bluuebunny/crossref_metadata_2025 huggingface dataset:
Late Quaternary climate–ocean changes in western North Africa: offshore geochemical evidence
Authors: Haslett Simon K , Davies Catherine F C
Published: March 2006

Understanding the North African response to natural climatic variability has become an important research focus in recent years, especially considering the uncertain influence of anthropogenic warming to present and future climate changes. Historic climatic perturbations are associated with changes in Atlantic circulation, which in turn have been linked to water resource and land degradation issues in North Africa. In this paper, Late Quaternary climate–ocean changes affecting western North Africa are investigated to provide a temporal contribution to the debate. Major and trace element palaeoenvironmental proxies recorded in a radiocarbon dated sediment core collected under an upwelling cell, offshore Cap Blanc (Mauritania), are analysed. Element groups representing terrigenous (Saharan dust) and biogenic (marine plankton) input, and ocean‐bottom redox conditions, indicate that the region is sensitive to previously documented North Atlantic climate–ocean perturbations, such as Bond Cycles, Heinrich and Dansgaard‐Oeschger events. Additionally, the African Humid Period is recognized and related to an intensification of the African monsoon system that enhanced North East Trade Wind driven upwelling. It appears from this study that North Atlantic sea‐surface temperature strongly influences North African precipitation throughout the Late Quaternary, with Atlantic sea‐surface warming associated with enhanced North African aridity.
Unequal access to foreign spaces: how states use visa restrictions to regulate mobility in a globalized world
Authors: Neumayer Eric
Published: March 2006

Nation‐states employ visa restrictions to manage the complex trade‐off between facilitating the entrance to their territory by passport holders from certain countries for economic and political reasons and deterring individuals from other countries for reasons of perceived security and immigration control. The resulting system is one of highly unequal access to foreign spaces, reinforcing existing inequalities. Trans‐national mobility is encouraged for passport holders from privileged nations, particularly rich Western countries, at the expense of severe restrictions for others. Visa restrictions manifest states’ unfaltering willingness to monitor, regulate and control entrance to their territory in a globalized world.
Taxonomy of Health Networks and Systems: A Reassessment
Authors: Luke Roice D.
Published: March 2006

Objective. To assess a widely recognized multihospital system taxonomy.

Data Sources. The original taxonomy was based on American Hospital Association (AHA) Annual Survey Data for the years 1994 and 1995 and a reexamined version, on 1998 AHA data.

Study Design. We assess the appropriateness of using data designed to capture local hospital/system interrelationships to develop a taxonomy of multihospital systems.

Data Abstraction Methods. The original and reexamined taxonomies used dichotomous measures of service availability, physician practice ownership, and managed care offerings.

Principal Findings. The data and measures used to formulate the taxonomy are not appropriate for classifying multihospital systems at the company level.

Conclusions. Taxonomic studies of multihospital systems are very much needed; future taxonomic studies should make clear distinctions between systems at local versus company levels.
Drug Treatment Service Utilization and Outcomes for Hispanic and White Methamphetamine Abusers
Authors: Niv Noosha , Hser Yih‐Ing
Published: March 2006

Objective. To examine differences in drug treatment service needs, utilization, satisfaction, and outcomes between Hispanic and white methamphetamine (meth) abusers.

Data Sources. Intake assessments and follow‐up interviews of 128 Hispanic and 371 non‐Hispanic white meth abusers admitted during 2000–2001 to 43 drug treatment programs in 13 counties across California.

Study Design. A prospective longitudinal study comparing ethnic differences in problem severity during pre‐ and posttreatment periods, as well as in services received during treatment.

Data Collection/Extraction Methods. The Addiction Severity Index (ASI) was administered at both intake and the 9‐month follow‐up to assess clients' problem severity in a number of domains. Service utilization and satisfaction were assessed 3 months following treatment admission.

Principal Findings. Hispanics were less educated and reported more employment difficulties than whites. Whites were more likely to be treated in residential programs than Hispanics despite similar severity in drug and alcohol use, legal, medical and family/social problems, and psychiatric status. Significantly more whites than Hispanics received psychiatric services, likely because more of them were treated in residential programs. Whites also reported receiving greater numbers of total services and services addressing alcohol and psychiatric problems. While no ethnic differences were found in treatment satisfaction and several other outcomes, Hispanics demonstrated better family and social outcomes than whites.

Conclusions. Both Hispanic and white meth abusers improved after treatment, although benefits from treatment can be further enhanced if services underscore different facets of their psychosocial problems.
Why Do Managers Voluntarily Issue Cash Flow Forecasts?
Authors: WASLEY CHARLES E. , WU JOANNA SHUANG
Published: March 2006

We study a relatively recent change in voluntary disclosure practices by management, namely, the issuance of cash flow forecasts. We predict and find that management issues cash flow forecasts to signal good news in cash flow, to meet investor demand for cash flow information, and to precommit to a certain composition of earnings in terms of cash flow versus accruals, thus reducing the degree of freedom in earnings management. Our results also suggest that management discloses good news in cash flow to mitigate the negative impact of bad news in earnings, to lend credibility to good news in earnings, and to signal economic viability when the firm is young. Our finding that management cash flow forecasts primarily convey good news is in contrast to the generally negative nature of management earnings guidance and suggests that different incentives drive firms' disclosure of different financial information.
The Aquatic Conservation Strategy of the Northwest Forest Plan
Authors: REEVES GORDON H. , WILLIAMS JACK E. , BURNETT KELLY M. , GALLO KIRSTEN
Published: March 2006

