Showing papers by "Temple University published in 1996"

A Framework for Task-Based Learning

Abstract: *Lesson outlines show how the framework can be used to plan lessons *Includes over 200 ideas for tasks for classroom use and photocopiable Focus Pages for use in teacher training sessions

Effect of fasting on serum leptin in normal human subjects

Abstract: We have studied the effect of fasting on serum leptin levels in normal volunteers. Five normal-weight (BMI 28, 2 males/3 females) were fasted (0 Kcal) for 52 h. Mean plasma glucose decreased from 88 +/- 3 to 63 +/- 5 mg/dl, serum insulin from 16 +/- 1 to 10 +/- 1 microU/ml, plasma beta-hydroxybutyrate increased from 0.2 +/- 0.1 to 1.8 +/- 0.4 mumol/ml. Serum leptin levels were higher in the obese than in the normal-weight volunteers (31 +/- 12 vs 11 +/- 3 ng/ml, p < 0.01). In the obese, serum leptin decreased from 31 +/- 10 to 12 +/- 5 ng/ml aft552 h (-72%, p < 0.001); in the normal-weight it decreased from 11 +/- 3 to 4 +/- 0.5 ng/ml (-64%, p < 0.001). Serum leptin correlated positively with serum insulin (r = 0.51, p < 0.001) and with plasma glucose (r = 0.61, p < 0.001). To determine effects of fasting induced decreases in plasma glucose and insulin on serum leptin, four normal subjects (3 males/1 female) were fasted for 72 h while their plasma glucose was clamped at basal levels with a variable rate glucose infusion. In these volunteers, serum leptin and insulin concentrations remained unchanged. In summary, the rapid decrease in serum leptin levels during fasting indicated that leptin release was regulated by factors other than changes in body fat mass. The lack of leptin changes during fasting, when basal insulin and glucose levels were maintained at basal levels, suggested that insulin and/or glucose may play a role in the regulation of leptin release.

Tumor Marker Utility Grading System: a Framework to Evaluate Clinical Utility of Tumor Markers

Abstract: Introduction of tumor markers into routine clinical practice has been poorly controlled, with few criteria or guidelines as to how such markers should be used. We propose a Tumor Marker Utility Grading System (TMUGS) to evaluate the clinical utility of tumor markers and to establish an investigational agenda for evaluation of new tumor markers. A Tumor Marker Utility Grading Worksheet has been designed. The initial portion of this worksheet is used to clarify the precise characteristics of the marker in question. These characteristics include the marker designation, the molecule and/or substance and the relevant alteration from normalcy, the assay format and reagents, the specimen type, and the neoplastic disease for which the marker is being evaluated. To determine the clinical utility of each marker, one of several potential uses must be designated, including risk assessment, screening, differential diagnosis, prognosis, and monitoring clinical course. For each of these uses, associations between marker assay results and expected biologic process and end points must be determined. However, knowledge of tumor marker data should contribute to a decision in practice that results in a more favorable clinical outcome for the patient, including increased overall survival, increased disease-free survival, improvement in quality of life, or reduction in cost of care. Semiquantitative utility scales have been developed for each end point. The only markers recommended for use in routine clinical practice are those that are assigned utility scores of "++" or " " on a 6-point scale (ranging from 0 to ) in the categories relative to more favorable clinical outcomes. Each utility score assignment should be supported by documentation of the level of evidence used to evaluate the marker. TMUGS will establish a standardized analytic technique to evaluate clinical utility of known and future tumor markers. It should result in improved patient outcomes and more cost-efficient investigation and application of tumor markers.

