A Study on the Origin of Banded Agate

Agate in any of its varieties presents numerous problems in regard to its origin. Many types have been described and their beauty elaborated upon, but little has been written concerning their formation and the problems involved. The genesis of agate implicates an amazing complexity of physical and colloid­al chemistry, as well as, various principles of geology.

Keweenaw National Historical Park: Heritage Partnerships in an Industrial Landscape

This dissertation examines the genesis and development of Keweenaw National Historical Park in Michigan's Upper Peninsula. After the decline of a once-thriving copper mining industry, local residents pursued the creation of a national park as a way to encourage economic development, revitalize their community, and preserve their historic resources. Although they were ultimately successful in creating a national park, the park that was established was not the park that they envisioned. Over the next twenty years, the National Park Service, the park's federal Advisory Commission, and the communities on the Keweenaw Peninsula struggled to align unrealistic expectations with the actual capabilities and limitations of the park. The first chapter of this dissertation includes a short history of the decline of the copper industry in and around the village of Calumet, Michigan. This chapter also includes a discussion about the techniques and challenges of preserving and interpreting industrial heritage. Chapters 2 and 3 cover the events from the initial park proposal, to the expansion of the original idea, to the establishment of the park. Chapter 4 includes an examination of the enabling legislation and a discussion about the opportunities and challenges it provided. Chapters 5 through 8 cover the tenure of each of the four NPS superintendents as they navigated the complexities presented by a park model that was part partnership park and part traditional national park. Chapter 9 includes some key lessons, an assessment of the park's success, and some considerations for the future. In particular, Chapter 9 argues for an increased focus on the partnership aspects of the park, a reduction in the perceived scope of responsibilities, and a renewed effort to rally the existing partners in pursuing additional philanthropic support for the overall park.

Evaluation of early tissue reactions after lumbar intertransverse process fusion using CT in a rabbit

OBJECTIVE: The objective of the study was to evaluate tissue reactions such as bone genesis, cartilage genesis and graft materials in the early phase of lumbar intertransverse process fusion in a rabbit model using computed tomography (CT) imaging with CT intensity (Hounsfield units) measurement, and to compare these data with histological results. MATERIALS AND METHODS: Lumbar intertransverse process fusion was performed on 18 rabbits. Four graft materials were used: autograft bone (n = 3); collagen membrane soaked with recombinant human bone morphogenetic protein-2 (rhBMP-2) (n = 5); granular calcium phosphate (n = 5); and granular calcium phosphate coated with rhBMP-2 (n = 5). All rabbits were euthanized 3 weeks post-operatively and lumbar spines were removed for CT imaging and histological examination. RESULTS: Computed tomography imaging demonstrated that each fusion mass component had the appropriate CT intensity range. CT also showed the different distributions and intensities of bone genesis in the fusion masses between the groups. Each component of tissue reactions was identified successfully on CT images using the CT intensity difference. Using CT color mapping, these observations could be easily visualized, and the results correlated well with histological findings. CONCLUSIONS: The use of CT intensity is an effective approach for observing and comparing early tissue reactions such as newly synthesized bone, newly synthesized cartilage, and graft materials after lumbar intertransverse process fusion in a rabbit model.