Abstract:  Implemented in 1994, the Aquatic Conservation Strategy of the Northwest Forest Plan was designed to restore and maintain ecological processes for aquatic and riparian area conservation on federal lands in the western portion of the Pacific Northwest. We used decision support models to quantitatively evaluate changes in the condition of selected watersheds. In the approximately 10 years since strategy implementation, watershed condition scores changed modestly, but conditions improved in 64% of 250 sampled watersheds, declined in 28%, and remained relatively the same in 7%. Watersheds that had the largest declines included some where wildfires burned 30–60% of their area. The overall statistical distribution of the condition scores did not change significantly, however. Much of the increase in watershed condition was related to improved riparian conditions. The number of large trees (>51 cm diameter at breast height) increased 2–4%, and there were substantial reductions in tree harvest and other disturbances along streams. Whether such changes will translate into longer‐term improvements in aquatic ecosystems across broader landscapes remains to be seen.
Conservation of the Marbled Murrelet under the Northwest Forest Plan
Authors: RAPHAEL MARTIN G.
Published: March 2006

Abstract:  The Marbled Murrelet (Brachyramphus marmoratus) was listed as threatened in 1992, primarily because of loss of its old‐forest nesting habitat. Monitoring conducted over the first 10 years following implementation of the Northwest Forest Plan shows at‐sea murrelet populations appear to be stationary, but recruitment is very low and demographic models project a 4–6% annual rate of decline. Monitoring of nesting habitat indicated there were about 1.6 million ha of higher‐suitability nesting habitat on all lands at the start of the plan, about half of which occurred on federal lands. Most (88%) of higher‐suitability habitat on federal lands was protected within reserves. Over the past 10 years, losses of habitat due primarily to fire have totaled about 2% on federal lands. Losses have been much greater (12%) on nonfederal lands, due primarily to timber harvest. Habitat is expected to accrue within reserves as younger forest matures and attains sufficient diameter to support nesting sites. At‐sea estimates of population size are strongly and positively correlated with amounts of adjacent nesting habitat at a broad scale, supporting the idea that amounts of nesting habitat are a primary driver in wide‐scale murrelet population distribution. Conditions at sea, however, such as temperature regimes, prey availability, and pollutants, continue to affect murrelet populations. The system of large reserves seems to have achieved the short‐term objective of conserving much of the remaining nesting habitat on federal lands. These reserves are also likely to contribute to the long‐term objective of creating large, contiguous blocks of nesting habitat. The plan has a primary role in conserving and restoring nesting habitat on federal land but will succeed in this role only if land allocations calling for such protection are in place for many decades.
Status of Mature and Old‐Growth Forests in the Pacific Northwest
Authors: STRITTHOLT JAMES R. , DELLASALA DOMINICK A. , JIANG HONG
Published: March 2006

Abstract:  Nearly 10 million ha of federal lands in the Pacific Northwest have been managed under the Northwest Forest Plan since 1994. The plan reduced logging levels by 80%; only recently, however, have inventories on status and condition of mature and old‐growth forests become available. Our objectives were to (1) determine the areal extent of old (>150 years) and mature (50–150 years) conifer forests based on 2000 Landsat 7 ETM+ imagery, (2) examine levels of protection, (3) determine the degree of additional protection afforded to old and mature conifer forests if late‐successional reserves (LSRs) and inventoried roadless areas (IRAs) were fully protected, and (4) review management options to achieve greater protection of older forests. The historical extent of old‐growth forest in the Pacific Northwest was roughly two‐thirds (16,672,976 ha) of the total land area. Since the time of European settlement, approximately 72% of the original old‐growth conifer forest has been lost, largely through logging and other developments. Of the remaining old growth, the Central and Southern Cascades and Klamath‐Siskiyou account for nearly half. Mature conifer area (4,758,596 ha) nearly equaled the amount of old conifer. More than 78% of the old growth and 50% of mature forest were located on public lands. Approximately one‐quarter (1,201,622 ha) of the old‐growth conifer (or 7% of the historical old‐growth area) was classified as GAP status 1 (strictly protected) or GAP status 2 (moderately protected). The total area of LSRs was slightly more than 3 million ha, approximately 36% (1,073,299 ha) of which contained old‐growth conifer forest. Combined old and mature conifer within LSRs was approximately 59% of the total LSR area. The total amount of IRA for the Pacific Northwest was approximately 1,563,370 ha; of this, 526,912 ha (34%) was old growth. The combined area of old‐growth conifer forest accounted for by protected areas (GAP 1 and 2), LSRs, and IRAs was 2,401,780 ha, which accounts for 66% of the old‐growth conifer forests on public land, 51% of the old conifer in the region, and 14% of the amount that occurred historically. Outside these land designations, an additional 1,240,271 ha of old growth are on other public land and another 1,023,392 ha are on private lands throughout the Pacific Northwest. Our results indicate the need to periodically monitor status and condition of older forests and strengthen protections of old growth in the region.
Protecting Rare, Old‐Growth, Forest‐Associated Species under the Survey and Manage Program Guidelines of the Northwest Forest Plan
Authors: MOLINA RANDY , MARCOT BRUCE G. , LESHER ROBIN
Published: March 2006

