Litter Environment Affects Behavior and Brain Metabolic Activity of Adult Knockout Mice

In mammals, the formative environment for social and anxiety-related behaviors is the family unit; in the case of rodents, this is the litter and the mother-young bond. A deciding factor in this environment is the sex ratio of the litter and, in the case of mice lacking functional copies of gene(s), the ratio of the various genotypes in the litter. Both Sex and Genotype ratios of the litter affect the nature and quality of the individual's behavior later in adulthood, as well as metabolic activity in brain nuclei that underlie these behaviors. Mice were raised in litters reconstituted shortly after to birth to control for sex ratio and genotype ratio (wild type pups versus pups lacking a functional estrogen receptor α). In both males and females, the Sex and Genotype of siblings in the litter affected aggressive behaviors as well as patterns of metabolic activity in limbic nuclei in the social behavior network later in adulthood. Further, this pattern in males varied depending upon the Genotype of their brothers and sisters. Principal Components Analysis revealed two components comprised of several amygdalar and hypothalamic nuclei; the VMH showed strong correlations in both clusters, suggesting its pivotal nature in the organization of two neural networks

Progress and bottlenecks in the early domestication of the perennial oilseed Silphium integrifolium, a sunflower substitute

Silflower (Silphium integrifolium Michx.) is in the early stages of domestication as a perennial version of oilseed sunflower, its close relative. Grain crops with deep perennial root systems will provide farmers with new alternatives for managing soil moisture and limiting or remediating soil erosion, fertilizer leaching, and loss of soil biota. Several cycles of selection for increased seed production potential following initial germplasm evaluation in 2002 have provided opportunities to document the botany and ecology of this relatively obscure species, to compare agronomic practices for improving its propagation and management, and to evaluate the differences between semi-domesticated and wild accessions that have accrued over this time through intentional and unintentional genetic processes. Key findings include: domestication has increased aboveground biomass at seedling and adult stages; seed yield has increased more, achieving modest improvement in harvest index. Harvest index decreases with nitrogen fertilization. Silflower acquires nitrogen and water from greater depth than typical crops. In agricultural silflower stands within its native range, we found that Puccinia silphii (rust) and Eucosma giganteana (moth) populations build up to unacceptable levels, but we also found genetic variation for traits contributing to resistance or tolerance. Breeding or management for reduced height and vegetative plasticity should be top priorities for future silflower research outside its native range.Fil: Vilela, Alejandra Elena. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: González Paleo, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Turner, Kathryn. The Land Institute; Estados UnidosFil: Peterson, Kelsey. The Land Institute; Estados UnidosFil: Ravetta, Damián Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Crews, Timothy E.. The Land Institute; Estados UnidosFil: Van Tassel, David. The Land Institute; Estados Unido

The Cytokine mRNA Increase Induced by Withdrawal from Chronic Ethanol in the Sterile Environment of Brain is Mediated by CRF and HMGB1 Release

