Home About us Contact
|
Home About us Contact | ||
|
|
||
Longitudinal Comparisons (longitudinal + comparison)
Selected AbstractsUtilizing Peer Nominations in Middle School: A Longitudinal Comparison Between Complete Classroom-Based and Random List MethodsJOURNAL OF RESEARCH ON ADOLESCENCE, Issue 2 2010Amy Bellmore Although peer nominations provide invaluable data on social status and reputations of classmates, the large size and organizational structure of secondary schools pose a practical challenge to utilizing nomination methods. Particularly problematic is determining the appropriate reference group when students are no longer in self-contained classrooms. In the current study, we compared a random list method as an alternative to complete classroom-based or grade list peer nominations. In a 3-year longitudinal study of 2,307 middle school students, the temporal stability and construct validity of the method were assessed regarding peer acceptance, rejection, coolness, aggression, and victimization. The findings suggested that the random list procedure provides a feasible method to study large peer groups in secondary school settings. [source] Cross-Sectional and Longitudinal Studies of the Development of Group Differences in Acoustic Features of Coo Calls in Two Groups of Japanese MacaquesETHOLOGY, Issue 1 2006Toshiaki Tanaka Japanese macaques, Macaca fuscata, frequently utter coo calls to maintain vocal contact. Cross-sectional and longitudinal comparisons were conducted on the acoustic features of coo vocalizations of two groups of M. fuscata, Yakushima and Ohirayama groups, to explore the possibility of vocal plasticity. These two groups derive from the same local population but have been separated for more than 34 yr. The Yakushima group is non-provisioned, while the Ohirayama group is provisioned. Initially, coo calls in the two groups were compared cross-sectionally in females ranging from 0 to 18 yr. Mean values of the four variables studied (start, end, maximum, and minimum frequencies) were consistently lower in all age groups of the Ohirayama individuals compared with the Yakushima individuals. Secondly, longitudinal comparisons were conducted on individuals in the 1,4 yr after birth. Mean values of the five frequency variables studied (start, end, maximum, minimum and average frequencies) were again consistently lower in all age groups of Ohirayama compared with Yakushima individuals, although mean values of both groups gradually declined with an increase in age. Inter-group differences were significant at all ages in minimum frequency and at the first, second and third years in start frequency. Longitudinal comparisons of individuals aged 4,11 mo were also conducted. Regarding the four variables that differed between the two groups in the cross-sectional study, the mean values of minimum and start frequency did not differ significantly between the two groups at 4,5 mo, but were significantly lower in Ohirayama individuals aged 7,8 and 9,11 mo. Although provisioning may have had an effect on the weight difference between the groups, and consequently on vocalization frequency, these results suggest that the inter-group differences in coo call features form approximately 6,7 mo after birth as a result of vocal plasticity. [source] Delayed umbilical cord clamping at birth has effects on arterial and venous blood gases and lactate concentrationsBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 6 2008N Wiberg Objective, To estimate the influence of delayed umbilical cord clamping at birth on arterial and venous umbilical cord blood gases, bicarbonate (), base excess (BE) and lactate in vigorous newborns. Setting, University hospital. Design, Prospective observational. Sample, Vaginally delivered term newborns. Material and methods, Umbilical cord arterial and venous blood was sampled repeatedly every 45 seconds (T0= time zero; T45= 45 seconds, T90= 90 seconds) until the cord pulsations spontaneously ceased in 66 vigorous singletons with cephalic vaginal delivery at 36,42 weeks. Longitudinal comparisons were performed with the Wilcoxon signed-ranks matched pairs test. Mixed effect models were used to describe the shape of the regression curves. Main outcome measures, Longitudinal changes of umbilical cord blood gases and lactate. Results, In arterial cord blood, there were significant decreases of pH (7.24,7.21), (18.9,18.1 mmol/l) and BE (,4.85 to ,6.14 mmol/l), and significant increases of PaCO2 (7.64,8.07 kPa), PO2 (2.30,2.74 kPa) and lactate (5.3,5.9 mmol/l) from T0 to T90, with the most pronounced changes at T0,T45. Similar changes occurred in venous blood pH (7.32,7.31), (19.54,19.33 mmol/l), BE (,4.93 to ,5.19 mmol/l), PaCO2 (5.69,5.81 kPa) and lactate (5.0,5.3 mmol/l), although the changes were smaller and most pronounced at T45,T90. No significant changes were observed in venous PO2. Conclusion, Persistent cord pulsations and delayed cord clamping at birth result in significantly different measured values of cord blood acid,base parameters. [source] Longitudinal Diminution of Tumor Size for Basal Cell Carcinoma Suggests Shifting Referral Patterns for Mohs SurgeryDERMATOLOGIC SURGERY, Issue 1 2008ANDREW L. KAPLAN MD BACKGROUND The Mohs technique for removal of cutaneous malignancies offers tissue-sparing benefits compared with other treatment methods. With wider acceptance and availability of Mohs surgery, referral patterns may be shifting toward the treatment of smaller, lower-risk tumors. OBJECTIVE The objective was to examine whether referral patterns for basal cell carcinoma (BCC) at an academic Mohs surgery practice have shifted over recent years toward referral for smaller, lower risk tumors. METHODS A retrospective longitudinal comparison of tumor characteristics was performed for BCCs treated at our institution from a recent year (2004) and a past year (1996). Statistical analyses were used to identify differences in tumor size, distribution by anatomic site, and