Abstract: The Survey and Manage Program of the Northwest Forest Plan (NWFP) represents an unparalleled attempt to protect rare, little‐known species associated with late‐successional and old‐growth forests on more than 9.7 million ha of federal lands. Approximately 400 species of amphibians, bryophytes, fungi, lichens, mollusks, vascular plants, arthropod functional groups, and one mammal were listed under this program because viability evaluations indicated the plan's network of reserve land allocations might not sustain the species over time. The program's standards and guidelines used an adaptive approach, protecting known sites and collecting new information to address concerns for species persistence and to develop management strategies. Since implementation in 1994, approximately 68,000 known sites have been recorded at an expense of several tens of millions of dollars. New knowledge from surveys reduced concern for nearly 100 species, and they were removed from the protection list. Although successful in protecting hundreds of rare species not typically considered in most conservation programs, some of the enacted conservation measures created conflicts in meeting other management objectives of the plan, particularly timber harvest. The program accrued important gains in knowledge, reduced uncertainty about conservation of a number of species, and developed new methods of species inventory that will be useful in future management planning and implementation at many scales. The program, however, was not completed because of changes in land‐management philosophy. Ongoing litigation regarding its termination and potential changes to the plan cast further uncertainty on how the original goal of maintaining persistence of late‐successional and old‐growth species will be met and measured. The outcomes, controversies, and management frustrations of the program exemplify the inherent difficulties in balancing broad, regional conservation goals with social and economic goals of the NWFP. Defining acceptable trade‐offs to reach that balance and developing practical conservation solutions remain challenges for the science and management communities. Lessons learned from the program provide a valuable biological and managerial reference to benefit future discussion on meeting those challenges.
Conservation of the Northern Spotted Owl under the Northwest Forest Plan
Authors: NOON BARRY R. , BLAKESLEY JENNIFER A.
Published: March 2006

Abstract: Development of the Northwest Forest Plan (NWFP) was motivated by concerns about the overharvest of late‐seral forests and the effects of intensive forest management on the long‐term viability of the Northern Spotted Owl (Strix occidentalis caurina). Following several years of intense political and legal debates, the final NWFP was approved in 1994. Even though the plan evolved with a broad ecosystem perspective, it remained anchored in the Spotted Owl reserve design proposed in 1990. Based on a criterion of stable or increasing populations, a decade later it remains unclear whether the enactment of the NWFP has improved the conservation status of Spotted Owls. The results of intensive monitoring of several Spotted Owl populations for over a decade suggest a continuing range‐wide decline even though rates of timber harvest have declined dramatically on federal lands. The cause of the decline is difficult to determine because the research needed to establish cause and effect relations has not been done. One plausible hypothesis is that the owl's life history greatly constrains its rate of population growth even when habitat is no longer limiting. Since enactment of the NWFP, new threats have arisen, including the movement of Barred Owls (S. varia) into the range of the Spotted Owl, political pressure to increase levels of timber harvest, and recent changes to forest laws that eliminate the requirement to assess the viability of wildlife populations on U.S. Department of Agriculture Forest Service lands. At this time is appears that Spotted Owl conservation rests critically on continued implementation of the protections afforded by the NWFP and the U.S. Endangered Species Act.
The Northwest Forest Plan as a Model for Broad‐Scale Ecosystem Management: a Social Perspective
Authors: CHARNLEY SUSAN
Published: March 2006

Abstract: I evaluated the Northwest Forest Plan as a model for ecosystem management to achieve social and economic goals in communities located around federal forests in the U.S. Pacific Northwest. My assessment is based on the results of socioeconomic monitoring conducted to evaluate progress in achieving the plan's goals during its first 10 years. The assessment criteria I used related to economic development and social justice. The Northwest Forest Plan incorporated economic development and social justice goals in its design. Socioeconomic monitoring results indicate that plan implementation to achieve those goals met with mixed success, however. I hypothesize there are two important reasons the plan's socioeconomic goals were not fully met: some of the key assumptions underlying the implementation strategies were flawed and agency institutional capacity to achieve the goals was limited. To improve broad‐scale ecosystem management in the future, decision makers should ensure that natural‐resource management policies are socially acceptable; land‐management agencies have the institutional capacity to achieve their management goals; and social and economic management goals (and the strategies for implementing them) are based on accurate assumptions about the relations between the resources being managed and well‐being in local communities. One of the difficulties of incorporating economic development and social justice goals in conservation initiatives is finding ways to link conservation behavior and development activities. From a social perspective, the Northwest Forest Plan as a model for ecosystem management is perhaps most valuable in its attempt to link the biophysical and socioeconomic goals of forest management by creating high‐quality jobs for residents of forest communities in forest stewardship and ecosystem management work, thereby contributing to conservation.
Conserving Old‐Growth Forest Diversity in Disturbance‐Prone Landscapes
Authors: SPIES THOMAS A. , HEMSTROM MILES A. , YOUNGBLOOD ANDREW , HUMMEL SUSAN
Published: March 2006