Background—Many neurobiological factors may initiate and sustain alcoholism. Recently, dysregulation of the neuroimmune-system by chronic-ethanol (CE) has implicated toll-like receptor-4 (TLR4)-activation. Even though TLR4s are linked to CE-initiation of brain cytokine mRNAs, the means by which CE influences neuroimmune signaling in the sterile environment of brain remains uncertain. Therefore, the hypothesis is tested that release of an endogenous TLR4 agonist, high-mobility group box 1 (HMGB1) and/or CRF during CE-withdrawal are responsible for CE-protocols increasing cytokine-mRNAs. Methods—Acute-ethanol 2.75g/kg) and acute-LPS (lipopolysaccharide)(250μg/kg) dosing on cytokine-mRNAs are first compared. Then, the effects of chronic-LPS exposure (250 μg/kg for 10-days) on cytokine-mRNAs are compared to changes induced by CE-protocols [15-days of continuous 7% ethanol-diet (CE-protocol) or three-intermittent 5-day cycles of 7%-ethanol-diet (CIE-protocol)]. Additionally, TLR4-, HMGB1- and down-stream effector mRNAs are assessed after CE, CIE, and chronic-LPS. To test whether HMGB1 and/or CRF support the CE-withdrawal increase in cytokine-mRNAs, the HMGB1-antagonists, glycyrrhizin and ethyl-pyruvate, and a CRF1-receptor-antagonist (CRF1RA) are administered during 24-hours of CE-withdrawal. Results—While cytokine-mRNAs were not increased following acute-ethanol, acute-LPS increased all cytokine-mRNAs 4-hours after injection. CE produced no change in cytokine mRNAs prior to CE-removal; however, the CE- and CIE-protocols increased cytokine-mRNAs by 24-hours after withdrawal. In contrast, chronic-LPS produced no cytokine-mRNA changes 24-hours after LPS-dosing. TLR4-mRNA was elevated 24-hours following both CE-protocols and chronic-LPS exposure. While chronic-LPS had no effect on HMGB1-mRNA, withdrawal from CE-protocols significantly elevated HMGB1-mRNA. Systemic administration of HMGB1-antagonists or a CRF1RA significantly reduced the cytokine-mRNA increase following CE-withdrawal. The CRF1RA and the HMGB1-antagonist, ethyl-pyruvate, also reduced the HMGB1-mRNA increase that followed CE-withdrawal. Conclusion—By blocking HMGB1 or CRF action during CE-withdrawal, evidence is provided that HMGB1- and CRF-release are critical for the CE-withdrawal-induction of selected brain cytokine-mRNAs. Consequently, these results clarify a means by which withdrawal from CE exposure activates neuroimmune-function in the sterile-environment of brain

Designing timber connections for ductility – A review and discussion

This paper discusses the design principles of timber connections for ductility with focus on laterally-loaded dowel-type fasteners. Timber connections are critical components of timber structures: not only do they join members, but they also affect load capacity, stiffness, and ductility of the overall system. Moreover, due to the brittle failure behaviour of timber when loaded in tension or shear, they are often the only source of ductility and energy dissipation in the structure in case of overloading, much like a fuse in an electrical circuit. This paper addresses current challenges in connection design for ductility, reviews selected best-practice design approaches to ensure ductility in timber connections, suggests simple performance-based design criteria to design connections for ductility, and aims to stimulate a discussion around potential solutions to implement safe design principles for ductile connections in future design codes and connection testing regimes

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to display male-typical copulatory behavior. Since both this propensity and AVT abundance are controlled by androgens, we compared testosterone-implanted and control animals within each group. Testosterone treatment generally increased AVT abundance, except in lab-reared parthenoforms, in which testosterone treatment was the least effective in inducing male-like copulatory behavior. Copyright © 2007 S. Karger AG, Basel Arginine vasotocin (AVT) and its mammalian counterpart vasopressin (AVP) function in a range of maletypical behaviors in vertebrates, including aggression and courtship. In many species these sexually dimorphic behaviors correlate with the abundance of AVT/AVP neurons in various brain areas Abstract In nonmammalian vertebrates the abundance of arginine vasotocin (AVT) neurons in the brain is sexually dimorphic, a pattern that is modulated by testicular androgen. This peptide is thought to be involved in the control of male-typical mounting behaviors. The all-female desert-grasslands whiptail (Cnemidophorus uniparens) reproduces by obligate parthenogenesis and in nature no males exist, but eggs treated with aromatase inhibitor hatch into individuals (called virago C. uniparens ) having testes, accessory sex structures, high circulating concentrations of androgens, and exhibiting only male-like copulatory behavior. To examine the 'sexual' dimorphism of AVT-containing neurons in these animals, we compared AVT immunoreactivity in gonadectomized control and virago C. uniparens , with that of gonadectomized male and female Cnemidophorus inornatus , a sexual species that is the maternal ancestor to the parthenogenetic species. Mounting behavior is elicited in both species and both sexes by testosterone, and it was predicted that the distribution and abundance of AVT cell bodies and fibers would reflect the propensity of males and females of the two specie