Effective Population Size, Demography, and Viability of Eastern Massasaugas (Sistrurus catenatus) in Southwest Michigan

As humans increasingly exploit natural areas, wildlife populations face a growing number of threats that often result in population decline and isolation. Small, isolated populations are vulnerable to extirpation due to both genetic and demographic factors. Yet, low detectability of many imperiled species often precludes the collection of population-level data important for assessing population viability and implementing successful conservation. The eastern massasauga (Sistrurus catenatus) is a cryptic pitviper that has been extirpated throughout much of its historic range due to agricultural conversion of wetland habitat and other synergistic threats. Consequently, this species is federally listed as threatened in both the United States and Canada, and most remnant populations are believed to be small and isolated. However, most extant populations lack data on population size and long-term survival rates, making effective management, monitoring, and viability assessments difficult. To address these data deficiencies, I estimated the genetic effective population size (Ne) and census population size (Nc) for eastern massasaugas at two sites in southwest Michigan. My results revealed small Nc, with approximately 108 (95% CI = 87–165) and 148 (95% CI = 102–295) adults estimated at the study sites in Cass County and Barry County, respectively. Estimates of Ne were even smaller: approximately 29.5 (95% CI = 22.2–40.5) for Cass County and 44.2 (95% CI =29.7–73.4) for Barry County. Additionally, Ne/Nc ratios were similar across study sites. Secondly, for the Barry County population, I used mark-recapture data spanning 2008–2016 to estimate annual apparent survival rates of adults. Using these estimates and other parameter values obtained from my site and a nearby population, I modeled population viability over the next 100 years. I also performed a sensitivity analysis to assess the relative influence of model parameters on extinction risk. I estimated annual apparent survival rates of 0.79 (95% CI = 0.68–0.87) for adult males and 0.78 (95% CI = 0.68–0.86) for adult females. Results of my sensitivity analysis suggest that actions promoting high survival of adult females should be a management priority, followed by activities that facilitate high reproductive output and neonate survival

Membrane traffic in polarized neurons

AbstractThe plasma membrane of neurons can be divided into two domains, the soma-dendritic and the axonal. These domains perform different functions: the dendritic surface receives and processes information while the axonal surface is specialized for the rapid transmission of electrical impulses. This functional specialization is generated by sorting and anchoring mechanisms that guarantee the correct delivery and retention of specific membrane proteins. Our understanding of neuronal membrane protein sorting is primarily based on studies of protein overexpression in cultured neurons. These studies revealed that newly synthesized membrane proteins are segregated in the Golgi apparatus in the cell body from where they are transported to the axonal or dendritic surface. Such segregation presumably depends on sorting motifs in the proteins’ primary structure. They appear to be located in the cytoplasmic tail for dendritic proteins and in the transmembrane-ectodomain for axonal proteins. Recent studies on neurotransmitter segregation suggest that anchoring in the correct subdomain of the plasma membrane also requires cytoplasmic tail information for binding to the cytoskeleton either directly or by linker proteins. Both mechanisms, sorting and retention, gradually mature during neural development. Young neurons appear to develop initial polarity by other mechanisms, presumably analogous to the mechanisms used by migrating cells

Microtubule stabilization specifies initial neuronal polarization

Axon formation is the initial step in establishing neuronal polarity. We examine here the role of microtubule dynamics in neuronal polarization using hippocampal neurons in culture. We see increased microtubule stability along the shaft in a single neurite before axon formation and in the axon of morphologically polarized cells. Loss of polarity or formation of multiple axons after manipulation of neuronal polarity regulators, synapses of amphids defective (SAD) kinases, and glycogen synthase kinase-3β correlates with characteristic changes in microtubule turnover. Consistently, changing the microtubule dynamics is sufficient to alter neuronal polarization. Application of low doses of the microtubule-destabilizing drug nocodazole selectively reduces the formation of future dendrites. Conversely, low doses of the microtubule-stabilizing drug taxol shift polymerizing microtubules from neurite shafts to process tips and lead to the formation of multiple axons. Finally, local stabilization of microtubules using a photoactivatable analogue of taxol induces axon formation from the activated area. Thus, local microtubule stabilization in one neurite is a physiological signal specifying neuronal polarization

The Ethics of Medical Brigades in Honduras: Who are we helping?

The current thesis poses a focused critique and ethical analysis of medical brigades as they currently operate in Honduras. The first chapter defines the concept of medical brigades and provides an account of their presence and actions within Honduras. The second chapter addresses the need for a theoretical framework with which to ethically analyze the endeavors of these brigades. Due to an insufficient amount of attention and scrutiny, no authoritative standard yet exists for evaluating the ethics of developed countries providing health care interventions in developing countries. In order to overcome this challenge, the current thesis creates a hybrid framework by looking to established codes of conduct from several pre-existing models of engagement with potentially vulnerable populations, all of which have already addressed some pertinent aspect of medical brigades. Through examining the principles, ethics and relevance of the doctor-patient relationship, Standard of Care debates and Community-Based Participatory Research, this thesis places certain obligations on medical brigade participants and their affiliated organizations, which must to be fulfilled in order for their actions to be considered ethical. In the third chapter, I maintain that medical brigades fail to fulfill these obligations based on the harms they pose to the communities and community members they serve. Fundamentally, these brigades pose a risk because of their short-term nature that does not provide accountability or follow-up care, nor addresses community-relevant health care needs. Finally, the fourth chapter demonstrates the ways in which the developed world can improve upon this model and carry out ethical health care interventions in the developing world, specifically by avoiding these harms and fulfilling the aforementioned obligations. To facilitate this discussion, I will present the Shoulder to Shoulder model, the Community-Oriented Primary Care model and SEED-SCALE as ethical alternatives to the medical brigade model. These examples collectively provide a solid platform on which to base a much needed change in the current medical brigade model, and a bright future for the direction of health care provided by volunteers in developing countries

