Notes on the Trematode Subfamily Loimoinae (Monogenea), with a Description of a New Genus

The subfamily Loimoinae was named by Price (1936) for a peculiar monogenetic trematode, Loimos salpinggoides MacCal lum, 1917, from the gills of a dusky shark, Carcharias obscurus (Lesueur), at Woods Hole, Massachusetts, USA. Price (1938) redescribed this trematode, correcting several errors made by MacCallum. Manter (1938) described Tricotyle scoliodoni from a shark, Scoliodon terrae-novae (Richardson), from Beaufort, North Carolina, USA. He noted some similarities between Tricotyle and Loimos. The redescription of Loimos by Price increased these similarities

THE NEW FEDERALISM: WHAT IT MEANS FOR MINNESOTANS

Public Economics,

THE NEW FEDERALISM: HOW WOULD IT AFFECT MINNESOTA?

Community/Rural/Urban Development, Political Economy,

Electronic Data Transmission Pathways: Implications for Site Selection

Current technology and cost of on-site data transmission hardware, site communications channels, and interface equipment allow a firm the capability to routinely achieve both high speed and high quality of data transmission. However, the firm can easily exceed the capability of a common carrier's local and regional pathways (lines and switch gear), resulting in reduced cost effectiveness of business operations. This study presents a telecommunications evaluation structure that can be integrated into the firm's site selection and facilities planning decision framework. This structure is used to assess the capability of sites to meet required telecommunications support. Additional considerations affecting data transmission capability are included to assist the analyst in the evaluation progress.

Aerodynamic Characteristics of a 45 Degree Swept-wing Fighter-Airplane Model and Aerodynamic Loads on Adjacent Stores and Missiles at Mach Numbers of 1.57, 1.87, 2.16, and 2.53

An investigation was performed in the Langley Unitary Plan wind tunnel to determine the aerodynamic characteristics of a model of a 450 swept-wing fighter airplane, and to determine the loads on attached stores and detached missiles in the presence of the model. Also included was a determination of aileron-spoiler effectiveness, aileron hinge moments, and the effects of wing modifications on model aerodynamic characteristics. Tests were performed at Mach numbers of 1.57, 1.87, 2.16, and 2.53. The Reynolds numbers for the tests, based on the mean aerodynamic chord of the wing, varied from about 0.9 x 10(exp 6) to 5 x 10(exp 6). The results are presented with minimum analysis

Transient entrainment and interruption of atrioventricular node tachycardia

The possibility of transiently entraining and interrupting the common type of atrioventricular (AV) node tachycardia (anterograde slow, retrograde fast AV node pathway) was studied using atrial and ventricular pacing in 18 patients with paroxysmal AV node tachycardia. Transient entrainment occurred in all patients. During atrial pacing, localized block in the AV node for one beat followed by anterograde conduction over the fast pathway was observed in three patients. During ventricular pacing, localized block for one beat followed by retrograde conduction over the slow pathway was not observed in any patient. Neither atrial nor ventricular fusion beats were observed during entrainment.These observations indicate in a way not previously shown that reentry involving two functionally dissociated pathways in the AV node is the underlying mechanism of paroxysmal AV node tachycardia. The inability to demonstrate atrial or ventricular fusion beats during entrainment suggests a true intranodal location of the reentrant circuit. Finally, the ability to transiently entrain intranodal tachycardia demonstrates that this electrophysiologic phenomenon is not exclusively limited to macroreentrant circuits

A new animal model of atrial flutter

A new, simple and reliable model of atrial flutter utilizing postpericardiotomy pericarditis was developed in the dog. Using a sterile technique, the pericardium was opened by way of a right thoracotomy, Teflon-coated, stainless steel wire electrodes were fixed to three selected sites on the atria and exteriorized, the atrial surfaces were generously dusted with talcum powder and a single layer of gauze was placed on the free left and right atrial walls. The dogs were allowed to recover. Subsequently, the inducibility of atrial flutter and selected electrophysiologic properties of the atria were determined by daily programmed atrial stimulation studies with the dogs in the conscious, nonsedated state.Atrial flutter could be induced in 23 of 25 dogs initially studied. It was sustained (that is, lasting ≥5 min) in 17 of the 23. Neither atrial excitability, Intraatrial conduction time nor atrial refractoriness determined by pacing and recording from the three fixed sites predicted the inducibility of atrial flutter. One hundred thirty-nine episodes of atrial flutter induced in these 23 dogs were analyzed. The mean sustained atrial flutter cycle length was 131 ± 20 ms (mean ± SD) (range 100 to 170); the atrial flutter cycle length was 150 ms or more in 23 episodes, between 120 and 150 ms in 64 episodes and 120 ms or less in 52 episodes.In five dogs, the stability of the atrial flutter cycle length during sustained atrial flutter was studied and shown to be remarkably stable in all five until interrupted by rapid atria) pacing 35 to 95 minutes after its induction. Seventeen dogs were submitted to reoperation for epicardial mapping purposes and atrial flutter could be induced in the open chest state in 12. In conclusion, this sterile pericarditis model of atrial flutter in the canine heart proved to be highly reliable, reproducible and easy to create

