Shunt Group Research Articles

Bifurcations of a predator–prey system with cooperative hunting and Holling III functional response

In this paper, we consider the dynamics of a predator–prey system of Gause type with cooperative hunting among predators and Holling III functional response. The known work numerically shows that the system exhibits saddle-node and Hopf bifurcations except homoclinic bifurcation for some special parameter values. Our results show that there are a weak focus of multiplicity three and a degenerate equilibrium with double zero eigenvalues (i.e., a cusp of codimension two) for general parameter conditions and the system can exhibit various bifurcations as perturbing the bifurcation parameters appropriately, such as the transcritical and the pitchfork bifurcations at the degenerate boundary equilibrium, the saddle-node and the Bogdanov–Takens bifurcations at the degenerate positive equilibrium and the Hopf bifurcation around the weak focus. The comparative study demonstrates that the dynamics are far richer and more complex than that of the system without cooperative hunting among predators. The analysis results reveal that appropriate intensity of cooperative hunting among predators is beneficial for the persistence of predators and the diversity of ecosystem.

Numbers matter: Predatory ability increases with forager group size in omnivorous ant species with similar predatory traits

Abstract Predation is an important force structuring ecological communities. However, it is still controversial whether larger predator groups are more efficient at exploiting abundant resources. Here, we explored the association between the number of foragers and predation ability in generalist ant species that differ in forager numbers when exploiting resources. We conducted a field experiment by increasing caterpillar density around nests of two abundant Dorymyrmex ant species in the semiarid Patagonian steppe, where D. tener allocates a higher number of foragers to resource exploitation than D. antarcticus. We (1) compared the association between predation effectiveness (success to complete a task) and efficiency (speed of task performance and economy of foragers) with the number of foragers involved between species, and (2) studied how they responded numerically to increasing prey densities, by sequentially adding 3, 6 and 12 larvae in the same foraging arena. Finally, (3) we compared behavioural and morphological traits related to predation between these ant species. Although D. tener discovered a similar number of arenas with larvae than D. antarcticus, it was more effective as it recruited more and removed more larvae. This species was also more efficient than D. antarcticus in all predation subtasks, and the time used to remove one larva depended on prey density, being faster for the high‐larvae density. Besides the number of foragers, ant species did not differ in other behavioural traits, and D. tener's foragers were slightly larger than those of D. antarcticus. This study illustrates how, in social predators, the predator group size and individual behavioural characteristics may act in conjunction, with relevant consequences at ecological, evolutionary, and applied levels, including potential implications for pest control.

Sleep restriction increases coordination failure

When group outcomes depend on minimal effort (e.g., disease containment, work teams, or group hunt success), a classic coordination problem exists. Using a well- established paradigm, we examine how a common cognitive state (insufficient sleep) impacts coordination outcomes. Our data indicate that insufficient sleep increases coordination failure costs, which suggests that the sleep or, more generally, cognitive composition of a group might determine its ability to escape from a trap of costly miscoordination and wasted cooperative efforts. These findings are first evidence of the potentially large externality of a commonly experienced biological state (insufficient sleep) that has infiltrated many societies.

Intracranial drainage versus extracranial shunt in the treatment of intracranial arachnoid cysts: a meta-analysis.

To review the literature and analyze the efficacy and safety of two surgery procedures, intracranial drainage and extracranial shunt, for intracranial arachnoid cysts. We searched the online Medlars, PubMed, and Cochrane Central electronic databases and collected studies of patients with intracranial arachnoid cysts treated with two surgical methods. The meta-analysis results shows that there were not statistically significant in clinical symptoms improvement, cyst reduction, the improvement of epilepsy, epidural hematoma, cerebrospinal fluid leak, and recurrence rate (P > 0.05, with RR values are 0.99, 0.94, 1.00, 0.94, 1.21, and 0.75 respectively). There was statistically significant in the occurrence rate of intracranial infection (P = 0.0004, RR = 0.28). The intracranial drainage group was lower than extracranial shunt group. The results indicated that the efficacy and safety of two surgery procedures are similar in the treatment of intracranial arachnoid cysts, but the intracranial drainage was better than extracranial shunt in reducing the risk of intracranial infection.

