bluuebunny/crossref_metadata_2025 huggingface dataset:
Emerging Trends in Psychological Practice in Long‐Term Care
Authors: Goldberg Roy J. , Devine Jeanne M.
Published: April 2004

Review of: Norris MP, Molinari V, Ogland‐Hand S, eds. Trends in Psychological Practice in Long‐Term Care, Copublished Clinical Gerontologist (Vol. 25, nos. 1/2/3/4, 2002), Binghamton, NY: The Haworth Press, 2002, pp 303.

Purpose: To bring geropsychologists up to date on the ever‐evolving field of geriatric mental health in long‐term care settings.

Background: Over the last 25 years, the number of older adults with mental disorders in nursing homes has surpassed the number in state mental health facilities as these facilities have closed down. This has made skilled nursing homes often times de facto inpatient psychiatric care units for older adults using a large amount of psychotropic and neuroleptic medications. In addition, many older adults with no premorbid history of mental illness develop a range of psychiatric, psychological, and behavioral disorders in response to the losses experienced through aging, illness, and subsequent placement in long‐term care (LTC) settings. The balance between appropriate therapeutic usage of psychoactive medications and overmedication resulting in usage as chemical restraint has always been a difficult one. With the institution of the Omnibus Budget Reconciliation Act of 1987, which restricted use of physical and chemical restraints in nursing homes, opting instead for psychological and behavioral interventions, the role of the psychologist has become more important in the LTC setting. Not only are there far fewer iatrogenic effects, but also nursing home residents' quality of life has improved, enabling each of them to achieve the highest practical, physical, mental, and psychosocial well‐being.

Emerging Trends in Psychological Practice in Long‐Term Care has been copublished as Clinical Gerontologist, Volume 25, Numbers 1/2/3/4, 2002. Margaret P. Norris, PhD, president, Psychologists in Long‐Term Care, Victor Molinari, PhD, president‐elect, American Psychological Association section on clinical geropsychology, and Suzann Ogland‐Hand, PhD, geropsychologist and former secretary for Psychologists in Long‐Term Care, edited it. Each editor is also a contributor of a chapter in the book.

Contents: The book is divided into three sections.
Physician Management of Pacemaker and Implantable Cardioverter Defibrillator Advisories
Authors: MAISEL WILLIAM H.
Published: April 2004

This study was designed to determine how physicians manage pacemaker (PM) and implantable cardioverter defibrillator (ICD) recalls and safety alerts (collectively “advisories”) and to determine which factors influence physicians' clinical decisions. Although PM and ICD advisories affected over 500,000 patients in the past decade, physician clinical management of advisory devices has not been well studied. Advisories continue to occur frequently and are increasing in number and rate. Five‐hundred physician members of the North American Society of Pacing and Electrophysiology (NASPE) were randomly surveyed by mail and were asked to make clinical recommendations regarding the management of various PM and ICD advisory scenarios. One hundred sixty‐two physicians (32%) responded to the survey (cardiac electrophysiologist 69%, general cardiologist 22%, surgeon 6%, and other 3%). There was consensus among physicians regarding the management of some PM and ICD advisories but not others. Factors associated with a higher likelihood of physician recommendation for prophylactic advisory device replacement include: ICD implanted for secondary prevention (vs primary prevention, P < 0.001), pacemaker dependence (P < 0.001), prior appropriate ICD therapy (P < 0.001), higher likelihood of device malfunction (P < 0.001), and physician in practice <10 years (P = 0.02). The number of devices implanted or followed per year and physician specialty had no impact on advisory device management. Physician consensus exists regarding the management of some PM and ICD advisories and can be used to guide clinical practice. Substantial differences of opinion, however, are present regarding the management of many other advisories. Evidence based guidelines incorporating the indication for device implantation and the likelihood of device malfunction would greatly facilitate clinical management of PM and ICD advisory devices. (PACE 2004; 27:437–442)
Impact of Premature Atrial Contractions in Atrial Fibrillation
Authors: JENSEN THOMAS J. , HAARBO JENS , PEHRSON STEEN M. , THOMSEN BLOCH
Published: April 2004

In spite of the increasing knowledge about paroxysmal atrial fibrillation (PAF), details on mode of initiation in unselected patients are scarce. This paper focuses on trigger mechanisms of spontaneous onset of AF in consecutive patients with PAF. One hundred eight consecutive patients with two or more ECG documented AF episodes within the previous year had a 24‐hours Holter recording performed. All AF episodes (n = 157) were reviewed and, within the last 10 beats prior to AF initiation. PP intervals were measured on 25 mm/s paper printouts and premature atrial contractions (PACs) were counted. Additionally, randomly selected coupling intervals (PP′) for PACs not triggering AF were measured and compared to AF triggering intervals and to PP′ intervals from healthy controls. PACs preceded all AF episodes. AF initiation displayed a wide variety in terms of PP coupling intervals and number of PACs prior to initiation within and between subjects. In episodes with PACs within the last 10 beats prior to initiation, we observed a long‐short PP sequence at the time of initiation. Mean PP′ interval (± SE) for AF triggering PACs was 403 ± 9 ms, significantly shorter, P < 0.0001, than PP′ for nontriggering PACs (584 ± 8 ms) and PACs in healthy controls (589 ± 6 ms). However, a large proportion of nontriggering PACs had short PP′ coupling intervals without triggering AF. These observations highlight the importance of other factors than the trigger per se, such as the arrhythmogenic substrate, and suggest that therapeutic maneuvers aimed at curing PAF should target these as well as the trigger mechanisms. (PACE 2004; 27:447–452)
Use of Automatic Threshold Tracking Function with Non‐Low Polarization Leads:
Authors: LURIA DAVID , GUREVITZ OSNAT , LEV DAVID BAR , TKACH YANA , ELDAR MICHAEL , GLIKSON MICHAEL
Published: April 2004

