bluuebunny/crossref_metadata_2025 huggingface dataset:
Neurotrophin‐3 null mutant mice display a postnatal motor neuropathy
Authors: Woolley Adele G. , Sheard Philip W. , Duxson Marilyn J.
Published: May 2005

This paper examines early postnatal development of the neuromuscular system in mice with a null mutation in the gene for neurotrophin‐3. We report that alpha‐motoneurons at first develop substantially normally, despite a known 15% deficit in their somal size [Woolley et al. (1999)Neurosci. Lett., 272, 107–110.] and the absence of proprioceptive input [Ernfors et al. (1994)Cell, 77, 503–512]. At birth, motor axons have extended into the muscle, forming normal‐looking neuromuscular junctions with focal accumulations of acetylcholine receptors. Detailed ultrastructural analysis does however, reveal subtle abnormalities at this time, particularly a decrease in the extent of occupancy of the postsynaptic site by nerve terminals, and a small but significant deficit in myofibre number. After the relative normality of this early neuromuscular development, there then occurs a catastrophic postnatal loss of motor nerve terminals, resulting in complete denervation of hindlimb muscles by P7. In systematic semi‐serial samples through the entire muscle endplate zones, no neuromuscular junctions can be found. Intramuscular axons are fragmented, as shown by both electron microscopic observations and neurofilament immunohistochemistry, and alpha‐bungarotoxin detection of acetylcholine receptors indicates dispersal of the junctional accumulation. At earlier times (postnatal days three and four) the terminal Schwann cells show ultrastructural abnormalities, and preliminary observations suggest marked disturbance of myelination. Based on comparison with other literature, the peripheral nerve degeneration seems unlikely to have arisen as a secondary effect of de‐afferentation. We discuss whether the neural degeneration is secondary to the disturbance of Schwann cell function, or due directly to a loss of neurotrophin‐3 based support of the motoneuron.
Speed limits in the cerebellum: constraints from myelinated and unmyelinated parallel fibers
Authors: Wyatt Krysta D. , Tanapat Patima , Wang Samuel S.‐H.
Published: May 2005

Cerebellar parallel fibers are among the thinnest known vertebrate axons and represent an extreme anatomical adaptation. Until now a systematic examination of their properties across species has not been carried out. We used transmission electron microscopy and light microscopy to compare parallel fibers in mammals of different brain sizes. From mouse to macaque, the average unmyelinated parallel fiber diameter was 0.2–0.3 µm, consistent with the idea that they are evolutionarily selected for compactness. Average unmyelinated parallel fiber diameter scaled up slightly with brain size, and across species the estimated total conduction time is 5–10 ms. However, these conduction times can vary by milliseconds, and unmyelinated PFs consume large amounts of energy per action potential. These functional disadvantages are overcome in myelinated parallel fibers, which we found in the deep regions nearest the Purkinje cell layer in marmoset, cat and macaque. These axons were 0.4–1.1 µm wide, have expected conduction times of 0.5–1.0 ms, and may convey fast feedfoward inhibition via basket cells to Purkinje cells.
Controlling pathological pain by adenovirally driven spinal production of the anti‐inflammatory cytokine, interleukin‐10
Authors: Milligan Erin D. , Langer Stephen J. , Sloane Evan M. , He Lin , Wieseler‐Frank Julie , O'Connor Kevin , Martin David , Forsayeth John R. , Maier Steven F. , Johnson Kirk , Chavez Raymond A. , Leinwand Leslie A. , Watkins Linda R.
Published: May 2005

Gene therapy for the control of pain has, to date, targeted neurons. However, recent evidence supports that spinal cord glia are critical to the creation and maintenance of pain facilitation through the release of proinflammatory cytokines. Because of the ability of interleukin‐10 (IL‐10) to suppress proinflammatory cytokines, we tested whether an adenoviral vector encoding human IL‐10 (AD‐h‐IL10) would block and reverse pain facilitation. Three pain models were examined, all of which are mediated by spinal pro‐inflammatory cytokines. Acute intrathecal administration of rat IL‐10 protein itself briefly reversed chronic constriction injury‐induced mechanical allodynia and thermal hyperalgesia. The transient reversal caused by IL‐10 protein paralleled the half‐life of human IL‐10 protein in the intrathecal space (t1/2 ∼ 2 h). IL‐10 gene therapy both prevented and reversed thermal hyperalgesia and mechanical allodynia, without affecting basal responses to thermal or mechanical stimuli. Extra‐territorial, as well as territorial, pain changes were reversed by this treatment. Intrathecal AD‐h‐IL10 injected over lumbosacral spinal cord led to elevated lumbosacral cerebrospinal fluid (CSF) levels of human IL‐10, with far less human IL‐10 observed in cervical CSF. In keeping with IL‐10's known anti‐inflammatory actions, AD‐h‐IL10 lowered CSF levels of IL‐1, relative to control AD. These studies support that this gene therapy approach provides an alternative to neuronally focused drug and gene therapies for clinical pain control.
Institutionalized norms of conducting research and social realities: A research synthesis of empirical works from 1983 to 2002
Authors: Farashahi Mehdi , Hafsi Taïeb , Molz Rick
Published: May 2005