How should we treat long-standing overt ventriculomegaly in adults (LOVA)? A retrospective cohort study

Long-standing overt ventriculomegaly in adults (LOVA) is a heterogenous group of conditions with differing presentations. Few studies have evaluated success rates of available surgical treatments, or ascertained the natural history. There is a need to assess the efficacy of both endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt (VPS) as first-line treatments. We conducted a retrospective, single-centre study of adults with LOVA at a tertiary neurosurgery centre in England, UK, aiming to identify presentation, management strategy, and outcome following treatment. A total of 127 patients were included (mean age 48.1 years, 61/127 male). Most patients were symptomatic (73.2%, n = 93/127, median symptom duration 10 months). The most common symptoms were gait ataxia, headache, and cognitive decline (52.8%, 50.4%, and 33.9%, respectively). Fourteen patients had papilloedema. Ninety-one patients (71.7%) underwent surgery (84 ETV, 7 VPS). Over a median follow-up of 33.0 months (interquartile range [IQR] 19.0–65.7), 82.4% had a clinical improvement after surgery, and 81.3% had radiological improvement. Clinical improvement rates were similar between ETV and VP shunt groups (82.1% vs 85.7%, p = 0.812). Surgical complication rates were significantly lower in the ETV group than the VP shunt group (4.8% vs 42.9%, p < 0.001). Of the patients treated surgically, 20 (22.0%) underwent further surgery, with 14 patients improving. This study demonstrates the efficacy of ETV as a first-line treatment for LOVA.

The effects of social rank and payoff structure on the evolution of group hunting.

Group hunting is common among social carnivores, and mechanisms that promote this behavior are a central topic in evolutionary biology. Increased prey capture success and decreased losses from competitors are often invoked as factors promoting group hunting. However, many animal societies have linear dominance hierarchies where access to critical resources is determined by social rank, and group-hunting rewards are shared unequally. Despite this inequality, animals in such societies cooperate to hunt and defend resources. Game theoretic models predict that rank and relative rewards from group hunting vs. solitary hunting affect which hunting strategies will evolve. These predictions are partially supported by empirical work, but data needed to test these predictions are difficult to obtain in natural systems. We use digital evolution to test how social rank and tolerance by dominants of subordinates feeding while sharing spoils from group hunting influence which hunting strategies evolve in digital organisms. We created a computer-simulated world to reflect social and hunting dynamics of spotted hyenas (Crocuta crocuta). We found that group hunting increased as tolerance increased and as the relative payoff from group hunting increased. Also, top-ranking agents were more likely to group hunt than lower-ranking agents under despotic sharing conditions. These results provide insights into mechanisms that may promote cooperation in animal societies structured by dominance hierarchies.

A comparison of mixed‐mode survey designs for collecting deer and fall turkey harvest data in North Dakota

AbstractAchieving state wildlife agency biological goals for deer (Odocoileus spp.) and turkey (Meleagris gallopavo) rely on high quality data collection via hunter harvest surveys. Concomitantly, better information is needed to optimize harvest survey methods. From 2017 to 2019, we surveyed North Dakota, USA, deer and fall turkey hunters using a self‐administered mail survey as a control and 3 mixed‐mode, internet/mail surveys to evaluate the efficacy of alternative survey designs for estimating harvest of game populations and informing future management. We measured response rates across segments of North Dakota deer and fall turkey hunters, and across mixed‐mode treatments that could easily be implemented with existing wildlife agency resources. We also determined whether early survey respondents were more likely to harvest deer or turkey. Finally, we estimated the effects of demographic factors that may be associated with hunters returning survey treatment modes to further North Dakota Game and Fish Department's ability to tailor surveys to certain hunter groups. We found that internet‐mail and mail‐internet treatments resulted in significantly higher response rates than a traditional mail‐only survey mode. We also found that hunters who successfully harvested an animal were more likely to return questionnaires shortly after the initial wave of surveying. Finally, we found that older, nonresident, and urban hunters were more likely to return questionnaires. Our research demonstrates potential use of tailored mixed‐mode surveys to increase response rates.

Navigation Situation Assessment of Autonomous Surface Vehicles in a Cooperative Hunting Environment

Abstract This paper proposes a navigation situation assessment method for autonomous surface vehicles (ASVs) in a cooperative hunting environment. By virtue of the repulsion function expressed in the artificial potential field, the navigation situation of hunting ASVs and target ASVs is firstly described. And the hunting situation is also constructed to describe the cooperative hunting. Based on the navigation situation and the hunting situation, a navigation situation assessment method for cooperative hunting of multiple ASVs is designed, where the number of hunting vehicles and the hunting radius can be successfully computed. Simulation results show that this proposed situation assessment method can give an optimised formation pattern and provide an effective reference for cooperative hunting of ASVs.

