Familial Ménière's disease: clinical and genetic aspects

ABSTRACT Background and purpose:Mre's disease is not uncommon, with an incidence in Caucasians of about one in 2000. The incidence peaks in the fifth decade. Cases are usually isolated or sporadic, but in perhaps five per cent other family members are affected. We report here the clinical and genetic characteristics of a comprehensive set of familial Mre's disease cases from the UK.Methods:Forty-six affected families were studied. All cases were diagnosed using the American Academy of Otolaryngolog 8211;Head and Neck Surgery committee on hearing and equilibrium 1995, or more stringent, criteria.Outcomes and results:Autosomal dominant inheritance with reduced penetrance was the most likely mode of inheritance overall. Apparent genetic anticipation was observed, but may also be a result of ascertainment bias given the collection strategy. There was also a slight tendency for cases to result from maternal transmission within the families in this set. The family pedigrees are presented, and the authors have also set up a website at which all the pedigrees may be viewed in greater detai

Historical Gloss and the Separation of Powers

Arguments based on historical practice are a mainstay of debates about the constitutional separation of powers. Surprisingly, however, there has been little sustained academic attention to the proper role of historical practice in this context. The scant existing scholarship is either limited to specific subject areas or focused primarily on judicial doctrine without addressing the use of historical practice in broader conceptual or theoretical terms. To the extent that the issue has been discussed, most accounts of how historical practice should inform the separation of powers require “acquiescence” by the branch of government whose prerogatives the practice implicates, something that is viewed as critical to giving historical practice the force of law. Yet the concept of acquiescence has been treated much too casually in the literature. Claims about acquiescence are typically premised on a Madisonian conception of interbranch competition, pursuant to which Congress and the Executive Branch are each assumed to have the tools and the motivation consistently to guard against encroachments on their authority. It has become apparent from political science scholarship, however, that the Madisonian model does not accurately reflect the dynamics of modern congressional-executive relations. This requires a reexamination of the premises and implications of the idea of institutional acquiescence in particular, and of the role of historical practice more generally. Ultimately, we argue, the problems with the Madisonian model are not fatal to crediting historical practice in interpreting the separation of powers. But they do require more attention to the reasons why such practice is invoked, the extent to which the reasons demand institutional acquiescence, and the precise method by which such acquiescence is identified. To illustrate the importance of each of these questions, we present three case studies of constitutional debates concerning the separation of powers in which practice-based arguments are prominent - war powers, congressional-executive agreements, and removal of executive officers

Presidential Power, Historical Practice, and Legal Constraint

The scope of the President’s legal authority is determined in part by historical practice. This Essay aims to better understand how such practice-based law might operate as a constraint on the presidency. Some scholars have suggested that presidential authority has become “unbounded” by law, and is now governed only or primarily by politics. At the same time, there has been growing skepticism about the ability of the familiar political checks on presidential power to work in any systematic or reliable fashion. Skepticism about law’s potential to constrain in this context is heightened by the customary nature of much of what purports to be the law of presidential power, and by the limited availability of judicial review. As the Essay explains, no examination of whether law constrains the President can succeed without careful specification of what constraint entails and how it relates to distinct but related phenomena like genuine disagreement about the content of the law. After attempting such specification, the Essay identifies various internal and external causal mechanisms through which law, including practice-based law, could constrain the President. The Essay explains, among other things, that one way that law might constrain the President is through the simple fact that issues of presidential power are publicly criticized and defended in legal terms. To gain additional traction on the topic, the Essay considers two other areas of debate that pose analogous questions about the constraining effect of law: whether the doctrine of stare decisis (itself a practice-based norm) constrains Supreme Court decision making, and whether international law (including the international law that is based on customary practice) constrains the behavior of nation-states. The Essay concludes by suggesting some avenues of possible empirical research

Single Crystal Membranes

Single crystal a- and c-axis tubes and ribbons of sodium beta-alumina and sodium magnesium beta-alumina were grown from sodium oxide rich melts. Additional experiments grew ribbon crystals containing sodium magnesium beta, beta double prime, beta triple prime, and beta quadruple prime. A high pressure crystal growth chamber, sodium oxide rich melts, and iridium for all surfaces in contact with the melt were combined with the edge-defined, film-fed growth technique to grow the single crystal beta-alumina tubes and ribbons. The crystals were characterized using metallographic and X-ray diffraction techniques, and wet chemical analysis was used to determine the sodium, magnesium, and aluminum content of the grown crystals

Petrogenesis of calcic plagioclase megacrysts in Archean rocks

Anorthositic complexes with large equidimensional plagioclase grains of highly calcic composition occur in nearly all Archean cratons. Similar plagioclase occur as megacrysts in many Archean sills, dikes, and volcanic flows. In the Canadian Shield these units occur throughout the Archean portions of the entire shield and are particularly common as dikes over an area of a few 100,000 sq km in Ontario and Manitoba during a period of at least 100 m.y. in many different rock types and metamorphic grades. The plagioclase generally occurs in three modes: as inclusions in mafic intrusions at various stages of fractionation, as crystal segregations in anorthosite complexes, or as megacrysts in fractionated sills, dikes, and flows. Most occurrences suggest that the plagioclase was formed elsewhere before being transported to its present location. The evidence seems to be quite clear that occurrences of these types of calcic plagioclase require: (1) ponding of a relatively undifferentiated Archean tholeiitic melt at some depth; (2) isothermal crystallization of large, equidimensional homogeneous plagioclase crystals; (3) separation of the plagioclase crystals from any other crystalline phases; (4) further fractionation of melt; (5)transport of various combinations of individual plagioclase crystals and clusters of crystals by variously fractionated melts; and (6) emplacement as various types of igneous intrusions or flows