New decapod crustaceans from Porto Rico

9 p. : ill. ; 24 cm.Includes bibliographical references

Single site radiofrequency catheter ablation of atrial fibrillation: studies guided by simultaneous multisite mapping in the canine sterile pericarditis model

AbstractOBJECTIVESTo test the hypothesis that when activation of Bachmann’s bundle (BB) is critical to the unstable reentrant circuits that maintain atrial fibrillation (AF) in the sterile pericarditis canine model, a lesion in BB would prevent induction of stable AF.BACKGROUNDOne mechanism of induced AF in this model is multiple unstable reentrant circuits, which frequently include BB as part of the reentrant pathway.METHODSSimultaneous multisite mapping studies during AF and after ablation of BB were performed by recording (384 to 396 electrodes) from both atria and the atrial septum during six induced AF episodes in six dogs with sterile pericarditis. Activation maps of AF (mean duration, 24 ± 28 min) during 12 consecutive 100-ms windows were analyzed.RESULTSDuring AF, multiple unstable reentrant circuits (mean, 1.2 ± 0.2 per window; range, 1 to 4) were observed, 68% involving BB. Nonactivation zones (mean duration, 57 ± 16 ms in the right atrium and 53 ± 23 ms in the left atrium) observed during AF were reactivated by a wave front most often coming from the atrial septum via BB (right atrium, 62%; left atrium, 67%). After successful radiofrequency catheter ablation of the midportion of BB, AF >5 s was not induced in all dogs. Mapping studies of transient AF (≤5 s) induced after ablation showed neither reentrant circuits nor wave fronts activating the right atrium via BB.CONCLUSIONSIn this AF model, catheter ablation of BB terminates and prevents the induction of AF by preventing 1) formation of unstable reentrant circuits that involve BB, and 2) activation of the atrial-free walls after a nonactivation period

Insights into the electrophysiology study versus electrocardiographic monitoring trial: Its programmed stimulation protocol may introduce bias when assessing long-term antiarrhythmic drug therapy

AbstractObjectives. We hypothesized that if the Electrophysiology Study Versus Electrocardiographic Monitoring (ESVEM) trial programmed stimulation protocol misclassified some drug trials as effective, then the misclassification rate would be proportionally greater for drugs other than sotalol.Background. In the ESVEM trial, patients treated with sotalol had fewer arrhythmic recurrences than those treated with other antiarrhythmic drugs despite similar efficacy predictions during electrophysiologic testing.Methods. We retrospectively compared the standard programmed stimulation protocol used at Case Western Reserve University, which used three extrastimuli during all follow-up studies, with the ESVEM protocol in 176 antiarrhythmic drug trials: sotalol (n = 54), procainamide (n = 73) and quinidine/mexiletine (n = 49).Results. Predictions of efficacy were higher in the sotalol trials (14 of 54 standard, 20 of 54 ESVEM) than in procainamide trials (7 of 73 standard, 14 of 73 ESVEM) or quinidine/mexiletine trials (1 of 49 standard, 7 of 49 ESVEM). Thus, the two protocols classified 19 of 176 trials differently: not effective by the standard protocol but effective by the ESVEM trial. Discordant predictions of drug efficacy constituted a smaller proportion of ESVEM protocol efficacy predictions for sotalol (6 [30%] of 20) than for the other drugs (13 [62%] of 21, p ⩽ 0.05).Conclusions. In the present study, the ESVEM programmed stimulation protocol predicted efficacy more often than the standard protocol. Discordant predictions represented a smaller portion of efficacy predictions for sotalol than for the other drugs. Thus, in the ESVEM trial, the superior long-term follow-up observed in patients assigned to sotalol may have been an artifact of the stimulation protocol utilized by the ESVEM investigators