Age-related differences in delay discounting: Income matters.

Although the authors of a recent meta-analysis concluded there were no age-related differences in the discounting of delayed rewards, they did not examine the effects of income (Seaman et al., 2022). Accordingly, the present study compared discounting by younger and older adults (Ages 35-50 and 65-80) differing in household income. Two procedures were used: the Monetary Choice Questionnaire and the Adjusting-Amount procedure. Whereas no age difference was observed between the higher income (> $80,000) age groups, a significant difference was observed between younger and older adults with lower incomes (< $50,000): The younger adults discounted more steeply than the older adults. These findings, which were observed with both discounting procedures, support our buffering hypothesis, which assumes that the scarcity associated with a lower income is a stressor that can lead to steeper discounting, but that age-related increases in emotional stability can buffer such stressors, leading to age-related differences between lower income age groups. In contrast, no age difference was observed in higher income adults who experience much less scarcity. Further support for the buffering hypothesis comes from the finding that there was no age-related difference in discounting by the lower income groups when distress was statistically controlled. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Electro-Sorting Create Heterogeneity: Constructing A Multifunctional Janus Film with Integrated Compositional and Microstructural Gradients for Guided Bone Regeneration.

Biology remains the envy of flexible soft matter fabrication because it can satisfy multiple functional needs by organizing a small set of proteins and polysaccharides into hierarchical systems with controlled heterogeneity in composition and microstructure. Here, it is reported that controlled, mild electronic inputs (<10 V; <20 min) induce a homogeneous gelatin-chitosan mixture to undergo sorting and bottom-up self-assembly into a Janus film with compositional gradient (i.e., from chitosan-enriched layer to chitosan/gelatin-contained layer) and tunable dense-porous gradient microstructures (e.g., porosity, pore size, and ratio of dense to porous layers). This Janus film performs is shown multiple functions for guided bone regeneration: the integration of compositional and microstructural features confers flexible mechanics, asymmetric properties for interfacial wettability, molecular transport (directional growth factor release), and cellular responses (prevents fibroblast infiltration but promotes osteoblast growth and differentiation). Overall, this work demonstrates the versatility of electrofabrication for the customized manufacturing of functional gradient soft matter.

Programmable Electro-Assembly of Collagen: Constructing Porous Janus Films with Customized Dual Signals for Immunomodulation and Tissue Regeneration in Periodontitis Treatment.

Currently available guided bone regeneration (GBR) films lack active immunomodulation and sufficient osteogenic ability- in the treatment of periodontitis, leading to unsatisfactory treatment outcomes. Challenges remain in developing simple, rapid, and programmable manufacturing methods for constructing bioactive GBR films with tailored biofunctional compositions and microstructures. Herein, the controlled electroassembly of collagen under the salt effect is reported, which enables the construction of porous films with precisely tunable porous structures (i.e., porosity and pore size). In particular, bioactive salt species such as the anti-inflammatory drug diclofenac sodium (DS) can induce and customize porous structures while enabling the loading of bioactive salts and their gradual release. Sequential electro-assembly under pre-programmed salt conditions enables the manufacture of a Janus composite film with a dense and DS-containing porous layer capable of multiple functions in periodontitis treatment, which provides mechanical support, guides fibrous tissue growth, and acts as a barrier preventing its penetration into bone defects. The DS-containing porous layer delivers dual bio-signals through its morphology and the released DS, inhibiting inflammation and promoting osteogenesis. Overall, this study demonstrates the potential of electrofabrication as a customized manufacturing platform for the programmable assembly of collagen for tailored functions to adapt to specific needs in regenerative medicine.

Social familiarity and reinforcement value: a behavioral-economic analysis of demand for social interaction with cagemate and non-cagemate female rats.