Use of the Berg Balance Test to Predict Falls in Elderly Persons

Abstract: Background and Purpose. The purpose of this study was to determine whether the Berg balance test could be used to predict an elderly person's risk of falling. Subjects. Sixty-six residents of two independent life-care communities, aged 69 to 94 years (X=79.2, SD=6.2), participated. Methods. Subjects completed a questionnaire pertaining to their fall history and activity level. The Berg balance test, consisting of 14 functional subtests, was then administered. Six months later, subjects again completed the questionnaire. Results. Performance of activities of daily living predicted 43% of the subjects' scores. There was a difference between the subjects who were prone to falling and those who were not prone to falling, but the test demonstrated poor sensitivity for predicting who would fall. The specificity of the test was very strong. The use of an assistive device was a strong predictor of performance on the Berg balance test. No relationship was noted between increasing age and decreasing performance on the Berg balance test. Conclusion and Discussion. Although the Berg balance test demonstrated only 53% sensitivity, the results support the test developers' use of 45 (out of 56) as a generalized cutoff score. Older adults who scored higher than the cutoff score on the test were less likely to fall than were those adults who scored below the cutoff score. Decreased scores, however, did not predict increased frequency of falls. Results must be viewed cautiously because self-report was the sole means of documenting fall history.

Ecological Assessments of Community Disorder: Their Relationship to Fear of Crime and Theoretical Implications

Abstract: Researchers suggest that fear of crime arises from community disorder, cues in the social and physical environment that are distinct from crime itself. Three ecological methods of measuring community disorder are presented: resident perceptions reported in surveys and on-site observations by trained raters, both aggregated to the street block level, and content analysis of crime- and disorder-related newspaper articles aggregated to the neighborhood level. Each method demonstrated adequate reliability and roughly equal ability to predict subsequent fear of crime among 412 residents of 50 blocks in 50 neighborhoods in Baltimore, MD. Pearson and partial correlations (controlling for sex, race, age, and victimization) were calculated at multiple levels of analysis: individual, individual deviation from block, and community (block/neighborhood). Hierarchical linear models provided comparable results under more stringent conditions. Results linking different measure of disorder with fear, and individual and aggregated demographics with fear inform theories about fear of crime and extend research on the impact of community social and physical disorder. Implications for ecological assessment of community social and physical environments are discussed.

A Reaction-Diffusion Model of Cancer Invasion

Abstract: We present mathematical analyses, experimental data, and clinical observations which support our novel hypothesis that tumor-induced alteration of microenvironmental pH may provide a simple but complete mechanism for cancer invasion. A reaction-diffusion model describing the spatial distribution and temporal development of tumor tissue, normal tissue, and excess H+ ion concentration is presented. The model predicts a pH gradient extending from the tumor-host interface, which is confirmed by reanalysis of existing experimental data. Investigation of the structure and dynamics of the tumor-host interaction within the context of the model demonstrates a transition from benign to malignant growth analogous to the adenoma-carcinoma sequence. The effect of biological parameters critical to controlling this transition are supported by experimental and clinical observations. Tumor wave front velocities determined via a marginal stability analysis of the model equations are consistent with in vivo tumor growth rates. The model predicts a previously unrecognized hypocellular interstitial gap at the tumor-host interface which we demonstrate both in vivo and in vitro. A direct correlation between the interfacial morphology and tumor wave front velocity provides an explicit, testable, clinically important prediction.

Maturity of judgment in adolescence: Psychosocial factors in adolescent decision making.

Abstract: To date, analyses of differences between adolescents' and adults' judgment have emphasized age differences in cognitive factors presumed to affect decision making. In contrast, this article examines research and theory on threepsychosocial aspects of maturity of judgment: responsibility, temperance, and perspective. For several psychosocial dimensions of maturity that are likely to affect judgment, the existing pvidence, while indirect and imperfect, indicates that the greatest differences are found in comparisons between early adolescents versus middle and late adolescents. Developmental research on maturity that focuses specifically on mid-and late adolescence, that simultaneously examines both cognitive and noncognitive factors, and that investigates the relation between these factors and the ability to make good decisions is greatly needed.

Specifying the direct and indirect effects of low self-control and situational factors in offenders' decision making: Toward a more complete model of rational offending

Abstract: This paper builds on work by Nagin and Paternoster in which they contend that two recent developments in criminological theory, self-control and rational choice, have been explored separately rather than in conjunction with one another. In their analysis, Nagin and Paternoster found direct effects for variables from each of these theories and called for more research into simultaneous examination of the two. We build on their work by delineating a more highly specified model of rational offending, in which we observe that the research thus far has not examined the indirect effects of low self-control. We believe that this area is grossly underdeveloped and that such an examination is necessary for a more complete understanding of criminal offending. We advance three hypotheses concerning the integration of low self-control into a rational choice framework: (1) that low self-control will have both direct and indirect effects via situational characteristics on intentions to shoplift and drive drunk; (2) tha...

