Restoration of Bison (\u3ci\u3eBison bison\u3c/i\u3e) to Agate Fossil Beds National Monument, A Feasibility Study

Executive Summary Agate Fossil Beds National Monument is a 3,057-acre park located in western Nebraska. The unit is comprised of northern mixed-grass prairie vegetation, typical of the Northern Great Plains. Weather, fire, and grazing are generally considered to be the ecological drivers of prairie ecosystems and critical for prairie health. However, grazing has essentially been absent since the 1960s. In 2014, a Department of the Interior report explicitly listed the park as a high priority for bison restoration. This report evaluates the feasibility, management options, benefits, and challenges of restoring bison to Agate Fossil Beds National Monument. A potential bison pasture encompasses about 2,676 acres within the park, essentially the area east of Highway 29. Assuming 2,676 acres are available to bison, a forage intake rate of 2.667%, a natural sex and age structure for the herd, an average bison weight of 1,000 pounds, and an allocation of 33% of annual plant productivity to bison consumption, the park could support 166 bison in the fall in a normal-precipitation year including calves, or about 136 yearlings and adults. Using the same assumptions the dry year carrying capacity is 129 animals and the wet year carrying capacity is 219 animals (including calves). Changes in other assumptions and objectives result in different modeled carrying capacities ranging from 52 to 443 animals, demonstrating the latitude available to management. Using the assumptions listed above, if the portion of the park that encompasses the visitor center, park housing, and a private in-holding is excluded from the bison pasture (an area of about 300 acres) then the carrying capacity is reduced to about 147 bison in the fall. If bison were restored to the park they would occur in a closed system absent of natural predation to affect population growth. Assuming a starting population of 40 yearlings (at a 50:50 sex ratio), the herd would reach carrying capacity about 9-11 years later. Numerous anthropogenic options are available to manage the herd size; however, the most conventional and feasible consists of the park periodically rounding up and transferring live animals to other entities such as Native American tribes. This approach is used by many NPS units with bison. Tradeoffs exist between the frequency of the removal operations and the quantity and age-sex classes of the animals removed in a cull. For example, assuming a goal of a long-term average population of 166 bison in the fall, an annual cull of 70% of the yearlings (about 23 animals) would maintain the herd at that level as would a cull conducted every third year that removed 40% of all age and sex classes (removing about 81 animals total). The greater the duration between culls the greater the variability in herd size, e.g., a cull every fifth year that removes 60% of the herd results in a population that fluctuates between 99 and 202 animals. Other considerations in selecting a culling strategy include ecological objectives, bison genetic goals, available funding and infrastructure, drought, and availability and desires of the recipients of the bison. The conservation of bison genetics is a high priority within the NPS. Frequent smaller culls better conserve bison genetics as the population does not experience the deep nadirs caused by the removal of large numbers of animals necessitated by less frequent culls. The larger the herd the better genetic diversity is conserved, all else being equal. Genetic diversity could be better conserved if an Agate Fossil Beds herd was managed as a metapopulation with other NPS herds. The park could also choose to manage bison in partnership neighbors, one of whom owns about 5,000 acres. Such a partnership would greatly increase the size of the herd, ecological function, and genetic conservation. The potential benefits of restoring bison to Agate Fossil Beds National Monument include: 1) restoring a native species to the park, 2) restoring an ecological process to the park that enhances the conservation of biodiversity, 3) improving visitor experience and understanding, 4) benefitting local communities via increased tourism, 5) restoring a Native American ethnographic and cultural resource, 6) contributing to meeting DOI and NPS bison goals, 7) establishing a metapopulation that contributes to agency and global conservation of bison genetic diversity, 8) establishing a genetically pure bison herd (assuming the needed technology is completed), 9) establishing a satellite herd that provides redundancy in case of a catastrophe to another NPS herd(s), 10) being a repository for Yellowstone National Park or other park bison, if needed. The challenges to bison restoration at the park include the cost and potential impacts of bison-associated infrastructure and maintenance, the need to hire staff with natural resource expertise, and the need to foster support within the agency and with stakeholders. Depending on the location of the bison pastures the park may also need to address private inholdings within the park administrative boundary, impacts on paleontological resources, issues associated with a county road, and impacts to the park administrative areas and structures. The small size of the park makes a well-designed prescribed fire program and an active vegetation monitoring program especially important to assure park goals are being met. This feasibility study primarily provides a scientific evaluation of restoring bison to Agate Fossil Beds National Monument. Ultimately a full evaluation that considers other concerns and impacts (e.g. cultural resources) would need to be conducted as part of an environmental assessment and management plan. This report tries to facilitate that process wherever possible by analyzing and presenting a range of values. An environmental assessment would also need to consider action alternatives that were not fully vetted here, such as introducing cattle in lieu of bison for purposes of restoring the grazing process. From an ecological and conservation perspective there would be many benefits to restoring bison to the park, and it would be very feasible

BOOK REVIEWS: American Serengeti: The Last Big Animals of the Great Plains. Dan Flores.