Rats were studied in social reinforcement procedures in which lever presses opened a door separating two adjacent spaces, permitting access to social interaction with a partner rat. The number of lever presses required for social interaction was systematically increased across blocks of sessions according to fixed-ratio schedules, generating demand functions at three different social reinforcement durations: 10 s, 30 s, and 60 s. The social partner rats were cagemates in one phase, and non-cagemates in a second phase. The rate at which social interactions were produced declined with the fixed-ratio price, and was well described by an exponential model that has been successfully employed with a range of social and non-social reinforcers. None of the main parameters of the model varied systematically with social interaction duration or with the social familiarity of the partner rat. On the whole, the results provide further evidence of the reinforcing value of social interaction, and its functional parallels with non-social reinforcers.

Individual differences in degree of discounting: Do different procedures and measures assess the same construct?

The present study compared the two most prominent procedures for measuring delay discounting, the Adjusting-Amount procedure and the Monetary Choice Questionnaire (MCQ). Of interest was whether the two procedures measure the same construct. Results obtained from two online samples recruited using the Prolific (N = 150) and MTurk (N = 243) platforms revealed generally similar results for both procedures. Regardless of the procedure, the sample, the reward amount, and whether the discounting measure used was theoretically based (i.e., log k) or was atheoretical (i.e., area under the curve, proportion of choices of the delayed reward option), the degree of discounting on the Adjusting-Amount procedure was highly correlated with the degree of discounting on the MCQ, consistent with the hypothesis that both procedures assess the same construct.

Does improving basic public health services promote household consumption of rural migrant workers? Evidence from China.

Background: Transforming rural migrant workers' consumption potential into a consumption booster requires ensuring their equal rights as urban residents. The adequate access to Basic Public Health Services (BPHS) help effectively tackle rural migrant workers' health challenges and promote the well-being of this vulnerable population. Assessing the welfare effects of BPHS through a consumption perspective offers valuable insights and provides policy implications for enhancing the equity of BPHS and achieving common prosperity. Methods: Utilizing the household-level data from China Migrants Dynamic Survey 2017 (CMDS 2017), this study comprehensively evaluated the effects of BPHS on rural migrant workers' household consumption by combining the methods of OLS, PSM, and IV. Results: The enhancement of BPHS promotes rural migrant workers' household consumption even after considering endogeneity problems. Mechanism analysis indicates that BPHS imposes its positive effects on rural migrant workers through improving health literacy and increasing citizenization willingness. Furthermore, we identified heterogeneous effects across individual and household characteristics of rural migrant workers, and their flow patterns. Conclusion: Our analysis indicates that BPHS plays a greater role in promoting household consumption of socially vulnerable groups, such as trans-provincial migration, rural migrant workers in old generations, and with lower-level income. Overall, these results suggest that the welfare effects of BPHS are inclusive in China.

Laser Additive Manufacturing of Anti-Tetrachiral Endovascular Stents with Negative Poisson's Ratio and Favorable Cytocompatibility.

Laser additive manufacturing (LAM) of complex-shaped metallic components offers great potential for fabricating customized endovascular stents. In this study, anti-tetrachiral auxetic stents with negative Poisson ratios (NPR) were designed and fabricated via LAM. Poisson's ratios of models with different diameters of circular node (DCN) were calculated using finite element analysis (FEA). The experimental method was conducted with the LAM-fabricated anti-tetrachiral stents to validate their NPR effect and the simulation results. The results show that, with the increase in DCN from 0.6 to 1.5 mm, the Poisson ratios of anti-tetrachiral stents varied from -1.03 to -1.12, which is in line with the simulation results. The interrelationship between structural parameters of anti-tetrachiral stents, their mechanical properties and biocompatibility was demonstrated. The anti-tetrachiral stents with a DCN of 0.9 mm showed the highest absolute value of negative Poisson's ratio, combined with good cytocompatibility. The cytocompatibility tests indicate the envisaged cell viability and adhesion of the vascular endothelial cell on the LAM-fabricated anti-tetrachiral auxetic stents. The manufactured stents exhibit great superiority in the application of endovascular stent implantation due to their high flexibility for easy maneuverability during deployment and enough strength for arterial support.

