bluuebunny/crossref_metadata_2025_split huggingface dataset:
Teachers’ pedagogical beliefs and their planning and conduct of computer‐mediated classroom lessons
Authors: Lim Cher Ping , Chai Ching Sing 
Published: October 2007

AbstractIn this study, we observed and interviewed six teachers from two Singapore primary school classrooms. The schools were reportedly achieving high levels of computer integration as reflected in a nationwide questionnaire survey. Out of the 18 lessons that we observed, 14 lessons have incorporated some elements of constructivist teaching. However, closer examination revealed that the underlying orientation of the lessons was inclined towards information acquisition and regurgitation. Five out of the six teachers we interviewed were reportedly inclined towards constructivist notion of teaching. The teachers accounted for the inconsistency between their espoused beliefs and the teacher‐centric teaching practice as due to contextual constraints. The teachers expressed that the need to complete the syllabi according to stipulated schedules so as to get the students ready for examination was the main barriers that prevented them from engaging in more constructivist teaching. This case study therefore highlights that although it is necessary for teachers to hold pedagogical beliefs that are compatible with the constructivist notion of teaching and learning, this is an insufficient condition to shift traditional teaching practice. Changes in assessment systems and substantial professional development are further conditions that have to be addressed.
The effects of cognitive thinking styles, trust, conflict management on online students' learning and virtual team performance
Authors: Liu Xiaojing , Magjuka Richard J. , Lee Seung‐hee 
Published: October 2007

AbstractCognitive style has been regarded as one of the important variables to predict individual cognitive functioning. This paper describes an empirical study that examined the role of thinking styles in relation to students' online learning and teamwork performance. Two hundred and eight students in an online MBA (Master of Business Administration) program participated in the study. Data were collected through surveys and content analysis of online conference transcripts. Sternberg's thinking style inventory was used to measure two dimensions of cognitive style: levels and scope. A personal reflection questionnaire was administrated to measure some variables concerning virtual team experiences including trust, conflict management styles and teamwork satisfaction. The evidence gathered suggests that cognitive styles may be a poor indicator of students' overall online learning performance. However, cognitive style had predictive power over the students' satisfaction with their teamwork experience, as well as the level of trust they exhibited in their team members. This study implies that it would be useful to integrate cognitive styles of individual students as one of the design factors which could foster successful online virtual team experiences.
A Graphical Chain Model for Reciprocal Relationships Between Women’s Gender Role Attitudes and Labour Force Participation
Authors: Berrington Ann , Hu Yongjian , Smith Peter W. F. , Sturgis Patrick 
Published: October 2007

SummaryWe use a graphical chain model to investigate the reciprocal relationships between changes in women’s labour force participation following entry into parenthood and changes in gender role attitude. Results suggest that attitudes are not fixed and that revision of these attitudes in the light of recent life course events is an important process. The adaptation of attitudes to events appears to be stronger than the selection of individuals on the basis of attitudes. We show that it is not entry into parenthood as such, but the change in economic activity that is related to this event that is associated with attitude change.
A Joint Latent Class Changepoint Model to Improve the Prediction of Time to Graft Failure
Authors: Garre Francisca Galindo , Zwinderman Aeilko H. , Geskus Ronald B. , Sijpkens Yvo W. J. 
Published: October 2007

SummaryThe reciprocal of serum creatinine concentration, RC, is often used as a biomarker to monitor renal function. It has been observed that RC trajectories remain relatively stable after transplantation until a certain moment, when an irreversible decrease in the RC levels occurs. This decreasing trend commonly precedes failure of a graft. Two subsets of individuals can be distinguished according to their RC trajectories: a subset of individuals having stable RC levels and a subset of individuals who present an irrevocable decrease in their RC levels. To describe such data, the paper proposes a joint latent class model for longitudinal and survival data with two latent classes. RC trajectories within latent class one are modelled by an intercept-only random-effects model and RC trajectories within latent class two are modelled by a segmented random changepoint model. A Bayesian approach is used to fit this joint model to data from patients who had their first kidney transplantation in the Leiden University Medical Center between 1983 and 2002. The resulting model describes the kidney transplantation data very well and provides better predictions of the time to failure than other joint and survival models.
Criteria for Surrogate End Points
Authors: Chen Hua , Geng Zhi , Jia Jinzhu 
Published: October 2007