Abstract: A decade after its creation, the Northwest Forest Plan is contributing to the conservation of old‐growth forests on federal land. However, the success and outlook for the plan are questionable in the dry provinces, where losses of old growth to wildfire have been relatively high and risks of further loss remain. We summarize the state of knowledge of old‐growth forests in the plan area, identify challenges to conserve them, and suggest some conservation approaches that might better meet the goals of the plan. Historically, old‐growth forests in these provinces ranged from open, patchy stands, maintained by frequent low‐severity fire, to a mosaic of dense and open stands maintained by mixed‐severity fires. Old‐growth structure and composition were spatially heterogeneous, varied strongly with topography and elevation, and were shaped by a complex disturbance regime of fire, insects, and disease. With fire suppression and cutting of large pines ( Pinusspp.) and Douglas‐firs (Pseudotsuga menziesii[Mirbel] Franco), old‐growth diversity has declined and dense understories have developed across large areas. Challenges to conserving these forests include a lack of definitions needed for planning of fire‐dependent old‐growth stands and landscapes, and conflicts in conservation goals that can be resolved only at the landscape level. Fire suppression has increased the area of the dense, older forest favored by Northern Spotted Owls (Strix occidentalis caurina) but increased the probability of high‐severity fire. The plan allows for fuel reduction in late‐successional reserves; fuel treatments, however, apparently have not happened at a high enough rate or been applied in a landscape‐level approach. Landscape‐level strategies are needed that prioritize fuel treatments by vegetation zones, develop shaded fuel breaks in strategic positions, and thin and apply prescribed fire to reduce ladder fuels around remaining old trees. Evaluations of the current and alternative strategies are needed to determine whether the current reserve‐matrix approach is the best strategy to meet plan goals in these dynamic landscapes.
Service Personnel, Technology, and Their Interaction in Influencing Customer Satisfaction*
Authors: Froehle Craig M.
Published: March 2006

Managing both the technologies and the personnel needed for providing high‐quality, multichannel customer support creates a complex and persistent operational challenge. Adding to this difficulty, it is still unclear how service personnel and these new communication technologies interact to influence the customer's perceptions of the service being provided. Motivated by both practical importance and inconsistent findings in the academic literature, this exploratory research examines the interaction of media richness, represented by three different technology contexts (telephone, e‐mail, and online chat), with six customer service representative (CSR) characteristics and their influences on customer satisfaction. Using a large‐sample customer survey data set, the article develops a multigroup structural equation model to analyze these interactions. Results suggest that CSR characteristics influence customer service satisfaction similarly across all three technology‐mediated contexts. Of the characteristics studied, service representatives contribute to customer satisfaction more when they exhibit the characteristics of thoroughness, knowledgeableness, and preparedness, regardless of the richness of the medium used. Surprisingly, while three other CSR characteristics studied (courtesy, professionalism, and attentiveness) are traditionally believed to be important in face‐to‐face encounters, they had no significant impact on customer satisfaction in the technology‐mediated contexts studied. Implications for both practitioners and researchers are drawn from the results and future research opportunities are discussed.
Reexamining the Nurse Scheduling Problem: Staffing Ratios and Nursing Shortages*
Authors: Wright P. Daniel , Bretthauer Kurt M. , Côté Murray J.
Published: March 2006

Legislators at the state and national levels are addressing renewed concerns over the adequacy of hospital nurse staffing to provide quality care and ensure patient safety. At the same time, the well‐known nursing shortage remains an ongoing problem. To address these issues, we reexamine the nurse scheduling problem and consider how recent health care legislation impacts nursing workforce management decisions. Specifically, we develop a scheduling model and perform computational experiments to evaluate how mandatory nurse‐to‐patient ratios and other policies impact schedule cost and schedule desirability (from the nurses' perspective). Our primary findings include the following: (i) nurse wage costs can be highly nonlinear with respect to changes in mandatory nurse‐to‐patient ratios of the type being considered by legislators; (ii) the number of undesirable shifts can be substantially reduced without incurring additional wage cost; (iii) more desirable scheduling policies, such as assigning fewer weekends to each nurse, have only a small impact on wage cost; and (iv) complex policy statements involving both single‐period and multiperiod service levels can sometimes be relaxed while still obtaining good schedules that satisfy the nurse‐to‐patient ratio requirements. The findings in this article suggest that new directions for future nurse scheduling models, as it is likely that nurse‐to‐patient ratios and nursing shortages will remain a challenge for health care organizations for some time.
The Impact of Manufacturers' Wholesale Prices on a Retailer's Shelf‐Space and Pricing Decisions*
Authors: Martín‐Herrán Guiomar , Taboubi Sihem , Zaccour Georges
Published: March 2006