A Novel Chimp Optimization Algorithm with Refraction Learning and Its Engineering Applications

The Chimp Optimization Algorithm (ChOA) is a heuristic algorithm proposed in recent years. It models the cooperative hunting behaviour of chimpanzee populations in nature and can be used to solve numerical as well as practical engineering optimization problems. ChOA has the problems of slow convergence speed and easily falling into local optimum. In order to solve these problems, this paper proposes a novel chimp optimization algorithm with refraction learning (RL-ChOA). In RL-ChOA, the Tent chaotic map is used to initialize the population, which improves the population’s diversity and accelerates the algorithm’s convergence speed. Further, a refraction learning strategy based on the physical principle of light refraction is introduced in ChOA, which is essentially an Opposition-Based Learning, helping the population to jump out of the local optimum. Using 23 widely used benchmark test functions and two engineering design optimization problems proved that RL-ChOA has good optimization performance, fast convergence speed, and satisfactory engineering application optimization performance.

Quantitative analysis of contrast-enhanced ultrasound estimates intrahepatic portal vascularity in dogs with single extrahepatic portosystemic shunt.

To evaluate the clinical impact on quantitative analysis of contrast-enhanced ultrasound (CEUS) on single extrahepatic portosystemic shunt (PSS) in dogs. 21 client-owned dogs with single extrahepatic PSS and 5 healthy Beagles. In all dogs, CEUS was performed to calculate the rising time (RT), rising rate (RR), and portal vein-to-hepatic parenchyma transit time (ΔHP-PV) from the time-intensity curve obtained in the hepatic parenchyma and portal vein. All dogs in the PSS group underwent preoperative CT angiography (CTA) and surgery. The CEUS variables in the PSS group were compared with those in the healthy dogs (control group) and were analyzed for shunt types and grades of intrahepatic portal venous branches based on CTA findings, intraoperative portal pressure, and surgical procedures. All 3 CEUS variables showed no significant differences between the PSS and control groups. The RT and ΔHP-PV in the left gastrophrenic shunt group were significantly longer than in the other shunt types. In the intrahepatic portal vascularity, the RT in grade 1 was significantly shorter than in grades 3 and 4, and the RR in grade 1 was significantly higher than in grade 4. The RT and ΔHP-PV were significantly correlated with portal pressure variables. The RT in dogs with partial ligation was significantly shorter than in dogs with complete ligation and percutaneous transvenous coil embolization. Quantitative assessments of CEUS may be useful for estimating intrahepatic portal vascularity in dogs with single extrahepatic PSS.

Hunting of wild animals by Saubeba Community in Manokwari, West Papua, Indonesia

Abstract. Sawaki S, Taran D, Taran F, Bomoi R, Rumateray M. 2022. Hunting of wild animals by Saubeba Community in Manokwari, West Papua, Indonesia. Biodiversitas 23: 2411-2416. Hunting is a way to harvest wild animals from nature and it is still a common practice by local communities in Papua, Indonesia. This study aims to investigate traditional ecological knowledge of hunting wild animals by Saubeba community in Manokwari, West Papua, Indonesia. The data was collected through open interviews to 32 respondents determined using the snowball sampling technique. The result showed that hunting is performed in a group of 4-8 members when the dark moon happens. A group of hunters consists of adult men and teenage boys aged above 15 years old. They hunt 3-4 times per month with a duration of 2-3 days in the forest. Modern hunting is carried out using weapons, while traditional hunting is performed with the help of dogs, used arrows, spears and snares. Women are not allowed to hunt and they are prohibited to touch all hunting equipment and the catches. Among the wild animals hunted, nine out of sixteen species are categorized as protected animals and some of them have high conservation concerns in the International Union for Conservation of Nature (IUCN) Red List and Convention on International Trades on Endangered Species (CITES) list. No conservation efforts are planned and applied by the hunters and the community. However, there is a shift in the diet, in which eleven respondents stop hunting and start to raise livestock for consumption purposes. This suggests that assistance in livestock rearing programs by government is required to reduce the hunting pressure on the remaining wild animals.

