Skill of managers and the wisdom of herds: examining an alternative approach to grazing management in larkspur habitat, The

2019 Spring.Includes bibliographical references.The many species of larkspur (Delphinium spp. L.) are among the most dangerous poisonous plants on rangelands in the western United States, causing death losses estimated at 2-5% (up to 15%) per year for cattle grazing in larkspur habitat. Research has estimated the value of these losses at $234 million per year. Other effects, such as altered grazing management practices and consequent lost forage quantity and quality, are significant but poorly understood. Current best management practice recommendations stress seasonal avoidance of pastures with larkspur present, with little evidence that this is practical or ultimately effective. Alternative approaches to addressing this complex challenge are difficult to design, test, and apply due to the threat of dead livestock. In this dissertation I explore an alternative approach based on the idea that it may be possible to manage cattle grazing such that no individual consumes a lethal dose, regardless of timing of grazing or larkspur density. This idea was inspired by producers past and present who have reported such success. I examine this hypothesis using agent-based models and a field experiment with Geyer's larkspur (D. geyeri Greene), the focal species throughout this research. Chapter 2 presents a conceptual model that situates this work within the broader context of livestock grazing management and rangeland science. This synthesis also highlights the potential for conceptual models to aid in the design, application, communication, and consilience of research in rangelands. Drawing on a wide range of work, this model challenges the discipline of rangeland science to integrate a broader array of methods and epistemologies to create knowledge sufficient to the complexity of the systems under study. Agent-based models (ABMs) provide an effective method of testing alternate management strategies without risk to livestock. ABMs are especially useful for modeling complex systems such as livestock grazing management and allow for realistic bottom-up encoding of cattle behavior. In Chapter 3, I introduce a spatially-explicit, behavior-based ABM of cattle grazing in a pasture with a dangerous amount of D. geyeri. This model tests the role of herd cohesion and stocking density in larkspur intake, finds that both are key drivers of larkspur-induced toxicosis, and indicates that alteration of these factors within realistic bounds can mitigate risk. Crucially, the model points to herd cohesion, which has received little attention in the discipline, as playing an important role in reducing lethal acute toxicosis. As the first agent-based model to simulate grazing behavior at realistic scales, this study also demonstrates the tremendous potential of ABMs to illuminate grazing management dynamics, including fundamental aspects of livestock behavior amidst ecological heterogeneity. Chapter 3 raises the question of the potential response of larkspur to being grazed. In Chapter 4, I examine the response of D. geyeri to two seasons of 25% or 75% aboveground plant mass removal. The 75% treatment led to significantly lower alkaloid concentrations (mg•g-1) and pools (mg per plant), while the 25% treatment had a lesser effect. Combined with lessons from previous studies, this indicates that Geyer's larkspur plants subject to aboveground mass removal such as may occur via grazing can be expected to become significantly less dangerous to cattle. We suggest that the mechanisms for this reduction are both alkaloid removal and reduced belowground root mass, as significant evidence indicates that alkaloids are synthesized and stored in the roots. The most common explanations for the evolution and persistence of herd behavior in large herbivores relate to decreased risk of predation. However, poisonous plants such as larkspur can present a threat comparable to predation. Chapters 3 and 4 point to the cattle herd itself as the potential solution to this seemingly intractable challenge and suggest that larkspur and forage patchiness may drive deaths. In Chapter 5, I present an agent-based model that incorporates neutral landscape models to assess the interaction between plant patchiness and herd behavior within the context of poisonous plants as predator and cattle as prey. The simulation results indicate that larkspur patchiness is indeed a driver of toxicosis and that highly cohesive herds can greatly reduce the risk of death in even the most dangerous circumstances. By placing the results in context with existing theories about the utility of herds, I demonstrate that grouping in large herbivores can be an adaptive response to patchily distributed poisonous plants. Lastly, the results hold significant management-relevant insight, both for cattle producers managing grazing in larkspur habitat and in general as a call to reconsider the manifold benefits of herd behavior among domestic herbivores. The findings in this dissertation build a strong case for an alternative approach to grazing management in larkspur habitat but fall short of actionable recommendations. For one, this is because a one-size-fits-all solution that would work across the great diversity of habitats and management systems in which larkspur is found is unlikely. Instead, these findings must be placed in context with existing knowledge and the complex multiscale decision-making processes of producers. Future work will thus focus on improving our understanding of the diverse set of management circumstances under which the many species of problematic larkspur are found

The relationship between dispositional mindfulness and eating : an analysis of self-reported and in vivo eating behaviors in undergraduate females.

