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Simple Summary: This study examined the potential food inclination of crab-eating macaques, a species that frequently participates in animal behavior research, in a laboratory environment. This study aimed to understand the potential food inclination of crab-eating macaques to enhance positive reinforcement training and health optimization, which are important for behavioral assessments. We observed a strong inclination for plant-based foods like fruits and vegetables over animal-based proteins. Notably, nuts were highly favored. Additionally, our research revealed individual variation in inclination and a time-dependent increase in protein inclination. Our results emphasize the need for a diverse range of inclined foods in positive reinforcement training and health optimization, with consideration for individual variation. This study offers guidelines for ethical and effective training practices, ensuring the well-being of these monkeys in research settings. This understanding of their potential food inclination can improve the overall welfare of crab-eating macaques, enhance the success of behavioral assessments, and provide valuable insights for researchers in various fields. Positive reinforcement and training for health optimization are pivotal for successful studies with monkeys. Potential food inclination is important for studies on crab-eating macaques in laboratory environments, but evaluations remain scarce. We explored crab-eating macaques' potential food inclination to establish a reward system for future behavioral assessments. Twelve male and three female monkeys underwent a food inclination assessment in which they were offered four food categories—fruits, vegetables, proteins, and nuts. The monkeys exhibited a higher inclination for plant-based foods, particularly fruits and vegetables, over animal-based proteins like chicken and tuna (p < 0.0001), with a notable inclination for nuts (eaten/provided = 100%). Additionally, the consistency of potential food inclination after repeated offerings was investigated, revealing a time-dependent increase in inclination for protein items. Food consumption ratios correlated positively with caloric intake (r = 0.59, p = 0.02), implying that individuals with a regular high caloric intake and increased body weight are more likely to accept food during positive reinforcement training. Our findings suggest fruits, vegetables, protein-rich foods, and nuts can help with health optimization. However, animal-based protein-rich foods initially had a low preference, which may increase over time. Our study can provide guidelines for positive reinforcement training and health optimization. [ABSTRACT FROM AUTHOR]

P22 viral capsids and ferritin proteincages are utilized as templatingmacromolecules to conjugate Gd(III)-chelating agent complexes, andwe systematically investigates the effects of the macromolecules’size and the conjugation positions of Gd(III)-chelating agents onthe magnetic resonance (MR) relaxivities and the resulting image contrasts.The relaxivity values of the Gd(III)-chelating agent-conjugated P22viral capsids (outer diameter: 64 nm) are dramatically increased ascompared to both free Gd(III)-chelating agents and Gd(III)-chelatingagent-conjugated ferritins (outer diameter: 12 nm), suggesting thatthe large sized P22 viral capsids exhibit a much slower tumbling rate,which results in a faster T1relaxationrate. Gd(III)-chelating agents are attached to either the interioror exterior surface of P22 viral capsids and the conjugation positionsof Gd(III)-chelating agents, however, do not have a significant effecton the relaxivity values of the macromolecular conjugates. The contrastenhancement of Gd(III)-chelating agent-conjugated P22 viral capsidsis confirmed by in vitro phantom imaging at a short repetition times(TR) and the potential usage of Gd(III)-chelating agent-conjugatedP22 viral capsids for in vivo MR imaging is validated by visualizinga mouse’s intravascular system, including the carotid, mammaryarteries, the jugular vein, and the superficial vessels of the headat an isotropic resolution of 250 μm. [ABSTRACT FROM AUTHOR]

Positive reinforcement and training for health optimization are pivotal for successful studies with monkeys. Potential food inclination is important for studies on crab-eating macaques in laboratory environments, but evaluations remain scarce. We explored crab-eating macaques' potential food inclination to establish a reward system for future behavioral assessments. Twelve male and three female monkeys underwent a food inclination assessment in which they were offered four food categories-fruits, vegetables, proteins, and nuts. The monkeys exhibited a higher inclination for plant-based foods, particularly fruits and vegetables, over animal-based proteins like chicken and tuna ( p < 0.0001), with a notable inclination for nuts (eaten/provided = 100%). Additionally, the consistency of potential food inclination after repeated offerings was investigated, revealing a time-dependent increase in inclination for protein items. Food consumption ratios correlated positively with caloric intake ( r = 0.59, p = 0.02), implying that individuals with a regular high caloric intake and increased body weight are more likely to accept food during positive reinforcement training. Our findings suggest fruits, vegetables, protein-rich foods, and nuts can help with health optimization. However, animal-based protein-rich foods initially had a low preference, which may increase over time. Our study can provide guidelines for positive reinforcement training and health optimization.

Surface engineered iron oxide nanoparticles (IONPs) with catecholic ligands have been investigated as alternative T 1 contrast agents. However, complex oxidative chemistry of catechol during IONP ligand exchange causes surface etching, heterogeneous hydrodynamic size distribution, and low colloidal stability because of Fe 3+ mediated ligand oxidation. Herein, we report highly stable and compact (∼10 nm) Fe 3+ rich ultrasmall IONPs functionalized with a multidentate catechol-based polyethylene glycol polymer ligand through amine-assisted catecholic nanocoating. The IONPs exhibit excellent stability over a broad range of pHs and low nonspecific binding in vitro . We also demonstrate that the resultant NPs have a long circulation time (∼80 min), enabling high resolution T 1 magnetic resonance angiography in vivo . These results suggest that the amine assisted catechol-based nanocoating opens a new potential of metal oxide NPs to take a step forward in exquisite bio-application fields., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)