Self-Organizing Cooperative Pursuit Strategy for Multi-USV with Dynamic Obstacle Ships

A self-organizing cooperation strategy for multiple unmanned surface vessels (USVs) to pursue intelligent evaders in the case of a dynamic obstacle vessel is proposed. Firstly, a self-organizing cooperative hunting strategy is proposed to form an Apollonius circle. According to the escape strategies of evaders under different encirclement states, the pursuers are divided into pursuit group and ambush group. The pursuit group drives the evaders into the ambush area and completes the encirclement together with the ambush group. In order to better deal with the dynamic obstacle ships encountered in the pursuit process in the dynamic ocean environment, the artificial potential field-based collision avoidance method for inter-USV and dynamic collision avoidance strategy for encountering obstacle ships based on International Regulations for Preventing Collisions at Sea (COLREGs) are proposed. The simulation results show that the algorithm can make the pursuers complete the encirclement of the evaders and has good obstacle avoidance performance and flexibility in the environment with dynamic obstacle ships.

HYBRID MULTI-AGENT METHOD FOR OPTIMIZATION OF FUZZY COMPUTER SYSTEMS

Recently, intelligent computer systems based on fuzzy logic and soft computing are used quite effectively to solve a wide range of complex applied problems in various fields of human activity. One of the promising areas of modern research in the field of artificial intelligence is the creation and testing of bioinspired multi-agent and evolutionary methods for the synthesis and optimization of fuzzy automatic control systems (ACS) and decision support systems (DSS). This paper is devoted to the development and research of a multi-agent method of parametric optimization of fuzzy systems (FS) based on hybrid improved grey wolf algorithms. The proposed method allows optimizing the parameters of fuzzy computer systems more efficiently, compared to the basic and improved grey wolf methods. This method uses group hunting and dimensional learning-based hunting strategies, as well as local search strategies based on algorithms of gradient descent and extended Kalman filter, which significantly reduces computational costs and increases the rate of convergence to optimal solutions when optimizing parameters of complex fuzzy systems. To study the effectiveness of the developed hybrid multi-agent method in this work, the synthesis and parametric optimization of the fuzzy flight control system for the unmanned aerial vehicle (UAV) is carried out. In particular, the optimization of the vectors of normalizing coefficients, adjustable parameters of linguistic terms (LT), and weight coefficients of the rule's consequences of the rule base (RB) for the altitude controller of the fuzzy ACS for the UAV is performed. The obtained results of the comparative analysis confirm the significant advantages of the developed hybrid multi-agent method of parametric optimization, as well as the feasibility of its application for the synthesis of different types of ACSs and DSSs based on fuzzy logic.

Immediate results of using both internal thoracic arteries for coronary artery bypass surgery in patients with ischemic artery disease

Objective: To compare direct results of «in situ» and Y-graft bimammary autoarterial bypass in patients having coronary artery disease.Methods: From January 2018 to November 2020, 107 patients having ischemic artery disease undergone coronary artery bypass surgery in the Cardiac Surgery Department No.1 of the Federal State Budgetary Institution "Federal Center for Cardiovascular Surgery" of the Ministry of Health of the Russian Federation (Krasnoyarsk). The distribution of the groups was carried out in a 3:1 ratio: in the first group (24 patients) both internal thoracic arteries were used for myocardial revascularization according to the «in situ» technique, in the second group (composite bypass surgery) (83 patients) the right internal thoracic artery was anastomosed with a free graft with the left internal thoracic artery (Y- graft).Results: There were no cases of hospital mortality. The duration of operations in the composite bypass group was significantly higher than in the «in situ» group (126.4 minutes ± 20.1 minutes versus 172.3 minutes ± 27.1 minutes, p = 0.038). The reason for extra time is the necessity to put a large number of distal anastomoses. Bleeding in the early postoperative period was observed only in one case (1.2%) in the composite bypass group. Perioperative myocardial infarctions, neurological complications, and deep wound infection of the sternum weren't observed in any group. One patient from the «in situ» group (4.2%) and one patient from the composite bypass grafting group (1.2%), experienced the postoperative period complicated by a superficial wound infection in the area of the sternotomy access (p = 0.649). In the «in situ» group, average blood flow velocity according to flowmetry data was 32 ml / min ± 8.1 ml / min, and in the composite shunting group it counted 51.8 ml / min ± 12.3 ml / min, p = 0.001.Conclusions. Using both internal thoracic arteries for coronary artery bypass surgery provides a favorable effect of surgical treatment in the postoperative period. This operation technique can be safely performed with low mortality rate and less complications. It may be associated with improved long-term patient survival; but this requires further analysis of the study results in a longer period.