Perioperative anaesthetic management of mediastinal mass in adults

Mediastinal mass syndrome remains an anaesthetic challenge that cannot be underestimated. Depending on the localization and the size of the mediastinal tumour, the clinical presentation is variable ranging from a complete lack of symptoms to severe cardiorespiratory problems. The administration of general anaesthesia can be associated with acute intraoperative or postoperative cardiorespiratory decompensation that may result in death due to tumour-related compression syndromes. The role of the anaesthesiologist, as a part of the interdisciplinary treatment team, is to ensure a safe perioperative period. However, there is still no structured protocol available for perioperative anaesthesiological procedure. The aim of this article is to summarize the genesis of and the diagnostic options for mediastinal mass syndrome and to provide a solid detailed methodology for its safe perioperative management based on a review of the latest literature and our own clinical experiences. Proper anaesthetic management of patients with mediastinal mass syndrome begins with an assessment of the preoperative status, directed foremost at establishing the localization of the tumour and on the basis of the clinical and radiological findings, discerning whether any vital mediastinal structures are affected. We have found it helpful to assign 'severity grade' (using a three-grade clinical classification scale: 'safe', 'uncertain', 'unsafe'), whereby each stage triggers appropriate action in terms of staffing and apparatus, such as the provision of alternatives for airway management, cardiopulmonary bypass and additional specialists. During the preoperative period, we are guided by a 12-point plan that also takes into account the special features of transportation into the operating theatre and patient monitoring. Tumour compression on the airways or the great vessels may create a critical respiratory and/or haemodynamic situation, and therefore the standard of intraoperative management includes induction of anaesthesia in the operating theatre on an adjustable surgical table, the use of short-acting anaesthetics, avoidance of muscle relaxants and maintenance of spontaneous respiration. In the case of severe clinical symptoms and large mediastinal tumours, we consider it absolutely essential to cannulate the femoral vessels preoperatively under local anaesthesia and to provide for the availability of cardiopulmonary bypass in the operating theatre, should extracorporeal circulation become necessary. The benefits of establishing vascular access under local anaesthesia clearly outweigh any associated degree of patient discomfort. In the case of patients classified as 'safe' or 'uncertain', a preoperative consensus with the surgeons should be reached as to the anaesthetic approach and the management of possible complications.

Introduction to Realistic Neural Modeling

This document corresponds to the tutorial on realistic neural modeling given by David Beeman at WAM-BAMM*05, the first annual meeting of the World Association of Modelers (WAM) Biologically Accurate Modeling Meeting (BAMM) on March 31, 2005 in San Antonio, TX. Part I - Introduction to Realistic Neural Modeling for the Beginner: This is a general overview and introduction to compartmental cell modeling and realistic network simulation for the beginner. Although examples are drawn from GENESIS simulations, the tutorial emphasizes the general modeling approach, rather than the details of using any particular simulator. Part II - Getting Started with Modeling Using GENESIS: This builds upon the background of Part I to describe some details of how this approach is used to construct cell and network simulations in GENESIS. It serves as an introduction and roadmap to the extended hands-on GENESIS Modeling Tutorial.

Realistic Single Cell Modeling – from Experiment to Simulation

This tutorial gives a step by step explanation of how one uses experimental data to construct a biologically realistic multicompartmental model. Special emphasis is given on the many ways that this process can be imprecise. The tutorial is intended for both experimentalists who want to get into computer modeling and for computer scientists who use abstract neural network models but are curious about biological realistic modeling. The tutorial is not dependent on the use of a specific simulation engine, but rather covers the kind of data needed for constructing a model, how they are used, and potential pitfalls in the process.

Modeling Calcium Concentration and Biochemical Reactions

Almost all regions of the brain receive one or more neuromodulatory inputs, and disrupting these inputs produces deficits in neuronal function. Neuromodulators act through intracellular second messenger pathways to influence the electrical properties of neurons, integration of synaptic inputs, spatio-temporal firing dynamics of neuronal networks, and, ultimately, systems behavior. Second messengers pathways consist of series of bimolecular reactions, enzymatic reactions, and diffusion. Calcium is the second messenger molecule with the most effectors, and thus is highly regulated by buffers, pumps and intracellular stores. Computational modeling provides an innovative, yet practical method to evaluate the spatial extent, time course and interaction among second messenger pathways, and the interaction of second messengers with neuron electrical properties. These processes occur both in compartments where the number of molecules are large enough to describe reactions deterministically (e.g. cell body), and in compartments where the number of molecules is small enough that reactions occur stochastically (e.g. spines). – In this tutorial, I explain how to develop models of second messenger pathways and calcium dynamics. The first part of the tutorial explains the equations used to model bimolecular reactions, enzyme reactions, calcium release channels, calcium pumps and diffusion. The second part explains some of the GENESIS, Kinetikit and Chemesis objects that implement the appropriate equations. In depth explanation of calcium and second messenger models is provided by reviewing code, both in XPP, Chemesis and Kinetikit, that implements simple models of calcium dynamics and second messenger cascades.

