Showing papers by "University of Kansas published in 2003"

Identification of the haematopoietic stem cell niche and control of the niche size

Abstract: Haematopoietic stem cells (HSCs) are a subset of bone marrow cells that are capable of self-renewal and of forming all types of blood cells (multi-potential). However, the HSC 'niche'--the in vivo regulatory microenvironment where HSCs reside--and the mechanisms involved in controlling the number of adult HSCs remain largely unknown. The bone morphogenetic protein (BMP) signal has an essential role in inducing haematopoietic tissue during embryogenesis. We investigated the roles of the BMP signalling pathway in regulating adult HSC development in vivo by analysing mutant mice with conditional inactivation of BMP receptor type IA (BMPRIA). Here we show that an increase in the number of spindle-shaped N-cadherin+CD45- osteoblastic (SNO) cells correlates with an increase in the number of HSCs. The long-term HSCs are found attached to SNO cells. Two adherens junction molecules, N-cadherin and beta-catenin, are asymmetrically localized between the SNO cells and the long-term HSCs. We conclude that SNO cells lining the bone surface function as a key component of the niche to support HSCs, and that BMP signalling through BMPRIA controls the number of HSCs by regulating niche size.

Eutrophication of freshwater and coastal marine ecosystems a global problem

Abstract: Humans now strongly influence almost every major aquatic ecosystem, and their activities have dramatically altered the fluxes of growth-limiting nutrients from the landscape to receiving waters. Unfortunately, these nutrient inputs have had profound negative effects upon the quality of surface waters worldwide. This review examines how eutrophication influences the biomass and species composition of algae in both freshwater and costal marine systems. An overview of recent advances in algae-related eutrophication research is presented. In freshwater systems, a summary is presented for lakes and reservoirs; streams and rivers; and wetlands. A brief summary is also presented for estuarine and coastal marine ecosystems. Eutrophication causes predictable increases in the biomass of algae in lakes and reservoirs; streams and rivers; wetlands; and coastal marine ecosystems. As in lakes, the response of suspended algae in large rivers to changes in nutrient loading may be hysteretic in some cases. The inhibitory effects of high concentrations of inorganic suspended solids on algal growth, which can be very evident in many reservoirs receiving high inputs of suspended soils, also potentially may occur in turbid rivers. Consistent and predictable eutrophication-caused increases in cyanobacterial dominance of phytoplankton have been reported worldwide for natural lakes, and similar trends are reported here both for phytoplankton in turbid reservoirs, and for suspended algae in a large river. A remarkable unity is evident in the global response of algal biomass to nitrogen and phosphorus availability in lakes and reservoirs; wetlands; streams and rivers; and coastal marine waters. The species composition of algal communities inhabiting the water column appears to respond similarly to nutrient loading, whether in lakes, reservoirs, or rivers. As is true of freshwater ecosystems, the recent literature suggests that coastal marine ecosystems will respond positively to nutrient loading control efforts. Our understanding of freshwater eutrophication and its effects on algal-related water quality is strong and is advancing rapidly. However, our understanding of the effects of eutrophication on estuarine and coastal marine ecosystems is much more limited, and this gap represents an important future research need. Although coastal systems can be hydrologically complex, the biomass of marine phytoplankton nonetheless appears to respond sensitively and predictably to changes in the external supplies of nitrogen and phosphorus. These responses suggest that efforts to manage nutrient inputs to the seas will result in significant improvements in coastal zone water quality. Additional new efforts should be made to develop models that quantitatively link ecosystem-level responses to nutrient loading in both freshwater and marine systems.

The genome sequence of the filamentous fungus Neurospora crassa

Abstract: Neurospora crassa is a central organism in the history of twentieth-century genetics, biochemistry and molecular biology. Here, we report a high-quality draft sequence of the N. crassa genome. The approximately 40-megabase genome encodes about 10,000 protein-coding genes—more than twice as many as in the fission yeast Schizosaccharomyces pombe and only about 25% fewer than in the fruitfly Drosophila melanogaster. Analysis of the gene set yields insights into unexpected aspects of Neurospora biology including the identification of genes potentially associated with red light photobiology, genes implicated in secondary metabolism, and important differences in Ca21 signalling as compared with plants and animals. Neurospora possesses the widest array of genome defence mechanisms known for any eukaryotic organism, including a process unique to fungi called repeat-induced point mutation (RIP). Genome analysis suggests that RIP has had a profound impact on genome evolution, greatly slowing the creation of new genes through genomic duplication and resulting in a genome with an unusually low proportion of closely related genes.