What Are the “Costs and Benefits” of Meat-Eating in Human Evolution? The Challenging Contribution of Behavioral Ecology to Archeology

Despite the omnivorous diet of most human populations, meat foraging gradually increased during the Paleolithic, in parallel with the development of hunting capacities. There is evidence of regular meat consumption by extinct hominins from 2 Ma onward, with the first occurrence prior to 3 Ma in Eastern Africa. The number of sites with cut-marked animal remains and stone tools increased after 2 Ma. In addition, toolkits became increasingly complex, and various, facilitating carcass defleshing and marrow recovery, the removal of quarters of meat to avoid carnivore competition, and allowing the emergence of cooperative (i.e., social) hunting of large herbivores. How can we assess the energy costs and benefits of meat and fat acquisition and consumption for hunter-gatherers in the past, and is it possible to accurately evaluate them? Answering this question would provide a better understanding of extinct hominin land use, food resource management, foraging strategies, and cognitive abilities related to meat and fat acquisition, processing, and consumption. According to the Optimal Foraging Theory (OFT), resources may be chosen primarily on the basis of their efficiency rank in term of calories. But, could other factors, and not only calorific return, prevail in the choice of prey, such as the acquisition of non-food products, like pelts, bone tools or ornaments, or symbolic or traditional uses? Our main goal here is to question the direct application of behavioral ecology data to archeology. For this purpose, we focus on the issue of animal meat and fat consumption in human evolution. We propose a short review of available data from energetics and ethnographic records, and provide examples of several various-sized extant animals, such as elephants, reindeer, or lagomorphs, which were some of the most common preys of Paleolithic hominins.

A variable refractory period increases collective performance in noisy environments

Synchronized oscillations are found in all living systems, from cellsto ecosystems and on varying time scales. A generic principlebehind the production of oscillations involves a delay in theresponse of one entity to stimulations from the others in the sys-tem. Communication among entities is required for the emergenceof synchronization, but its efficacy can be impaired by surroundingnoise. In the social spiderAnelosimus eximius, individuals coordi-nate their activity to catch large prey that are otherwise inaccessi-ble to solitary hunters. When hunting in groups, dozens of spidersmove rhythmically toward their prey by synchronizing movingand stopping phases. We proposed a mechanistic model imple-menting individual behavioral rules, all derived fromfield experi-ments, to elucidate the underlying principles of synchronization.We showed that the emergence of oscillations in spiders involvesa refractory state, the duration of which depends on the relativeintensity of prey versus conspecific signals. Thisflexible behaviorallows individuals to rapidly adapt to variations in their vibrationallandscapes. Exploring the model reveals that the benefits of syn-chronization resulting from improved accuracy in prey detectionand reduced latency to capture prey more than offset the cost ofthe delay associated with immobility phases. Overall, our studyshows that a refractory period whose duration is variable anddependent on information accessible to all entities in the systemcontributes to the emergence of self-organized oscillations innoisy environments. Ourfindings may inspire the design of artifi-cial systems requiring fast andflexible synchronization betweentheir components.

Method for Nest Detection of the Yellow-Legged Hornet in High Density Areas.

The Asian hornet Vespa velutina is a social predator that has invaded several countries of Europe and Asia, impacting pollinators, apiculture and human health. One of the few effective control methods developed so far is the early destruction of nests. However, they are often built within dense vegetation, being difficult to detect. The aim of the method described here is to detect nests with a simple procedure, utilizing readily available materials, for widespread use in infested areas. The method has two phases, the first phase involves capturing and marking hornets, lured to a protein bait, and recording the flight directions of individuals to the nest and the time needed to complete a bait-nest-bait round trip, to estimate the distance. Collecting this information from two (or more) bait stations allows to delineate the approximate location of the nest. The second phase aims to determine the precise location of the nest, using sugary baits in the vicinity of the nest and conspicuous marks attached to the released hornets, to visually follow them up to their nest. This method is an alternative to other methods that are either ineffective in areas with high nest density or require expensive equipment and specialized training.

Nest Provisioning and Sociality at Harris's Hawk Nests in South Texas

ABSTRACT The Harris's Hawk (Parabuteo unicinctus), a social raptor species, often breeds and hunts cooperatively in groups typically consisting of a dominant breeding pair and one or more auxiliary group members. Why these birds form social groups is not completely understood, but one hypothesis is that the ability to hunt cooperatively may benefit groups with a higher hunting success rate or facilitate the capture of larger prey than an individual hawk could catch on its own. To test the hypothesis that group hunting affects patterns of prey delivery and the types of prey delivered to nests, we recorded videos of prey deliveries in May and June at nests of five breeding groups and five breeding pairs in Cameron County and Willacy County, Texas. In contrast to the diets of Harris's Hawks in New Mexico and Arizona that depend heavily on lagomorphs, we documented mostly avian prey items (39.1% of prey deliveries) and rodent prey items (39.1%), and only 0.7% lagomorphs (n = 284 prey items recorded). Significantly more prey items per day were delivered to nests with more nestlings. Importantly, and contrary to our hypothesis, pairs delivered more prey items per day on average than groups; this pattern was not significant, but this may be attributable in part to a small sample size of nests. These results suggest that the presence of auxiliaries may not necessarily provide direct benefits to offspring during the nest provisioning stage at late spring and summer nests in south Texas.