Before describing what Flores’ book is, I must state what it is not. It is not a technical book designed for scholarly readers. Sources are not fully cited, and the bibliography is of limited scope. Nor is it a comprehensive book of all the megafauna of the Great Plains. Although chapters are devoted to extant species such as American bison (Bison bison), pronghorn (Antilocapra americana), and coyote (Canis latrans), there are only passing references to mule and white-tailed deer (Odocoileus hemionus and O. virginianus, respectively), elk (Cervus canadensis), and bighorn sheep (Ovis canadensis). Rather, Flores devotes chapters to grizzly bears (Ursus arctos) and wolves (Canus lupus), two species that are essentially absent from the current Great Plains. Interestingly, the modern horse (Equus caballus), recently returned to the region by Europeans, is afforded a chapter. The somewhat arbitrary list of species could have been selected by the author because he viewed them as the epitome of Great Plains wildlife, or because they best told the story of the relationship that humans have had with large Great Plains animals, or because the author simply had a personal interest in those species. Flores mentions, but doesn’t weigh in on the sensitive topic of what caused the extinction of most of the region’s megafauna about 10,000 years ago (e.g., aboriginal people), when the Great Plains truly rivaled the Serengeti in terms of large animal diversity. I think it fair to say that this isn’t really a book about the large animals of the Great Plains, but rather, is about the people and cultures that essentially destroyed one Great Plains ecosystem and replaced it with another. Ultimately, this is a book about societies, cultural attitudes toward nature, and the psyche of the people who pulled the triggers. For that goal, it succeeds

Observations of Bobcats, Lynx rufus, Hunting Black-Tailed Prairie Dogs, Cynomys ludovicianus, in Western South Dakota

There is a paucity of scientific literature describing Bobcat (Lynx rufus) hunting strategies. I document 13 observations of Bobcats hunting Black-tailed Prairie Dogs (Cynomys ludovicianus) in western South Dakota. In all cases the Bobcats stationed themselves next to a prairie dog mound in an attempt to ambush prairie dogs emerging from their burrows. In eight cases the Bobcats successfully captured a prairie dog emerging from the burrow, in one case the Bobcat turned and captured a prairie dog that had walked up behind it, and in the other cases the Bobcats lunged at the burrow openings, but did not capture a prairie dog. There were two variations of the tactic: in some cases Bobcats entered a colony prior to prairie dog emergence and stationed themselves next to a mound, whereas in other cases Bobcats stationed themselves next to a burrow that a prairie dog had just escaped to. One Bobcat appeared to have waited next to the same mound for at least 7.5 hr. Prairie dogs may comprise a large portion of a Bobcat's winter diet in landscapes where prairie dog colonies exist in close proximity to badlands or woody cover

Cas9+ conditionally-immortalized macrophages as a tool for bacterial pathogenesis and beyond.

Macrophages play critical roles in immunity, development, tissue repair, and cancer, but studies of their function have been hampered by poorly-differentiated tumor cell lines and genetically-intractable primary cells. Here we report a facile system for genome editing in non-transformed macrophages by differentiating ER-Hoxb8 myeloid progenitors from Cas9-expressing transgenic mice. These conditionally immortalized macrophages (CIMs) retain characteristics of primary macrophages derived from the bone marrow yet allow for easy genetic manipulation and a virtually unlimited supply of cells. We demonstrate the utility of this system for dissection of host genetics during intracellular bacterial infection using two important human pathogens: Listeria monocytogenes and Mycobacterium tuberculosis

Axonal response of mitochondria to demyelination and complex IV activity within demyelinated axons in experimental models of multiple sclerosis