Altruism and Prosocial Behavior

Abstract: Prosocial behavior covers the broad range of actions intended to benefit one or more people other than oneself—actions such as helping, comforting, sharing, and cooperation. Altruism is motivation to increase another person's welfare; it is contrasted to egoism, the motivation to increase one's own welfare. There is no one-to-one correspondence between prosocial behavior and altruism. Prosocial behavior need not be motivated by altruism; altruistic motivation need not produce prosocial behavior. Over the past 30 years, the practical concern to promote prosocial behavior has led to both a variance-accounted-for empirical approach, which focuses on identifying situational and dispositional determinants of helping, and the application of existing psychological theories. Theories invoked to explain prosocial behavior include social learning, tension reduction, norm, exchange or equity, attribution, esteem-enhancement, and moral reasoning theories. In addition, new theoretical perspectives have been developed by researchers focused on anomalous aspects of why people do—and don't—act prosocially. Their research has raised the possibility of a multiplicity of social motives—altruism, collectivism, and principlism, as well as egoism. It has also raised questions—as yet unanswered—about how these motives might be most effectively orchestrated to increase prosocial behavior. Keywords: altruism; egoism; helping; prosocial behavior; prosocial motivation

Physical Performance Measures in the Clinical Setting

Abstract: OBJECTIVES: To assess the ability of gait speed alone and a three-item lower extremity performance battery to predict 12-month rates of hospitalization, decline in health, and decline in function in primary care settings serving older adults. DESIGN: Prospective cohort study. SETTING: Primary care programs of a Medicare health maintenance organization (HMO) and Veterans Affairs (VA) system. PARTICIPANTS: Four hundred eighty-seven persons aged 65 and older. MEASUREMENTS: Lower extremity performance Established Population for Epidemiologic Studies of the Elderly (EPESE) battery including gait speed, chair stands, and tandem balance tests; demographics; health care use; health status; functional status; probability of repeated admission scale (Pra); and primary physician's hospitalization risk estimate. RESULTS: Veterans had poorer health and higher use than HMO members. Gait speed alone and the EPESE battery predicted hospitalization; 41% (21/51) of slow walkers (gait speed 1.0 m/s) (P < .0001). The relationship was stronger in the HMO than in the VA. Both performance measures remained independent predictors after accounting for Pra. The EPESE battery was superior to gait speed when both Pra and primary physician's risk estimate were included. Both performance measures predicted decline in function and health status in both health systems. Performance measures, alone or in combination with self-report measures, were more able to predict outcomes than self-report alone. CONCLUSION: Gait speed and a physical performance battery are brief, quantitative estimates of future risk for hospitalization and decline in health and function in clinical populations of older adults. Physical performance measures might serve as easily accessible “vital signs” to screen older adults in clinical settings.

Functional analysis of problem behavior: a review

Abstract: Functional analysis methodology focuses on the identification of variables that influence the occurrence of problem behavior and has become a hallmark of contemporary approaches to behavioral assessment. In light of the widespread use of pretreatment functional analyses in articles published in this and other journals, we reviewed the literature in an attempt to identify best practices and directions for future research. Studies included in the present review were those in which (a) a pretreatment assessment based on (b) direct observation and measurement of (c) problem behavior was conducted under (d) at least two conditions involving manipulation of an environmental variable in an attempt (e) to demonstrate a relation between the environmental event and behavior. Studies that met the criteria for inclusion were quantified and critically evaluated along a number of dimensions related to subject and setting characteristics, parametric and qualitative characteristics of the methodology, types of assessment conditions, experimental designs, topographies of problem behaviors, and the manner in which data were displayed and analyzed.