Archaean megacrystic plagioclase units and the tectonic setting of greenstones

Large (up to 20 cm), equidimensional, commonly euhedral, plagioclase megacrysts of highly calcic composition (An sub 80-90) occur commonly in all Archean cratons in one or more of three distinct associations: (1) as cumulate crystal segregations of anorthosite or as megacrysts in basaltic dikes, sills, and flows in greenstone belts that vary in metamorphic grade from greenschist to granulite. Throughout 100's of thousands of square kilometers of northwestern Ontario and Manitoba the plagioclase megacrysts occur in pillowed and massive flows, sills, dikes, large inclusions in dikes, and intrusive anorthositic complexes with areas of up to a few 100 sq km and spanning a period of at least 100 m.y. in the 2.7 to 2.8 b.y. time frame; (2) as basaltic dike swarms in stable cratonic areas forming parallel to subparallel patterns over hundreds of thousands of square kilometers intruding both granitic gneisses and supracrustal belts including greenstones. These swams include the Ameralik-Saglek system at 3.1 to 3.4 b.y., the Matachewan system at 2.5 to 2.6 b.y., and the Beartooth-Bighorn system at 2.2 to 2.3 b.y.; and, (3) as anorthositic complexes associated with marbles and quartzites (Sittampundi, India and Messina, South Africa) in granulite grade terrains. Initial attempts to correlate tectonic settings of similar modern crystbearing units with their Archean counterparts were only partially successful

Local cytokine transcription in naïve and previously infected sheep and lambs following challenge with Teladorsagia circumcincta

<b>Background</b><p></p> The abomasal helminth Teladorsagia circumcincta is one of the most economically important parasites affecting sheep in temperate regions. Infection is particularly detrimental to lambs, in which it can cause pronounced morbidity and severe production losses. Due to the spreading resistance of this parasite to all classes of anthelmintic drugs, teladorsagiosis is having an increasingly severe impact on the sheep industry with significant implications for sheep welfare. Protective immunity develops slowly, wanes rapidly and does not appear to be as effective in young lambs. To investigate the development of immunity to T. circumcincta in sheep and lambs, we used cytokine transcript profiling to examine differences in the abomasal mucosa and gastric lymph node of naïve and previously infected sheep and lambs following challenge.<p></p> <b>Results</b><p></p> The results of these experiments demonstrated that the abomasal mucosa is a major source of cytokines during abomasal helminth infection. A local Th2-type cytokine response was observed in the abomasal mucosa and gastric lymph node of the previously infected sheep and lambs when compared with those of the naïve during the early stages of infection. In contrast, a pro-inflammatory component more was evident in the abomasal mucosa and gastric lymph node of the naïve sheep when compared with those of the previously infected, which was not observed in the lambs.<p></p> <b>Conclusions</b><p></p> The greater levels of Th2-type cytokine transcripts in both the abomasum and gastric lymph node of the previously infected compared with naïve sheep and lambs emphasises the importance of these mechanisms in the immune response to T. circumcincta infection. Younger lambs appear to be able to generate similar Th2-type responses in the abomasum suggesting that the increased morbidity and apparent lack of resistance in younger lambs following continuous or repeated exposure to T. circumcincta is unlikely to be due to a lack of appropriate Th2-type cytokine production

The Petrogenetic significance of Plagioclase megacrysts in Archean rocks

The petrogenetic significance of plagioclase megacryst-bearing Archean rocks was considered. It was suggested that these developed in mid-to upper-crustal magma chambers that were repeatedly replenished. Crystallization of megacrysts from a primitive liquid that evolves to an Fe-rich tholeiite (with LREE enrichment) is nearly isothermal and is an equilibrium process. Cumulates probably form near the margins of the chambers and liquids with megacrysts are periodically extracted and can appear as volcanics. Some flows and intrusives are found in arc-like settings in greenstone belts. Megacrystic dikes represent large volumes of melt and dike swarms such as the Metachawan swarm of Ontario suggest multiple sources of similar compositions. A complex series of melt ponding and migration are probable and involve large amounts of liquid

On Krein-like theorems for noncanonical Hamiltonian systems with continuous spectra: application to Vlasov-Poisson

The notions of spectral stability and the spectrum for the Vlasov-Poisson system linearized about homogeneous equilibria, f_0(v), are reviewed. Structural stability is reviewed and applied to perturbations of the linearized Vlasov operator through perturbations of f_0. We prove that for each f_0 there is an arbitrarily small delta f_0' in W^{1,1}(R) such that f_0+delta f_0$is unstable. When$f_0$ is perturbed by an area preserving rearrangement, f_0 will always be stable if the continuous spectrum is only of positive signature, where the signature of the continuous spectrum is defined as in previous work. If there is a signature change, then there is a rearrangement of f_0 that is unstable and arbitrarily close to f_0 with f_0' in W^{1,1}. This result is analogous to Krein's theorem for the continuous spectrum. We prove that if a discrete mode embedded in the continuous spectrum is surrounded by the opposite signature there is an infinitesimal perturbation in C^n norm that makes f_0 unstable. If f_0 is stable we prove that the signature of every discrete mode is the opposite of the continuum surrounding it.Comment: Submitted to the journal Transport Theory and Statistical Physics. 36 pages, 12 figure