Nature, extent, and importance of what psychotherapy trainees do not disclose to their supervisors.

Abstract: Nondisclosures in supervision were studied for 108 supervisees. Supervisees reported an average of 8.06 nondisclosures ranging in importance level. Negative reactions to the supervisor were the most frequent type of nondisclosure. The most frequent reasons for nondisclosures were perceived unimportance, that the nondisclosure was too personal, negative feelings, and a poor alliance. The manner of nondisclosure was usually passive. Most nondisclosures were discussed with someone else, typically a peer. Supervisor style was related to content of and reasons for nondisclosure. Supervisees were less satisfied when they reported more negative reactions to supervisors and when they did not disclose because of poor alliances, supervisor incompetence, and fear of political suicide. Thus, nondisclosure affects the process of supervision. Further research is needed on how nondisclosures in supervision affect supervision and therapy processes.

Transducers of life and death: TNF receptor superfamily and associated proteins.

Abstract: Signal transduction pathways which are initiated by members of the TNF superfamily utilize receptors which are devoid of intrinsic catalytic activity. Isolation and characterization of death domain (TNF-RI, Fas, TRADD, FADD/MORT-1, RIP) and TRAF domain-containing proteins (TRAF-1, TRAF-2, TRAF-3) have partially bridged a large molecular gap within one of several signaling pathways which originate at the plasma membrane and terminate in the nucleus. The ability of these two protein families to selectively dimerize and bind to related receptors allows them to govern diverse cellular responses which culminate in cellular proliferation, differentiation, effector functions, and apoptosis.

Partial Liquid Ventilation with Perflubron in Premature Infants with Severe Respiratory Distress Syndrome

Abstract: Background The intratracheal administration of a perfluorocarbon liquid during continuous positive-pressure ventilation (partial liquid ventilation) improves lung function in animals with surfactant deficiency. Whether partial liquid ventilation is effective in the treatment of infants with severe respiratory distress syndrome is not known. Methods We studied the efficacy of partial liquid ventilation with perflubron in 13 premature infants with severe respiratory distress syndrome in whom conventional treatment, including surfactant therapy, had failed. Partial liquid ventilation was initiated by instilling perflubron during conventional mechanical ventilation to a volume approximating the functional residual capacity. Infants were considered to have completed the study if they received partial liquid ventilation for at least 24 hours. Results Ten infants received partial liquid ventilation for 24 to 76 hours. In the other three infants, partial liquid ventilation was discontinued within four hours in fa...

Structure of a unique binuclear manganese cluster in arginase

Abstract: Each individual excretes roughly 10 kg of urea per year, as a result of the hydrolysis of arginine in the final cytosolic step of the urea cycle. This reaction allows the disposal of nitrogenous waste from protein catabolism, and is catalysed by the liver arginase enzyme. In other tissues that lack a complete urea cycle, arginase regulates cellular arginine and ornithine concentrations for biosynthetic reactions, including nitric oxide synthesis: in the macrophage, arginase activity is reciprocally coordinated with that of NO synthase to modulate NO-dependent cytotoxicity. The bioinorganic chemistry of arginase is particularly rich because this enzyme is one of very few that specifically requires a spin-coupled Mn2+-Mn2+ cluster for catalytic activity in vitro and in vivo. The 2.1 angstrom-resolution crystal structure of trimeric rat liver arginase reveals that this unique metal cluster resides at the bottom of an active-site cleft that is 15 angstroms deep. Analysis of the structure indicates that arginine hydrolysis is achieved by a metal-activated solvent molecule which symmetrically bridges the two Mn2+ ions.

