Central Taurine Attenuates Hyperthermia and Isolation Stress Behaviors Augmented by Corticotropin-Releasing Factor with Modifying Brain Amino Acid Metabolism in Neonatal Chicks

The objective of this study was to determine the effects of centrally administered taurine on rectal temperature, behavioral responses and brain amino acid metabolism under isolation stress and the presence of co-injected corticotropin-releasing factor (CRF). Neonatal chicks were centrally injected with saline, 2.1 pmol of CRF, 2.5 μmol of taurine or both taurine and CRF. The results showed that CRF-induced hyperthermia was attenuated by co-injection with taurine. Taurine, alone or with CRF, significantly decreased the number of distress vocalizations and the time spent in active wakefulness, as well as increased the time spent in the sleeping posture, compared with the saline- and CRF-injected chicks. An amino acid chromatographic analysis revealed that diencephalic leucine, isoleucine, tyrosine, glutamate, asparagine, alanine, β-alanine, cystathionine and 3-methylhistidine were decreased in response to taurine alone or in combination with CRF. Central taurine, alone and when co-administered with CRF, decreased isoleucine, phenylalanine, tyrosine and cysteine, but increased glycine concentrations in the brainstem, compared with saline and CRF groups. The results collectively indicate that central taurine attenuated CRF-induced hyperthermia and stress behaviors in neonatal chicks, and the mechanism likely involves the repartitioning of amino acids to different metabolic pathways. In particular, brain leucine, isoleucine, cysteine, glutamate and glycine may be mobilized to cope with acute stressors.

498 Late-Breaking: Identifying Meaningful Measures of Dam and Puppy Welfare in Commercial-breeding (CB) Kennels

Maternal factors such as fear and stress influence offspring welfare in many species, but this area of research has been underexplored in dogs. As a large proportion of society’s dogs originate from commercial-breeding (CB) kennels, further investigation in this environment is crucial to ensure canine welfare. The current study aimed to refine a set of welfare metrics used to explore associations between maternal factors and litter welfare in CB kennels. Dams (n = 28) from five USDA-licensed CB kennels were tested at 6 and 1-week prepartum, and 4 and 8-weeks postpartum using a stranger approach test, physical health assessment, exposure to novel stimuli, social isolation test, hair cortisol concentration, fecal glucocorticoid metabolites (FGM) and fecal immunoglobulin A (IgA) concentrations. Puppies (n = 138) were tested at 4 (4W) and 8-weeks (8W) old using equivalent measures. Preliminary analyses of the metrics collected during puppy social isolation revealed that locomotion was positively correlated with exploration (4W: rs=0.46, P < 0.001; 8W: rs=0.39, P < 0.001), escape attempt duration (4W: rs=0.26, P = 0.002; 8W: rs=0.31, P < 0.001), frequency of stress behaviors (4W: rs=0.22, P = 0.01; 8W: rs=0.40, P < 0.001), vocalization (4W: rs=0.18, p=0.04; 8W: rs=0.20, P = 0.02), and fecal IgA (4W: rs=0.24, P = 0.05). Stationary behavior was negatively correlated with escape attempt duration (4W: rs=-0.37, P < 0.001; 8W: rs=-0.43, P < 0.001), frequency of stress behaviors (4W: rs=-0.22, P = 0.01; 8W: rs=-0.32, P < 0.001), and physiologic metrics (4W: fecal IgA rs=-0.25, P = 0.04; 8W: FGM rs=-0.23, P = 0.01). Results suggest that, in response to social isolation, 4W and 8W old puppies exhibit one of two coping styles, proactive or passive, and the latter is associated with lower activation of the immune and stress response. The outcomes of this study will inform future research exploring maternal risk factors, including behavioral and physiologic stressors, affecting puppy developmental welfare in CB kennels.

Intranasal oxytocin treatment on the day of weaning does not decrease walking behavior or improve plasma metabolites in beef calves placed on pasture

The purpose of this study was to evaluate the effect that intranasal oxytocin administered at abrupt weaning (day 0) had on weaning stress behaviors such as walking distance and time devoted to walking, calf body weight, and plasma non-esterified fatty acids (NEFA), β-hydroxybutyrate (β-HB), and cortisol. Twenty Simmental × Angus heifer calves were randomly assigned to one of two treatments, intranasal oxytocin (OXT; n = 10) or intranasal saline (CON; n = 10). All calves were given the respective intranasal treatment on the day of weaning (day 0), and then placed on pasture together. Calves were weighed and a blood sample was obtained on days 0, 1, 7, and 14 post-weaning. Blood samples were subsequently used to quantify plasma NEFA, β-HB, and cortisol concentrations. All calves in both treatment groups were fitted with an individual global positioning system (GPS) that recorded calf location every ten seconds for a 16 hour period on days 0, 7, and 14 to quantify and evaluate walking behaviors. There was no treatment × day effect for distance walked (P = 0.82), walking time (P = 0.80), non-walking time (P = 0.88), area utilization index (P = 0.84), calf body weight (P = 0.82), average daily gain (P = 0.54), NEFA (P = 0.22), or cortisol concentrations (P = 0.32). There was a tendency for a treatment × day effect observed for average walking speed (P = 0.09) and β-HB (P = 0.10), such that calves in the CON treatment tended to have lesser average walking speeds on day 14 and tended to have greater β-HB concentration after weaning. There was a treatment effect (P = 0.02) for NEFA concentrations, with the CON calves having a greater plasma NEFA concentration throughout the study compared with OXT calves. These data imply that OXT calves may have had differing metabolic responses immediately after weaning that could have altered the mobilization of NEFA, but this change was not substantial enough to impact body weights or walking behaviors.