SummaryA surrogate end point is often used to evaluate the effects of treatments or exposures on the true end point in medical researches. Various criteria for the statistical surrogate, principal surrogate and strong surrogate have been proposed. We first illustrate that, with a surrogate end point that is defined by these criteria, it is possible that a treatment has a positive effect on the surrogate, which in turn has a positive effect on the true end point, but the treatment has a negative effect on the true end point. We define such a phenomenon as a surrogate paradox. The surrogate paradox also means that the sign of the treatment effect on the true end point is unpredictable by the effect signs of both the treatment on the surrogate and the surrogate on the true end point. Then we propose two notions for a consistent surrogate and a strictly consistent surrogate to avoid the surrogate paradox. With the causal network that was presented by Lauritzen, we discuss the conditions for a strong surrogate to be a consistent surrogate and a strictly consistent surrogate.
Octatonicism inLuigiDallapiccola'sTwelve‐NoteMusic
Authors: Alegant Brian , Levey John 
Published: October 2007

ABSTRACTThis survey addresses perhaps the least‐known aspect of Luigi Dallapiccola's twelve‐note music, namely the composer's preference for octatonic collections. Part I summarises the different arrangements of octatonic hexachords that are possible within a twelve‐note context. Parts II–IV then examine some of the octatonic characteristics which recur across a number of specific works, several of which have not previously been the subject of critical attention. Octatonicism is thereby revealed as a consistent feature of Dallapiccola's harmonic language that runs throughout his twelve‐note canon.
Estimating the effect of inbreeding on survival
Authors: Armstrong D. P. , Cassey P. 
Published: October 2007

AbstractConservation biologists need to be able to estimate reliably the effects of inbreeding on survival, and need to be able to do so with a range of different data types. Kalinowski and Hedrick described a non‐linear maximum likelihood estimation procedure for modelling relationships between survivorship and inbreeding. Although their method is useful for illustrating the concepts involved in modelling such relationships, it is only applicable to simple datasets. We illustrate that the parameter estimates generated by Kalinowski and Hedrick's method are easily obtained using generalized linear modelling procedures available in standard statistical packages, and that these offer several advantages even with simple datasets. We suggest procedures that can be used for modelling relationships between survival and inbreeding with more complex data types, including datasets with multiple and ragged encounters, uncertain detection and random effects.
Response of waterbird colonies in southern Louisiana to recent drought and hurricanes
Authors: Leberg P. L. , Green M. C. , Adams B. A. , Purcell K. M. , Luent M. C. 
Published: October 2007

AbstractAlthough hurricanes have been implicated in causing shifts in waterbird use of individual colonies, little is known about whether or not these effects are consistent across broader areas affected by a storm. We examined the effects of Hurricane Rita, and to a lesser extent Katrina, and a subsequent drought, on the nesting activity of waterbirds across colonies located in southern Louisiana. Using ground counts, we compared changes in numbers of nesting pairs between 2005 and 2006, the years encompassing the hurricanes and drought, with changes between 2004 and 2005. Following the hurricanes, colonies were more likely to become inactive or experience large shifts in numbers of nesting pairs, compared with the period before the hurricanes. Although one third of the surveyed colonies became inactive following the hurricanes, total numbers of nesting birds of most species increased. We hypothesize that these increases were the result of birds shifting from damaged to active colonies. Colony use was negatively associated with the maximum wind speeds experienced at each site, apparently as a result of damage to nesting habitat. There were no associations of colony use with either storm‐related flooding or localized rainfall during the drought; however, this may be due to manipulation of water levels by management agencies. Our results suggest that monitoring colonies over a broad area is necessary to understand the influence of hurricanes on the nesting activity of waterbirds.
cisprimertool: software to implement a comparative genomics strategy for the development of conserved intron scanning (CIS) markers
Authors: JAYASHREE B. , JAGADEESH V. T. , HOISINGTON D. 
Published: October 2007