Based on a systematic review of the last 20 years of empirical research grounded in institutional theory, we identify some of the main norms of conducting research in this literature. The level of institutions, the formal/informal institutional pillars and the direction of effects are the foundation of these norms addressed by researchers in the last two decades. This review indicates that empirical research is well behind changes in social realities. This may be related to both the institutionalization process that takes place in any academic research and to the suggested difficulty that scholars find in moving away from widely accepted research models and practices, given the context within which they evolve. It is also concluded that local/national regulative institutions are giving up their position to more global normative and cognitive organizational field institutions. As the business environment become more global, giving more importance to transnational and informal institutions will be more crucial in institutional analysis of organizations.
Phylloclimate or the climate perceived by individual plant organs: What is it? How to model it? What for?
Authors: Chelle Michaël
Published: May 2005

This review introduces the emergence of a new research topic, phylloclimate, located at the crossroads between ecophysiology and canopy microclimate research. Phylloclimate corresponds to the physical environment actually perceived by each individual aerial organ of a plant population, and is described by physical variables such as spectral irradiance, temperature, on‐leaf water and features of around‐organ air (wind speed, temperature, humidity, etc.). Knowing the actual climate in which plant organs grow may enable advances in the understanding of plant–environment interactions, as knowing surface temperature instead of air temperature enabled advances in the study of canopy development. Characterizing phylloclimate variables, using experimental work or modeling, raises many questions such as the choice of suitable space‐ and time‐scale as well as the ability to individualize plant organs within a canopy. This is of particular importance when aiming to link phylloclimate and function–structure plant models. Finally, recent trends and challenging questions in phylloclimate research are discussed, as well as the possible applications of phylloclimate results.
Plant immunophilins: functional versatility beyond protein maturation
Authors: Romano Patrick , Gray Julie , Horton Peter , Luan Sheng
Published: May 2005

Originally identified as the cellular targets of immunosuppressant drugs, the immunophilins encompass two ubiquitous protein families: the FK‐506 binding proteins or FKBPs, and the cyclosporin‐binding proteins or cyclophilins. Present in organisms ranging from bacteria to animals and plants, these proteins are characterized by their enzymatic activity; the peptidyl–prolyl cis–trans isomerization of polypeptides. Whilst this function is important for protein folding, it has formed the functional basis for more complex interactions between immunophilins and their target proteins. Beginning with a brief historical overview of the immunophilin family, and a representative illustration of the current state of knowledge that has accumulated for these proteins in diverse organisms, a detailed description is presented of the recent advances in the elucidation of the role of this ubiquitous protein family in plant biology. Though still in its infancy, investigation into the function of plant immunophilins has so far yielded interesting results – as a significant component of the chloroplast proteome, the abundance of immunophilins located in the thylakoid lumen suggests that these proteins may play important roles in this relatively uncharacterized subcellular compartment. Moreover, the importance of the complex multidomain immunophilins in functions pertaining to development is underscored by the strong phenotypes displayed by their corresponding mutants.

Contents

Summary
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I.
A historical perspective
754

II.
The mechanism of immunosuppression
754

III.
PPIase activity and protein folding
755

IV.
Immunophilins are ubiquitous proteins
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V.
Plant immunophilins
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VI.
Specific functions of plant immunophilins
759

VII.
Concluding remarks
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References
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Randomized, Controlled Trial of a Nonpharmacological Intervention to Improve Abnormal Sleep/Wake Patterns in Nursing Home Residents
Authors: Alessi Cathy A. , Martin Jennifer L. , Webber Adam P. , Cynthia Kim E. , Harker Judith O. , Josephson Karen R.
Published: May 2005

Objectives: Abnormal sleep/wake patterns are common in nursing home residents. Lifestyle and environmental factors likely contribute to these poor sleep patterns. The objective of this study was to test a multidimensional, nonpharmacological intervention to improve abnormal sleep/wake patterns in nursing home residents.

Design: Randomized, controlled trial.

Setting: Four nursing homes in the Los Angeles area.

Participants: Residents were screened for excessive daytime sleeping (asleep ≥15% of daytime observations) and nighttime sleep disruption (asleep <80% of nighttime hours, according to wrist actigraphy). Four hundred ninety‐two residents were screened; 339 had excessive daytime sleeping. Of these, 133 had nighttime sleep disruption and consented to participate; 120 completed baseline assessments, and 118 (77% female, mean age 86.9, 90% non‐Hispanic white) were randomized to intervention versus usual care.

Intervention: Five consecutive days and nights of efforts to decrease daytime in‐bed time, 30 minutes or more of daily sunlight exposure, increased physical activity, structured bedtime routine, and efforts to decrease nighttime noise and light.

Measurements: Seventy‐two consecutive hours of wrist actigraphy (nighttime sleep) and structured behavioral observations (daytime sleep and participation in social and physical activities and social conversation) at baseline and repeated at follow‐up while the intervention or usual care condition was in place.

Results: The only effect on nighttime sleep was a modest decrease in mean duration of nighttime awakenings in intervention participants (10.6 minutes at baseline, 9.8 minutes at follow‐up) versus an increase in controls (9.8 minutes at baseline, 13.8 minutes at follow‐up) (F=4.27, P=.04). There were no significant effects on percentage of nighttime sleep or number of nighttime awakenings. There was a significant decrease in daytime sleeping in intervention participants (32% of daytime observations asleep at baseline, 21% at follow‐up), with no change in controls (32% at baseline, 30% at follow‐up; F=20.68, P<.001). Intervention participants had increased participation in social (F=22.42, P<.001) and physical (F=12.65, P=.001) activities and social conversation (F=5.04, P=.03).