This dissertation theorized that higher levels of dispositional mindfulness (DM), the innate tendency to be aware and accepting of the present moment, is associated with fewer maladaptive eating behaviors, particularly in response to stress and negative emotions. Previous research has established that DM is predictive of decreased stress perception and more skillful emotion regulation. However, few studies have explored how this quality might relate to eating behaviors, which can be influenced by psychological stress and negative affect. A sample of non-clinical female undergraduates (N = 158) completed self-report questionnaires assessing DM, perceived stress, emotional regulation skills, and problematic eating patterns. Participants were also randomized to complete either solvable anagrams (low stress condition) or unsolvable anagrams (high stress condition). Four snack foods, varying in fat content (high/low) and flavor (sweet/salty), were offered for participants to consume during the stress induction, in order to examine food selection and intake. Participants also provided estimates of the amount of each food consumed, to determine whether DM was associated with greater accuracy regarding the amount of food eaten. Bivariate correlations supported the association between DM and more adaptive stress management and emotion regulation. In addition, there were significant negative correlations between DM and several maladaptive eating behaviors, including: emotional eating, external eating, and uncontrolled eating. DM was significantly positively correlated with a measure of mindful eating. Participants were classified into three groups (low, average, and high DM). ANOVA analyses revealed that individuals with higher DM scores reported significantly less stress and negative affect in response to the stress manipulation. However, DM did not influence the amount or type of food consumed or the accuracy of estimated intake. This study reaffirms the strong relationship between mindfulness and reduced reactivity to stress. Although hypotheses regarding in vivo eating behaviors were not supported, self-report data suggests an inverse relationship between DM and several negative eating tendencies. Limitations of this study included use of an undergraduate sample and the somewhat high level of suspicion reported regarding the presence of food during the experiment. This study supports the possible utility of using mindfulness-enhancing interventions to cultivate more healthy eating patterns

Visual metaphors in computer-generated information graphics

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One place doesn't fit all: improving the effectiveness of sustainability standards by accounting for place

Includes bibliographical references (pages 8-10).The growing interest in incentivizing sustainable agricultural practices is supported by a large network of voluntary production standards, which aim to offer farmers and ranchers increased value for their product in support of reduced environmental impact. To be effective with producers and consumers alike, these standards must be both credible and broadly recognizable, and thus are typically highly generalizable. However, the environmental impact of agriculture is strongly place-based and varies considerably due to complex biophysical, socio-cultural, and management-based factors, even within a given sector in a particular region. We suggest that this contradiction between the placeless generality of standards and the placed-ness of agriculture renders many sustainability standards ineffective. In this policy and practice review, we examine this contradiction through the lens of beef production, with a focus on an ongoing regional food purchasing effort in Denver, Colorado, USA. We review the idea of place in the context of agricultural sustainability, drawing on life cycle analysis and diverse literature to find that recognition of place-specific circumstances is essential to understanding environmental impact and improving outcomes. We then examine the case of the Good Food Purchasing Program (GFPP), a broad set of food-purchasing standards currently being implemented for institutional purchasing in Denver. The GFPP was created through a lengthy stakeholder-inclusive process for use in Los Angeles, California, USA, and has since been applied to many cities across the country. The difference between Los Angeles' process and that of applying the result of Los Angeles' process to Denver is instructive, and emblematic of the flaws of generalizable sustainability standards themselves. We then describe the essential elements of a place-based approach to agricultural sustainability standards, pointing toward a democratic, process-based, and outcome-oriented strategy that results in standards that enable rather than hinder the creativity of both producers and consumers. Though prescription is anathema to our approach, we close by offering a starting point for the development of standards for beef production in Colorado that respect the work of people in place

Role of soluble gp130 in the tumour necrosis factor-alpha expression and its production by peripheral blood mononuclear cells.

Background: In our previous study we found that rhsIL-6R, along with recombinant human interleukin-6, plays a regulatory role in the immune response by modulating the tumour necrosis factor-α (TNF-α) expression and its production by peripheral blood mononuclearcells (PBMC). We also suggested that sIL-6R with IL-6 secreted by human PMN (neutrophils) influenced the TNF-α expression and its production by autologous PBMC

Structural network heterogeneities and network dynamics: a possible dynamical mechanism for hippocampal memory reactivation

The hippocampus has the capacity for reactivating recently acquired memories [1-3] and it is hypothesized that one of the functions of sleep reactivation is the facilitation of consolidation of novel memory traces [4-11]. The dynamic and network processes underlying such a reactivation remain, however, unknown. We show that such a reactivation characterized by local, self-sustained activity of a network region may be an inherent property of the recurrent excitatory-inhibitory network with a heterogeneous structure. The entry into the reactivation phase is mediated through a physiologically feasible regulation of global excitability and external input sources, while the reactivated component of the network is formed through induced network heterogeneities during learning. We show that structural changes needed for robust reactivation of a given network region are well within known physiological parameters [12,13].Comment: 16 pages, 5 figure