This article examines shelf‐space allocation and pricing decisions in the marketing channel as the results of a static game played à la Stackelberg between two manufacturers of competing brands and one retailer. The competing manufacturers act as leaders that play a simultaneous and noncooperative game. They fix their transfer prices by taking into account the shelf‐space allocation and price‐markup decisions of their common exclusive dealer. The results indicate that the wholesale prices of brands are strongly linked to their share of the shelf. The main results of our numerical simulations may be summarized as follows: first, the lower the unit cost and/or the greater the price elasticity, the greater the shelf space allocated to that brand. Second, the higher the shelf‐space elasticity, the lower are the wholesale prices and the profits of all channel members.
The Rhythm ID Going Head to Head Trial (RIGHT): Design of a Randomized Trial Comparing Competitive Rhythm Discrimination Algorithms in Implantable Cardioverter Defibrillators
Authors: BERGER RONALD D. , LEREW DARIN R. , SMITH JOSEPH M. , PULLING CHRIS , GOLD MICHAEL R.
Published: March 2006

Background: The implantable cardioverter defibrillator (ICD) has become primary therapy for the prevention of sudden death. One of the major morbidities of ICD use remains inappropriate therapy for supraventricular arrhythmias (SVA). Detection enhancements have increased therapy specificity, but their impact on inappropriate therapy is not well studied. Moreover, ICD manufacturers have developed unique algorithms to meet this goal, with no previous clinical direct comparisons. RIGHT is a randomized, prospective study that will assess the differential efficacy of ICDs from two different manufacturers. It is the first trial to compare directly competitive ICD rhythm discrimination algorithms on a large scale.

Objective: The primary objective of this study is to assess arrhythmia discrimination in Guidant versus Medtronic ICDs by comparing the time to first inappropriate therapy after the predischarge visit.

Methods: The study will enroll approximately 2,000 patients in 100 centers. Patients will be randomized to Guidant or Medtronic using a permuted block design, stratified by center and by single/dual chamber device types. Patients will receive a commercially available Guidant VITALITY® 2 family ICD with Rhythm ID™ or a Medtronic ICD using the Enhanced PR Logic™ or Wavelet™ discrimination algorithms, and will be followed according to the schedule shown until a common closing date with a minimum follow‐up of 12 months. All events will be reviewed by an independent committee to determine the appropriateness of rhythm classification and therapy delivery.

Conclusion: RIGHT is the first randomized, large scale, head‐to‐head comparison of ICD discrimination algorithms.
Inaccuracy of Wolff‐Parkinson‐White Accessory Pathway Localization Algorithms in Children and Patients with Congenital Heart Defects
Authors: BAR‐COHEN YANIV , KHAIRY PAUL , MORWOOD JAMES , ALEXANDER MARK E. , CECCHIN FRANK , BERUL CHARLES I.
Published: March 2006

Introduction: ECG algorithms used to localize accessory pathways (AP) in patients with Wolff‐Parkinson‐White (WPW) syndrome have been validated in adults, but less is known of their use in children, especially in patients with congenital heart disease (CHD). We hypothesize that these algorithms have low diagnostic accuracy in children and even lower in those with CHD.

Methods: Pre‐excited ECGs in 43 patients with WPW and CHD (median age 5.4 years [0.9–32 years]) were evaluated and compared to 43 consecutive WPW control patients without CHD (median age 14.5 years [1.8–18 years]). Two blinded observers predicted AP location using 2 adult and 1 pediatric WPW algorithms, and a third blinded observer served as a tiebreaker. Predicted locations were compared with ablation‐verified AP location to identify (a) exact match for AP location and (b) match for laterality (left‐sided vs right‐sided AP).

Results: In control children, adult algorithms were accurate in only 56% and 60%, while the pediatric algorithm was correct in 77%. In 19 patients with Ebstein's anomaly, diagnostic accuracy was similar to controls with at times an even better ability to predict laterality. In non‐Ebstein's CHD, however, the algorithms were markedly worse (29% for the adult algorithms and 42% for the pediatric algorithms). A relatively large degree of interobserver variability was seen (kappa values from 0.30 to 0.58).

Conclusions: Adult localization algorithms have poor diagnostic accuracy in young patients with and without CHD. Both adult and pediatric algorithms are particularly misleading in non‐Ebstein's CHD patients and should be interpreted with caution.
Aspergillus niger Aortitis after Aortic Valve Replacement Diagnosed by Transesophageal Echocardiography
Authors: Duygu Hamza , Nalbantgil Sanem , Ozerkan Filiz , Kirilmaz Bahadir , Yagdi Tahir
Published: March 2006

Aspergillus aortitis following cardiac surgery has an important role among the cardiac infections as almost all affected cases result in death. Survival of the patient with Aspergillus aortitis is dependent on early initiation of aggressive medical and surgical treatment. Transesophageal echocardiography proved very useful in the diagnosis of this uncommon case of aortitis. In this paper, we present a patient with aortitis caused by Aspergillus niger that hasn't been reported previously diagnosed by transesophageal echocardiography following cardiac surgery.
The Wake of a Large Vortex Is Associated with Intraventricular Filling Delay in Impaired Left Ventricles with a Pseudonormalized Transmitral Flow Pattern
Authors: Ishizu Tomoko , Seo Yoshihiro , Ishimitsu Toshiyuki , Obara Kenichi , Moriyama Naoko , Kawano Satoru , Watanabe Shigeyuki , Yamaguchi Iwao
Published: March 2006