Conclusion: A multidimensional, nonpharmacological intervention into lifestyle and environmental factors that likely contribute to abnormal sleep/wake patterns in nursing home residents resulted in decreased daytime sleeping and increased participation in social and physical activities and social conversation. Nonpharmacological interventions should be considered in the management of abnormal sleep/wake patterns in nursing home residents. The main effect may be a significant decrease in daytime sleeping, which may translate to an improvement in quality of life.
Legionnaires' Disease in Long‐Term Care Facilities: Overview and Proposed Solutions
Authors: Seenivasan Meena H. , Yu Victor L. , Muder Robert R.
Published: May 2005

Pneumonia is a leading cause of morbidity and mortality in nursing home patients. In acute care hospitals, there is considerable evidence to indicate that Legionnaires' disease is a significant cause of nosocomial pneumonia, the source of which is the potable water system. A relatively limited amount of data exists as to the role of Legionnaires' disease as a cause of pneumonia acquired in long‐term care residents. Several lines of evidence suggest that Legionnaires' disease may be an important but underrecognized cause of pneumonia in long‐term care residents. These include reports of outbreaks, prospective studies of community‐acquired pneumonia that include nursing home patients, and prospective studies of individual long‐term care facilities linking Legionnaires' disease to colonization of the potable water system with Legionella. Multiinstitutional studies combining environmental and clinical surveillance for Legionella are needed to further confirm the relationship between colonization of potable water and the occurrence of disease in the long‐term care facilities. Until these studies are completed, it is recommended that individual facilities undertake annual sampling of the potable water system for Legionella, coupled with introduction of the rapid Legionella urinary antigen test should L. pneumophila serogroup 1 be found.
Quality of Internet Geriatric Health Information: The GeriatricWeb Project
Authors: Hajjar Ihab , Gable Sarah A. , Jenkinson Victor P. , Kane Laura T. , Riley Ruth A.
Published: May 2005

Many physicians report that Internet health information can affect their clinical decisions. Much of Internet geriatric health information (IGHI) is not controlled for quality, and there is no available process to assess the quality of IGHI used in clinical practice or in medical education. The objective of this project was to describe the development of an assessment process of IGHI and to report on the quality of existing IGHI through the GeriatricWeb project. The assessment was a trilevel process: identification, screening, and peer review. Medical librarians completed the identification of resources, and geriatric specialists conducted the screening and peer review. The peer‐review process was accomplished using a developed tool (4 domains: credibility, accuracy, design, educational features; score 0–100, favorable assessment score=≥75). More than 5,000 IGHI resources were identified, and 1,142 (22%) were advanced for screening. Of those, 246 (21%) were already peer reviewed, and 354 (31%) were advanced for peer review. Of those, 181 (51% or 20% of all those advanced for screening excluding those already peer reviewed) had a favorable assessment. Poor credibility and educational features contributed to this low quality. IGHI authored by national, federal, or academic organizations and targeted to higher academic levels was more likely to have a favorable assessment (P=0.01). Much publicly available IGHI is of suboptimal quality, particularly with regard to credibility and educational domains. Healthcare professionals need to be aware of how to locate high‐quality IGHI and how to assess the quality of available IGHI.
Exploring Chronically Ill Seniors' Attitudes About Discussing Death and Postmortem Medical Procedures
Authors: Perkins Henry S. , Shepherd Krysten J. , Cortez Josie D. , Hazuda Helen P.
Published: May 2005

Proxy decisions about postmortem medical procedures must consider the dead patient's likely preferences. Ethnic‐and sex‐based attitudes surely underlie such preferences but lack sufficient characterization to guide decisions. Therefore, this exploratory study interviewed Mexican‐American, Euroamerican, and African‐American seniors in San Antonio, Texas, for their attitudes about discussing death before it occurs and about organ donation, autopsy, and practice on cadavers. A rigorous content analysis identified themes. Majority attitudes of an ethnic group or sex subgroup here may characterize the group generally.

Attitudes about discussing death differed only by ethnic group. Mexican Americans and Euroamericans favored such discussions, but African Americans did not. Attitudes about the postmortem procedures differed by ethnic group and sex. Overall, Mexican Americans viewed the procedures most favorably; Euroamericans, less so; and African Americans, least so. Men and women differed further within ethnic groups. Mexican‐American men and women split evenly over organ donation, the men expressed no majority preference about autopsies and the women agreed to them, and the men refused and the women agreed to practice on their cadavers. Euroamerican men expressed no majority preferences, but Euroamerican women agreed to organ donation, had no majority preference about autopsies, and refused practice on their cadavers. African‐American men expressed no majority preferences, and African‐American women expressed none about organ donation or autopsies but refused practice on their cadavers.