AbstractThe availability of complete, annotated genomic sequence information in model organisms is a rich resource that can be extended to understudied orphan crops through comparative genomic approaches. We report here a software tool (cisprimertool) for the identification of conserved intron scanning regions using expressed sequence tag alignments to a completely sequenced model crop genome. The method used is based on earlier studies reporting the assessment of conserved intron scanning primers (called CISP) within relatively conserved exons located near exon‐intron boundaries from onion, banana, sorghum and pearl millet alignments with rice. The tool is freely available to academic users at http://www.icrisat.org/gt‐bt/CISPTool.htm.
The Staffing–Outcomes Relationship in Nursing Homes
Authors: Konetzka R. Tamara , Stearns Sally C. , Park Jeongyoung 
Published: October 2007

Objective. To assess longitudinally whether a change in registered nurse (RN) staffing and skill mix leads to a change in nursing home resident outcomes while controlling for the potential endogeneity of staffing.Data Sources. Minimum Data Set (MDS) nursing home resident assessment data from five states merged with Online Survey Certification and Reporting (OSCAR) data from 1996 through 2000.Study Design. Resident‐level longitudinal analysis with facility fixed effects and instrumental variables. Outcomes studied are incidence of pressure sores and urinary tract infections. RN staffing was measured as the care hours per resident‐day and skill mix was measured as RN staffing hours as a proportion of total staffing hours.Data Extraction Method. We use all quarterly MDS assessments that fall within 120 days of an annual OSCAR data point, resulting in 399,206 resident‐level observations.Principal Findings. Controlling for endogeneity of staffing increases the estimated impact of staffing on outcomes in nursing homes. Greater RN staffing significantly decreases the likelihood of both adverse outcomes. Increasing skill mix only reduces the incidence of urinary tract infections.Conclusions. Research that fails to account for endogeneity of the staffing–outcomes relationship may underestimate the benefit from increased RN staffing. Increases in RN staffing are likely to reduce adverse outcomes in some nursing homes. More research using a broader array of instruments and a national sample would be beneficial.
Prescription Drug Coverage and Effects on Drug Expenditures among Elderly Medicare Beneficiaries
Authors: Huh Soonim , Rice Thomas , Ettner Susan L. 
Published: October 2007

Objective. To identify determinants of drug coverage among elderly Medicare beneficiaries and to investigate the impact of drug coverage on drug expenditures with and without taking selection bias into account.Data Sources/Study Setting. The primary data were from the 2000 Medicare Current Beneficiary Survey (MCBS) Cost and Use file, linked to other data sources at the county or state‐level that provided instrumental variables. Community‐dwelling elderly Medicare beneficiaries who completed the survey were included in the study (N=7,525). A probit regression to predict the probability of having drug coverage and the effects of drug coverage on drug expenditures was estimated by a two‐part model, assuming no correlation across equations. In addition, the discrete factor model estimated choice of drug coverage and expenditures for prescription drugs simultaneously to control for self‐selection into drug coverage, allowing for correlation of error terms across equations.Principal Findings. Findings indicated that unobservable characteristics leading elderly Medicare beneficiaries to purchase drug coverage also lead them to have higher drug expenditures on conditional use (i.e., adverse selection), while the same unobservable factors do not influence their decisions whether to use any drugs. After controlling for potential selection bias, the probability of any drug use among persons with drug coverage use was 4.5 percent higher than among those without, and drug coverage led to an increase in drug expenditures of $308 among those who used prescription drugs.Conclusions. Given significant adverse selection into drug coverage before the implementation of the Medicare Prescription Drug Improvement and Modernization Act, it is essential that selection effects be monitored as beneficiaries choose whether or not to enroll in this voluntary program.
Prolonged Transient Atrial Electrical Silence Following Termination of Chronic Atrial Tachyarrhythmias
Authors: TURITTO GIOIA , SAPONIERI CESARE , ONUORA AFAMEFUNA , EL‐SHERIF NABIL 
Published: October 2007

Introduction:

Atrial standstill is a rare heterogeneous arrhythmia characterized by electrical and mechanical standstill and electrical inexcitability. A long‐lasting progressive form is seen with cardiac and neuromuscular diseases, and a familial or idiopathic form may have a genetic basis. A transient form was described secondary to drug intoxication, electrolyte imbalance, cardiac inflammation, and ischemia.
Methods:

We investigated three patients with long‐standing atrial tachyarrhythmia (AT) (atrial flutter in two, and focal atrial tachycardia in one). All patients underwent a complete electrophysiological study with mapping of right and left atrial activity and radiofrequency ablation (RF Abl) of AT.
Results:

Following RF Abl of AT, all three patients manifested transient atrial electrical silence in the absence of known reversible causes. Atrial electrical silence was observed when, following AT termination, an escape atrioventricular (AV) junctional rhythm (in two patients) and an escape VVI pacemaker rhythm (in one patient) showed transient ventriculo‐atrial (VA) conduction block (up to 30 seconds). A dominant sinus rhythm was observed to return 30 minutes, 90 minutes, and 12 hours, respectively, in the three patients. Two patients received a dual chamber pacemaker and a decision was made not to upgrade the patient with VVI pacemaker.
Discussion and Conclusions:

The present report expands the spectrum of the syndrome of atrial standstill and raises interesting questions regarding possible electrophysiologic mechanism(s) of prolonged post overdrive atrial standstill. The report suggests that chronic overdrive of sinus and subsidiary atrial pacemakers may result in calcium overloading of cardiac cells, which is known to cause suppression of pacemaker activity as well as increased intracellular resistance. These mechanisms can possibly result in either prolonged suppression of sinus and atrial pacemaker activity and/or pacemaker exit block.
Longitudinal Echocardiographic Follow‐Up in Children with Congenital Complete Atrioventricular Block
Authors: BEAUFORT‐KROL GERTIE C.M. , SCHASFOORT‐VAN LEEUWEN MIEK J.M. , STIENSTRA YMKJE , BINK‐BOELKENS MARGREET Th.E. 
Published: October 2007

Background: Due to a low heart rate (HR) in children with congenital complete atrioventricular block (CCAVB), a larger stroke volume of the left ventricle (LV) may be expected. If so, end‐diastolic (LVEDD) and end‐systolic (LVESD) diameters may be enlarged and even dilated cardiomyopathy (DCM) may occur. The aim of this study was to answer the question if children with CCAVB develop LV dilatation. Furthermore, we investigated whether LV dilatation would decrease after pacing.
Methods: We longitudinally evaluated echocardiographic data (LVEDD, LVESD, shortening fraction [SF]) in 36 children with CCAVB. Age at the first visit was 2.5 ± 3.3 years (mean ± SD); follow‐up 10.6 ± 7.3 years.
Results: Three children had DCM, already at 1st visit. LVEDD and LVESD Z scores in all children with CCAVB were larger than in normal controls (LVEDD Z score 1.38 ± 1.80; LVESD Z score 0.64 ± 1.35). Both Z scores were larger when HR was lower. Both Z scores increased over time in children who met criteria for pacing, but did not change in non‐paced children. Physiologic pacing decreased both Z scores. SF of all children was normal and remained normal during follow‐up (0.39 ± 0.05 1st visit vs 0.39 ± 0.06 last visit).
Conclusions: We conclude that children with CCAVB have LV dilatation, which is progressive in children who met criteria for pacing. LV dilatation regressed by physiologic pacing. LV dilatation was larger when HR was lower. SF does not deteriorate over time. DCM occurs early in the disease and does not develop during childhood, not even in children with LV dilatation.
Cardiac Resynchronization Therapy:
Authors: LILLI ALESSIO , RICCIARDI GIUSEPPE , PORCIANI MARIA CRISTINA , PERINI ALESSANDRO PAOLETTI , PIERAGNOLI PAOLO , MUSILLI NICOLA , COLELLA ANDREA , PACE STEFANO DEL , MICHELUCCI ANTONIO , TURRENI FEDERICO , SASSARA MASSIMO , ACHILLI AUGUSTO , SERGE BAROLD S. , PADELETTI LUIGI 
Published: October 2007

Aim:

Gender related differences in epidemiology, treatment, and prognosis of heart failure (HF) have been reported. We examined the sex influence in patients treated with cardiac resynchronization therapy (CRT).
Methods and Results:

Out of 334 consecutive HF patients (19.7% women) who underwent CRT, 195 patients reached clinical and echocardiographic evaluation at six and 12 months and were selected for analysis. A reduction in left ventricular (LV) end‐diastolic volume/m2 (EDVi) and end systolic volume/m2 (ESVi) was evident in the overall population at six months (P < 0.001) and from six to 12 months (P < 0.001). Compared to men, women showed significantly greater changes in LV volumes at mid (P < 0.05) and long‐term (P < 0.001) follow‐up and a significantly higher LV ejection fraction (EF) (40.8 ± 12.3 vs 34.1 ± 10.1, P < 0.01) at one year. Multiple regression analysis, including several demographic and clinical parameters, revealed that female gender is independently associated with greater reduction in LV ESVi. At the 12‐month follow‐up, the proportion of responders (defined in terms of ESV reduction by at least 10%) was higher in women than in men (76.1% vs 59.3%, P < 0.05).
Conclusions:

CRT induced a gender specific LV remodeling response.
Experience of ICD Management at a UK Center:
Authors: KOA‐WING MICHAEL , WRIGHT IAN , PETERS NICHOLAS S. , DAVIES D. WYN , FRANCIS DARREL P. , KANAGARATNAM PRAPA 
Published: October 2007

Background: It would be useful to identify patients at high risk of implantable cardioverter defibrillator (ICD) therapy via additional antiarrhythmic measures to minimize the morbidity of ICD therapies.
Objective: We assessed baseline characteristics for predictors of device therapy in a general ICD population. We also compared the likelihood of therapy delivery by replacement ICDs implanted for battery depletion with the original implants.
Methods: Clinical and ICD interrogation data from patients followed up at a UK center were analyzed looking for predictors of appropriate ICD therapy. Univariate and multivariate analysis was performed using Cox regression. We compared time to first appropriate therapy between first and second ICDs in patients who had undergone ICD replacement for battery depletion by log‐rank testing.
Results: One hundred and sixty‐one patients were studied (129 men, age 65.7 ± 12.9 years, follow‐up 908 ± 676 days). Appropriate therapy was delivered in 68 patients (42%). Univariate risk factors for appropriate ICD therapy were presentation with stable ventricular tachycardia (VT) (P = 0.0002), ischemic etiology (P = 0.03), tiered therapy programmed ICDs (P = 0.01), and beta‐blocker use (P = 0.001). Stable VT and beta blocker use were independent predictors of ICD therapy on multivariate analysis. Thirty‐three patients (20%) had at least one ICD replacement. Time to first appropriate therapy was no different between first and second ICD implants (P = 0.8).
Conclusion: Patients who present with cardiovascularly stable VT have a higher probability of receiving appropriate ICD therapy than those who do not. Following battery depletion of an original ICD, the replacement device is no less likely to administer therapy than the first.
Morphology of the RV Electrogram during LV Pacing is Related to the Hemodynamic Effect in Cardiac Resynchronization Therapy
Authors: VAN GELDER BERRY M. , BRACKE FRANK A. , MEIJER ALBERT , PILMEYER ART , PIJLS NICO H.J. 
Published: October 2007

Background:

Biventricular (BiV) pacing and left ventricular (LV) pacing both improve LV function in patients with heart failure and LV dyssynchrony. We studied the hemodynamic effect of the atrioventricular (AV) interval and the associated changes in the right ventricular (RV) electrogram (EGM) during LV pacing and compared this with the hemodynamic effect of optimized sequential BiV pacing.
Methods:

In 16 patients with New York Heart Association (NYHA) class II to IV, sinus rhythm with normal AV conduction, left bundle branch block (LBBB), QRS > 130 ms, and optimal medical therapy, the changes in RV EGM during LV pacing with varying AV intervals were studied. The hemodynamic effect associated with these changes was evaluated by invasive measurement of LVdP/dtmax and compared with the result of optimized sequential BiV pacing in the same patient.
Results:

All patients showed electrocardiographic fusion during LV pacing. The morphology of the RV EGM showed changes in the RV activation that indicated a shift in the extent of fusion from LV pacing. These changes were associated with significant changes in LVdP/dtmax. Baseline LV dP/dtmax was 734 ± 177 mmHg/s, which increased to 927 ± 202 mmHg/s (P<0.0001) with optimized LV pacing and to 920 ± 209 mmHg/s (P<0.0001) with optimized sequential BiV pacing.
Conclusion:

The RV EGM is a proper indicator for intrinsic activation over the right bundle during LV pacing and reveals the transition to fusion in the RV EGM that is associated with a decrease in LVdP/dtmax. The hemodynamic effect of optimized LV pacing is equal to optimized sequential BiV pacing.