The ecology of empowerment: Predicting participation in community organizations

Abstract: The community empowerment model of grassroots organizing is briefly described. A particular ecological framework of physical, economic, and social environmental predictors of citizen participation in grassroots community or ganizations is presented. Individual and block-level (contextual) survey and observational data from New York City, Baltimore, and Salt Lake City were used to predict residents' participation in such organizations, cross-sectionally and after a one-year time lag. Longitudinal data from one city were used to predict the viability of block associations seven years later. Crime and fear were unrelated to participation. Defensible space, territoriality, and physical incivilities were sometimes negatively and sometimes positively related to participation. Income, home ownership, minority status, and residential stability were positively, but inconsistently, related to participation. Community-focused social cognitions (organizational efficacy, civic responsibility, community attachments) and behaviors (neighboring, volunteer work through churches and other community organizations) were consistently and positively predictive of participation at both the individual and block levels. The model explained up to 28% of the variance in individual participation and up to 52% of the variance in block-level participation. Implications for theory, research, and community organizing are discussed.

Long-term follow-up of a cognitive-behavioral therapy for anxiety-disordered youth.

Abstract: This study examined the long-term effects of a psychosocial treatment for anxiety-disordered youth. Clients (N = 36) who had completed treatment 3.35 years earlier (on average) were reassessed using self- and parent-report instruments as well as structured diagnostic interviews. Results indicated that previously documented treatment gains were maintained. An examination of participants' recalled events within therapy suggested that the therapeutic relationship, games and activities, and discussion of problems were salient treatment components. Theoretically important components of treatment were also recalled by clients, and some were found to be related to long-term positive outcome.

Neighborhood responses to disorder and local attachments: The systemic model of attachment, social disorganization, and neighborhood use value

Abstract: This paper investigates neighborhood-level connections between ecological structure, responses to disorder, and local attachment and social involvement. We develop predictions integrating the systemic model of community attachment, neighborhood use value, and the social disorganization perspective. The systemic model predicts neighborhood stability will deepen attachment and local involvement; the social disorganization perspective anticipates effects of stability on responses to disorder; and neighborhood use value suggests effects of status, racial composition, and problems such as crime and deterioration on attachment. We further propose, building on earlier work, that attachment may influence responses to disorder, or vice versa. Data include resident surveys, census information, on-site assessments, and crime rates from 66 randomly selected Baltimore, Maryland, neighborhoods. In support, respectively, of the systemic and neighborhood use value models, we find strong impacts of stability and class on neighborhood attachment/involvement. Neighborhood fear and perceived informal social control depend upon emotional investment and social integration. We see no overall impacts of deterioration on responses to disorder, calling into question some key aspects of the incivilities thesis. Earlier investigations of deterioration and responses to disorder that excluded person-place transactions may have been misspecified. Results underscore the strong relationship between person-environment transactions and responses to disorder. Asking how to encourage citizens to resist disorder is questioning, in part, how to increase the bonds residents have with the locale and with one another.

Ethnicity and Community Context as Moderators of the Relations between Family Decision Making and Adolescent Adjustment

Abstract: This study investigated whether the impact of 3 types of family decision making on the adjustment of 14–16-year-old youth was moderated by ethnicity, community context, or both. For joint and unilateral youth decision making, community context interacted with ethnicity in 3 patterns of influence: for Hispanic-American youth, variations in decision making had a stronger impact in ethnically mixed than in predominantly white communities; for African-American youth, the negative impact of unilateral youth decision making was stronger in predominantly white communities; and for Asian- and European-American youth, community context did not make a difference. For unilateral parental decision making, the popular hypothesis that apparent ethnic differences in the influence of parental strictness on adolescent adjustment are primarily due to differences in community context was not supported. Rather, the positive impact of unilateral parental decision making was similar among African-American youth living in predominantly white, and more affluent, communities or in more disadvantaged, ethnically mixed neighborhoods. The negative impact of authoritarian parenting was similar among European-American youth living in less advantaged communities as well as more affluent ones. There was no relation between unilateral parental control and adolescent adjustment of Asian- or Hispanic-American youth in either type of community.

Applying cognitive-social theory to health-protective behavior: breast self-examination in cancer screening.