Predicting the geography of species' invasions via ecological niche modeling

Abstract: Species’ invasions have long been regarded as enormously complex processes, so complex as to defy predictivity Phases of this process, however, are emerging as highly predictable: the potential geographic course of an invasion can be anticipated with high precision based on the ecological niche characteristics of a species in its native geographic distributional area This predictivity depends on the premise that ecological niches constitute long‐term stable constraints on the potential geographic distributions of species, for which a sizeable body of evidence is accumulating Hence, although the entire invasion process is indeed complex, the geographic course that invasions are able to take can be anticipated with considerable confidence

A justification-suppression model of the expression and experience of prejudice.

Abstract: The authors propose a justification-suppression model (JSM), which characterizes the processes that lead to prejudice expression and the experience of one's own prejudice. They suggest that "genuine" prejudices are not directly expressed but are restrained by beliefs, values, and norms that suppress them. Prejudices are expressed when justifications (e.g., attributions, ideologies, stereotypes) release suppressed prejudices. The same process accounts for which prejudices are accepted into the self-concept The JSM is used to organize the prejudice literature, and many empirical findings are recharacterized as factors affecting suppression or justification, rather than directly affecting genuine prejudice. The authors discuss the implications of the JSM for several topics, including prejudice measurement, ambivalence, and the distinction between prejudice and its expression.

Consensus guidelines for managing postoperative nausea and vomiting.

Abstract: IMPLICATIONS We present evidence-based guidelines developed by an international panel of experts for the management of postoperative nausea and vomiting.

The yellow brick road and the emerald city: benefit finding, positive reappraisal coping and posttraumatic growth in women with early-stage breast cancer.

Abstract: Predictors and outcomes of benefit finding, positive reappraisal coping, and posttraumatic growth were examined using interviews and questionnaires from a longitudinal study of women with early-stage breast cancer followed from primary medical treatment completion to 3 (n=92) and 12 months (n=60) later. Most women (83%) reported at least 1 benefit of their breast cancer experience. Benefit finding (i.e., identification of benefits, number of benefits), positive reappraisal coping, and posttraumatic growth had distinct significant predictors. Positive reappraisal coping at study entry predicted positive mood and perceived health at 3 and 12 months and posttraumatic growth at 12 months, whereas benefit finding did not predict any outcome. Findings suggest that benefit finding, positive reappraisal coping, and posttraumatic growth are related, but distinct, constructs.

Disentangling the "whys" from the "whats" of aggressive behaviour

Abstract: We examined the validity of a measurement system for the study of aggression that distinguishes among four principle dimensions of aggressive behaviour: overt and relational aggression (i.e., the "whats") and instrumental and reactive aggression (i.e., the "whys"). The sample comprised 1723 adolescents (Grades 5 through 10) from Berlin, Germany. The internal validity of the measurement system was strongly supported, revealing four discrete dimensions of aggression: two overriding forms (overt and relational) and two underlying functions (instrumental and reactive). The differential and unique patterns of criterion-related validity strongly supported the distinctions among the constructs. The importance of disentangling these dimensions in understanding the development of aggressive behaviour is discussed.

Resources for physical activity participation: Does availability and accessibility differ by neighborhood socioeconomic status?

Abstract: The purpose of this study was to determine whether the availability and accessibility of physical activity resources differed by neighborhood socioeconomic status (SES) in a small U.S. city (population = 133,046). U.S. census tracts (N = 32) were used to represent neighborhoods and categorized into high, medium, or low SES on the basis of the percentage of unemployed individuals, per capita income, and percentage of the population below the poverty threshold. We developed a geographic information system to generate a comprehensive list of physical activity resources available within each census tract in the city. We identified 112 parks, 33 sport facilities, 15 fitness clubs, 11 community centers, and 5 walking/biking trails. The total number of physical activity resources varied by neighborhood SES (p > .05); low-SES (M = 4.5±2.3) and medium-SES (M = 4.9±2.6) neighborhoods had significantly fewer resources than high-SES (M = 8.4±3.5) neighborhoods. Low-, medium-, and high-SES neighborhoods did not differ on the number of pay-for-use facilities; however, low-SES (M = 3.1±1.5) and medium-SES (M = 3.8±1.6) neighborhoods had significantly fewer free-for-use resources than high- (M = 6.1±2.4) SES neighborhoods (p > .01). Data suggest that individuals from lower SES neighborhoods may have limited ability to control their physical activity in the face of inaccessible environments. Community research and promotion efforts should include assessment and targeting of available and accessible physical activity resources.