Historical Clinical Outcomes of Children with Myelomeningocele Meeting the Criteria for Fetal Surgery: A Retrospective Cohort Survey of Brazilian Patients.

To analyze the historical clinical outcomes of children with myelomeningocele (MMC) meeting the criteria for fetal surgery, but who underwent postnatal primary repair. Data from children undergoing postnatal MMC repair between January 1995 and January 2015 were collected from the Neurosurgery Outpatient Clinic's medical records. Children were included if they had ≥ 1 year of postoperative follow-up and met the criteria for fetal surgery. The children's data were then stratified according to whether they received a shunt or not. The primary outcome was mortality, and secondary outcomes were educational delays, hospitalization, recurrent urinary tract infections (UTIs), and renal failure. Over the 20-year period, 231 children with MMC were followed up. Based on clinical data recorded at the time of birth, 165 (71.4%) qualify of fetal surgery. Of the 165 patients, 136 (82.4%) underwent shunt placement. The mortality rate was 5.1% in the group with shunt and 0% in the group without, relative risk (RR) 3.28 (95% confidence interval, 95% CI, 0.19-55.9). The statistically significant RRs for adverse outcomes in the shunted group were 1.86 (95% CI, 1.01-3.44) for UTI, 30 (95% CI, 1.01-537) for renal failure, and 1.77 (95% CI, 1.09-2.87) for hospitalizations. Children with MMC qualifying for fetal surgery who underwent shunt placement were more likely to have recurrent UTIs, develop renal failure, and be hospitalized. Since approximately half of the shunt procedures could be avoided by fetal surgery, there is a clinical benefit and a possible financial benefit to the implementation of this technology in our setting.

Immediate and Mid-term Outcomes of Blalock-Taussig Shunt versus Right Ventricular Outflow Tract Stenting in Symptomatic Neonates with Tetralogy of Fallot

Background: The initial management of symptomatic neonate patients with tetralogy of Fallot (TOF) associated with unfavorable anatomy and significantly reduced pulmonary vascular flow is controversial and continues to be a clinical challenge. Objective: The aim of this study was to describe the clinical evolution and to compare branch pulmonary artery growth in symptomatic neonatal TOF patients who received a modified Blalock Taussig (mBT) shunt versus right ventricular outflow tract stent placement (RVOTs) at the Department of Cardiology, Hospital de Niños de Córdoba, between March 2011 and March 2021. Methods: A retrospective, observational study identified 113 patients with TOF, 20 of which (18%) were symptomatic neonates requiring initial palliative intervention. Categorical variables are expressed as percentage and continuous variables as median and interquartile range (IQR). A p value &lt;0.05 was considered significant. Results: Among the 20 patients included in the study, 11 (55%) formed the mBT shunt group and 9 (45%) the RVOTs group. In the mBT shunt group, pre-palliation right pulmonary artery (RPA) Z score was -3 (IQR 4.20) and increased to -1.6 (IQR 1.56) (p= 0.11), and left pulmonary artery (LPA) Z score of -2.5 (IQR 4.8) increased to -1.80 (IQR 2.36) (p= 0.44). In the RVOTs group, RPA Z score prior to the palliative procedure was -3.45 (IQR 3.83) and increased to -2.5 (IQR 3.58) (p= 0.021) and LPA Z score of -4.10 (IQR 2.51) increased to -2.00 (IQR 3.75) (p= 0.011). Pre-intervention O2 saturation of 75% (IQR 6) increased to 87% (IQR 9) in the mBT shunt group (p= 0.005) and from 75% (IQR 16) to 91% (IQR 13) in the RVOTs group (p= 0.008). Mean length of hospital stay after the procedure was 10 days (IQR 11) in the mBT shunt group and 6 days (IQR 2) in the RVOTs group (p= 0.095). Conclusions: In symptomatic neonates with TOF, both palliative strategies improved the clinical condition. In patients who received RVOTs, there was greater branch pulmonary artery growth. A larger number of cases and longer-term follow-up will be necessary to confirm these findings.