed that graft type (p < 0.0001) and hyperlipidemia (p = 0.023) were significant predictors for graft occlusion. Left ventricular function improved significantly after CABG (p = 0.04). Reintervention (using percutaneous transluminal cardiac angioplasty) and reoperation rates were 0.97% and 1.4%, respectively. CONCLUSIONS: Off-pump coronary artery bypass grafting appears to produce midterm and long-term patency rates that are comparable to those of conventional techniques; that is especially true in cases of arterial conduits and of conduits anastomosed to the left anterior descending artery.

Paravalvular leakage after mitral valve replacement: is left atrial enlargement an additional indication for reoperation?

BACKGROUND AND AIM OF THE STUDY: Prostheses used to treat heart valve disease improve patient survival, but have certain disadvantages. Paravalvular leakage (PVL) is a rare complication after mitral valve replacement (MVR), and can impair cardiac function and reduce the patient's functional capacity, depending on the degree of periprosthetic regurgitation. METHODS: Between 1985 and July 1999, 2,502 patients underwent MVR with or without concomitant cardiac procedures. Of these patients, 33 (18 males, 15 females; mean age 39.8+/-15.3 years; range: 12-62 years) had PVL of differing degree. The interval between MVR and observation of PVL was 30.5+/-31.5 months (range: 1-126 months), and the period after diagnosis was 22.6+/-31.5 months (range: 2-114 months). Fourteen patients (42.4%) underwent reoperation (RO group), and 19 (57.6%) were followed medically (ME group). Indications for reoperation were reduction of functional capacity, echocardiographically proven serious mitral regurgitation, and hemolysis. RESULTS: Reoperative mortality was 3.0% (1/33), and late mortality 3.1% (1/32) for all patients. Cumulative survival after PVL was 90.2+/-6.7% at both five and ten years. Annular calcification (33.0%) and infective endocarditis (18.2%) were important predictive factors for development of PVL. Only one patient required second re-do surgery. Univariate and forward stepwise logistic regression analyses showed that there was no predictor for the development of severe PVL requiring a second reoperation. No difference was observed between left ventricular dimensions before and after periprosthetic regurgitation. The only significant finding between groups was an increase in left atrial diameter in RO patients after the development of PVL (p <0.05). CONCLUSION: Among patients undergoing MVR there are no clinical features to distinguish who will develop severe PVL during follow up. If PVL reduces the patient's functional capacity or causes serious hemolysis, or if severe PVL is evaluated echocardiographically, then reoperation must be performed. Mild or moderate mitral regurgitation without impairment of functional capacity may be followed medically. In asymptomatic patients, enlargement (>5%) of the left atrial diameter following development of moderate PVL may be a valuable criterion for deciding when to reoperate.

Mechanical versus biological valve prosthesis in the mitral position: a 10-year follow up of St. Jude Medical and Biocor valves.

BACKGROUND AND AIM OF THE STUDY: During the past 30 years, the development of mechanical and biological valves has led to major improvements in patient survival. Here, we present long-term results obtained with both types of prosthesis. METHODS: At our institution, between 1985 and 1989, 158 patients received a Biocor porcine bioprosthesis, and 100 patients a St. Jude Medical (SJM) mechanical valve. Preoperatively, mean age, male:female ratio, NYHA functional class and pathology of mitral valve disease were similar in both groups. RESULTS: The 30-day mortality was 4.4% in the Biocor group and 4% in the SJM group, the major cause being congestive heart failure. Late mortality was 17.9% and 15.6% respectively in the two groups, but valve-related mortality was very low in both (1.3% versus 4.2%). Ten-year survival was similar in each group (77.8+/-3.4% versus 81.0+/-3.9%; p = 0.538). Ten-year freedom from anticoagulant-related hemorrhage was higher with Biocor prostheses (99.3+/-0.7% versus 90.9+/-3.1%; p = 0.007). Valve thrombosis was seen only in the SJM group, and structural valve degeneration (SVD) only in the Biocor group. Ten-year freedom from reoperation was lower in the Biocor group (84.9+/-3.2% versus 92.2+/-2.8%; p = 0.206). The significant causes of reoperation were SVD in the Biocor group and valve thrombosis in the SJM group. Freedom from prosthetic valve endocarditis was similar in both groups (96.3+/-1.6% versus 95.5+/-2.2%). CONCLUSION: As no difference was seen in survival and reoperation rates between patients receiving either bioprostheses or mechanical valves, the valve used will depend on the surgeon's choice and the type of patient, notably elderly patients who are intolerant of anticoagulation, and young women wishing to have children.

Complete myocardial revascularization with left heart bypass without oxygenator on the beating heart.

BACKGROUND: Whereas the complete myocardial revascularization is necessary in high risk group patients, the CABG procedure on the beating heart on circumflex artery still presents a dilemma. METHODS: Between January 1994 and September 1996, we performed complete myocardial revascularization with left heart bypass in 62 patients (54 male, 8 female, mean age: 57) who had absolute or relative contraindications for CPB. RESULTS: The hospital mortality was 3.2%, late mortality was 1.6%. Peroperative MI was seen in 2 patients (3.2%). The mean number of distal anastomosis was 3.6 (ranged 2-6). CONCLUSION: Complete myocardial revascularization on the beating heart can be performed by using left heart bypass (LHBP) without using an oxygenerator safely in high risk patients.

Monofilament absorbable sutures in median sternotomy.

BACKGROUND: The most common material used for closure of median sternotomy incision is steel suture in open heart surgery. Some complications and disadvantages have been investigated recently. These complications are the breaking down of steel suture, erosion of sternum tabulae especially in osteoporotic patients, erosion of the dermis especially in patients with thin subdermic layer and cause of infection. Another disadventage of steel suture material is cosmetic problems or discomfort. For these reasons some suture materials such as silk, polyfilament polyester, monofilament material, polypropylene have been used recently. Silk and polyester have a risk of high infection, and polypropylene causes granulation tissue according to the number of knots. These facts encouraged the usage of an absorbable suture material. The available polyfilament absorbable sutures in the market a few years ago had a short absorption time, causing sternal infection and dehiscence. Polydiaxone, a monofilament suture material introduced recently has a considerably longer absorption time. METHODS: 153 sternal closures were performed with monofilament absorbable suture material in a period of seven months at the Kosuyolu Heart and Research Hospital. The mean age of the patients was 32.55, ranging from 8/12 to 71 years. The mean body weight is 48.37, ranging between 7 kg and 75 kg. RESULTS: Only two patients had sternal dehiscence. CONCLUSIONS: We conclude that monofilament absorbable suture is a safe alternative for all kinds of steel suture material for closure of sternotomy.