The AutoCapture (AC) function of new pacemakers (PM) from St Jude Medical (SJM) was originally recommended for use with low polarization (LP) ventricular leads only.
However, recent reports have encouraged the use of the AC function with various leads, including those lacking a special LP design. The objective of this study was to analyze the reliability and safety of the AC algorithm application with different types of pacing leads.
The study group comprised 30 consecutive patients with AC PMs connected to three different types of non‐LP leads. Ten patients with SJM LP leads served as the control group. The study protocol included a complete AC function test using four different pulse widths (PW). The pacing threshold was independently assessed by a manual/semiautomatic check. Erratic behavior of polarization measurements with increasing PWs was demonstrated in 43% (n = 13) of the study group. Invalid polarization measurements resulted in erroneous algorithm recommendation to apply AC function in 17% (n = 5) of the study patients. Subsequent AC function activation lead to incorrect threshold determination due to missed noncapture in three patients. AC function should be applied with caution with non‐LP leads. “Off label” use of these leads may cause erroneous polarization signal measurements which, in some cases, may result in incorrect pacing threshold determination, rendering a potential risk to dependent patients. (PACE 2004; 27:453–459)
Color Doppler Tissue Velocity Imaging Can Disclose Systolic Left Ventricular Asynchrony Independent of the QRS Morphology in Patients with Severe Heart Failure
Authors: SCHUSTER PETER , FAERESTRAND SVEIN , OHM OLE‐JØRGEN
Published: April 2004

A QRS width greater than 120 ms is assumed to be a marker of inter‐ and intraventricular asynchrony in severe heart failure (HF) patients. Color Doppler tissue velocity imaging (c‐TVI) with a time resolution of 10 ms was used to study regional left ventricular (LV) longitudinal systolic contraction pattern in HF patients with left and right bundle branch block (LBBB and RBBB) and in patients with normal QRS width. We studied 12 women and 23 men with severe HF, with a mean age of 66 ± 11 years in New York Heart Association functional Class 2.9 ± 0.6. Twenty patients had LBBB and 10 of those were accepted for cardiac resynchronization therapy by biventricular pacing (CRT). Ten patients had normal QRS width, and five had RBBB. In the echocardiographic apical four chamber view, regional peak LV tissue velocities and regional LV time differences of peak tissue velocities were compared at basal and mid‐LV segments. There were no significant differences in regional mean peak tissue velocities among the patient groups. In patients with LBBB accepted for CRT, the LV lateral free‐wall movement at basal LV was 29 ms delayed during main systole, almost significantly different from LBBB patients not accepted for CRT (P = 0.075). Even in HF patients with normal QRS width or RBBB, significant asynchronous longitudinal LV contraction was observed. Conclusions: For the detection of regional longitudinal LV contraction asynchrony in patients with severe HF, supplementary methods to the surface ECG, such as c‐TVI, are strongly recommended. (PACE 2004; 27:460–467)
Evaluation of Atrial Conduction Time at Various Sites of Right Atrial Pacing and Influence on Atrioventricular Delay Optimization by Surface Electrocardiography
Authors: STROHMER BERNHARD , PICHLER MAX , FROEMMEL MARTIN , MIGSCHITZ MARIO , HINTRINGER FLORIAN ,   on behalf of the ELVIS study group
Published: April 2004

Cardiac function and electrical stability may be improved by programming of optimal AV delay in DDD pacing. This study tested the hypothesis if the global atrial conduction time at various pacing sites can be derived from the surface ECG to achieve an optimal electromechanical timing of the left heart. Data were obtained from 60 patients following dual chamber pacemaker implantation. Right atrial septal pacing was associated with significantly shorter atrial conduction time (P < 0.0005) and P wave duration (P < 0.005), compared to standard right atrial pacing sites at the right atrial appendage or at the right free wall. The last two pacing sites showed no significant difference. In a group of 31 patients with AV block, optimal AV delay was achieved by programming a delay of 100 ms from the end of the paced P wave to peak/nadir of the paced ventricular complex. Optimization of AV delay resulted in a relative increase of echocardiographic stroke volume (SV) (10.9 ± 13.7%; 95% CI: 5.9–15.9%) when compared to nominal AV delay (170 ms). Optimized AV delay was highly variable (range 130–250 ms; mean 180 ± 35 ms). The hemodynamic response was characterized by a weak significant relationship between SV increase and optimized AV delay (R2= 0.196, R = 0.443, P = 0.047). The study validated that septal pacing is advantageous for atrial synchronization compared to conventional right atrial pacing. Tailoring the AV delay with respect to the surface ECG improved systolic function significantly and was superior to nominal AV delay settings in the majority of patients. (PACE 2004; 27:468–474)
New Onset of Pacemaker Dependency After Permanent Pacemaker Implantation
Authors: NAGATOMO TOSHIHISA , ABE HARUHIKO , KIKUCHI KAN , NAKASHIMA YASUHIDE
Published: April 2004