Although an intraventricular filling delay has been observed in patients with a psuedonormalized transmitral flow pattern, little is known about the underlying hydrodynamic nature of this phenomenon. Methods: To examine those hydrodynamics, we studied every echocardiographic frame showing ventricular inflow (80 Hz) in the apical long‐axis view and M‐mode image using contrast echocardiography in 29 patients with a psuedonormalized pattern and in 26 normal controls. The velocity of the filling flow front (Vp), the ratio of Vp to E, and the mean radius of the vortices associated with the filling flow were measured. Results: In both groups, vortices were observed at the ridge of the mitral valve during acceleration of the E‐wave. The mean radius of the vortices was greater in the pseudonormalized filling group than that in the control group (8 ± 2 vs 3 ± 1 mm, P < 0.0001). Vp was smaller in the pseudonormalized group than in the control group (36 ± 6 vs 47 ± 6 cm/sec, P = 0.0008). Vp/E was <1 and smaller in the pseudonormalized group than that in the control group (0.46 ± 0.13 vs 0.59 ± 0.07, P = 0.014) and negatively correlated with the mean radius of the vortices (r = 0.54, P < 0.0001). Conclusions: Contrast echocardiography identified uniform flow characteristics with blood in the filling flow front moving in well‐developed vortices and resulting in a left ventricular filling delay in the impaired left ventricle in spite of an increased early transmitral flow velocity.
In Vitro Validation of Right Ventricular Volume and Mass Measurement by Real‐Time Three‐Dimensional Echocardiography
Authors: Chen Guozhen , Sun Kun , Huang Guoying
Published: March 2006

Objective: To evaluate initially the feasibility and accuracy of real‐time three‐dimensional echocardiography (RT‐3DE) for quantifying right ventricular (RV) volume and wall mass in an in vitro experimental study. Methods: In ten excised porcine hearts, measurements of RV volume and free wall mass with RT‐3DE were outlined and calculated by 2‐, 4‐, 8‐ and 16‐plane methods with Tom Tec 4D Cardio‐View RT 1.0. The results were compared with those of 2D length method and 2D biplane Simpson method. The values of RV silicone latex cast and free wall mass measured by water displacement were served as reference values. Results: RV shapes of excised porcine hearts with RT‐3DE were similar to those of the actual anatomic RVs and RV silicone latex casts. From the findings of analysis of variance and Student‐Newman‐Keuls test, there was no significant difference between measurements of RV volume with RT‐3DE 16‐plane (mean 64.05 ml), 8‐plane (61.83 ml) and the reference values of RV silicone latex casts (62.94 ml). No significant difference was found between measurements of RV free wall mass with 16‐plane (72.81 g), 8‐plane (71.05 g) and the reference values of RV free wall masses (76.21 g). However, there was significant difference between measurements of RV volume and free wall mass with 2‐plane, 2D biplane Simpson method and the reference values. Furthermore, the measurements of RV volume and free wall mass with 16‐plane and 8‐plane were better correlated with the reference values than those with 4‐plane and 2D length method. Conclusions: RT‐3DE will be a valuable technique for quantifying irregular crescentic RV volume and wall mass.
Efficacy of Atropine as a Chronotropic Agent in Heart Transplant Patients Undergoing Dobutamine Stress Echocardiography
Authors: Kociolek Larry K. , Bierig S. Michelle , Herrmann Steven C. , Labovitz Arthur J.
Published: March 2006

Background: After heart transplant (HTX), the heart is completely denervated. While sympathetic reinnervation is likely to occur, there is conflicting evidence regarding parasympathetic reinnervation. Accordingly, it is unclear if atropine is efficacious as a chronotropic agent in HTX patients undergoing dobutamine stress echocardiography (DSE), since cholinergic cardiac stimulation is required for atropine to exert its effect. The purpose of this study was to demonstrate that atropine can sufficiently increase the heart rate (HR) in HTX patients undergoing DSE. Methods: A retrospective review was performed on 68 HTX patients who underwent DSE as part of their routine annual HTX follow‐ups. Dobutamine was administered in the standard fashion of 10, 20, 30, 40, 50 mcg/kg per minute with blood pressure and electrocardiographic
monitoring. If target HR was not attained, atropine was administered to aid in achieving 85% of maximum age‐predicted HR. Results: Mean patient age was 58 ± 10 years. Mean period since transplant was 9 ± 4 years. Forty‐seven (69%) patients received dobutamine only, and 21 (31%) required additional atropine to reach target HR. Of the 21 patients who received atropine, 10 (48%) reached target HR. Neither time from transplant, age, gender, resting HR, medications, nor atherosclerotic risk factors predicted responsiveness to atropine. Those responding to dobutamine had a significantly greater resting HR than those receiving additional atropine. Conclusions: The adjunctive use of atropine in HTX patients during DSE aids in reaching 85% of maximum predicted HR in some patients. Furthermore, resting HR may predict the additional need of atropine during DSE.
Cardiac Contributions to Exercise Training Responses in Patients with Chronic Heart Failure: A Strain Imaging Study
Authors: Smart Neil , Haluska Brian , Jeffriess Leanne , Case Colin , Marwick Thomas H.
Published: March 2006