Temporal responses of NDVI to precipitation and temperature in the central Great Plains, USA

Abstract: Normalized Difference Vegetation Index (NDVI) is generally recognized as a good indicator of terrestrial vegetation productivity. Understanding climatic influences, in particular precipitation and temperature, on NDVI enables prediction of productivity changes under different climatic scenarios. We examined temporal responses of remotely sensed NDVI to precipitation and temperature during a nine-year period (1989-97) in Kansas. Biweekly (every two weeks) and monthly precipitation data were derived from 410 weather stations and biweekly temperature data were derived from 17 weather stations inside and around the borders of Kansas. Biweekly and monthly climate maps were derived by interpolation. Biweekly growing season (March-October) NDVI values for Kansas were calculated using National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) NDVI images. Average growing season NDVI values were highly correlated with precipitation received during the current growing se...

Prosocial and Coercive Configurations of Resource Control in Early Adolescence: A Case for the Well-Adapted Machiavellian

Abstract: This is the publisher's version, which is also available electronically from http://www.jstor.org/stable/23096057.

Comorbidity of migraine and depression: Investigating potential etiology and prognosis

Abstract: Background: An association between migraine and major depression has been observed in clinical and community samples. The factors that contribute to this association and their implications remain unclear. Objective: To determine the factors contributing to the association of migraine and major depression. Methods: A cohort study of persons aged 25 to 55 years with migraine (n = 496) or with other headaches of comparable severity (n = 151) and control subjects with no history of severe headaches (n = 539) randomly selected from the general community were interviewed first in 1997 and then reinterviewed in 1999. Results: Major depression at baseline predicted the first-onset migraine during the 2-year follow-up period (odds ratio [OR] = 3.4; 95% CI = 1.4, 8.7) but not other severe headaches (OR = 0.6; 95% CI = 0.1, 4.6). Migraine at baseline predicted the first-onset major depression during follow-up (OR = 5.8; 95% CI = 2.7, 12.3); the prospective association from severe headaches to major depression was not significant (OR = 2.7; 95% CI = 0.9, 8.1). Comorbid major depression did not influence the frequency of migraine attacks, their persistence, or the progression of migraine-related disability over time. Conclusions: Major depression increased the risk for migraine, and migraine increased the risk for major depression. This bidirectional association, with each disorder increasing the risk for first onset of the other, was not observed in relation to other severe headaches. With respect to other severe headaches, there was no increased risk associated with pre-existing major depression, although the possibility of an influence in the reverse direction (i.e., from severe headaches to depression) cannot be securely ruled out.

Randomized Clinical Trial of Therapeutic Exercise in Subacute Stroke

Abstract: Background and Purpose— Rehabilitation care after stroke is highly variable and increasingly shorter in duration. The effect of therapeutic exercise on impairments and functional limitations after stroke is not clear. The objective of this study was to determine whether a structured, progressive, physiologically based exercise program for subacute stroke produces gains greater than those attributable to spontaneous recovery and usual care. Methods— This randomized, controlled, single-blind clinical trial was conducted in a metropolitan area and 17 participating healthcare institutions. We included persons with stroke who were living in the community. One hundred patients (mean age, 70 years; mean Orpington score, 3.4) consented and were randomized from a screened sample of 582. Ninety-two subjects completed the trial. Intervention was a structured, progressive, physiologically based, therapist-supervised, in-home program of thirty-six 90-minute sessions over 12 weeks targeting flexibility, strength, balan...