Abstract: This article applies recent developments in cognitive-social theory to health-protective behavior, articulating a Cognitive-Social Health Information Processing (C-SHIP) model. This model of the genesis and maintenance of health-protective behavior focuses on the individual's encodings and construals, expectancies, affects, goals and values, self-regulatory competencies, and their interactions with each other and the health-relevant information in the course of cognitive-affective processing. In processing health information, individuals are assumed to differ in both the accessibility of these mental representations and the organization of relationships among them. In this article, the model is applied to analyze and integrate the often-confusing findings on breast self-examination in cancer screening. Implications are considered for assessments and interventions to enhance adherence to complex, long-term, health-protective regimens, tailored to the needs and characteristics of the individual.

A Re-Examination of Financial Analysts' Differential Earnings Forecast Accuracy

Abstract: This research re-examines whether there are differences in the forecast accuracy of financial analysts by comparing their annual earnings per share forecasts. The comparison of analyst forecast accuracy is made on both an ex post (within sample) and an ex ante (out of sample) basis. Early examinations of this issue by O'Brien (1990), Richards (1976), Brown and Rozeff (1980), O'Brien (1987), Coggin and Hunter (1989), Butler and Lang (1991) were ex post and suggest the absence of analysts who can provide relatively more accurate forecasts over multiple years. Contrary to the results of prior research, and consistent with the belief in the popular press, we document that differences do exist in financial analysts' ex post forecast accuracy. We show that the previous studies failed to find differences in forecast accuracy due to inadequate (or no) control for differences in the recency of forecasts issued by the analysts. It has been well documented in the literature that forecast recency is positively related to forecast accuracy (Crichfield, et al, 1978; O'Brien, 1988; Brown, 1991). Thus, failure to control for forecast recency may reduce the power of tests, making it difficult to reject the null hypothesis of no differences in forecast accuracy even if they do exist.

Tau Is Enriched on Dynamic Microtubules in the Distal Region of Growing Axons

Abstract: It is widely held that tau determines the stability of microtubules in growing axons, although direct evidence supporting this hypothesis is lacking. Previous studies have shown that the microtubule polymer in the distal axon and growth cone is the most dynamic of growing axons; it turns over more rapidly and is more sensitive to microtubule depolymerizing drugs than the polymer situated proximally. We reasoned that if the stability of axonal microtubules is directly related to their content of tau, then the polymer in the distal axon should have less tau than the polymer in the proximal axon. We tested this proposition by measuring the relative tau content of microtubules along growing axons of cultured sympathetic neurons immunostained for tau and tubulin. Our results show that the tau content of microtubules varies along the axon, but in the opposite way predicted. Specifically, the relative tau content of microtubules increases progressively along the axon to reach a peak near the growth cone that is severalfold greater than that observed proximally. Thus, tau is most enriched on the most dynamic polymer of the axon. We also show that the gradient in tau content of microtubules does not generate corresponding gradients in the extent of tubulin assembly or in the sensitivity of axonal microtubules to nocodazole. On the basis of these findings, we propose that tau in growing axons has functions other than promoting microtubule assembly and stability and that key sites for these functions are the distal axon and growth cone.

Fluorochemical liquid augmented cryosurgery

Abstract: This invention is a method for cryogenic treatment of a lesion (20) which comprises the steps of delivering a fluoro-chemical liquid to the lesion (20), placing at least one cryoprobe (26) into the lesion (20), and circulating a cryogenic fluid causing an ice ball (30) to form in a vicinity around the cryoprobe (26), wherein the ice ball (30) obliterates at least a portion of the lesion (20). The fluoro-chemical liquid is utilized to augment the cryosurgical procedure and is perfused or injected into and/or around the lesion site prior and/or during the application of a cryprobe (26) to the site. In one embodiment of the invention, the fluoro-chemical liquid acts as a contrast agent to enhance real time medical imaging of the lesion area and modifies the environment in and around the lesion area. In another embodiment of the invention, the fluoro-chemical liquid augments cryosurgical procedures by controlling the size and shape of ice balls (30) formed during the cryosurgical procedures. In this embodiment, a fluoro-chemical liquid with a properly chosen thermal conductivity and freezing point is utilized. Depending on the thermal properties chosen, the liquid either augments freezing of the target area and/or promotes thermal conduction to freeze larger areas, or limits the freezing of the target area and reduces thermal conduction. In an non-cryoprobe embodiment, the liquid is cooled to a temperature below the freezing point of the biological tissue. The cooled liquid is then infused into or around the cystic lesion to produce ablation.