Pacemaker dependency has dangerous consequences under conditions of electromagnetic interference, unrecognized lead dysfunction, and battery depletion, and has been associated with cardiovascular and overall mortality. The aim of this study was to examine the incidence of new onset of pacemaker dependency during long‐term follow‐up after pacing system implantation. The study included 518 patients (mean age 72.9 ± 10.4 years) who presented with intrinsic rhythms at the time of implantation. Indications for pacing were sick sinus syndrome (SSS) in 275 (53%) patients, AV block in 209 (40%), and AF with bradycardia in 34 (7%) patients. The mean follow‐up was 3.7 ± 2.7 years (range 1–17). Pacemaker dependency was defined as the absence of an intrinsic rhythm during backup pacing at 30 beats/min for 30 seconds. New onset of pacemaker dependency was observed in 23 (4.4%) of the 518 patients at a mean of 3.1 ± 2.7 years of follow‐up. Pacing indications were SSS in 6 (2.2%) of 275 patients, AV block in 15 (7.2%) of 209, and AF with bradycardia in 2 (5.9%) of 34. Patients with AV block had a significantly higher incidence of pacemaker dependency than patients with SSS (odds ratio 3.51; 95% CI 1.3 to 9.3; P = 0.012). The average annual rate of new pacemaker dependency was 1.6% during an 8‐year follow‐up. The incidence of new onset of pacemaker dependency varied among pacing indications, and was significantly higher in patients with AV block than patients with SSS. (PACE 2004; 27:475–479)
Incremental Value of Isolating the Right Inferior Pulmonary Vein During Pulmonary Vein Isolation Procedures in Patients With Paroxysmal Atrial Fibrillation
Authors: ORAL HAKAN , CHUGH AMAN , SCHARF CHRISTOPH , HALL BURR , CHEUNG PETER , VEERAREDDY SRIKAR , GOOD ERIC , PELOSI JR. FRANK , MORADY FRED
Published: April 2004

Electrical isolation of the left superior, left inferior, and right superior pulmonary veins (PVs) is often, but not always, effective in eliminating paroxysmal atrial fibrillation (PAF). The incremental clinical value of also isolating the right inferior PV has not been well defined. PV isolation by ostial applications of radiofrequency energy guided by PV potentials was performed in 176 consecutive patients (mean age 52 ± 11 years) with PAF. The left superior, left inferior, and right superior PVs were targeted in 106 patients, and all four PVs were targeted 70 patients. Successful isolation was achieved in 96% of targeted PVs. The mean duration of follow‐up was 15 ± 7 months. At 1‐year follow‐up, 58% of patients in whom three PVs were isolated were free of recurrent PAF in the absence of antiarrhythmic drug therapy, compared to 73% of patients in whom all four PVs were isolated (P = 0.07). There is a trend towards a better outcome when all four PVs are isolated than when only the three major PVs are isolated. Whenever feasible, the right inferior PV should be isolated along with the other three PVs during the first ablation procedure in patients with PAF. (PACE 2004; 27:480–484)
Nitrous Oxide Sedation Reduces Discomfort Caused by Atrial Defibrillation Shocks
Authors: UJHELYI MICHAEL , HOYT ROBERT H. , BURNS KRIS , FISHMAN ROYCE S. , MUSLEY SHAILESH , SILVERMAN MICHAEL H.
Published: April 2004

An implantable cardioverter defibrillator with atrial therapies (ICD‐ATs) is an effective therapy to manage atrial tacharrhythmias. Acceptance of this therapy is limited by atrial shock related anxiety and discomfort. Inhaled nitrous oxide (N2O) is a potent sedative‐analgesic‐anxiolytic agent that may mitigate shock discomfort and anxiety and improve patient ICD‐AT acceptance. ICD‐AT patients with more than one ambulatory atrial shock within 12 months were enrolled and grouped by ICD‐AT shock method; awake (n = 9) or asleep (n = 4) when ambulatory ICD‐AT shock is delivered. A baseline questionnaire assessed the most recent ambulatory ICD‐AT shock (3 ± 3 months). A 65% N2O/35% O2 mixture was inhaled for 4 minutes followed by an ICD‐AT test shock (18 ± 8 J). The test shock mimicked the awake shock method. The test shock experience during N2O was evaluated via questionnaire immediately following and 24 hours after the shock. Shock related anxiety, intensity, pain, and discomfort were assessed using a ten‐point rank scale. Baseline test shock scores were similar between the shock method groups. In the awake shock method group, N2O greatly reduced preshock anxiety by 48% (6.4 ± 2.4 to 3.3 ± 2.0, or), and shock related intensity (5.9 ± 3.1 to 3.3 ± 2.5), pain (5.0 ± 2.6 to 2.0 ± 2.1), and discomfort (5.6 ± 2.4 to 1.3 ± 1.4) from baseline values by 45%, 60%, and 78% (P < 0.05), respectively. The asleep shock method group reported no changes in shock related anxiety, intensity, pain, or discomfort. Atrial shock concern, assessed via a five‐point rank scale (5 = extreme concern) was improved by N2O but only in the awake group (3.1 ± 1.0 baseline to 1.6 ± 0.5 N2O, P = 0.008). There were no adverse events with N2O and patients fully recovered within 5 minutes after N2O. In conclusion, 65% N2O greatly reduced shock related pain and discomfort, and significantly reduced atrial shock concern but only in the awake shock method group. The benefits of N2O therapy may expand the use and acceptability of ICD‐AT therapy into a larger atrial fibrillation
cohort. (PACE 2004; 27:485–491)
Feasibility of the Inframammary Location for Insertable Loop Recorders in Young Women and Girls
Authors: KANNANKERIL PRINCE J. , BIBEAU DEBORAH A. , FISH FRANK A.
Published: April 2004