AIMS: Axonal injury in multiple sclerosis (MS) and experimental models is most frequently detected in acutely demyelinating lesions. We recently reported a compensatory neuronal response, where mitochondria move to the acutely demyelinated axon and increase the mitochondrial content following lysolecithin-induced demyelination. We termed this homeostatic phenomenon, which is also evident in MS, the axonal response of mitochondria to demyelination (ARMD). The aim of this study is to determine whether ARMD is consistently evident in experimental demyelination and how its perturbation relates to axonal injury.METHODS: In the present study, we assessed axonal mitochondrial content as well as axonal mitochondrial respiratory chain complex IV activity (cytochrome c oxidase or COX) of axons and related these to axonal injury in nine different experimental disease models. We used immunofluorescent histochemistry as well as sequential COX histochemistry followed by immunofluorescent labelling of mitochondria and axons.RESULTS: We found ARMD a consistent and robust phenomenon in all experimental disease models. The increase in mitochondrial content within demyelinated axons, however, was not always accompanied by a proportionate increase in complex IV activity, particularly in highly inflammatory models such as experimental autoimmune encephalomyelitis (EAE). Axonal complex IV activity inversely correlated with the extent of axonal injury in experimental disease models.CONCLUSIONS: Our findings indicate that ARMD is a consistent and prominent feature and emphasise the importance of complex IV activity in the context of ARMD, especially in autoimmune inflammatory demyelination, paving the way for the development of novel neuroprotective therapies.</p

The use of novel diffuse optical spectroscopies for improved neuromonitoring during neonatal cardiac surgery requiring antegrade cerebral perfusion

BackgroundSurgical procedures involving the aortic arch present unique challenges to maintaining cerebral perfusion, and optimal neuroprotective strategies to prevent neurological injury during such high-risk procedures are not completely understood. The use of antegrade cerebral perfusion (ACP) has gained favor as a neuroprotective strategy over deep hypothermic circulatory arrest (DHCA) due to the ability to selectively perfuse the brain. Despite this theoretical advantage over DHCA, there has not been conclusive evidence that ACP is superior to DHCA. One potential reason for this is the incomplete understanding of ideal ACP flow rates to prevent both ischemia from underflowing and hyperemia and cerebral edema from overflowing. Critically, there are no continuous, noninvasive measurements of cerebral blood flow (CBF) and cerebral oxygenation (StO2) to guide ACP flow rates and help develop standard clinical practices. The purpose of this study is to demonstrate the feasibility of using noninvasive, diffuse optical spectroscopy measurements of CBF and cerebral oxygenation during the conduct of ACP in human neonates undergoing the Norwood procedure.MethodsFour neonates prenatally diagnosed with hypoplastic left heart syndrome (HLHS) or a similar variant underwent the Norwood procedure with continuous intraoperative monitoring of CBF and cerebral oxygen saturation (StO2) using two non-invasive optical techniques, namely diffuse correlation spectroscopy (DCS) and frequency-domain diffuse optical spectroscopy (FD-DOS). Changes in CBF and StO2 due to ACP were calculated by comparing these parameters during a stable 5 min period of ACP to the last 5 min of full-body CPB immediately prior to ACP initiation. Flow rates for ACP were left to the discretion of the surgeon and ranged from 30 to 50 ml/kg/min, and all subjects were cooled to 18°C prior to initiation of ACP.ResultsDuring ACP, the continuous optical monitoring demonstrated a median (IQR) percent change in CBF of −43.4% (38.6) and a median (IQR) absolute change in StO2 of −3.6% (12.3) compared to a baseline period during full-body cardiopulmonary bypass (CPB). The four subjects demonstrated varying responses in StO2 due to ACP. ACP flow rates of 30 and 40 ml/kg/min (n = 3) were associated with decreased CBF during ACP compared to full-body CPB. Conversely, one subject with a higher flow6Di rate of 50 ml/kg/min demonstrated increased CBF and StO2 during ACP.ConclusionsThis feasibility study demonstrates that novel diffuse optical technologies can be utilized for improved neuromonitoring in neonates undergoing cardiac surgery where ACP is utilized. Future studies are needed to correlate these findings with neurological outcomes to inform best practices during ACP in these high-risk neonates

Enhanced axonal response of mitochondria to demyelination offers neuroprotection:implications for multiple sclerosis