primary versus recurrent status. RESULTS Complete data were available for 603 BCCs treated in 1996 and 1,514 BCCs treated in 2004. A 24% decrease in preoperative tumor surface area was observed from 1996 (1.25 cm2) to 2004 (0.95 cm2). Tumors were twice as likely to be recurrent in 1996 (15.1%) than in 2004 (7.4%). There were no significant differences in the anatomic distribution of lesions in the years compared. CONCLUSIONS Findings at our institution suggest that in recent years, referral patterns have shifted toward a preference for Mohs surgery for the treatment of smaller, primary BCCs. This may be a result of increased awareness by the dermatologic and medical community of the numerous advantages of Mohs surgery and a greater appreciation of its tissue-sparing properties, which may result in less complex and more successful aesthetic reconstructions. [source] Stability of negative self-structures: A longitudinal comparison of depressed, remitted, and nonpsychiatric controlsJOURNAL OF CLINICAL PSYCHOLOGY, Issue 4 2007David J. A. Dozois To be considered a vulnerability marker for depression, a variable should, in addition to demonstrating sensitivity and specificity, also show evidence of temporal stability (i.e., remain present in the absence of depressive symptomatology). Although many cognitive factors are associated with depression, the majority of them appear to be episode rather than vulnerability markers. This study examined cognitive organization of positive and negative interpersonal and achievement content in clinically depressed, remitted, and nonpsychiatric controls. At initial assessment, a sample of 54 clinically depressed individuals and 37 never-depressed controls completed self-report measures of positive and negative automatic thoughts and two cognitive organizational tasks. They were retested 6 months later when half of the depressed group no longer met diagnostic criteria for major depression. Negative automatic thoughts decreased and positive automatic thoughts increased significantly in individuals who had improved clinically. The organization of negative interpersonal content remained stable despite symptom amelioration, but negative achievement content was less interconnected at follow-up in those patients who had improved. The structure of relational schemas, in particular, appears to be stable and may be an important cognitive vulnerability factor for depression. © 2007 Wiley Periodicals, Inc. J Clin Psychol 63: 319,338, 2007. [source] Citation levels and collaboration within library and information scienceJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 3 2009Jonathan M. Levitt Collaboration is a major research policy objective, but does it deliver higher quality research? This study uses citation analysis to examine the Web of Science (WoS) Information Science & Library Science subject category (IS&LS) to ascertain whether, in general, more highly cited articles are more highly collaborative than other articles. It consists of two investigations. The first investigation is a longitudinal comparison of the degree and proportion of collaboration in five strata of citation; it found that collaboration in the highest four citation strata (all in the most highly cited 22%) increased in unison over time, whereas collaboration in the lowest citation strata (un-cited articles) remained low and stable. Given that over 40% of the articles were un-cited, it seems important to take into account the differences found between un-cited articles and relatively highly cited articles when investigating collaboration in IS&LS. The second investigation compares collaboration for 35 influential information scientists; it found that their more highly cited articles on average were not more highly collaborative than their less highly cited articles. In summary, although collaborative research is conducive to high citation in general, collaboration has apparently not tended to be essential to the success of current and former elite information scientists. [source] Using Quality Management Tools to Enhance Feedback from Student EvaluationsDECISION SCIENCES JOURNAL OF INNOVATIVE EDUCATION, Issue 1 2005John B. Jensen ABSTRACT Statistical tools found in the service quality assessment literature,the T2 statistic combined with factor analysis,can enhance the feedback instructors receive from student ratings. T2 examines variability across multiple sets of ratings to isolate individual respondents with aberrant response patterns (i.e., outliers). Analyzing student responses that are outside the "normal" range of responses can identify aspects of the course that cause pockets of students to be dissatisfied. This fresh insight into sources of student dissatisfaction is particularly valuable for instructors willing to make tactical classroom changes that accommodate individual students rather than the traditional approach of using student ratings to develop systemwide changes in course delivery. A case study is presented to demonstrate how the recommended procedure minimizes data overload, allows for valid schoolwide and longitudinal comparisons of correlated survey responses, and helps instructors identify priority areas for instructional improvement. [source] Cross-Sectional and Longitudinal Studies of the Development of Group Differences in Acoustic Features of Coo Calls in Two Groups of Japanese MacaquesETHOLOGY, Issue 1 2006Toshiaki Tanaka Japanese macaques, Macaca fuscata, frequently utter coo calls to maintain vocal contact. Cross-sectional and longitudinal comparisons were conducted on the acoustic features of coo vocalizations of two groups of M. fuscata, Yakushima and Ohirayama groups, to explore the possibility of vocal plasticity. These two groups derive from the same local population but have been separated for more than 34 yr. The Yakushima group is non-provisioned, while the Ohirayama group is provisioned. Initially, coo calls in the two groups were compared cross-sectionally