Method of vibration isolating an aircraft engine

A method for coupling an engine to a support frame for mounting to a fuselage of an aircraft using a three point vibration isolating mounting system in which the load reactive forces at each mounting point are statically and dynamically determined. A first vibration isolating mount pivotably couples a first end of an elongated support beam to a stator portion of an engine with the pivoting action of the vibration mount being oriented such that it is pivotable about a line parallel to a center line of the engine. An aft end of the supporting frame is coupled to the engine through an additional pair of vibration isolating mounts with the mounts being oriented such that they are pivotable about a circumference of the engine. The aft mounts are symmetrically spaced to each side of the supporting frame by 45 degrees. The relative orientation between the front mount and the pair of rear mounts is such that only the rear mounts provide load reactive forces parallel to the engine center line, in support of the engine to the aircraft against thrust forces. The forward mount is oriented so as to provide only radial forces to the engine and some lifting forces to maintain the engine in position adjacent a fuselage. Since each mount is connected to provide specific forces to support the engine, forces required of each mount are statically and dynamically determinable

Criticality without frustration for quantum spin-1 chains

Frustration-free (FF) spin chains have a property that their ground state minimizes all individual terms in the chain Hamiltonian. We ask how entangled the ground state of a FF quantum spin-s chain with nearest-neighbor interactions can be for small values of s. While FF spin-1/2 chains are known to have unentangled ground states, the case s=1 remains less explored. We propose the first example of a FF translation-invariant spin-1 chain that has a unique highly entangled ground state and exhibits some signatures of a critical behavior. The ground state can be viewed as the uniform superposition of balanced strings of left and right parentheses separated by empty spaces. Entanglement entropy of one half of the chain scales as log(n)/2 + O(1), where n is the number of spins. We prove that the energy gap above the ground state is polynomial in 1/n. The proof relies on a new result concerning statistics of Dyck paths which might be of independent interest.Comment: 11 pages, 2 figures. Version 2: minor changes in the proof of Lemma

Zonisamide (CI-912) and Cognition: Results from Preliminary Study

Nine patients with refractory partial seizures were evaluated in a pilot study of a new anticonvulsant compound, zonisamide (l,2-benzisoxazole-3-methane-sulfonamide; CI-912). Cognitive functioning was evaluated prior to treatment with zonisamide and repeated after 12 and 24 weeks of treatment with zonisamide. At minimum steady-state plasma concentrations >30 jjug/ml, zonisamide appeared to affect specific cognitive functions such as acquisition and consolidation of new information. Previously learned material, such as vocabulary, and psychomotor performance were not affected. Verbal learning was affected, while visual-perceptual learning was unimpaired. These cognitive effects were observed in the absence of the usual clinical signs and symptoms of toxicity. A linear relationship was found between impairment of cognitive abilities and the minimum plasma concentration (r = -0.73; p < 0.05). Findings also suggest the development of tolerance to the adverse cognitive effects. RESUMEN En un estudio piloto realizado para valorar la eficacia de la zonisamida (1,2-Bencisoxazol-melanosulfonamida [CI-912]), un nuevo compuesto anticonvulsive se han evaluado unos 9 pa-cientes con ataques parciales refractarios al tratamiento. Se de-terminÓ la capacidad cognitiva anterior al tratamiento y se re-pitio 12 y 24 semanas despuÉs del tratamiento con zonisamida. Con concentraciones plasmÁticas mÍnimas estables per encima de 30 mcg/ml, la zonisamida afectÓ las funciones cognitives especÍficas tales como la adquisiciÓn y consolidaciÓn de nueva informaciÓn. El material aprendido previamente, tal como el vo-cabulario, y las funciones psicomotoras no se afectaron. El aprendizaje verbal se modificÓ mientras que el aprendizaje visuo-perfectivo no se modificÓ. Estos efectos cognitivos se ob-servaron en ausencia de los habituales signos y sÍntomas clÍnicos de toxicidad. Se encontrÓ una relaciÓn lineal entre la alteraciÓn de las posibilidades cognitivas y la concentraciÓn plasmÁtica mÍnima (r = -0.73, p < 0.05). Estos hallazgos tambiÉn sugieren el desarrollo de una tolerancia a los efectos cognitivos adversos. ZUSAMMENFASSUNG 9 Patienten mit rezidivierenden Partial-AnfÄllen wurden in einer Pilotstudie mit einer neuen antiepileptischen Substanz: Zonisamide untersucht. Die kognitiven Funktionen wurden vor der Behandlung mit Zonisamide geprtÜft und nach 12 und 24 Therapiewochen mit Zonisamide wiederholt. Bei einem Min-destplasmaspiegel von 30 mcg/ml schien Zonisamide spezifische kognitive FÄhigkeiten wie Aufnahme und Speicherung neuer In-formationen zu beeintrÄchtigen. Vorher gelernte Inhalte wie sprachliche und psychomotorische Fertigkeiten wurden nicht beeinflußt. Verbales Lernen war ebenfalls betroffen, wÄhrend visuell, perzeptives Lernen nicht verschlechtert war. Diese BeeintrÄchtigung kognitiver Funktionen wurde bei fehlenden klinischen Intoxikationszeichen beobachtet. Eine lineare Bezie-hung zwischen Verschlechterung kognitiver FÄhigkeiten und Mindest-Plasmaspiegel konnte hergestellt werden (r = -0,73; p < 0,05). Allerdings lassen die Ergebnisse auch auf eine GewÖhnung an diese unerwÜnschten Nebenwirkungen schließen.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65995/1/j.1528-1157.1987.tb03624.x.pd