Axonal loss is the key pathological substrate of neurological disability in demyelinating disorders, including multiple sclerosis (MS). However, the consequences of demyelination on neuronal and axonal biology are poorly understood. The abundance of mitochondria in demyelinated axons in MS raises the possibility that increased mitochondrial content serves as a compensatory response to demyelination. Here, we show that upon demyelination mitochondria move from the neuronal cell body to the demyelinated axon, increasing axonal mitochondrial content, which we term the axonal response of mitochondria to demyelination (ARMD). However, following demyelination axons degenerate before the homeostatic ARMD reaches its peak. Enhancement of ARMD, by targeting mitochondrial biogenesis and mitochondrial transport from the cell body to axon, protects acutely demyelinated axons from degeneration. To determine the relevance of ARMD to disease state, we examined MS autopsy tissue and found a positive correlation between mitochondrial content in demyelinated dorsal column axons and cytochromecoxidase (complex IV) deficiency in dorsal root ganglia (DRG) neuronal cell bodies. We experimentally demyelinated DRG neuron-specific complex IV deficient mice, as established disease models do not recapitulate complex IV deficiency in neurons,and found that these mice are able to demonstrate ARMD, despite the mitochondrial perturbation.Enhancement of mitochondrial dynamics in complex IV deficient neurons protects the axon upon demyelination. Consequently, increased mobilisation of mitochondria from the neuronal cell body to the axon is a novel neuroprotective strategy for the vulnerable, acutely demyelinated axon. We propose that promoting ARMD is likely to be a crucial preceding step for implementing potential regenerative strategies for demyelinating disorders.</p

Development and Validation of a Seizure Prediction Model in Neonates Following Cardiac Surgery

BACKGROUND Electroencephalographic seizures (ES) following neonatal cardiac surgery are often subclinical and have been associated with poor outcomes. An accurate ES prediction model could allow targeted continuous electroencephalographic monitoring (CEEG) for high-risk neonates. METHODS Development and validation of ES prediction models in a multi-center prospective cohort where all postoperative neonates with cardiopulmonary bypass (CPB) underwent CEEG. RESULTS ES occurred in 7.4% of neonates (78 of 1053). Model predictors included gestational age, head circumference, single ventricle defect, DHCA duration, cardiac arrest, nitric oxide, ECMO, and delayed sternal closure. The model performed well in the derivation cohort (c-statistic 0.77, Hosmer-Lemeshow p=0.56), with a net benefit (NB) over monitoring all and none over a threshold probability of 2% in decision curve analysis (DCA). The model had good calibration in the validation cohort (Hosmer-Lemeshow, p=0.60); however, discrimination was poor (c-statistic 0.61) and in DCA there was no NB of the prediction model between the threshold probabilities of 8% and 18%. Using a cut-point that emphasized negative predictive value (NPV) in the derivation cohort, 32% (236 of 737) of neonates would not undergo CEEG, including 3.5% (2 of 58) with ES (NPV 99%, sensitivity 97%). CONCLUSIONS In this large prospective cohort, a prediction model of ES in neonates following CPB had good performance in the derivation cohort with a NB in DCA. However, performance in the validation cohort was weak with poor discrimination, calibration, and no NB in DCA. These findings support CEEG monitoring of all neonates following CPB

Identification of a Rare Coding Variant in Complement 3 Associated with Age-related Macular Degeneration

Macular degeneration is a common cause of blindness in the elderly. To identify rare coding variants associated with a large increase in risk of age-related macular degeneration (AMD), we sequenced 2,335 cases and 789 controls in 10 candidate loci (57 genes). To increase power, we augmented our control set with ancestry-matched exome sequenced controls. An analysis of coding variation in 2,268 AMD cases and 2,268 ancestry matched controls revealed two large-effect rare variants; previously described R1210C in the CFH gene (fcase = 0.51%, fcontrol = 0.02%, OR = 23.11), and newly identified K155Q in the C3 gene (fcase = 1.06%, fcontrol = 0.39%, OR = 2.68). The variants suggest decreased inhibition of C3 by Factor H, resulting in increased activation of the alternative complement pathway, as a key component of disease biology

Optical imaging and spectroscopy for the study of the human brain: status report.

This report is the second part of a comprehensive two-part series aimed at reviewing an extensive and diverse toolkit of novel methods to explore brain health and function. While the first report focused on neurophotonic tools mostly applicable to animal studies, here, we highlight optical spectroscopy and imaging methods relevant to noninvasive human brain studies. We outline current state-of-the-art technologies and software advances, explore the most recent impact of these technologies on neuroscience and clinical applications, identify the areas where innovation is needed, and provide an outlook for the future directions