The improvement of exercise capacity due to exercise training in heart failure has been associated with peripheral adaptation, but the contribution of cardiac responses is less clear. We sought the extent to which the improvement of functional capacity in patients undergoing exercise training for heart failure was related to myocardial performance. Thirty‐seven patients (35 men, age 64 ± 11) with symptomatic heart failure and left ventricular ejection fraction ≤35% (29 ± 9%) were studied during a 16‐week exercise training program. LV function was assessed by resting and exercise 2D‐echocardiography, tissue Doppler derived myocardial strain, and strain rate. Peak oxygen consumption (VO2) and LV function were measured at baseline and follow‐up, and the contribution of LV function at baseline and its response to training to the change of each parameter was sought. Baseline peak VO2 (12.4 ± 4.6) increased by 9% at 8 weeks (13.5 ± 4.2, P = 0.26), and by 21% at 16 weeks (15.0 ± 4.9, P < 0.001). Although there were no overall changes in myocardial parameters in this study, change in peak VO2 at 16 weeks was significantly correlated with baseline strain (r = 0.51, P = 0.003) and the improvement of strain at 8 weeks (r = 0.44, P = 0.01), independent of baseline functional capacity and clinical variables. Thus, change in peak VO2 following 16 weeks exercise training is related to myocardial function at baseline.
Multiple Coronary Artery Fistulae Communicating through a Sinusoid and Emptying into the Left Ventricle
Authors: Ortega Nellie , Prakash Anita M. , Rafael Marva , Ashley William , Nagaraj Ashwin , McPherson David
Published: March 2006

This case report describes the occurrence of multiple coronary artery fistulae emptying into the left ventricle and includes a small communication into the left atrium. The initial diagnosis of a coronary artery fistula was made by standard and nonstandard transthoracic two‐dimensional echocardiogram and Doppler interrogation. Later, multiple coronary fistulae communicating through a sinusoid and draining into the left‐sided chambers were confirmed by angiography.
Possible Paradoxical Embolism as a Rare Cause for an Acute Myocardial Infarction
Authors: Rovner Aleksandr , Valika Ali A. , Kovacs Attila , Kates Andrew M.
Published: March 2006

Paradoxical embolus is a rare entity and it has been incriminated as a cause of both cryptogenic strokes and myocardial infarctions (MI). Herein, we present a case of a patient diagnosed with a pulmonary embolism 1 week prior who now presented with an acute MI. Subsequent evaluation revealed a patent foramen ovale and a large thrombus in the right pulmonary artery. It was presumed that the etiology of her infarct was due to paradoxical embolus. The management of the patient is discussed and the literature is reviewed.
Pericardial Fat Mimicking Pericardial Effusion on Two‐Dimensional Echocardiography
Authors: Kanna Balavenkatesh , Osorio Federico , Dharmarajan Lekshmi
Published: March 2006

A 78‐year‐old overweight woman with diabetes mellitus, bronchial asthma, and Sheehan's syndrome on chronic steroid therapy presented with mild short‐lived hematemesis, significant hypotension disproportionate to the degree of bleeding and radiographic evidence of cardiomegaly. Endoscopy showed duodenal ulcer. During evaluation of the unexplained brief hypotension and cardiomegaly, 2D‐echocardiogram demonstrated anterior and posterior echo‐free spaces consistent with large pericardial effusion (PE). However, subsequent elective surgical pericardiotomy unexpectedly revealed large amounts of pericardial fat. Pericardial fat was also noted on magnetic resonance imaging of the chest. Our case illustrates a potential pitfall of 2D‐echocardiography in the diagnosis of PE.
Mechanism for Salt Scaling
Authors: Valenza John J. , Scherer George W.
Published: March 2006

Over the past 60 years, concrete infrastructure in cold climates has deteriorated by “salt scaling,” which is superficial damage that occurs during freezing in the presence of saline water. It reduces mechanical integrity and necessitates expensive repair or replacement. The phenomenon can be demonstrated by pooling a solution on a block of concrete and subjecting it to freeze/thaw cycles. The most remarkable feature of salt scaling is that the damage is absent if the pool contains pure water, it becomes serious at concentrations of a few weight percent, and then stops at concentrations above about 6 wt%. In spite of a wealth of research, the mechanism responsible for this damage has only recently been identified. In this article, we show that salt scaling is a consequence of the fracture behavior of ice. The stress arises from thermal expansion mismatch between ice and concrete, which puts the ice in tension as the temperature drops. Considering the mechanical and viscoelastic properties of ice, it is shown that this mismatch will not cause pure ice to crack, but moderately concentrated solutions are expected to crack. Cracks in the brine ice penetrate into the substrate, resulting in superficial damage. At high concentrations, the ice does not form a rigid enough structure to result in significant stress, so no damage occurs. The morphology of cracking is predicted by fracture mechanics.
Height, weight and body mass index in early adulthood and risk of schizophrenia
Authors: Sørensen H. J. , Mortensen E. L. , Reinisch J. M. , Mednick S. A.
Published: March 2006

Objective:  To illuminate the possible associations between height, weight, and body mass index (BMI) during early adulthood and the development of schizophrenia.

