To holistically understand the biology of animals, we must unravel the complexities and specificities of host-microbe interactions across animal taxa. Birds represent enigmatic and scientifically compelling hosts in which to understand these interactions. Here, we present a brief summary of a series of conversations among avian microbiome researchers regarding methodological challenges facing the avian microbiome field, where most research to date has focused on bacterial communities of the gut. Collectively, we acknowledged a commonly shared but underreported issue facing the avian microbiome field: that of difficulty in obtaining high-quality and high-yield microbial DNA from avian fecal samples. We discuss some of the potential reasons underlying low DNA yields, such as inhibitory compounds and rapid DNA degradation, and provide recommendations for how researchers in the avian microbiome field might cope with these methodological challenges. Collective and dedicated efforts to address these challenges will be required for a robust understanding of host-microbe interactions in avian systems.
Cocoa agroforestry expansion is widespread in eastern Democratic Republic of Congo, posing a significant threat to the integrity of protected areas. Despite this threat, the impact of this expansion on forest bird communities remains largely unexamined. This study investigated bird community composition in the Okapi Wildlife Reserve (OWR) and surrounding agroforestry areas using a combination of mist netting and passive acoustic monitoring. Specifically, it examined species richness, diversity, evenness, feeding guild abundance and habitat-specific indicator species across 19 sites. A total of 95 bird species were documented, with acoustic monitoring accounting for 73% and mist netting 43% of the recorded species. Significant differences in species richness, diversity and evenness were observed across habitat types. While cocoa farms exhibited higher species richness than primary forest sites or annual cultures, primary forests had the highest diversity indices, followed by cocoa farms and annual cultures. Bird communities were most even in annual cultures, compared to primary forest sites and cocoa farms. Additionally, 18 bird species showed strong associations with specific habitat types based on combined data from both mist netting and acoustic methods. This study highlights the importance of protected areas such as the OWR for sustaining bird communities, as well as emphasising the potential value of structurally complex agroforestry landscapes for subsets of forest bird communities. Furthermore, it demonstrates the effectiveness of combining mist netting and acoustic monitoring methods in understanding avian community composition amid land use changes. L'expansion des agrofor & ecirc;ts & agrave; cacao est tr & egrave;s r & eacute;pandue dans l'est de la R & eacute;publique D & eacute;mocratique du Congo, ce qui constitue une menace importante pour l'int & eacute;grit & eacute; des zones prot & eacute;g & eacute;es. Malgr & eacute; cette menace, l'impact de cette expansion sur les communaut & eacute;s d'oiseaux forestiers reste largement m & eacute;connu. Cette & eacute;tude a examin & eacute; la composition des communaut & eacute;s d'oiseaux dans la R & eacute;serve de faune & agrave; Okapis (OWR) et les zones agroforesti & egrave;res environnantes & agrave; l'aide d'une combinaison de captures avec filets et de suivis acoustiques passifs. Elle a examin & eacute; la richesse, la diversit & eacute; et l'uniformit & eacute; des esp & egrave;ces, l'abondance des guildes alimentaires et les esp & egrave;ces indicatrices sp & eacute;cifiques & agrave; l'habitat sur 19 sites. Au total, 95 esp & egrave;ces d'oiseaux ont & eacute;t & eacute; r & eacute;pertori & eacute;es, dont 73% document & eacute;es par le suivi acoustique et 43% par captures. Des diff & eacute;rences significatives en termes de richesse, de diversit & eacute; et d'uniformit & eacute; des esp & egrave;ces ont & eacute;t & eacute; observ & eacute;es entre les diff & eacute;rents types d'habitats. Si les plantations de cacao pr & eacute;sentaient une richesse en esp & egrave;ces plus & eacute;lev & eacute;e que les sites forestiers primaires ou les cultures annuelles, les for & ecirc;ts primaires affichaient les indices de diversit & eacute; les plus & eacute;lev & eacute;s, suivies par les plantations de cacao et les cultures annuelles. Les communaut & eacute;s d'oiseaux & eacute;taient plus uniformes dans les cultures annuelles que dans les sites de for & ecirc;t primaire et les plantations de cacao. En outre, 18 esp & egrave;ces d'oiseaux ont montr & eacute; une forte association avec des types d'habitats sp & eacute;cifiques. Cette & eacute;tude souligne l'importance des zones prot & eacute;g & eacute;es, telles que l'OWR, pour la pr & eacute;servation des communaut & eacute;s d'oiseaux, tout en mettant en avant la valeur potentielle des paysages agroforestiers & agrave; structure complexe pour certaines populations d'oiseaux forestiers. Elle d & eacute;montre en outre l'efficacit & eacute; de la combinaison des m & eacute;thodes de suivis par captures (filets japonais) et enregistrements acoustiques pour comprendre la composition des communaut & eacute;s d'oiseaux dans un contexte de changements d'utilisation des sols.