Adult Outcomes for Students with Cognitive Disabilities Three-Years After High School: The Impact of Self-Determination

Abstract: This article reports afollow-up study of school leavers with mental retardation or learning disabilities who were surveyed 1- and 3-years after they left school to determine what they were doing in major life areas (employment, independent living or community integration). Students were divided into two groups based on self-determination scores collected during theirfinal year at high school. Comparisons between these groups on outcomes at I and 3 years post-graduation indicate that students who were more self-determined fared better across multiple life categories, including employment and access to health and other benefits, financial independence, and independent living. Over the last decade there has been consider- able focus in special education literature on the importance of self-determination in the education of students with disabilities. Due largely to the federal emphasis on and fund- ing for promoting self-determination as a component of transition services for youth with disabilities, numerous resources are now available to support instruction to achieve this outcome. Such resources range from curricu- lar materials and guides to instructional strat- egies and methods (Field & Hoffman, 1996a; Field, Martin, Miller, Ward, & Wehmeyer,

Assessing overweight, obesity, diet, and physical activity in college students

Abstract: The authors surveyed 738 college students aged 18 to 27 years to assess overweight, obesity, dietary habits, and physical activity. They used BMI (body mass index) > or = 25 kg/m2 or BMI > or = 85th percentile and BMI > or = 30 kg/m2 or BMI > or = 95th percentile to estimate overweight and obesity in those aged or = 20 years, they used BMI > or = 25 kg/m2 and > or = 30 kg/m2. They found overweight rates of 21.6% using BMI directly and 16.2% using BMI percentile and obesity rates of 4.9% using BMI directly and 4.2% using BMI percentile. More than 69% of the participants reported < 5 servings of fruits and vegetables per day and more than 67% reported < 20 g of fiber per day; participants reported physical activity on fewer than 3 d/wk. Most college students are not meeting dietary and physical activity guidelines, suggesting the need for prevention interventions and increased understanding of overweight in college students.

Predicting distributions of known and unknown reptile species in Madagascar

Abstract: Despite the importance of tropical biodiversity, informative species distributional data are seldom available for biogeographical study or setting conservation priorities. Modelling ecological niche distributions of species offers a potential solution; however, the utility of old locality data from museums, and of more recent remotely sensed satellite data, remains poorly explored, especially for rapidly changing tropical landscapes. Using 29 modern data sets of environmental land coverage and 621 chameleon occurrence localities from Madagascar (historical and recent), here we demonstrate a significant ability of our niche models in predicting species distribution. At 11 recently inventoried sites, highest predictive success (85.1%) was obtained for models based only on modern occurrence data (74.7% and 82.8% predictive success, respectively, for pre-1978 and all data combined). Notably, these models also identified three intersecting areas of over-prediction that recently yielded seven chameleon species new to science. We conclude that ecological niche modelling using recent locality records and readily available environmental coverage data provides informative biogeographical data for poorly known tropical landscapes, and offers innovative potential for the discovery of unknown distributional areas and unknown species.

The Infant–Toddler Social and Emotional Assessment (ITSEA): Factor Structure, Reliability, and Validity

Abstract: In this paper the refinement and psychometric properties of the Infant-Toddler Social and Emotional Assessment (ITSEA) are described. Results from a sociodemographically diverse birth cohort sample of 1,235 parents of children between the ages of 12 and 36 months are presented. Confirmatory factor analyses supported the hypothesized Internalizing, Externalizing, Regulatory, and Competence domains as well as the 17 individual scales that comprise the ITSEA. Findings for 3 additional indices useful in identifying significant psychopathology are presented. Subgroup analyses revealed structural invariance and expected mean level differences across both child sex and 6-month age bands. Child sex differences emerged for some problem and most competence scales, with boys rated as higher on Activity/Impulsivity and girls rated higher on Anxiety and most Competence scales. All competence scores increased across age groups. Problem behaviors showed a more mixed developmental pattern. Test-retest and interrater reliability were acceptable. Associations between the ITSEA and independent evaluator ratings and parental ratings of child behavior problems, temperament, and parental distress support the validity of the instrument.