in females ranging from 0 to 18 yr. Mean values of the four variables studied (start, end, maximum, and minimum frequencies) were consistently lower in all age groups of the Ohirayama individuals compared with the Yakushima individuals. Secondly, longitudinal comparisons were conducted on individuals in the 1,4 yr after birth. Mean values of the five frequency variables studied (start, end, maximum, minimum and average frequencies) were again consistently lower in all age groups of Ohirayama compared with Yakushima individuals, although mean values of both groups gradually declined with an increase in age. Inter-group differences were significant at all ages in minimum frequency and at the first, second and third years in start frequency. Longitudinal comparisons of individuals aged 4,11 mo were also conducted. Regarding the four variables that differed between the two groups in the cross-sectional study, the mean values of minimum and start frequency did not differ significantly between the two groups at 4,5 mo, but were significantly lower in Ohirayama individuals aged 7,8 and 9,11 mo. Although provisioning may have had an effect on the weight difference between the groups, and consequently on vocalization frequency, these results suggest that the inter-group differences in coo call features form approximately 6,7 mo after birth as a result of vocal plasticity. [source] A prospective longitudinal population-based study of clinical miscarriage in an urban Swedish populationBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 2 2008F Blohm Objective, To describe the incidence of clinical miscarriage and to investigate the factors influencing the occurrence of clinical miscarriage. Design, Prospective study with both cross-sectional and longitudinal comparisons. Setting, City of Göteborg, Sweden. Population, Population-based study in cohorts of 19-year-old women followed longitudinally. Main outcome measures, Incidence of miscarriage and pregnancy outcome. Material and methods, A postal questionnaire was sent to women born in 1962 and resident in the city of Göteborg in 1981 (n= 656) regarding pregnancy outcome, clinical miscarriage and other reproductive health factors. Responders in 1981 were contacted again and requested to answer a similar questionnaire every fifth year up to 2001. The same process was repeated in 1991 with women born in 1972 (n= 780) with follow up of these responders in 1996 and 2001. A third cohort of 19-year-old women born in 1982 (n= 666) was interviewed in 2001. The self-reported pregnancy data were verified from hospital files. Results, Complete data were available for 341 women born in 1962 and assessed up to the age of 39 years (ever pregnant, n= 320, 94%). There were in total 887 pregnancies (live birth, n= 590, 67%; miscarriage, n= 108, 12%; legal abortion, n= 173, 20% and ectopic pregnancy, n= 16, 2%). Of the 320 ,ever pregnant' women, 80 women (25%) had experienced a miscarriage. 76.3% had experienced one miscarriage, 16.3% had two miscarriages and 7.4% had three or more miscarriages. The clinical miscarriage rates in women at different ages were as follows: 20,24 years 13.5%, 25,29 years 12.3%, 30,34 years 10.3% and 35,39 years 17.5%. The corresponding miscarriage rate in the 1972 cohort followed from 19 to 29 years of age was 11%, and in the 1982 cohort assessed at 19 years of age, the miscarriage rate was 9%. No risk factor for miscarriage could be reliably identified. Conclusions, Clinical miscarriage constituted 12% of all pregnancies, and one in four women who had been pregnant up to 39 years of age had experienced a miscarriage. Three or more miscarriages were experienced by 7.4%. The occurrence of a miscarriage was not influenced by the order of the pregnancy. [source] Cross-sectional and longitudinal comparisons of health-related quality of life between patients with prostate carcinoma and matched controls,,§CANCER, Issue 9 2004M.P.H., Richard M. Hoffman M.D. Abstract BACKGROUND Prostate carcinoma and treatments affect health-related quality of life (HRQOL). The authors prospectively compared prostate and general HRQOL between prostate carcinoma cases and an age-matched and ethnicity-matched control group. METHODS The case cohort consisted of 293 men with localized prostate carcinoma who were selected randomly from the population-based New Mexico Tumor Registry, and the control cohort consisted of 618 men who were selected randomly from administrative databases and matched for age and ethnicity. Subjects completed a baseline survey of demographics, socioeconomic status, comorbidity, and prostate and general HRQOL. Also, 210 cases (71.7%) and 421 controls (67.8%) completed a follow-up survey 5 years later. Multinomial logistic regression models compared baseline characteristics as well as 5-year general HRQOL outcomes measured by selected domains of the Medical Outcomes Study SF-36. The authors used a mixed-model repeated-measures analysis of variance and multinomial regression analyses to compare longitudinal changes in urinary, bowel, and sexual function between groups. RESULTS At baseline, patients with prostate carcinoma had better urinary control and sexual function than controls. Over 5 years, sexual function declined significantly among controls, although urinary function remained stable. However, patients with cancer subsequently reported significant declines in both domains and were left with much worse function and more bother than controls. Bowel function and general HRQOL were similar for both groups at follow-up. CONCLUSIONS Prostate carcinoma treatment led to significant 5-year declines in urinary and sexual function that far exceeded age-related changes in controls. Patients with cancer had significantly worse function and more bother than controls for these disease-specific domains of HRQOL. Bowel function and general HRQOL were not affected by cancer status. Cancer 2004. Published 2004 American Cancer Society. [source] | |||||||||||||