The parasternal location for the insertable loop recorder (ILR) has potential for erosion in small patients, and can be aesthetically unappealing, especially for young women. We assessed the feasibility of the inframammary location in nine patients, utilizing a 2 cm transverse incision at the inferior and medial border of the left or right breast. Signal quality was adequate with clearly discernable atrial and ventricular electrograms. No complications involving the surgical site were observed. Cosmetically, placement of the scar in the natural breast crease has been favorably accepted. Inframammary implantation of the ILR is feasible, and is the preferred method in young women and girls at our center. (PACE 2004; 27:492–494)
Saline Irrigated Catheter Ablation for Pulmonary Vein Isolation in Pigs:
Authors: PENG JIAN , MADRID ANTONIO H. , PALMEIRO ALBERTO , REBOLLO JOSE MARIA G , LIMÓN LILIANNA , NANNINI SEBASTIAN , MARÍN IRENE , BERNAL ENRIQUE , ESCOBAR CARLOS , VIANA MARIA , MORO CONCEPCION
Published: April 2004

Focal AF is amenable to radical cure by RF ablation within the PV. The primary purpose of this study was to compare lesion characteristics for irrigated versus standard ablation using three power settings for PV isolation in pigs. Secondary analyses were the comparisons of ablation time and temperature characteristics, and evaluation of short‐term safety in the pig model. In 20 pigs from 25 to 35 kg in weight, transseptal catheterization was performed and then the ablation catheter was advanced into the PV. RF energy was delivered to the ostium of the PV until its isolation was achieved. The animals were euthanized 1 week after ablation for pathological examination. Electrophysiological isolation of the PV was achieved, although it was difficult to achieve a complete circumferencial lesion in the ostium of the PV. Both of these catheters can produce transmural necrosis, even using 15 W of power. The authors did not see any stenosis of the PV. This might be due to the low energy delivery and the short follow‐up. Pulmonary hemorrhage was present in two animals with 50 W of power, high energy output is dangerous for the ablation of the PV. (PACE 2004; 27:495–501)
Intra‐ and Interatrial Conduction Delay:
Authors: DAUBERT JEAN‐CLAUDE , PAVIN DOMINIQUE , JAUVERT GAËL , MABO PHILIPPE
Published: April 2004

Atrial conduction disorders are frequent in elderly subjects and/or those with structural heart diseases, mainly mitral valve disease, hyperthrophic cardiomyopathies, and hypertension. The resultant electrophysiological and electromechanical abnormalities are associated with a higher risk of paroxysmal or persistent atrial tachyarrhythmias, either atrial fibrillation, typical or atypical flutter or other forms of atrial tachycardias. Such an association is not fortuitous because intra‐ and interatrial conduction abnormalities delays disrupt (spatial and temporal dispersion) electrical activation, thus promoting the initiation and perpetuation of reentrant circuits. Preventive therapeutic interventions induce variable, sometimes paradoxical effects as with the proarrhythmic effect of class I antiarrhythmic drugs. Similarly, atrial pacing may promote proarrhythmias or an antiarrhythmic effect according to the pacing site(s) and mode. Multisite atrial pacing was conceived to correct, as much as possible, abnormal activation induced by spontaneous intra‐ or interatrial conduction disorders or by single site atrial pacing, which are situations responsible for commonly refractory arrhythmias. Atrial electrical resynchronization can also be used to correct mechanical abnormalities like left heart AV dyssynchrony resulting from intraatrial conduction delays. (PACE 2004; 27:507–525)
Use of DDDRP Pacing Device in Prevention and Treatment of Tachy‐Brady Syndrome After Mustard Procedure
Authors: DRAGO FABRIZIO , SILVETTI MASSIMO STEFANO , GRUTTER GIORGIA , SANTIS ANTONELLA DE , GAGLIARDI MARIA GIULIA , GIANNICO SALVATORE
Published: April 2004

A 13‐year‐old male patient, who underwent Mustard operation for a very complex congenital heart disease (CHD), after palliation presented a decrease of the sinus node function, developing a tachy‐brady syndrome and a mild dysfunction of atrioventricular (AV) conduction. He was successfully treated using a DDDRP pacemaker, which ensured a suitable atrial rhythm and was able to interrupt supraventricular tachycardia episodes. Until now, hospitalization related to episodes of heart failure or symptomatic arrhythmia, has not been necessary. (PACE 2004; 27:530–532)
Dual Antegrade Response Tachycardia Induced Cardiomyopathy
Authors: GABA DEEPAK , PAVRI BEHZAD B. , GREENSPON ARNOLD J. , HO REGINALD T.
Published: April 2004

We report a rare case of tachycardia induced cardiomyopathy resulting from nearly incessant dual antegrade response tachycardia. Criteria necessary for sustaining dual antegrade responses are discussed, including: (1) sufficient antegrade dissociation of the AV node; (2) absence of retrograde conduction over each AV nodal pathway following antegrade conduction over its counterpart; (3) difference between fast and slow pathway conduction times exceeding His‐Purkinje refractoriness; and (4) critical timing of sinus impulses relative to preceding AV nodal conduction. Both the arrhythmia and cardiomyopathy were successfully treated by slow pathway ablation. (PACE 2004; 27:533–536)
Multiple Distinct Right Atrial Endocardial Origins in a Patient with Atrial Tachycardia:
Authors: SEGAL OLIVER R. , MARKIDES VIAS , KANAGARATNAM PRAPA , WONG TOM , PETERS NICHOLAS S.
Published: April 2004