Matrix vesicles and calcification

Abstract: Matrix vesicles (MVs) are extracellular, 100 nM in diameter, membrane-invested particles selectively located at sites of initial calcification in cartilage, bone, and predentin. The first crystals of apatitic bone mineral are formed within MVs close to the inner surfaces of their investing membranes. Matrix vesicle biogenesis occurs by polarized budding and pinching-off of vesicles from specific regions of the outer plasma membranes of differentiating growth plate chondrocytes, osteoblasts, and odontoblasts. Polarized release of MVs into selected areas of developing matrix determines the nonrandom distribution of calcification. Initiation of the first mineral crystals, within MVs (phase 1), is augmented by the activity of MV phosphatases (eg, alkaline phosphatase, adenosine triphosphatase and pyrophosphatase) plus calcium-binding molecules (eg, annexin I and phosphatidyl serine), all of which are concentrated in or near the MV membrane. Phase 2 of biologic mineralization begins with crystal release through the MV membrane, exposing preformed hydroxyapatite crystals to the extracellular fluid. The extracellular fluid normally contains sufficient Ca2+ and PO4 3- to support continuous crystal proliferation, with preformed crystals serving as nuclei (templates) for the formation of new crystals by a process of homologous nucleation. In diseases such as osteoarthritis, crystal deposition arthritis, and atherosclerosis, MVs initiate pathologic calcification, which, in turn, augments disease progression.

Mitochondrial Polymorphisms Significantly Reduce the Risk of Parkinson Disease

Abstract: Mitochondrial (mt) impairment, particularly within complex I of the electron transport system, has been implicated in the pathogenesis of Parkinson disease (PD). More than half of mitochondrially encoded polypeptides form part of the reduced nicotinamide adenine dinucleotide dehydrogenase (NADH) complex I enzyme. To test the hypothesis that mtDNA variation contributes to PD expression, we genotyped 10 single-nucleotide polymorphisms (SNPs) that define the European mtDNA haplogroups in 609 white patients with PD and 340 unaffected white control subjects. Overall, individuals classified as haplogroup J (odds ratio [OR] 0.55; 95% confidence interval [CI] 0.34–0.91; P=.02) or K (OR 0.52; 95% CI 0.30–0.90; P=.02) demonstrated a significant decrease in risk of PD versus individuals carrying the most common haplogroup, H. Furthermore, a specific SNP that defines these two haplogroups, 10398G, is strongly associated with this protective effect (OR 0.53; 95% CI 0.39–0.73; P=.0001). SNP 10398G causes a nonconservative amino acid change from threonine to alanine within the NADH dehydrogenase 3 (ND3) of complex I. After stratification by sex, this decrease in risk appeared stronger in women than in men (OR 0.43; 95% CI 0.27–0.71; P=.0009). In addition, SNP 9055A of ATP6 demonstrated a protective effect for women (OR 0.45; 95% CI 0.22–0.93; P=.03). Our results suggest that ND3 is an important factor in PD susceptibility among white individuals and could help explain the role of complex I in PD expression.

The reliability and concurrent validity of the scoliosis research society-22 patient questionnaire for idiopathic scoliosis.

Abstract: STUDY DESIGN Outcome study to determine response distribution, internal consistency, reproducibility, and concurrent validity of the Scoliosis Research Society-22 (SRS-22) health-related quality-of-life (HRQL) questionnaire. OBJECTIVES Further refinement of an HRQL questionnaire specific for idiopathic scoliosis. SUMMARY OF BACKGROUND DATA Previous experience with the original and modified SRS HRQL questionnaires suggested a need for further refinement and more complete validation. METHODS The SRS-22 and Short Form 36 (SF-36) HRQL questionnaires were mailed to 83 previously surveyed postoperative idiopathic scoliosis patients. RESULTS Fifty-eight (70%) patients returned the first set of questionnaires. Their average age at surgery was 14.6 years, and their average follow-up interval since surgery was 10.8 years. Fifty-one (88%) of the 58 returned the second set of questionnaires an average of 28 days later. The psychometric attributes of the instruments were comparable: score distribution, SRS-22 56.9% ceiling and 1.7% floor, SF-36 79.3% ceiling and 1.7% floor; internal consistency (Cronbach alpha), SRS-22 0.92 to 0.75, SF-36 0.91 to 0.36; and reproducibility (intraclass correlation coefficient), SRS-22 0.96 to 0.85, SF-36 0.92 to 0.61. Concurrent validity, determined by Pearson Correlation Coefficients between SRS-22 and SF-36 domains, was 0.70 or greater ( < 0.0001) for 17 relevant comparisons. CONCLUSION The SRS-22 HRQL questionnaire is reliable with internal consistency and reproducibility comparable to SF-36. In addition, it demonstrated concurrent validity when compared to SF-36. It is shorter and more focused on the health issues related to idiopathic scoliosis than SF-36.