If confirmed, these ethnic‐ and sex‐based attitudes can help health professionals tailor postmortem care to individual patients' preferences.
Family Loyalty and Adolescent Problem Behavior: The Validity of the Family Group Effect
Authors: Delsing Marc J. M. H. , Van Aken Marcel A. G. , Oud Johan H. L. , De Bruyn Eric E. J. , Scholte Ron H. J.
Published: May 2005

Erratum. Journal of Law and Society Volume 32 Issue 3

The present study examined the relation between perceived justice and trust within family relationships and adolescent internalizing and externalizing problem behavior. Data were gathered from the father, the mother, and two of their adolescent children in 288 families. The social relations model was used to assess perceived justice and trust at the family level and the individual level. Adolescent internalizing and externalizing problem behavior turned out to be best predicted at the family level. Adolescents from families with less just or trustworthy climates showed more of these problem behaviors. Also associations between adolescent problem behavior and individual characteristics of the adolescents were found: adolescents who were generally viewed as less just/trustworthy were reported to have more problems. Our findings suggest that processes at different levels of family functioning (i.e., individual, whole‐family) should be taken into account when investigating associations between family characteristics and children's outcomes.
Self‐Esteem Trajectories among Ethnic Minority Adolescents: A Growth Curve Analysis of the Patterns and Predictors of Change
Authors: Greene Melissa L. , Way Niobe
Published: May 2005

The current study presents a growth curve analysis of self‐esteem among Black, Latino, and Asian American high school students. A series of hierarchical linear models were used to examine patterns and predictors of change in self‐esteem over time. Results revealed an average increase in self‐esteem with age. Although boys and girls experienced similar trajectories of self‐esteem, ethnicity was a significant moderator of developmental change. Black adolescents reported higher self‐esteem, while Asian American adolescents reported lower self‐esteem, compared with their Latino peers. Latino adolescents experienced a sharper increase in self‐esteem over time compared with Black adolescents. The unique and conjoint effects of adolescents' experiences with peers, family, and school were examined in relation to self‐esteem trajectories. Results revealed that each perceived context was significantly associated with self‐esteem trajectories when examined independently, but family experiences emerged as most strongly related to changes in self‐esteem. Results underscore the need to examine change at the individual level, as well as the importance of studying the unique and conjoint effects of individual and contextual‐level variables on developmental processes among ethnic minority adolescents.
Debt Dynamics
Authors: HENNESSY CHRISTOPHER A. , WHITED TONI M.
Published: May 2005

We develop a dynamic trade‐off model with endogenous choice of leverage, distributions, and real investment in the presence of a graduated corporate income tax, individual taxes on interest and corporate distributions, financial distress costs, and equity flotation costs. We explain several empirical findings inconsistent with the static trade‐off theory. We show there is no target leverage ratio, firms can be savers or heavily levered, leverage is path dependent, leverage is decreasing in lagged liquidity, and leverage varies negatively with an external finance weighted average Q. Using estimates of structural parameters, we find that simulated model moments match data moments.
Housing Collateral, Consumption Insurance, and Risk Premia: An Empirical Perspective
Authors: LUSTIG HANNO N. , VAN NIEUWERBURGH STIJN G.
Published: May 2005

In a model with housing collateral, the ratio of housing wealth to human wealth shifts the conditional distribution of asset prices and consumption growth. A decrease in house prices reduces the collateral value of housing, increases household exposure to idiosyncratic risk, and increases the conditional market price of risk. Using aggregate data for the United States, we find that a decrease in the ratio of housing wealth to human wealth predicts higher returns on stocks. Conditional on this ratio, the covariance of returns with aggregate risk factors explains 80% of the cross‐sectional variation in annual size and book‐to‐market portfolio returns.
What Explains the Stock Market's Reaction to Federal Reserve Policy?
Authors: BERNANKE BEN S. , KUTTNER KENNETH N.
Published: May 2005

This paper analyzes the impact of changes in monetary policy on equity prices, with the objectives of both measuring the average reaction of the stock market and understanding the economic sources of that reaction. We find that, on average, a hypothetical unanticipated 25‐basis‐point cut in the Federal funds rate target is associated with about a 1% increase in broad stock indexes. Adapting a methodology due to Campbell and Ammer, we find that the effects of unanticipated monetary policy actions on expected excess returns account for the largest part of the response of stock prices.
Demand–Deposit Contracts and the Probability of Bank Runs
Authors: GOLDSTEIN ITAY , PAUZNER ADY
Published: May 2005

Diamond and Dybvig (1983) show that while demand–deposit contracts let banks provide liquidity, they expose them to panic‐based bank runs. However, their model does not provide tools to derive the probability of the bank‐run equilibrium, and thus cannot determine whether banks increase welfare overall. We study a modified model in which the fundamentals determine which equilibrium occurs. This lets us compute the ex ante probability of panic‐based bank runs and relate it to the contract. We find conditions under which banks increase welfare overall and construct a demand–deposit contract that trades off the benefits from liquidity against the costs of runs.
The Choice of Payment Method in European Mergers and Acquisitions
Authors: FACCIO MARA , MASULIS RONALD W.
Published: May 2005

We study merger and acquisition (M&A) payment choices of European bidders for publicly and privately held targets in the 1997–2000 period. Europe is an ideal venue for studying the importance of corporate governance in making M&A payment choices, given the large number of closely held firms and the wide range of capital markets, institutional settings, laws, and regulations. The tradeoff between corporate governance concerns and debt financing constraints is found to have a large bearing on the bidder's payment choice. Consistent with earlier evidence, we find that several deal and target characteristics significantly affect the method of payment choice.
Prevalence of Venous Obstruction in Permanent Endovenous Pacing in Newborns and Infants: Follow‐Up Study
Authors: STOJANOV PETAR , VRANES MILE , VELIMIROVIC DUSAN , ZIVKOVIC MIRJANA , KOCICA MLADEN J. , DAVIDOVIC LAZAR , NESKOVIC VOISLAVA , STAJEVIC MILA
Published: May 2005

Objective: We examined the prevalence of venous obstruction in 12 newborns and infants with permanent endovenous ventricular pacing, clinically, and by ultrasonographic assessment of hemodynamics (spontaneity, phasicity, velocity, and turbulence of flow) and morphologic parameters (compressibility, wall thickness, and thrombus presence).