Noncontact mapping identified the endocardial origins of four distinct atrial tachycardias in a young patient with drug refractory palpitations and effected successful ablation with no recurrence of symptoms in 5 months of follow‐up. (PACE 2004; 27:541–544)
Electrical Storm After Coronary Artery Bypass Grafting Due to a Kinked Left Internal Mammary Artery Graft
Authors: PERZANOWSKI CHRISTIAN , PAI SUDHA M.
Published: April 2004

Ischemic postoperative ventricular arrhythmias may complicate coronary artery bypass surgery, and may be difficult to treat unless the ischemic substrate is rescued. This report describes a case of a kinked graft that caused incessant polymorphic ventricular arrhythmia. The treatment was surgical correction of the crook. (PACE 2004; 27:545–546)
Percutaneous Isolation of Multiple Pulmonary Veins Using an Expandable Circular Cryoablation Catheter
Authors: WONG TOM , MARKIDES VIAS , PETERS NICHOLAS S. , WRIGHT ANDREW R. , DAVIES D. WYN
Published: April 2004

Although radiofrequency pulmonary vein (PV) ablation is effective in the treatment of atrial fibrillation (AF), it is associated with small but significant risks of PV stenosis and systemic thromboembolism. The characteristics of cryothermic tissue injury may reduce the likelihood of such complications, but using conventionally tipped cryoablation catheters can be time consuming and may, thus, not permit isolation of all PVs during a single procedure. We describe a case of rapid and effective isolation of all electrically connected PVs in a patient with paroxysmal AF, using a percutaneous self‐expanding circular‐tipped cryoablation catheter. (PACE 2004; 27:551–554)
Peripartum Cardiomyopathy Presenting with Repetitive Monomorphic Ventricular Tachycardia
Authors: GEMICI GÖKMEN , TEZCAN HAKAN , FAK ALI SERDAR , OKTAY AHMET
Published: April 2004

A 30‐year‐old asymptomatic pregnant woman at 38 weeks' gestation was noticed to have repetitive monomorphic ventricular tachycardia. A dilated left ventricle with moderately reduced systolic function was found on echocardiographic examination. To the best of our knowledge, a case of peripartum cardiomyopathy presenting with repetitive monomorphic ventricular tachycardia has not been previously reported. (PACE 2004; 27:557–558)
Ventricular Tachycardia with Figure Eight Pattern Originating From the Right Ventricle in A Patient with Cardiac Sarcoidosis
Authors: NODA TAKASHI , SUYAMA KAZUHIRO , SHIMIZU WATARU , SATOMI KAZUHIRO , OTOMO KIYOSHI , OKAMURA HIDEO , KURITA TAKASHI , AIHARA NAOHIKO , KAMAKURA SHIRO
Published: April 2004

This case report describes VT with figure eight pattern originating from the right ventricle in a 33‐year‐old patient with cardiac sarcoidosis. Multiple radiofrequency linear ablation could abolish the VT, and this patient has been clinically free from symptoms of VT during a 6‐month follow‐up. (PACE 2004; 27:561–562)
Orthotripsy Mimicking Asystole
Authors: VLAY STEPHEN C.
Published: April 2004

An insertable loop recorder implanted to evaluate dizziness, documented an apparent arrhythmia during an orthotripsy procedure. Review of the tracing revealed artefact related to an electrostatic discharge that should not be mistaken for ventricular asystole. (PACE 2004; 27:1)
Optical Properties of the Conics Derived from an Elementary Kinematic Consideration
Authors: Criado C. , Alamo N.
Published: April 2004

In a recent article appearing in this journal,1 the optical property of the ellipse is derived from energy conservation. In this paper we derive this property as well as the analogous for the other conics, i.e., hyperbola and parabola, from a very elemental kinematic consideration. The same argument can be used to prove the converse — that only the conics have these optical properties.
Reflections on Handedness
Authors: DeWeerd Alan J. , Hill S. Eric
Published: April 2004

When introducing the optics of mirrors, an obvious place to start is comparing the appearance of objects to their images. Image distance and magnification are usually covered the most thoroughly, but the handedness of images in various shapes of mirrors has also been discussed in The Physics Teacher1–5 and elsewhere.6 However, there has not been a systematic treatment of handedness. We describe a general criterion in terms of axis inversions for whether or not handedness is preserved by a mirror. We consider how the rotation of mirrors affects the orientation of their images. We also make some suggestions for introducing these topics in introductory courses.
A Fun General Education Physics Course: Physics of Sports
Authors: Goff John Eric
Published: April 2004

During a two-year visiting appointment at Oberlin College in Oberlin, OH, I offered a course called Physics of Sports for the fall 2000 semester and the fall 2001 semester. While preparing the course, I faced a challenge that confronts many physics teachers: How can I make a general education physics course fun for nonscience students? With only an algebra prerequisite for the course, the typical student did not have a particularly strong mathematical background. My goal was to not only teach those students a little physics, but also show them how physicists try to understand and describe the world of sports. I also wanted to make the course sufficiently enjoyable that the students had a positive experience in what may have been the last science course some of them ever took. After discussions with the students, I feel the course succeeded in fulfilling my goals.
Teaching Special Relativity Using Physlets®
Authors: Belloni Mario , Christian Wolfgang , Dancy Melissa H.
Published: April 2004

In a recent paper in this journal1 we presented work on the creation and use of Physlet-based2 exercises to teach physical and wave optics. Since then we have developed ready-to-run exercises for introductory physics3,4 and have developed Physlet-based exercises for more advanced topics such as quantum mechanics. In this paper we describe the materials we have created to aid in the teaching and learning of introductory special relativity. There are many reasons to focus on special relativity. Special relativity is the first topic presented in the modern physics section of introductory physics courses and in the sophomore-level modern physics course. It is full of (apparent) paradoxes, and like quantum mechanics, is one of the intriguing theories that continues to captivate students' interest in physics. In addition, because special relativity focuses on abstract concepts, the visualization that Physlet-based material provides is especially valuable.
Reprise of a “Dense and Tense Story”
Authors: Mungan Carl E.
Published: April 2004