Gelation and Yielding Behavior of Polymer-Nanoparticle Hydrogels

Polymer-Nanoparticle hydrogels are a unique class of self-assembled, shear-thinning, yield-stress fluids which have demonstrated potential utility in many impactful applications. Here we present a thorough analysis of the gelation and yielding behavior of these materials with respect to the polymer and nanoparticle component stoichiometry. Through comprehensive rheological and diffusion studies, we reveal insights into the structural dynamics of the polymer nanoparticle network which identify that stoichiometry plays a key role in gelation and yielding, ultimately enabling the development of hydrogel formulations with unique shear-thinning and yield-stress behaviors. Access to these materials opens new doors for interest- ing applications in a variety of fields including tissue engineering, drug delivery, and controlled solution viscosity.

Creep Strain Behaviors of Ti-6Al-4V Using Gleeble 3500

During forging operations, strain can occur through three primary mechanisms: strain due to load applied through dies, strain due to thermal contraction, and strain due to creep. In materials behavior models, strain due to applied load and thermal contraction are directly considered and predictions are based on thermophysical properties and flow stress behaviors as inputs to the models. Strain due to creep after forging (during cooling) is often more difficult to predict and capture due to lack of materials data. In particular, data that capture the changing flow stress behavior during cooling (rather than from isothermal testing) are not commonly available. In this project, creep strain behavior during cooling was investigated by physical simulations using a Gleeble 3500. Standard cylinder-shaped Ti-6Al-4V samples with 10 mm diameter were heated to below β-transus temperature (1775°F) or above β-transus (1925°F), followed by constant cooling rates of 250°F/min and 1000°F/min with and without applied load during cooling to 1000°F. Total strain for the tests ranged from 2 – 6%. Characterization of prior microstructure and texture was carried out using XRD, optical microscopy, and SEM. The results provide insights on the relationship of flow stress behavior and microstructure as a function of temperature and cooling rate and are applicable to forging practices. These materials data can be used as input for future process modeling, potentially giving better prediction accuracy in industry applications.

Effect of Fractured Aggregate Particles on Linear Stress Ratio of Aggregate and Resilience Properties of Asphalt Mixes—A Way Forward for Sustainable Pavements

The interlocking and packing of aggregate particles play a key role in achieving high level of linear viscoelastic properties and rutting resistance in asphalt mix for sustainable pavements. In this study, the quantitative effect of fractured aggregate particles (FAPs) on loading (i.e., 500 kPa normal stress), along with the resilience properties of asphalt mixes, was evaluated. Linear and nonlinear stress behaviors of aggregates (from direct shear test) and asphalt mixes (from resilient modulus test) were analyzed. A new quantitative parameter (linear stress ratio), i.e., linear stress (Pi)/maximum stress (Pmax), is proposed to be used in selection of aggregates for asphalt mixes. It was observed that 15.5% increase in FAPs caused 19.5% increase in ϕ and 70.7% increase in linear stress ratio (LSR). The same content of FAPs resulted in 29.4% and 36% increases in total resilient modulus (MRT) and 34.2% and 24.5% increases in instantaneous resilient modulus (MRI) for 0.1 and 0.3 s load durations, respectively. The proposed LSR is observed to be superior to conventionally used ϕ for aggregate resistance in design of flexible pavements.

Sex differences in the behavioral responses of dogs exposed to human chemosignals of fear and happiness

This research focuses on sex differences in the behavioral patterns of dogs when they are exposed to human chemosignals (sweat) produced in happy and fear contexts. No age, breed or apparatus-directed behavior differences were found. However, when exposed to fear chemosignals, dogs’ behavior towards their owners, and their stress signals lasted longer when compared to being exposed to happiness as well as control chemosignals. In the happy odor condition, females, in contrast to males, displayed a significantly higher interest to the stranger compared to their owner. In the fear condition, dogs spent more time with their owner compared to the stranger. Behaviors directed towards the door, indicative of exit interest, had a longer duration in the fear condition than the other two conditions. Female dogs revealed a significantly longer door-directed behavior in the fear condition compared to the control condition. Overall the data shows that the effect of exposure to human emotional chemosignals is not sex dependent for behaviors related to the apparatus, the owner or the stress behaviors; however, in the happiness condition, females showed a stronger tendency to interact with the stranger.