Material and Methods: All implantations of single ventricular unipolar endovenous steroid leads, were performed via cephalic vein, and pacemakers were placed in subcutaneous pocket in right prepectoral region. After the vascular surgeon has carefully examined all children for presence of venous collaterals in the chest wall, morphologic and hemodynamic parameters of the subclavian, axillary, and internal jugular veins, were assessed by linear‐array color Doppler. Lead capacity (LC) was calculated for each patient.

Results: Mean age of patients at implant was 6.2 months (range 1 day–12 months), mean weight 6.5 kg (range 2.25–10 kg), and mean height 60.9 cm (range 48–78 cm). Mean LC was 1.99 (range 1.14–3.07). Total follow‐up was 1023 and mean follow‐up 85.2 pacing months (range 3–156). No clinical signs of venous obstruction were observed. Mild stenosis (20%) of subclavian vein was found by color Doppler in 2/12 patients. Both had adequate lead diameter for body surface.

Conclusion: Permanent endovenous pacing is a feasible procedure, even in children of body weight less than 10 kg, with quite acceptable impact on venous system patency.
Optimal Side of Implant for Single‐Lead VDD Pacing: Right‐Sided Versus Left‐Sided Implantation
Authors: HAGHJOO MAJID , ARYA ARASH , EMKANJOO ZAHRA , SADR‐AMELI MOHAMMAD ALI
Published: May 2005

Background: Atrial undersensing occurs in a considerable number of patients with single‐lead VDD pacing. This study tried to determine the role of implant side in maintenance of the VDD mode in patients with isolated atrioventricular (AV) block.

Methods: Eighty‐two patients with isolated AV block (46 females; mean age, 58 ± 17 years) received a single‐lead VDD pacemaker (Medtronic Kappa, n = 70 and St. Jude Medical Affinity, n = 12). The patients were randomly assigned to one of two implantation groups (group I: right‐sided VDD and group II: left‐sided VDD). In each group, the P‐wave amplitudes were determined at implantation, predischarge, 2‐month, and 6‐month follow‐up. At each follow‐up visit, stored event histograms of pacemaker were also retrieved. The atrial sensing measurements were compared between two groups.

Results: Implantation was easier from right side (1.7 ± 1.0 vs 2.8 ± 1.7 attempts, P = 0.001). Implant P‐wave was higher in group I compared to group II (4.2 ± 1.7 vs 2.7 ± 1.0 mV, P < 0.0001). During follow‐up, higher P‐wave amplitudes were obtained in group I both at predischarge (2.6 ± 1.3 vs 1.4 ± 1.1 mV, P < 0.0001), 2‐month (2.8 ± 1.8 vs 1.3 ± 1.0 mV, P < 0.0001), and 6‐month (2.9 ± 1.7 vs 1.3 ± 0.9 mV, P < 0.0001) evaluations but remained stable throughout the 6 months in both groups. After implantation, VDD function was better maintained in group I than group II (100% vs 90%, P = 0.026). Incidence of atrial undersensing was lower in group I than group II (P = 0.026) in last follow‐up visit.

Conclusions: Implant side has a significant influence on atrial sensing performance in single‐lead VDD pacing. Thus, right‐side implantation should be the preferred approach for the implantation of VDD single‐lead systems.
Effect of IKr Blocker Nifekalant on Atrial Action Potential Duration After Successful Internal Cardioversion of Chronic Atrial Fibrillation
Authors: KOFUNE TATSUYA , WATANABE ICHIRO , OKUBO KIMIE , OKUMURA YASUO , MASAKI RIKO , SHINDO ATSUSHI , SAITO SATOSHI
Published: May 2005

Background: Chronic atrial fibrillation (AF) is characterized by a marked decrease in the atrial effective refractory period (ERP) and in the ERP adaptation to rate as well as a decrease in the atrial conduction velocity. Little information is available about the ionic mechanisms underlying AF in humans.

Materials and Methods: We studied the effect of IKr blocker nifekalant on the rate‐dependent changes in atrial action potential duration in 11 patients after successful internal cardioversion of chronic AF of >2 months duration and in 7 patients without AF. In AF patients, right atrial (RA) monophasic action potential (MAP) was recorded at pacing cycle lengths (CLs) of 800–250 ms before and after administration of nifekalant. In control patients, RAMAP was recorded at CLs of 600 and 350 ms before and after administration of nifekalant.