Simulating in vivo-like Synaptic Input Patterns in Multicompartmental Models

In the laboratory of Dr. Dieter Jaeger at Emory University, we use computer simulations to study how the biophysical properties of neurons—including their three-dimensional structure, passive membrane resistance and capacitance, and active membrane conductances generated by ion channels—affect the way that the neurons transfer synaptic inputs into the action potential streams that represent their output. Because our ultimate goal is to understand how neurons process and relay information in a living animal, we try to make our computer simulations as realistic as possible. As such, the computer models reflect the detailed morphology and all of the ion channels known to exist in the particular neuron types being simulated, and the model neurons are tested with synaptic input patterns that are intended to approximate the inputs that real neurons receive in vivo. The purpose of this workshop tutorial was to explain what we mean by ‘in vivo-like’ synaptic input patterns, and how we introduce these input patterns into our computer simulations using the freely available GENESIS software package (http://www.genesis-sim.org/GENESIS). The presentation was divided into four sections: first, an explanation of what we are talking about when we refer to in vivo-like synaptic input patterns

XML for Model Specification in Neuroscience

One of the main roles of the Neural Open Markup Language, NeuroML, is to facilitate cooperation in building, simulating, testing and publishing models of channels, neurons and networks of neurons. MorphML, which was developed as a common format for exchange of neural morphology data, is distributed as part of NeuroML but can be used as a stand-alone application. In this collection of tutorials and workshop summary, we provide an overview of these XML schemas and provide examples of their use in down-stream applications. We also summarize plans for the further development of XML specifications for modeling channels, channel distributions, and network connectivity.

What is the Relation between Human Practical Action and an Accompanying Discourse? Discussing the Status of Practical Theory

The article discusses the function of an accompanying discourse in relation to the genesis of human practical action. On the one side, theory cannot be taken as the ground for practical action; practical action is not a realisation of intentions. On the other hand, human practical action is accompanied by series of explanations, justifications, declarations of intent, pre‑ and post-rationalisations, motivations etc. These accompanying discourses seem in one way or the other to be necessary for the actual realisation of human practical action. Following Pierre Bourdieu, it is suggested that an accompanying discourse cannot in a meaningful manner be separated from the human practical action, that practical theory should be regarded not as theory but as part of practice, and that practical theory first of all provides a common language for talking about practice and hence for reproducing a fundamentally arbitrary idea of the genesis of human practical action. Parallels are drawn to the education/formal training of semi-professionals.

Die Revolution von 1848 – Kulte um die Toten und die Lebenden

In dem Beitrag wird der Genesis des Totenkults von 1848/49 und ebenso des Kults um lebende Revolutionsheroen sowie den Formen, den Wandlungen und der Funktion der darauf basierenden Erinnerungskulturen nachgegangen. Gezeigt wird u.a. erstens, dass der revolutionäre Totenkult in Deutschland nicht geeignet war, zu einem Nationalmythos zu werden, der die verschiedenen sozialen Gruppen und politischen Strömungen einte. Die öffentliche Erinnerung an die gefallenen Revolutionäre spaltete die Nation vielmehr nachhaltig, in Deutschland, nicht dagegen in anderen europäischen Ländern wie Ungarn oder Italien. Die pathetisch-feierliche Erinnerung an die unterschiedlichen Toten der Revolution von 1848/49 und die jenen unterschobene politische Sendung gab den Parteien jedenfalls in Deutschland überhaupt erst Kontur. Die entstehende Linke wie die Rechte verstanden sich als Testamentsvollstrecker des vermeintlichen politischen Willens der im Kampf gefallenen Revolutionäre bzw. ihrer Kontrahenten, der im Kampf „für König und Vaterland“ getöteten Soldaten. Der Totenkult wurde – erstens – für beide Seiten zum politischen Code; für die Linke markiert er zugleich den Beginn einer Art revolutionärer Familientradition. Der Totenkult, gleich welcher Couleur, implizierte Inklusion – und ebenso Exklusion: War der Totenkult zum politischen Code geworden, wurde ihm als zusätzliches Element das politische und soziale Gegenüber als Feindbild implementiert. Kollektive Ausgrenzung erlaubte, die jeweiligen, zumeist komplexen histo­risch-politischen Konfliktkonstellationen auszublenden bzw. auf griffige und personalisierte Grundmuster zu reduzieren. Zweitens: Obgleich zur ‚Parteisache’ geworden, war der von einer mal kleineren, mal größeren Minderheit zelebrierte Totenkult um die am 18. März 1848 in Berlin gefallenen Barrikadenkämpfer in der gesamtnationalen Erinnerung latent immer präsent. Drittens: Die Totenkulte sowie die politische Funktionalisierung von Begräbnissen sollten nicht den Blick dafür verstellen, dass ihnen schon relativ bald ein gleichfalls quasi-religiös aufgeladener Kult um herausragende lebende Revolutionäre wie Friedrich Hecker u.a. an die Seite trat. Auch dieser überlebte das Revolutionsjahr 1848 um Jahrzehnte, im Grunde – ruft man sich die zahlreichen Hecker-Devotionalien des Jahres 1998 in Erinnerung – bis heute.