Evidence for a circadian rhythm of insulin secretion

Abstract: Insulin secretion was studied in healthy volunteers at three different levels of glycemia. Plasma glucose was clamped at approximately 5, approximately 8.8 and approximately 12.6 mM for 68 h. Measured were serum insulin concentration and insulin secretion rates (ISR), the latter by deconvolution of plasma C-peptide concentration. Rhythmic patterns of ISR were identified (with a refined first-order Fourier transform) at all three glucose concentrations tested but were most clearly seen at 12.6 mM. ISR and serum insulin concentration changed in a circadian (approximately 24 h) rhythm, increasing from a nadir between midnight and 6 A.M. and reaching a peak between noon and 6 P.M. At 12.6 mM hyperglycemia, the amplitude of the insulin concentration cycles was greater than that of the ISR cycles (+/- 13.0 vs. +/- 8.7%) due to a decrease in insulin clearance (from 1.55 to 0.5 l/min, P < 0.01). Plasma melatonin levels (a marker of light-dark rhythmicity) changed in the opposite direction, i.e., they peaked when ISR bottomed and bottomed when ISR peaked. We concluded that normal human subjects have a circadian rhythm of insulin secretion, which becomes more apparent with rising ISR, and that circadian changes in ISR, rising during the day and falling during the night, may be one explanation for the well-established observation that glucose tolerance and insulin responses to glucose and meals are higher in the morning than at night.

A revised teacher rating scale for reactive and proactive aggression.

Abstract: A teacher rating scale of reactive aggression, proactive aggression, and covert antisocial behavior was evaluated in a normative sample of third- to fifth-grade predominantly white lower middle class boys (N= 186). Factor analysis revealed independent and internally consistent Reactive Aggression (six reactive items), and Proactive Aggression (five proactive items, five covert items) factors. Although the factors were intercorrelated (r= .67), and each factor was significantly correlated with negative peer social status (r= .26 for each, controlling for grade), the independence of the factors was supported by the unique relation of Reactive Aggression with in-school detentions (r= .31), controlling for Proactive Aggression and grade. These results supported the reliability and validity of Reactive and Proactive Aggression as rated by teachers, which should facilitate further research of these constructs.

The impact of market and organizational characteristics on nursing care facility service innovation: a resource dependency perspective.

Abstract: OBJECTIVE Using resource dependency theory as a conceptual framework, this study investigates both the organizational and environmental factors associated with an emerging health care service delivery innovation, the provision of specialty care in designated units in nursing care facilities We consider two types of specialty units, Alzheimer's Disease and subacute care DATA SOURCES The Medicare/Medicaid Automated Certification Survey (MMACS) data file was merged with local market area data obtained from the 1992 Area Resource File and with state level regulatory data STUDY DESIGN The likelihood of providing Alzheimer's Disease or subacute care in dedicated units was estimated by separate logistic regressions PRINCIPAL FINDINGS Results indicate that facilities with fewer Medicare patients are more likely to operate a dedicated Alzheimer's care unit, while facilities located in markets with a large HMO population and greater hospital supply are more likely to operate a subacute care unit While competition among nursing homes, for the most part, is an incentive to innovate, greater regulatory stringency appears to constrain the development of specialty care units of both types Finally, organizational characteristics (eg, size and proprietary status) appear to be important enabling factors influencing the propensity to provide specialty care in dedicated units CONCLUSIONS Nursing care facilities are moving toward providing specialty care units partly as a response to a growing demand by resource providers and to maintain a competitive edge in tighter markets Loosening regulation directed at cost containment would further encourage the development of specialty care but should be preceded by some evaluation of population needs for specialty care and the effectiveness of specialty care units