Biochemical and computational approaches to understand venom toxin-toxin interaction.

Snake venoms are mainly composed of proteins and peptides (venom toxins). The venom transcriptomes and proteomes have been extensively investigated; however, venom toxin-toxin interactions remain poorly characterized. We detected the interaction of venom Asp49-PLA2 and 3FTx using biochemical and computational approaches. A stable structure of Asp49-PLA2-3FTx was identified, and the interface of Asp49-PLA2 and 3FTx was analyzed. The approaches will shed light on understanding the venom complexity and deciphering the synergistic effects of venom toxins.

Intervention Strategies and Lessons Learned From a Student-Led Initiative to Support Lactating Women in the University Setting.

The benefits of breastfeeding for mother and baby are strongly supported by research. However, lactating parents who return to school or work soon after delivery face many barriers to continued breastfeeding. This article presents a student-led initiative to support lactation at a large public university that emerged from advocacy efforts of student mothers of color. The socioecological model was used as a framework to understand and address the multifaceted influences on breastfeeding practices. Project activities included providing breastfeeding education to lactating parents and their partners, measuring availability and accessibility of lactation spaces, improving lactation spaces, connecting university stakeholders, and strengthening university lactation policies. The project achieved the following outcomes: formation of a stakeholder group with members across campus departments, improvement in accessibility and appropriateness of lactation spaces, provision of breastfeeding services through workshops and one-on-one appointments with lactation educators, and creation and dissemination of an online toolkit outlining parents' lactation rights and support available on campus. Comprehensive lactation support at universities is essential to enhance educational and professional equity for women and to promote postpartum and infant health. Throughout the project implementation, the team learned many lessons that can help guide similar university initiatives.

Turtling the Salamander: Tail Movements Mitigate Need for Kinematic Limb Changes during Walking in Tiger Salamanders (Ambystoma tigrinum) with Restricted Lateral Movement.

Lateral undulation and trunk flexibility offer performance benefits to maneuverability, stability, and stride length (via speed and distance traveled). These benefits make them key characteristics of the locomotion of tetrapods with sprawling posture, with the exception of turtles. Despite their bony carapace preventing lateral undulations, turtles are able to improve their locomotor performance by increasing stride length via greater limb protraction. The goal of this study was to quantify the effect of reduced lateral flexibility in a generalized sprawling tetrapod, the tiger salamander (Ambystoma tigrinum). We had two potential predictions: (1) either salamanders completely compensate by changing their limb kinematics, or (2) their performance (i.e., speed) will suffer due to the reduced lateral flexibility. This reduction was performed by artificially limiting trunk flexibility by attaching a 2-piece shell around the body between the pectoral and pelvic girdles. Adult tiger salamanders (n = 3; SVL = 9-14.5 cm) walked on a 1-m trackway under three different conditions: unrestricted, flexible shell (Tygon tubing), and rigid shell (PVC tubing). Trials were filmed in a single, dorsal view, and kinematics of entire midline and specific body regions (head, trunk, tail), as well as the fore and hind limbs, were calculated. Tygon individuals had significantly higher curvature than both PVC and unrestricted individuals for the body, but this trend was primarily driven by changes in tail movements. PVC individuals had significantly lower curvature in the trunk region compared with unrestricted individuals or Tygon; however, there was no difference between unrestricted and Tygon individuals suggesting the shells performed as expected. PVC and Tygon individuals had significantly higher curvature in the tails compared with unrestricted individuals. There were no significant differences for any limb kinematic variables among treatments including average, minimum, and maximum angles. Thus, salamanders respond to decreased lateral movement in their trunk by increasing movements in their tail, without changes in limb kinematics. These results suggest that tail undulations may be a more critical component to sprawling-postured tetrapod locomotion than previously recognized.

Tiger Salamanders (Ambystoma tigrinum) Increase Foot Contact Surface Area on Challenging Substrates During Terrestrial Locomotion.

Animals live in heterogeneous environments must navigate in order to forage or capture food, defend territories, and locate mates. These heterogeneous environments have a variety of substrates that differ in their roughness, texture, and other properties, all of which may alter locomotor performance. Despite such natural variation in substrate, many studies on locomotion use noncompliant surfaces that either are unrepresentative of the range of substrates experienced by species or underestimate maximal locomotor capabilities. The goal of this study was to determine the role of forefeet and hindfeet on substrates with different properties during walking in a generalized sprawling tetrapod, the tiger salamander (Ambystoma tigrinum). Adult salamanders (n = 4, SVL = 11.2-14.6 cm) walked across level dry sand (DS), semi-soft plaster of Paris (PoP), wet sand (WS), and a hard, noncompliant surface (table)-substrates that vary in compliance. Trials were filmed in dorsal and anterior views. Videos were analyzed to determine the number of digits and surface area of each foot in contact with the substrate. The surface area of the forelimbs contacting the substrate was significantly greater on DS and PoP than on WS and the table. The surface area of the hindlimbs contacting the substrate was significantly greater on DS than on all other substrates. There were no significant differences in the time that the fore- or hindfeet were in contact with the substrate as determined by the number of digits. We conclude that salamanders modulate the use of their feet depending on the substrate, particularly on DS which is known to increase the mechanical work and energy expended during locomotion owing to the fluid nature of its loose particles. More studies are needed to test a wider range of substrates and to incorporate behavioral data from field studies to get a better understanding of how salamanders are affected by different substrates in their natural environment.

Impact of Aging on Empathy: Review of Psychological and Neural Mechanisms.

Empathy in aging is a key capacity because it affects the quality of older adults' relationships and reduced levels are associated with greater loneliness. Many older adults also find themselves in the role of a caregiver to a loved one, and thus empathy is critical for the success of the caregiver-patient relationship. Furthermore, older adults are motivated to make strong emotional connections with others, as highlighted in the socioemotional selectivity theory. Consequently, reductions in empathy could negatively impact their goals. However, there is growing evidence that older adults experience at least some changes in empathy, depending on the domain. Specifically, the state of the research is that older adults have lower cognitive empathy (i.e., the ability to understand others' thoughts and feelings) than younger adults, but similar and in some cases even higher levels of emotional empathy (i.e., the ability to feel emotions that are similar to others' or feel compassion for them). A small number of studies have examined the neural mechanisms for age-related differences in empathy and have found reduced activity in a key brain area associated with cognitive empathy. However, more research is needed to further characterize how brain changes impact empathy with age, especially in the emotional domain of empathy. In this review, we discuss the current state of the research on age-related differences in the psychological and neural bases of empathy, with a specific comparison of the cognitive versus emotional components. Finally, we highlight new directions for research in this area and examine the implications of age-related differences in empathy for older adults.