Growing spatial correlations of particle displacements in a simulated liquid on cooling toward the glass transition

We define a correlation function that quantifies the spatial correlation of single-particle displacements in liquids and amorphous materials. We show for an equilibrium liquid that this function is related to fluctuations in a bulk dynamical variable. We evaluate this function using computer simulations of an equilibrium glass-forming liquid, and show that long range spatial correlations of displacements emerge and grow on cooling toward the mode coupling critical temperature

Pilot Study of Zonisamide (1,2-Benzisoxazole-3-methanesulfonamide) in Patients with Refractory Partial Seizures

A new anticonvulsant compound, zonisamide (1,2 benzioxazole-methanesulfonamide), was studied in 10 adults with medically refractory partial seizures. Following a single oral dose of 400 mg, peak plasma levels occurred an average of 2.8 h after dosing, and the mean clearance from plasma was 2.34 L/h. Whole blood concentrations were high than plasma concentrations because of red blood cell binding. steady-state plasma concentrations were high than predicted from a linear kinetic model. In most patients, seizure frequency was reduced after zonisamide was substituted for a standard antiepileptic drug. Dose-related reversible side effects in the central nervous and gastrointestinal system were observed. Most patients tolerated doses between 5.2 and 12.5 mg/kg/day. RÉSUMÉ Un nouveau produit anticonvulsivant, le zonisamide (1,2 benziosoxazole-methylsulfonamide) a ÉtÉ administrÉÀ 10 adultes atteints de crises partielles non contrÔlÉes par le traitement mÉdical. AprÈs une dose unique orale de 400 mg, le pic du taux plasmatique survient en moyenne 2 h 1/2 aprÉs l'ingestion, et la clairance plasmatique moyenne est de 2,34 litres par heure. les concentrations sanguines totales sont plus ÉlevÉes que les concentrations plasmatiques, en raison de la liaison aux globules rouges, les concentrations plasmatiques À l'État d'equilibre sont plus ÉlevÉes que celles que l'on peut dÉdurie d'un modÈle de cinÉtique linÉaire. Chez la plupart des patients, la frÉquence des crises a ÉtÉrÉduite par la substitution du zonisamide au traitement antiÉpileptique standard. Des effets secondaires doses-dÉpendants et rÉversibles ont ÉtÉ observÉs au niveau du systÈme nerveux central et du tube digestif. La plupart des patients ont tolÉrÉ des doses entre 5,2 et 12,5 mg/kg de poids par jour. RESUMEN En 10 adultos con ataques parciales refractarios a1 tratamiento mÉdico, se ha estudiado la acciÓn de un nuevo compuesto anticonvulsivo, la zonisamida (1,2 benzisoxazol-metanosulfonamida). Tras la ingestiÓn de una sola dosis oral de 400 mg., se alcanzaron los niveles pico en plasma en un promedio de 2.8 horas desputs de la dosis y el aclaramiento medio del plasma fuÉ de 2, 34 litros/hora. Las concentraciones en sangre fueron mÁs altas que las plasmÁticas debido a que la medicaciÓn se ligaba a los hematies. Las concentraciones plasmÁticas estables fueron mÁs altas que las previsibles de un modelo cinÉtico lineal. En la mayorÍa de los pacientes la frecuencia de los ataques se redujo despuÉs de cambiar la medicaciÓn antiepilÉptica standard por la zonisamida. TambiÉn se observaron los efectos colaterales sobre el tracto gastrointestinal y el sistema nervioso central que estaban relacionadas con la dosis y eran reversibles. La mayor parte de los pacientes tolerÓ dosis que oscilaban entre 5.2 y 12.5 mg/kg/dÍa. ZUSAMMENFASSUNG Ein neues Antikonvulsivum, Zonisamid (1,2 Benzisoxazol-Methansulfonamid) wurde bei 10 Envachsenen mit therapieresistenten PartialanfÄllen gesucht. Nach einer oralen Einzeldosis von 400 mg wurden Plasmaspitzenwerte im Durchschnitt nach 2, 8 Stunden erreicht. Die mittlere Clearance aus dem Plasma betrug 2, 34 L/Stunde. Ganzblutkonzentrationen waren hÖher als Plasmakonzentrationen aufgrund der Bindung an die roten BlutkÖrperchen. Die steady-state Plasmakonzentrationen waren hÖher als bei einem linearen kinetischen Modell zu envarten. Bei den meisten Patienten konnte die Anfallsfrequenz nach Substitution eines Standardantiepileptikums durch Zonisamid reduziert werden. Es bestanden dosisabhÄngige, reversible, zentral-nervÖse und gastrointestinale Nebenwirkungen. Die meisten Patienten tolerierten Dosen zwischen 5, 2 und 12, 5 mg/kg/Tag.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65938/1/j.1528-1157.1985.tb05407.x.pd