Consider the following problem.1 Two uniform cubes have sides of length L. Cube 1 has volume mass density ρ1, while cube 2 has density ρ2 > ρ1. Their average density, ρ = (ρ1 + ρ2)/2, is equal to that of an incompressible fluid filling a beaker. The two cubes are glued together and fully immersed in the fluid with the lighter cube 1 positioned directly above cube 2, such that the interface between them is at depth H. Suppose that the glue has a density equal to that of the fluid, so that the combination of blocks and glue is overall neutrally buoyant in the fluid. Denote by F the maximum tensile force that the glue can withstand before tearing apart. Under what conditions will the cubes break apart (resulting in cube 1 rising to the surface and cube 2 sinking to the bottom)?
Just What Did Archimedes Say About Buoyancy?
Authors: Graf Erlend H.
Published: April 2004

“A body immersed in a fluid is buoyed up with a force equal to the weight of the displaced fluid.” So goes a venerable textbook1 statement of the hydrostatic principle that bears Archimedes' name. Archimedes' principle is often proved for the special case of a right-circular cylinder or rectangular solid by considering the difference in hydrostatic forces between the (flat, horizontal) upper and lower surfaces, and then generalized by the even more venerable “it can be shown…” that the principle is in fact true for bodies of arbitrary shape.
Cloud Formation
Authors: Graham Mark Talmage
Published: April 2004

Cloud formation is crucial to the heritage of modern physics, and there is a rich literature on this important topic.1 In 1927, Charles T.R. Wilson was awarded the Nobel Prize in physics for applications of the cloud chamber.2 Wilson was inspired to study cloud formation after working at a meteorological observatory on top of the highest mountain in Scotland, Ben Nevis, and testified near the end of his life, “The whole of my scientific work undoubtedly developed from the experiments I was led to make by what I saw during my fortnight on Ben Nevis in September 1894.”3 To form clouds, Wilson used the sudden expansion of humid air.4 Any structure the cloud may have is spoiled by turbulence in the sudden expansion, but in 1912 Wilson got ion tracks to show up by using strobe photography of the chamber immediately upon expansion.5 In the interim, Millikan's study in 1909 of the formation of cloud droplets around individual ions was the first in which the electron charge was isolated. This study led to his famous oil drop experiment.6 To Millikan, as to Wilson, meteorology and physics were professionally indistinct. With his meteorological physics expertise, in WWI Millikan commanded perhaps the first meteorological observation and forecasting team essential to military operation in history.7 But even during peacetime meteorology is so much of a concern to everyone that a regular news segment is dedicated to it. Weather is the universal conversation topic, and life on land could not exist as we know it without clouds. One wonders then, why cloud formation is never covered in physics texts.
A Big Sunbird
Authors: Güémez J. , Valiente R. , Fiolhais C. , Fiolhais M.
Published: April 2004

The drinking bird is a toy that is suitable for demonstrations in the classroom. Since it is able to produce work for long periods, this device resembles a perpetuum mobile, but of course it is not.1 (With 30 cm3 of water, a drinking bird can operate for three to four days in summer.) The origin of its motion lies on a temperature gradient established between the lower part of the apparatus (the body) and its upper part (the head), by allowing water to evaporate off the head, which is kept wet.
“Suspend” Your Students' Interests
Authors: Wetherhold Jeffrey M.
Published: April 2004

For the past 19 years, Jeffrey M. Wetherhold has been teaching physics at Parkland High School in a suburb of Allentown, PA. He is a PTRA (Physics Teaching Resource Agent) and enjoys collecting toys that he can use in his physics classroom. Jeff's advice to new teachers is to become immersed in physics by getting involved in AAPT and NSTA functions, starting or joining a local physics teachers group, and reading science books religiously. He also recommends finding a good mentor or mentors in your school and being patient if your classroom facilities are less than adequate. Many, if not most, of the best physics teachers started out with very little. It takes time and patience to develop a good program.
Candida
Infections of Medical Devices
Authors: Kojic Erna M. , Darouiche Rabih O.
Published: April 2004

The number of indwelling medical devices is escalating, and an increasing proportion of device-related infections are being caused by Candida spp. Candida spp. produce biofilms on synthetic materials, which facilitates adhesion of the organisms to devices and renders them relatively refractory to medical therapy. Management of device-related Candida infections can be challenging. Removal of the infected device is generally needed to establish cure of Candida infections of medical devices. However, since the pathogenesis of Candida bloodstream infection is complicated, more studies are necessary to determine the role of catheter exchange in patients with both gastrointestinal tract mucositis and indwelling catheters. The medical and economic impact of these infections is enormous.
Determination of Fungicidal Activities against Yeasts and Molds: Lessons Learned from Bactericidal Testing and the Need for Standardization
Authors: Pfaller M. A. , Sheehan D. J. , Rex J. H.
Published: April 2004