Hazards and vulnerability in modern societies – using the example of a large-scale outage in the electricity supply. Summary

In modern, highly technical societies based on the division of labour, the supply of the population with (vital) goods and services is carried out by a highly developed, closely interwoven network of "critical infrastructures". These include information technology and telecommunications, transport and traffic, energy supply and health care. These are highly vulnerable due to their internal complexity and great interdependence. Terrorist attacks, natural disasters or particularly serious accidents have not only in the past decade made it clear what far-reaching consequences the impairment or failure of critical infrastructures can have for the social system as a whole. Due to the almost complete penetration of the living and working environment with electrically operated devices, the consequences of a prolonged and widespread power blackout would add up to a damage situation of special quality. All critical infrastructures would be affected, and a collapse of society as a whole could hardly be prevented. Despite this potential danger and catastrophe, society\u27s risk awareness is only rudimentary

What happens during a blackout: Consequences of a prolonged and wide-ranging power outage

Power outages in Europe and North America in recent years have given a lasting impression of the vulnerability of modern and high-tech societies. Although the power supply was interrupted for a week at most and only locally, massive functional and supply disruptions, threats to public order and damage amounting to billions of euros have already become apparent. This book shows what consequences a prolonged and widespread power blackout could have on society and its critical infrastructures and how Germany is prepared for such a large-scale disaster. By means of comprehensive consequence analyses, the authors drastically demonstrate that after only a few days, the supply of the population with (vital) goods and services can no longer be guaranteed in the affected area. It is also made clear that considerable efforts are required to increase the sustainability of critical infrastructures and to further optimise the capacities of the national disaster management system. The book is based on TAB Report Nr. 141 "Gefährdung und Verletzbarkeit moderner Gesellschaften - am Beispiel eines großräumigen und langandauernden Ausfalls der Stromversorgung"

Systemic epothilone D improves hindlimb function after spinal cord contusion injury in rats

Following a spinal cord injury (SCI) a growth aversive environment forms, consisting of a fibroglial scar and inhibitory factors, further restricting the already low intrinsic growth potential of injured adult central nervous system (CNS) neurons. Previous studies have shown that local administration of the microtubule-stabilizing drug paclitaxel or epothilone B (Epo B) reduce fibrotic scar formation and axonal dieback as well as induce axonal growth/sprouting after SCI. Likewise, systemic administration of Epo B promoted functional recovery. In this study, we investigated the effects of epothilone D (Epo D), an analog of Epo B with a possible greater therapeutic index, on fibrotic scarring, axonal sprouting and functional recovery after SCI. Delayed systemic administration of Epo D after a moderate contusion injury (150 kDyn) in female Fischer 344 rats resulted in a reduced number of footfalls when crossing a horizontal ladder at 4 and 8 weeks post-injury. Hindlimb motor function assessed with the BBB open field locomotor rating scale and Catwalk gait analysis were not significantly altered. Moreover, formation of laminin positive fibrotic scar tissue and 5-HT positive serotonergic fiber length caudal to the lesion site were not altered after treatment with Epo D. These findings recapitulate a functional benefit after systemic administration of a microtubule-stabilizing drug in rat contusion SCI

The role of aldosterone blockade in murine lupus nephritis

Abstract Background The purpose of this study was to examine the effect of aldosterone receptor blockade on the immunopathogenesis and progression of nephritis in the (NZB × NZW) F1 murine lupus model. Methods Female NZB/W F1 mice (11 weeks old) were treated daily with 25 or 50 mg/kg oral spironolactone or vehicle. Proteinuria, renal function, and serum autoantibody levels were monitored. Renal histopathology, immune complex deposition, and immunohistochemistry were analyzed at various time points. Targeted microarray analysis was performed on renal tissue, with subsequent real-time PCR analysis of several differentially expressed genes. Results Treatment with spironolactone was well tolerated by the mice throughout the course of their disease progression, with no significant differences in azotemia or serum potassium levels between vehicle-treated and spironolactone-treated animals. By 36 weeks of age, fewer spironolactone-treated mice developed nephrotic range proteinuria as compared with the control mice (control 70.8%, 25 mg/kg spironolactone 51.3%, and 50 mg/kg spironolactone 48.6%). Compared with control mice, mice treated with 25 mg/kg spironolactone had significantly lower serum anti-single-stranded DNA levels (2,042 μg/ml versus 1,036 μg/ml; P = 0.03) and anti-double-stranded DNA levels (3,433 μg/ml versus 614 μg/ml; P = 0.05). Spironolactone-treated mice exhibited decreased histopathologic evidence of inflammation and tissue damage, as compared with control mice. Additionally, spironolactone treatment resulted in decreased expression in the kidney of several inflammatory and proapoptotic genes, including those encoding interferon-γ, B lymphocyte stimulator (BlyS), tumor necrosis factor related apoptosis inducing ligand (TRAIL), tumor necrosis factor related weak inducer of apoptosis (TWEAK), and Fas ligand. Conclusion Aldosterone receptor blockade is safe and well tolerated in progressive murine lupus nephritis, and it results in decreased levels of clinical proteinuria, lower serum levels of autoantibodies, and decreased kidney damage. It appears to modulate inflammatory changes during the progression of glomerulonephritis and may also have a previously undescribed role in attenuating apoptosishttp://deepblue.lib.umich.edu/bitstream/2027.42/112839/1/13075_2007_Article_2203.pd