Results: Nifekalant significantly increased RAMAPD at 90% repolarization (RAMAPD90) at CLs of 800–300 ms in the AF patients. The increase in RAMAPD90 by nifekalant became significantly smaller at shorter CLs (42.5 ± 12.4 ms at a CL of 600 ms vs 32.8 ± 14.5 ms at a CL of 350 ms, P < 0.05). Effect of nifekalant on RAPMAPD was attenuated at CL of 600 ms in AF patients in comparison to control patients (increase in RAMAPD in control; 73.0 ± 36.6 ms vs increase in RAMAPD in AF; 42.5 ± 12.4 ms, P < 0.05); however, it was similar at a CL of 350 ms between control and AF patients.

Conclusions: Electrophysiological effects of nifekalant are significantly attenuated in the chronically remodeled human atrium at slower heart rates, but the beneficial effect of RAMAPD prolongation by IKr blocker was well‐preserved even at shorter CLs after chronic AF.
Situational Syncope Induced by Belching
Authors: KIM BYUNG JIN , SUNG KI CHUL , KIM BUM SU , KANG JIN HO , LEE MAN HO , PARK JUNG ROE
Published: May 2005

We describe a case of situational syncope induced by belching. The patient showed severe syncope with a high‐degree atrioventricular block just after belching, but has not experienced syncope or dizziness over a 3‐month follow‐up after permanent pacemaker implantation.
Pneumopericardium and Pneumothorax After Permanent Pacemaker Implantation
Authors: SEBASTIAN CLIFFORD C. , WU WEN‐CHIH , SHAFER MARK , CHOUDHARY GAURAV , PATEL PRANAV M.
Published: May 2005

We present a patient with chronic obstructive pulmonary disease who developed discomfort 2 days after dual‐chamber pacemaker implantation via the left cephalic vein approach. The pacer was placed with active‐fixation leads without obvious complications. A computed tomography (CT) scan taken in the emergency room showed right pneumothorax and associated pneumopericardium without pneumomediastinum. A three‐dimensional reconstruction of CT images confirmed the atrial lead protruding into the pleural space. This lead likely ruptured a bulla causing a pneumothorax followed by pneumopericardium through a pleuro‐pericardial communication. Chest tube placement relieved both pneumothorax and pneumopericardium without the need for atrial lead extraction.
Neutral Competence and Political Responsiveness: An Uneasy Relationship
Authors: West William F.
Published: May 2005

This essay examines the popular argument that a culture of nonpartisan objectivity within the career bureaucracy can effectively serve the interests of presidents and other political executives. A close reading of the literature reveals that neutral competence has become an ambiguous concept. Moreover, evidence drawn from recent studies of OMB (Office of Management and Budget) and from the bureaucratic politics literature more generally suggests that it may not be realistic to expect that civil servants can be nonpartisan and still satisfy the president's need for responsiveness. Although neutral competence is a highly relevant doctrine in some administrative contexts, it is difficult to reconcile with the goal of political responsiveness in areas where bureaucrats are called upon to exercise political discretion.
Redesigning Political Governance: Reforms in Parliamentary Committees’ Work in Switzerland
Authors: Schedler Kuno , Mastronardi Philippe
Published: May 2005

In the course of a major reform wave following the “new public management” as a model, Swiss parliaments at the state and local level have undergone a far‐reaching change process. Most of the intellectual and preparatory work was done in specialized parliamentary committees. We found significant differences in the way parliamentary committees in Switzerland organized the specific contexts to change their governance systems, and these differences had a visible impact on the success of the reforms. Our data show that parliamentary committees’ process designs were important to their functioning, especially in a change process. A constructive collaboration culture between the parliament and the cabinet was key to successful reforming of these two respective bodies.
Reduced fitness of the leafhopper vector Scaphoideus titanus exposed to Flavescence dorée phytoplasma
Authors: Bressan Alberto , Girolami Vincenzo , Boudon‐Padieu Elisabeth
Published: May 2005

Scaphoideus titanus Ball (Homoptera: Cicadellidae), a specialist and univoltine leafhopper on grapevine (Vitis vinifera L.) (Vitaceae), is a vector of Flavescence dorée phytoplasma (FDP) in vineyards of European temperate areas. Males and females of the leafhopper were exposed to FDP by feeding on infected broad bean (Vicia faba L.) (Fabaceae). Detection of FDP by the amplification of phytoplasma DNA with polymerase chain reaction assays of individual insects revealed an acquisition rate of 91.4% (96/105) after an acquisition access period of 13 days. The adult life span of FD‐exposed males and females was much less than that of leafhoppers fed on healthy broad bean, as revealed by ANOVA on the quartiles of survival distribution and Weibull scale parameter. The progeny of exposed females (number of nymphs emerging from eggs deposited on woody cane segments) was significantly less than the progeny of unexposed females. Eggs produced by FD‐exposed females were slightly but significantly delayed in hatching. Reduced fecundity was confirmed by dissecting FD‐exposed and non‐exposed 42‐day‐old females and counting the number of fully sized eggs in each leafhopper. There was no evidence of transovarial passage of FDP in the offspring of infected females after 72 nymphs were reared on a healthy grapevine until the fifth instar or adult appearance and then confined on broad bean seedlings.
Plant quality, progeny sequence, and the sex ratio of the sycamore aphid, Drepanosiphum platanoidis
Authors: Leather S.R. , Wade F.A. , Godfray H.C.J.
Published: May 2005

