Convergence in communication behavior and brain morphology in lizards: An evolutionary approach

Animal communication allows information to be transferred from a sender to a receiver, and can occur via visual, chemical, auditory, and tactile modalities. Communication behaviors are known to be generally associated with specific brain regions, but it is currently unknown how the cellular morphology of these regions differs in species that quantitatively differ in the use of particular communication modalities. Further, these relationships are rarely considered in an evolutionary context. In this thesis, I investigated the relationship between the use of communication modalities and neural morphologies (in particular, soma size and density) in the brains of six species of lizards: Anolis carolinensis, Aspidoscelis gularis, Hemidactylus turcicus, Leiocephalus carinatus, Sceloporus olivaceus, and Scincella lateralis. I performed behavioral observations of these species, quantifying their rates of visual and chemical communication behaviors. I then collected brains from 10 males of each species and measured soma size and density in two brain regions associated with visual behaviors (the lateral geniculate nucleus, and the optic tectum), one brain region associated with chemical behaviors (the nucleus sphericus), and one brain region generally associated with social behaviors (the preoptic area). I found that species that communicate with higher rates of visual displays had a denser lateral geniculate nucleus, and that species that communicate with a higher percentage of chemical displays had larger somas in the nucleus sphericus. These relationships between communication behaviors and neural morphologies suggest that structures within the brain have evolved convergently in species with similar communication behaviors

The relationship between the development of general offending and intimate partner violence perpetration in young adulthood

This study examined how patterns in general offending relate to the occurrence of and likelihood of persistence in intimate partner violence (IPV) perpetration in young adulthood. The study used longitudinal data from the cohort of 18 year olds from the Project on Human Development in Chicago Neighborhoods study. Self-reported offending was measured in all three waves, and data on IPV were collected in Waves 1 and 3. Group-based trajectory modeling identified three distinct general offending trajectory groups: non-offenders, low-rate offenders, and high-rate offenders. The majority of respondents engaged in psychological IPV perpetration, and half of all young adults reported physical IPV, but prevalence rates decreased over the waves. Binary logistic regression analyses showed that those involved in offending, especially those who showed a diverse offending pattern, were at increased risk of perpetrating psychological and (severe) physical IPV, as well as to show persistence in the different forms of IPV perpetration. The findings highlight an important overlap between general crime and IPV perpetration. In recognition that IPV is often part of a broader pattern of antisocial behavior, interventions should focus on interrupting the criminal careers of all young offenders to reduce the prevalence and harms of IPV

Extracellular vesicles from a muscle cell line (C2C12) enhance cell survival and neurite outgrowth of a motor neuron cell line (NSC-34)

Introduction: There is renewed interest in extracellular vesicles over the past decade or 2 after initially being thought of as simple cellular garbage cans to rid cells of unwanted components. Although there has been intense research into the role of extracellular vesicles in the fields of tumour and stem cell biology, the possible role of extracellular vesicles in nerve regeneration is just in its infancy. Background: When a peripheral nerve is damaged, the communication between spinal cord motor neurons and their target muscles is disrupted and the result can be the loss of coordinated muscle movement. Despite state-of-the-art surgical procedures only approximately 10% of adults will recover full function after peripheral nerve repair. To improve upon such results will require a better understanding of the basic mechanisms that influence axon outgrowth and the interplay between the parent motor neuron and the distal end organ of muscle. It has previously been shown that extracellular vesicles are immunologically tolerated, display targeting ligands on their surface, and can be delivered in vivo to selected cell populations. All of these characteristics suggest that extracellular vesicles could play a significant role in nerve regeneration. Methods: We have carried out studies using 2 very well characterized cell lines, the C2C12 muscle cell line and the motor neuron cell line NSC-34 to ask the question: Do extracellular vesicles from muscle influence cell survival and/or neurite outgrowth of motor neurons? Conclusion: Our results show striking effects of extracellular vesicles derived from the muscle cell line on the motor neuron cell line in terms of neurite outgrowth and survival

NASA's Space Launch System: An Evolving Capability for Exploration

Designed to meet the stringent requirements of human exploration missions into deep space and to Mars, NASA's Space Launch System (SLS) vehicle represents a unique new launch capability opening new opportunities for mission design. While SLS's super-heavy launch vehicle predecessor, the Saturn V, was used for only two types of missions - launching Apollo spacecraft to the moon and lofting the Skylab space station into Earth orbit - NASA is working to identify new ways to use SLS to enable new missions or mission profiles. In its initial Block 1 configuration, capable of launching 70 metric tons (t) to low Earth orbit (LEO), SLS is capable of not only propelling the Orion crew vehicle into cislunar space, but also delivering small satellites to deep space destinations. With a 5-meter (m) fairing consistent with contemporary Evolved Expendable Launch Vehicles (EELVs), the Block 1 configuration can also deliver science payloads to high-characteristic-energy (C3) trajectories to the outer solar system. With the addition of an upper stage, the Block 1B configuration of SLS will be able to deliver 105 t to LEO and enable more ambitious human missions into the proving ground of space. This configuration offers opportunities for launching co-manifested payloads with the Orion crew vehicle, and a new class of secondary payloads, larger than today's cubesats. The evolved configurations of SLS, including both Block 1B and the 130 t Block 2, also offer the capability to carry 8.4- or 10-m payload fairings, larger than any contemporary launch vehicle. With unmatched mass-lift capability, payload volume, and C3, SLS not only enables spacecraft or mission designs currently impossible with contemporary EELVs, it also offers enhancing benefits, such as reduced risk and operational costs associated with shorter transit time to destination and reduced risk and complexity associated with launching large systems either monolithically or in fewer components. As this paper will demonstrate, SLS represents a unique new capability for spaceflight, and an opportunity to reinvent space by developing out-of-the-box missions and mission designs unlike any flown before

NASA's Space Launch System Mission Capabilities for Exploration

Designed to enable human space exploration missions, including eventual landings on Mars, NASA's Space Launch System (SLS) represents a unique launch capability with a wide range of utilization opportunities, from delivering habitation systems into the lunar vicinity to high-energy transits through the outer solar system. Developed with the goals of safety, affordability and sustainability in mind, SLS is a foundational capability for NASA's future plans for exploration, along with the Orion crew vehicle and upgraded ground systems at the agency's Kennedy Space Center. Substantial progress has been made toward the first launch of the initial configuration of SLS, which will be able to deliver more than 70 metric tons of payload into low Earth orbit (LEO), greater mass-to-orbit capability than any contemporary launch vehicle. The vehicle will then be evolved into more powerful configurations, culminating with the capability to deliver more than 130 metric tons to LEO, greater even than the Saturn V rocket that enabled human landings on the moon. SLS will also be able to carry larger payload fairings than any contemporary launch vehicle, and will offer opportunities for co-manifested and secondary payloads. Because of its substantial mass-lift capability, SLS will also offer unrivaled departure energy, enabling mission profiles currently not possible. Early collaboration with science teams planning future decadal-class missions have contributed to a greater understanding of the vehicle's potential range of utilization. This presentation will discuss the potential opportunities this vehicle poses for the planetary sciences community, relating the vehicle's evolution to practical implications for mission capture. As this paper will explain, SLS will be a global launch infrastructure asset, employing sustainable solutions and technological innovations to deliver capabilities for space exploration to power human and robotic systems beyond our Moon and in to deep space