Lessons for Science from the "Year without a Summer" of 1816. What does it take for science to respond to climate change?

Science is responding in manifold ways to current climate change. What are the perquisites for response, and how can we structure the response? By studying the historical climatic event “Year without a Summer” of 1816 and by relating to Fleck’s theory of genesis and development of a scientific fact, we posit that responding refers to making interlinkages between different notions of climatic change.

Functional regulatory spaces

This article develops the concept of “Functional Regulatory Space” (FRS) in order to analyze the new forms of State action addressing (super) wicked problems. A FRS simultaneously spans several policy sectors, institutional territories and levels of government. It suggests integrating previous policy theories that focused on “boundary-spanning regime,” “territorial institutionalism” or multi-level governance. The FRS concept is envisaged as a Weberian “ideal-type” of State action and is applied to the empirical study of two European cases of potential FRS: the integrated management of water basins and the regulation of the European sky through functional airspace blocks. It will be concluded that the current airspace regulation does match the ideal-type of FRS any better than the water resource regulation does. The next research step consists in analyzing the genesis and institutionalization of potential FRS addressing other (super) wicked problems such as climate change and economic, security, health and immigration issues in different institutional contexts as well as at various levels of governance.

Dysregulation of voltage-gated sodium channels by ubiquitin ligase NEDD4-2 in neuropathic pain

Peripheral neuropathic pain is a disabling condition resulting from nerve injury. It is characterized by the dysregulation of voltage-gated sodium channels (Navs) expressed in dorsal root ganglion (DRG) sensory neurons. The mechanisms underlying the altered expression of Na(v)s remain unknown. This study investigated the role of the E3 ubiquitin ligase NEDD4-2, which is known to ubiquitylate Navs, in the pathogenesis of neuropathic pain in mice. The spared nerve injury (SNI) model of traumatic nerve injury-induced neuropathic pain was used, and an Na(v)1.7-specific inhibitor, ProTxII, allowed the isolation of Na(v)1.7-mediated currents. SNI decreased NEDD4-2 expression in DRG cells and increased the amplitude of Na(v)1.7 and Na(v)1.8 currents. The redistribution of Na(v)1.7 channels toward peripheral axons was also observed. Similar changes were observed in the nociceptive DRG neurons of Nedd4L knockout mice (SNS-Nedd4L(-/-)). SNS-Nedd4L(-/-) mice exhibited thermal hypersensitivity and an enhanced second pain phase after formalin injection. Restoration of NEDD4-2 expression in DRG neurons using recombinant adenoassociated virus (rAAV2/6) not only reduced Na(v)1.7 and Na(v)1.8 current amplitudes, but also alleviated SNI-induced mechanical allodynia. These findings demonstrate that NEDD4-2 is a potent posttranslational regulator of Na(v)s and that downregulation of NEDD4-2 leads to the hyperexcitability of DRG neurons and contributes to the genesis of pathological pain.