In certain unique clinical settings, the ability of the antimicrobial agent administered to kill the pathogen outright may be quite important. These situations invariably involve infection of a site not easily accessed by host defenses and/or of a structure with essential anatomic or physiologic function such as the heart (endocarditis), central nervous system (meningitis), or bone (osteomyelitis). Likewise, infections in immunosuppressed hosts, especially those who are neutropenic, are often thought to require microbicidal therapy. Proof of the cidal nature of an antimicrobial agent in vitro is tedious, complex, and fraught with error. Although several methods for assessing in vitro bactericidal activity have been standardized (NCCLS M26-A and M21-A), the clinical relevance of these determinations is questionable and the tests are performed infrequently in most laboratories. Most of the clinical data supporting the need for microbicidal therapy and testing have focused on bacterial infections. However, given the fact that most serious fungal infections occur in profoundly immunosuppressed individuals, it is generally assumed that a cidal regimen would be preferable in that setting as well. In view of this clinical concern and the perceived need to assess the fungicidal activity of a variety of agents, we considered that it would be useful to review what is known about the issues and problems in assessing bactericidal activity and the clinical utility of such measurements. Following this review, we discuss the issue of how one defines fungicidal activity in vitro and in vivo and how feasible it might be to determine the fungicidal activity of organism-drug combinations for purposes of both drug development and clinical care. Proposed methods for fungal time-kill determinations and minimal fungicidal concentration determinations are also discussed.
HLA-B27-Associated Reactive Arthritis: Pathogenetic and Clinical Considerations
Authors: Colmegna Inés , Cuchacovich Raquel , Espinoza Luis R.
Published: April 2004

Current evidence supports the concept that reactive arthritis (ReA) is an immune-mediated synovitis resulting from slow bacterial infections and showing intra-articular persistence of viable, nonculturable bacteria and/or immunogenetic bacterial antigens synthesized by metabolically active bacteria residing in the joint and/or elsewhere in the body. The mechanisms that lead to the development of ReA are complex and basically involve an interaction between an arthritogenic agent and a predisposed host. The way in which a host accommodates to invasive facultative intracellular bacteria is the key to the development of ReA. The details of the molecular pathways that explain the articular and extra-articular manifestations of the disease are still under investigation. Several studies have been done to gain a better understanding of the pathogenesis of ReA; these constitute the basis for a more rational therapeutic approach to this disease.
Microorganisms Resistant to Free-Living Amoebae
Authors: Greub Gilbert , Raoult Didier
Published: April 2004

Free-living amoebae feed on bacteria, fungi, and algae. However, some microorganisms have evolved to become resistant to these protists. These amoeba-resistant microorganisms include established pathogens, such asCryptococcus neoformans, Legionellaspp.,Chlamydophila pneumoniae,Mycobacterium avium,Listeria monocytogenes,Pseudomonas aeruginosa, andFrancisella tularensis, and emerging pathogens, such asBoseaspp.,Simkania negevensis, Parachlamydia acanthamoebae, andLegionella-like amoebal pathogens. Some of these amoeba-resistant bacteria (ARB) are lytic for their amoebal host, while others are considered endosymbionts, since a stable host-parasite ratio is maintained. Free-living amoebae represent an important reservoir of ARB and may, while encysted, protect the internalized bacteria from chlorine and other biocides. Free-living amoebae may act as a Trojan horse, bringing hidden ARB within the human “Troy,” and may produce vesicles filled with ARB, increasing their transmission potential. Free-living amoebae may also play a role in the selection of virulence traits and in adaptation to survival in macrophages. Thus, intra-amoebal growth was found to enhance virulence, and similar mechanisms seem to be implicated in the survival of ARB in response to both amoebae and macrophages. Moreover, free-living amoebae represent a useful tool for the culture of some intracellular bacteria and new bacterial species that might be potential emerging pathogens.
Foot-and-Mouth Disease
Authors: Grubman Marvin J. , Baxt Barry
Published: April 2004

Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals. The disease was initially described in the 16th century and was the first animal pathogen identified as a virus. Recent FMD outbreaks in developed countries and their significant economic impact have increased the concern of governments worldwide. This review describes the reemergence of FMD in developed countries that had been disease free for many years and the effect that this has had on disease control strategies. The etiologic agent, FMD virus (FMDV), a member of thePicornaviridaefamily, is examined in detail at the genetic, structural, and biochemical levels and in terms of its antigenic diversity. The virus replication cycle, including virus-receptor interactions as well as unique aspects of virus translation and shutoff of host macromolecular synthesis, is discussed. This information has been the basis for the development of improved protocols to rapidly identify disease outbreaks, to differentiate vaccinated from infected animals, and to begin to identify and test novel vaccine candidates. Furthermore, this knowledge, coupled with the ability to manipulate FMDV genomes at the molecular level, has provided the framework for examination of disease pathogenesis and the development of a more complete understanding of the virus and host factors involved.
Mercury Electrodes in Nucleic Acid Electrochemistry: Sensitive Analytical Tools and Probes of DNA Structure. A Review
Authors: Fojta Miroslav
Published: April 2004

This review is devoted to applications of mercury electrodes in the electrochemical analysis of nucleic acids and in studies of DNA structure and interactions. At the mercury electrodes, nucleic acids yield faradaic signals due to redox processes involving adenine, cytosine and guanine residues, and tensammetric signals due to adsorption/desorption of polynucleotide chains at the electrode surface. Some of these signals are highly sensitive to DNA structure, providing information about conformation changes of the DNA double helix, formation of DNA strand breaks as well as covalent or non-covalent DNA interactions with small molecules (including genotoxic agents, drugs, etc.). Measurements at mercury electrodes allow for determination of small quantities of unmodified or electrochemically labeled nucleic acids. DNA-modified mercury electrodes have been used as biodetectors for DNA damaging agents or as detection electrodes in DNA hybridization assays. Mercury film and solid amalgam electrodes possess similar features in the nucleic acid analysis to mercury drop electrodes. On the contrary, intrinsic (label-free) DNA electrochemical responses at other (non-mercury) solid electrodes cannot provide information about small changes of the DNA structure. A review with 188 references.
Spectral and Photoprototropic Characteristics of 4-Aminobiphenyl in β-Cyclodextrin
Authors: Muthu Vijayan Enoch Israel V. , Swaminathan Meenakshisundaram
Published: April 2004