Electrical Signal Initiates Kinetic Assembly of Collagen to Construct Optically Transparent and Geometry Customized Artificial Cornea Substitutes.

Corneal transplantation is an effective treatment for reconstructing injured corneas but is very limited due to insufficient donors, which has led to a growing demand for development of artificial corneal substitutes (ACSs). Collagen is a potential building block for ACS fabrication, whereas technically there are limited capabilities to control the collagen assembly for creating highly transparent collagen ACSs. Here, we report an electro-assembly technique to kinetically control collagen assembly on the nanoscale that allows the yielding collagen ACSs with structure determined superior optics. Structurally, the kinetically electro-assembled collagen (KEA-Col) is composed of partially aligned microfibrils (∼10 nm in diameter) with compacted lamellar organization. Optical analysis reveals that such microstructure is directly responsible for its optimal light transmittance by reducing light scattering. Moreover, this method allows the creation of complex three-dimensional geometries and thus is convenient to customize collagen ACSs with specific curvatures to meet refractive power requirements. Available properties (e.g., optics and mechanics) of cross-linked KEA-Cols were studied to meet the clinical requirement as ACSs, and in vitro tests further proved their beneficial characteristics of cell growth and migration. An in vivo study established a rabbit lamellar keratectomy corneal wound model and demonstrated the customized collagen ACSs can adapt to the defective cornea and support epithelial healing as well as stroma integration and reconstruction with lower immunoreaction compared with commercial xenografts, which suggests its promising application prospects. More broadly, this work illustrates the potential for enlisting electrical signals to mediate collagen's assembly and microstructure organization for specific structural functionalization for regenerative medicine.

Electro-assembly of a dynamically adaptive molten fibril state for collagen.

Collagen is a biological building block that is hierarchically assembled into diverse morphological structures that, in some cases, is dynamically adaptive in response to external cues and in other cases forms static terminal structures. Technically, there is limited capabilities to guide the emergence of collagen's hierarchical organization to recapitulate the richness of biological structure and function. Here, we report an electro-assembly pathway to create a dynamically adaptive intermediate molten fibril state for collagen. Structurally, this intermediate state is composed of partially aligned and reversibly associating fibrils with limited hierarchical structure. These molten fibrils can be reversibly reconfigured to offer dynamic properties such as stimuli-stiffening, stimuli-contracting, self-healing, and self-shaping. Also, molten fibrils can be guided to further assemble to recapitulate the characteristic hierarchical structural features of native collagen (e.g., aligned fibers with D-banding). We envision that the electro-assembly of collagen fibrils will provide previously unidentified opportunities for tailored collagen-based biomedical materials.

Failure to Find Altruistic Food Sharing in Rats.

Prior research has found that one rat will release a second rat from a restraint in the presence of food, thereby allowing that second rat access to food. Such behavior, clearly beneficial to the second rat and costly to the first, has been interpreted as altruistic. Because clear demonstrations of altruism in rats are rare, such findings deserve a careful look. The present study aimed to replicate this finding, but with more systematic methods to examine whether, and under what conditions, a rat might share food with its cagemate partner. Rats were given repeated choices between high-valued food (sucrose pellets) and 30-s social access to a familiar rat, with the (a) food size (number of food pellets per response), and (b) food motivation (extra-session access to food) varied across conditions. Rats responded consistently for both food and social interaction, but at different levels and with different sensitivity to the food-access manipulations. Food production and consumption was high when food motivation was also high (food restriction) but substantially lower when food motivation was low (unlimited food access). Social release occurred at moderate levels, unaffected by the food-based manipulations. When food was abundant and food motivation low, the rats chose food and social options about equally often, but sharing (food left unconsumed prior to social release) occurred at low levels across sessions and conditions. Even under conditions of low food motivation, sharing occurred on only 1% of the sharing opportunities. The results are therefore inconsistent with claims in the literature that rats are altruistically motivated to share food with other rats.