Research in attentional capture reveals a tendency for attention to be attracted to visually salient, unique pop-out stimuli. This tendency interferes with visual search. We hypothesized that the pop-out distractor stimuli are processed quite deeply. In a variant of a visual search task, participants were instructed to find a target stimulus (e.g., a green circle) among other stimuli (e.g., green squares), including a single pop-out distractor (e.g., a red square). Inside each shape, there was an arithmetic stimulus (e.g., 3 + 1). In the critical experimental conditions, the answers to the arithmetic problems of the distractor and target stimuli either matched or mismatched. A match would be when the target presents, for example, "3 + 2" and the distractor presents "4 + 1." We found a significant difference in reaction time between the match and mismatch conditions. This finding reveals that, in visual search tasks, pop-out distractors are processed more deeply than one might assume.
Through devices and techniques developed in instrumentation, it is possible to create low-cost systems to diagnose variables related to human movement. These systems can assist in rehabilitating individuals, analyzing pathologies, and enhancing performance. This work presents the development of an inertial sensor network dedicated to characterizing the spatial dynamics of the ankle-foot segment and analyzing asymmetries in human gait. The system consists of four Micro Electro-Mechanical Systems (MEMS) inertial modules strategically positioned on the ankle-foot segment. Each module includes a triaxial accelerometer and gyroscope, and their data are controlled through an Inter-Integrated Circuit (I²C) bus using a microcontroller. Anomalies in human gait and observations of how the ankle-foot segment behaves during the phases of the gait cycle were determined using the system. Factoring the maximum angles a segment can reach on each global axis, the X and Y axes exhibited greater relative deflections due to center of pressure variation and gait asymmetries. Taking into account the XY plane that makes up the transverse region of the foot, the resulting acceleration presented angles close to 25° in relation to the tibial axis during initial contact. Our results indicate that inertial sensors can be applied to determine the spatial dynamics of the ankle-foot segment during gait. The X and Y axes exhibited greater relative deflections .Given the commercial systems high cost, the use of low-cost capacitive sensors offers a good alternative for assessing human movement. This study demonstrated that it is possible to assess the spatial dynamics of the ankle-foot segment during gait using a low-cost system, enabling more physiotherapy clinics to access this technology.
Real-time hybrid simulation is an advanced structural testing methodology that divides a structural system into a numerical substructure for components with well-known behavior and a physical substructure for complex nonlinear components. To address synchronization challenges between numerical and experimental substructures, this study introduces a particle swarm optimization algorithm integrated with frequency-domain evaluation indices, aiming to automate the design of H infinity controllers while minimizing manual tuning through adaptive fitness functions targeting time delay and amplitude error. A self-centering viscous damper, characterized by strong nonlinearity, is utilized as the experimental substructure in virtual real-time hybrid simulation as well as laboratory tests for both single-actuator and dual-actuator scenarios. Both computational simulation and experimental results demonstrate that the proposed particle swarm-optimized robust H infinity control method significantly improves actuator tracking accuracy and system robustness, especially under parameter perturbations and various excitation frequencies.