The reproductive sequence of sexuparae of the sycamore aphid, Drepanosiphum platanoidis (Schrank) (Homoptera: Callaphididae), observed in the field and glasshouse was examined to elucidate the relationship between host nutrition and sex ratio. The observations were made in autumn when the transition from parthenogenetic to sexual reproduction occurred. A switch occurred in the reproductive sequence of the sexuparae. The production of apterous sexual females (oviparae) was followed by alate males, after a brief reproductive pause lasting 2.5–4.0 days. The switchover period was relatively constant across treatments and years. On poor hosts, the first appearance of the oviparae was a day later, whereas the first appearance of males was a day earlier than those on good nutrition. The primary sex ratio (i.e., proportion of males) was numerically female biased. Under semi‐natural field conditions it was 0.22, but altered to 0.18 and 0.29, respectively, under poor and good host nutrition in the glasshouse. In both the field and glasshouse, nymphal development time was significantly longer in oviparae (ca. 22 days) than in males (ca. 18 days). The time from birth to adult was significantly shorter on good hosts (oviparae: 20 days; males: 17 days) than on poor hosts (oviparae: 23 days; males: 19 days). The proportion of nymphs surviving to the adult moult was not dependent on sex in both the field and glasshouse, but the chances of survival were slightly enhanced under good (88%) compared with poor (82%) host nutritive status. In conclusion, the order of morph production and differences in maturation times ensured the synchronisation of the sexes so that mating and oviposition opportunities were optimised before the onset of winter. The female‐bias in the sex ratio maximised the fitness of sexuparae, and reduced the chances of local mate competition by economising in members of the competing sex.
Sexual dimorphism and the impact of temperature on the pupal and adult stages of Sepedon spinipes spinipes, a potential biological control agent of fascioliasis
Authors: McDonnell R. J. , Mulkeen C. J. , Gormally M. J.
Published: May 2005

The malacophagous feeding behaviour of larvae of members of the family Sciomyzidae makes the group ideal for the selection of potential biological control agents of snail hosts of trematode diseases. The aim of this study was to investigate the effects of temperature (14 °C, 17 °C, 20 °C, 23 °C, and 26 °C) on the pupal and adult stages of Sepedon spinipes spinipes (Scopoli) (Diptera: Sciomyzidae). Larval prey density effects on the pupal stage and the extent of sexual dimorphism within the species are also assessed. Optimum growth conditions for the pupal stage and pre‐oviposition/oviposition periods, and female fecundity are identified for mass culturing purposes. The tendency of mature third instar larvae to engage in wandering behaviour is highlighted, and the biological control implications of such behaviour are discussed. Female puparia were significantly (P<0.001) heavier than males for both larval prey densities. Such sexual dimorphism would enable the prediction of adult sex from puparial weight prior to eclosion, thereby facilitating culture establishment. The effect of three food types [honey/yeast mixture only, crushed Radix balthica (L.) (Gastropoda: Pulmonata: Lymnaeidae) only, and honey/yeast mixture plus a crushed snail] on adult longevity (laboratory conditions) was also determined and the results suggest that adults live longest when provided with a crushed snail and a honey/yeast mixture.
Extended life cycle in the chestnut weevil: prolonged or repeated diapause?
Authors: Soula Bertrand , Menu Frédéric
Published: May 2005

Many insect species extend the life cycle of a part of their population over several years. The adaptive value of these long cycles is now well documented, but the physiological processes underlying them have been little studied. Long life cycles are usually viewed as resulting from prolonged diapause proceeding from a simple extension of the usual winter diapause. However, this hypothesis has not been greatly tested, and information is lacking for species with a larval diapause. The energetic cost of a prolonged larval diapause also needs to be measured, because the few published estimates of lipid consumption concern an imaginal diapause. It is not therefore clear whether the negligible lipid consumption observed during adult prolonged diapause can be extrapolated to larval diapause. From microrespirometry and lipid measures in the chestnut weevil, Curculio elephas Gyllenhal (Coleoptera: Curculionidae), we show that: (1) in contrast to the usual hypothesis, the long cycle does not result from an extension of larval winter diapause, but is due to a prolonged diapause occurring secondarily to a developmental phase, and (2) energy consumption during the prolonged diapause is not negligible, but is provided for by a higher initial lipid content in the long cycle individuals. The adaptive value of the observed cycle is discussed.
COMMENTARY ON “EMPIRICAL AND ETHICAL PROBLEMS WITH CUSTODY RECOMMENDATIONS:” WHAT NOW?
Authors: Grisso Thomas
Published: May 2005

Replying to the paper by Tippins and Wittmann, this commentary notes that the problems they identify have been recognized for many years, yet this has resulted in little change in the practice of child custody evaluations. Three underlying reasons are offered for the stalemate that frustrates the implementation of standards for an empirically based child custody evaluation practice: (a) the economics of child custody evaluation practice; (b) inconsistencies between proposals to restrict testimony in this area and the lack of similar restrictions in most other areas of forensic practice; and (c) inadequate motivation for researchers who might contribute an empirical base for child custody evaluations. Directions for breaking the stalemate are offered for each of these problems.
COMMENTARY ON “EMPIRICAL AND ETHICAL PROBLEMS WITH CUSTODY RECOMMENDATIONS:”
Authors: Rotman Hon. Arline S.
Published: May 2005