Differential Interactions of Na+ Channel Toxins with T-type Ca2+ Channels

Two types of voltage-dependent Ca2+ channels have been identified in heart: high (ICaL) and low (ICaT) voltage-activated Ca2+ channels. In guinea pig ventricular myocytes, low voltage–activated inward current consists of ICaT and a tetrodotoxin (TTX)-sensitive ICa component (ICa(TTX)). In this study, we reexamined the nature of low-threshold ICa in dog atrium, as well as whether it is affected by Na+ channel toxins. Ca2+ currents were recorded using the whole-cell patch clamp technique. In the absence of external Na+, a transient inward current activated near −50 mV, peaked at −30 mV, and reversed around +40 mV (HP = −90 mV). It was unaffected by 30 μM TTX or micromolar concentrations of external Na+, but was inhibited by 50 μM Ni2+ (by ∼90%) or 5 μM mibefradil (by ∼50%), consistent with the reported properties of ICaT. Addition of 30 μM TTX in the presence of Ni2+ increased the current approximately fourfold (41% of control), and shifted the dose–response curve of Ni2+ block to the right (IC50 from 7.6 to 30 μM). Saxitoxin (STX) at 1 μM abolished the current left in 50 μM Ni2+. In the absence of Ni2+, STX potently blocked ICaT (EC50 = 185 nM) and modestly reduced ICaL (EC50 = 1.6 μM). While TTX produced no direct effect on ICaT elicited by expression of hCaV3.1 and hCaV3.2 in HEK-293 cells, it significantly attenuated the block of this current by Ni2+ (IC50 increased to 550 μM Ni2+ for CaV3.1 and 15 μM Ni2+ for CaV3.2); in contrast, 30 μM TTX directly inhibited hCaV3.3-induced ICaT and the addition of 750 μM Ni2+ to the TTX-containing medium led to greater block of the current that was not significantly different than that produced by Ni2+ alone. 1 μM STX directly inhibited CaV3.1-, CaV3.2-, and CaV3.3-mediated ICaT but did not enhance the ability of Ni2+ to block these currents. These findings provide important new implications for our understanding of structure–function relationships of ICaT in heart, and further extend the hypothesis of a parallel evolution of Na+ and Ca2+ channels from an ancestor with common structural motifs

The recovery of plant community composition following passive restoration across spatial scales

Human impacts have led to dramatic biodiversity change which can be highly scale-dependent across space and time. A primary means to manage these changes is via passive (here, the removal of disturbance) or active (management interventions) ecological restoration. The recovery of biodiversity, following the removal of disturbance, is often incomplete relative to some kind of reference target. The magnitude of recovery of ecological systems following disturbance depends on the landscape matrix and many contingent factors. Inferences about recovery after disturbance and biodiversity change depend on the temporal and spatial scales at which biodiversity is measured. We measured the recovery of biodiversity and species composition over 33 years in 17 temperate grasslands abandoned after agriculture at different points in time, collectively forming a chronosequence since abandonment from 1 to 80 years. We compare these abandoned sites with known agricultural land-use histories to never-disturbed sites as relative benchmarks. We specifically measured aspects of diversity at the local plot-scale (α-scale, 0.5 m2) and site-scale (γ-scale, 10 m2), as well as the within-site heterogeneity (β-diversity) and among-site variation in species composition (turnover and nestedness). At our α-scale, sites recovering after agricultural abandonment only had 70% of the plant species richness (and ~30% of the evenness), compared to never-ploughed sites. Within-site β-diversity recovered following agricultural abandonment to around 90% after 80 years. This effect, however, was not enough to lead to recovery at our γ-scale. Richness in recovering sites was ~65% of that in remnant never-ploughed sites. The presence of species characteristic of the never-disturbed sites increased in the recovering sites through time. Forb and legume cover declines in years since abandonment, relative to graminoid cover across sites. Synthesis. We found that, during the 80 years after agricultural abandonment, old fields did not recover to the level of biodiversity in remnant never-ploughed sites at any scale. β-diversity recovered more than α-scale or γ-scale. Plant species composition recovered, but not completely, over time, and some species groups increased their cover more than others. Patterns of ecological recovery in degraded ecosystems across space and long time-scales can inform targeted active restoration interventions and perhaps, lead to better outcomes