Method:  This prospective study is based on an all‐male sample of 3210 individuals from the Copenhagen Perinatal Cohort, comprising individuals born between 1959 and 1961. In 1999, cases of schizophrenia were identified in the Danish Psychiatric Central Register, and the cases were compared with the cohort pool of controls with respect to height, weight, and BMI from draft records. The effect of low BMI was adjusted for parental social status when the cohort members were 1 year old, birth weight, birth length, and maternal pre‐pregnancy BMI.

Results:  Forty‐five cases of schizophrenia had a lower young adult mean body weight and BMI than controls. A significant inverse relationship between BMI and risk of later schizophrenia was found. For each unit increase in BMI, the adjusted odds ratio was 0.81 (95% CI, 0.70–0.93) and the risk of schizophrenia decreased by 19%. Excluding individuals who had been admitted to an in‐patient facility before or within 5 years after appearing before the draft board, yielded virtually the same results. No significant differences between cases and controls were observed with respect to adult height.

Conclusion:  Independent of several possible confounders, an inverse relationship between young adult BMI and risk of later development of schizophrenia was demonstrated in this all‐male sample.
Predictors of psychological distress in survivors of the 1999 earthquakes in Turkey: effects of relocation after the disaster
Authors: Kılıç C. , Aydın İ. , Taşkıntuna N. , Özçürümez G. , Kurt G. , Eren E. , Lale T. , Özel S. , Zileli L.
Published: March 2006

Objective:  Relocations after disasters are known to cause added distress in survivors. This study examined the effects of migration and other factors on psychological status of survivors 4 years after the two severe earthquakes in Turkey.

Method:  Five hundred and twenty‐six adult survivors of the 1999 earthquakes currently living in Ankara were given self‐report measures assessing traumatic stress, depression, earthquake experience and social support.

Results:  The rates of current post‐traumatic stress disorder (PTSD) and depression were 25% and 11%, respectively. Although both traumatic stress and depression factors were predicted by some demographic and trauma severity variables, relocation status predicted depression but not traumatic stress.

Conclusion:  The rates of psychological distress were higher than expected in a city considered to be safe in terms of earthquake risk. Relocation after the disaster may increase psychological distress by disrupting the social network.
Does antipsychotic withdrawal provoke psychosis? Review of the literature on rapid onset psychosis (supersensitivity psychosis) and withdrawal‐related relapse
Authors: Moncrieff J.
Published: March 2006

Objective:  To examine the evidence that discontinuation of long‐term antipsychotic medication, including clozapine, may provoke a psychotic episode.

Method:  Databases were searched and citations scrutinised.

Results:  Evidence for a rapid onset psychosis (supersensitivity psychosis) following clozapine withdrawal was found and weaker evidence that this might occur with some other antipsychotic drugs. Some cases were reported in people without a psychiatric history. It appears that the psychosis may be a feature of drug withdrawal rather than the re‐emergence of an underlying illness, at least in some patients. Meta‐analyses of withdrawal studies have suggested that antipsychotic discontinuation may also increase the risk of relapse over and above the risk because of the underlying disorder, but not all individual studies show this effect. Mechanisms may relate to brain adaptations to long‐term drug use but data are sparse.

Conclusion:  These effects require further urgent research. Interventions to reduce morbidity after drug withdrawal need to be developed.
Epstein–Barr virus in oral diseases
Authors: Slots J. , Saygun I. , Sabeti M. , Kubar A.
Published: March 2006

Epstein–Barr virus (EBV), a B‐lymphotropic gamma‐herpesvirus, causes infectious mononucleosis and oral hairy leukoplakia, and is associated with various types of lymphoid and epithelial malignancies. Saliva is the main vehicle for EBV transmission from individual to individual. Recent studies have also implicated EBV in the pathogenesis of advanced types of periodontal disease. EBV DNA is detected in 60–80% of aggressive periodontitis lesions and in 15–20% of gingivitis lesions or normal periodontal sites. The periodontal presence of EBV is associated with an elevated occurrence of periodontopathic anaerobic bacteria. Moreover, EBV active infection occurs in ≈ 70% of symptomatic and large‐size periapical lesions. EBV and cytomegalovirus often co‐exist in marginal and apical periodontitis. Periodontal therapy can markedly suppress the EBV load in periodontal pockets as well as in saliva, which has the potential to reduce the risk of viral transmission between close individuals. EBV proteins up‐regulate cytokines and growth factors, which seem to play a central role in the proliferative response of tongue epithelial cells in oral hairy leukoplakia and in the cell‐transformation process of EBV‐associated malignancies. Further research is needed to identify the full range of EBV‐related diseases in the human oral cavity.
Should punitive damages be part of the judicial arsenal in contract cases?
Authors: Cunnington Ralph
Published: March 2006

This paper challenges the traditional assumption that punitive damages are unavailable for breach of contract. It is shown that Addis v Gramophone provides weak authority for this assumption. The paper considers whether there is a logically coherent argument for retaining punitive damages in tort, while denying them for breach of contract, and it is shown that there is not. The main arguments advanced against punitive damages in civil proceedings are examined and shown to be unpersuasive. Finally, the efficient breach theory is considered and rejected on the ground that it significantly underestimates the costs associated with breach. In conclusion, the paper recommends that punitive damages should be exceptionally awarded to deter outrageous breaches of contract in cases where compensatory damages are inadequate and gain-based damages are unavailable.