Whether or not custody evaluators, testifying as expert witnesses, continue to make specific custody recommendations, custody decision making will continue to be based upon inadequate and untested evidence unless and until we reform the family court system in American courtrooms. Judges and lawyers must have specialized knowledge and training about such things as the developmental needs of children, the effects of divorce on children, domestic violence, and child safety issues; lawyers must develop litigation as well as mediation and negotiation skills; specialized family courts utilizing individual calendars and case management techniques must be established; and the complexities and intellectual challenges of family law cases needs to be recognized.
BRINGING CHILDREN TO THE MEDIATION TABLE:
Authors: Schoffer Melissa J.
Published: May 2005

With the rise of divorce mediation as an effective means of resolving divorce and custody disputes, a question that arises is whether a child should actively participate in the mediation process to make his or her voice heard. This article discusses the costs and benefits of involvement, focusing on four specific approaches to the inclusion of children in divorce mediation. This article comes to the conclusion that the integration of children in mediation ought to be considered on a case‐by‐case basis, and further proposes that a child be included in divorce mediation in circumstances where the child's input is needed to help parents resolve an issue of dispute that concerns their child's interests.
Two-Dimensional Piezoelasticity and Zigzag Theory Solutions for Vibration of Initially Stressed Hybrid Beams
Authors: Kapuria S. , Alam N. , Jain N. K.
Published: May 2005

Two-dimensional (2D) exact piezoelasticity and one-dimensional coupled zigzag theory solutions are presented for vibration of initially stressed simply-supported cross-ply symmetrically laminated hybrid piezoelectric beams under axial strain and actuation potentials. In the 2D exact solution, the coupled governing equations for the vibration mode are derived using Fourier series. Using transfer matrix approach and the boundary conditions, homogeneous equations are set up for the variables at the bottom. The determinant of their coefficient matrix is set to zero to obtain the natural frequency. An efficient coupled zigzag theory is developed for vibration of initially stressed hybrid beams. A piecewise linear approximation of the potential field, an approximation for the deflection to account for the piezoelectric strain and a combination of global third-order variation and layer-wise linear variation for the axial displacement are employed. The conditions of absence of shear tractions at the top and bottom and the conditions of continuity of transverse shear stress at the layer interfaces are exactly satisfied. The governing equations are derived from extended Hamilton’s principle. Comparison of natural frequencies of beams and panels of different configurations with the exact 2D piezoelasticity solution establish that the present zigzag theory is generally very accurate for moderately thick beams. The first-order and third-order shear deformable theories, which are also assessed, are found in some cases to yield poor results even for thin beams.
Statistical Analysis of the Dynamic Mean Excitation for a Spur Gear
Authors: Gelman L. , Giurgiutiu V. , Bayoumi A.
Published: May 2005

An innovative statistical methodology and generic expressions have been developed for the ratio of the dynamic mean excitation to the transmitted mean load under the influence of the important gear characteristics. Simple expressions have been established for identifying cases in which the dynamic mean excitation is more than, less than, or equal to the transmitted mean load.
Optimizing Vibration Isolation of Flex Circuits in Hard Disk Drives
Authors: Brake M. R. , Wickert J. A.
Published: May 2005

A “flex circuit” is a laminate of polyimide substrate, adhesive, and copper conductors that is used to connect the stationary electronic components in a computer hard disk drive to the rotating arm that positions read/write heads above the disks. The flex circuit’s transverse and longitudinal vibrations couple with the arm, and those motions, although seemingly small, degrade performance during seek operations from one data track to another. The flex circuit and arm mechanism is defined by a number of geometric parameters, and some latitude is available at the design stage for choosing dimensions and angles so as to minimize vibration transmission from the flex circuit to the arm. In this paper, the results of parameter, optimization, and experimental studies are discussed with a view toward improving isolation of the arm from vibration of the flex circuit in one or several modes. Particularly for the mechanism’s odd modes, the flex circuit’s free length and the relative attachment angle between the arm’s centerline and the circuit can each be chosen to significantly reduce vibration transmission. A genetic algorithm was applied to minimize a metric of vibration coupling in several vibration modes, and, in the case study examined, vibration isolation was improved by over 80%.
Damping Characteristics of Beams with Enhanced Self-Sensing Active Constrained Layer Treatments Under Various Boundary Conditions
Authors: Gao J. X. , Liao W. H.
Published: May 2005

In this paper, an energy-based approach is developed to investigate damping characteristics of beams with enhanced self-sensing active constrained layer (ESACL) damping treatments. Analytical formulations for the active, passive, and total hybrid modal loss factors of the cantilever and simply-supported beams partially covered with the ESACL are derived. The analytical formulations are validated with the results in the literature and experimental data for the cantilever beam. Beams with other boundary conditions can also be solved and discussed using the presented approach. The results show that the edge elements in the ESACL can significantly improve the system damping performance as compared to the active constrained layer damping treatment. The effects of key parameters, such as control gain, edge element stiffness, location, and coverage of the ESACL patch on the system loss factors, have been investigated. It has also been shown that the boundary conditions play an important role on the damping characteristics of the beam structure with the ESACL treatment. With careful analysis on the location and coverage of the partially covered ESACL treatment, effective vibration control for beams under various boundary conditions for specific modes of interest would be achieved.