The photophysical and photoprototropic behaviour of 4-aminobiphenyl (4ABP) in aqueous β-cyclodextrin (β-CDx) solution has been investigated using steady-state and time-resolved fluorescence spectroscopy. Fluorescence of the neutral form of 4ABP is enhanced due to the formation of a 1:1 complex with β-CDx. The formation of this complex has been confirmed by time-resolved spectroscopy. In the presence of β-CDx, no change was observed in the ground state pKa value but the excited state pKa value changed. Based on its photophysical and photoprototropic characteristics in β-CDx, the structure of the 1:1 inclusion complex is proposed.
Intramolecular Triplet-Triplet Energy Transfer in Short Flexible Bichromophoric Amino Acids, Dipeptides and Carboxylic Acid Diester
Authors: Zabadal Miroslav , Heger Dominik , Klán Petr , Kříž Zdeněk
Published: April 2004

Efficiencies of the intramolecular triplet-triplet energy transfer (ITET) in various bichromophoric amino acids (glycine, valine, phenylalanine, and sarcosine), dipeptides (glycylglycine, phenylalanylphenylalanine), and a simple diester, with the benzoyl and naphthyl terminal groups serving as donor and acceptor, respectively, have been determined by the steady-state photokinetic measurements. The magnitude of the transfer rate constants (>108 s-1) and the number of bonds separating the chromophores (8 or 11 atoms) suggest a through-space exothermic exchange mechanism in all cases. The influence of interchromophore distance, the character of the connecting chain as well as of side chains, was evaluated. While the most efficient energy transfer was found in a flexible diester and in valine- and sarcosine-based molecules due to the steric effect of the side hydrocarbon groups, the benzyl groups in the phenylalanine and phenylalanylphenylalanine-based bichromophores had a suppressing effect on ITET. Rigidity of the peptide bond in short bichromophoric compounds causes that a large number of favorable geometries preexist already before excitation; thus the intramolecular processes are controlled by ground-state conformational distribution. Replacing this bond by a less rigid ester moiety would allow that certain unfavorable conformations may coil to favorable ones within the excited-state lifetime (a rotation-controlled photochemical model). Some conclusions were supported by a conformational search of the potential energy surface and molecular dynamics simulations.
Conformation of Aromatic Carbonyl Derivatives: An Infrared Study
Authors: Fiedler Pavel , Exner Otto
Published: April 2004

Infrared spectra of 14 methyl- and polymethyl-substituted acetophenones and of 14 equally substituted methyl benzoates were investigated in the carbonyl region in tetrachloromethane solution and correlated with their conformation. The ν(C=O) frequency depends moderately on the inductive effect of substituents and more sensitively on the steric effect of ortho substituents. Steric effects are not simply related to the torsion angle ϕ (calculated by the density functional theory) but are better described by dividing the methyl substituents into three classes: nonplanar derivatives with methyl groups in the two ortho positions, slightly nonplanar derivatives with two methyl groups in the positions 2 and 3 (buttressing effect), and the remaining derivatives existing in two equilibrium planar conformations. Eleven various physical properties of methyl-substituted acetophenones, measured or calculated previously, were now correlated by principal component analysis (PCA). Two components are necessary to explain 93% of variance; they relate roughly to the steric and inductive effects. Steric effect affects all properties while inductive effect is of importance mainly for the gas-phase basicities and wavelengths in the UV spectra. Both can be separated very effectively using the classic comparison of ortho and para derivatives; in this way, the steric effect is isolated and in a subsequent PCA only one component is sufficient to explain 94% of variance.
Experimental and Theoretical Study of the First Vanadocene(IV) Complexes of α-Amino Acids Prepared from Vanadocene Dichloride
Authors: Vinklárek Jaromír , Paláčková Hana , Honzíček Jan
Published: April 2004

The first bioinorganic vanadocene(IV) complexes of α-amino acids ([Cp2V(aa)]Cl, Cp = η5-C5H5, aa = glycine, L-alanine, L-valine) were prepared by reaction of vanadocene dichloride ([Cp2VCl2]) and α-amino acids in aqueous methanol. Analogous cationic complexes with PF6- counterions were obtained by metathetical reactions of the chloride precursors with KPF6. These compounds are of great interest as model systems for the vanadocene moiety binding to proteins. All complexes have been characterized by elemental analyses and IR, Raman and EPR spectroscopies. On the basis of EPR spectra, a chelate in all the studied complexes was proposed, formed by the carboxylato and amino groups. This structure has also been confirmed by density functional theory (DFT) calculations.
Utilization of Aromatic Denitrocyclization Reaction for the Synthesis of 3-Unsubstituted 1,4-Dihydroquinolin-4-one Derivatives
Authors: Rádl Stanislav , Obadalová Iva
Published: April 2004

Synthesis of 3-unsubstituted 1-alkyl- and 1-aryl-1,4-dihydroquinolin-4-ones from 2-nitroacetophenone via the corresponding 3-amino-1-(2-nitrophenyl)prop-2-en-1-ones and -but-2-en-1-ones by denitrocyclization reaction is described. The nucleophilic cyclization was achieved either by sodium hydride or potassium carbonate in DMF.