Showing papers by "University of Iowa published in 2002"

Theorizing Change: The Role of Professional Associations in the Transformation of Institutionalized Fields

Abstract: This study examines the role of professional associations in a changing, highly institutionalized organizational field and suggests that they play a significant role in legitimating change. A model...

Personality and leadership: a qualitative and quantitative review.

Abstract: This article provides a qualitative review of the trait perspective in leadership research, followed by a meta-analysis. The authors used the five-factor model as an organizing framework and meta-analyzed 222 correlations from 73 samples. Overall, the correlations with leadership were Neuroticism .24, Extraversion .31, Openness to Experience .24, Agreeableness .08, and Conscientiousness .28. Results indicated that the relations of Neuroticism, Extraversion, Openness to Experience, and Conscientiousness with leadership generalized in that more than 90% of the individual correlations were greater than 0. Extraversion was the most consistent correlate of leadership across study settings and leadership criteria (leader emergence and leadership effectiveness). Overall, the five-factor model had a multiple correlation of .48 with leadership, indicating strong support for the leader trait perspective when traits are organized according to the five-factor model.

Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences.

Abstract: The National Institutes of Health Mammalian Gene Collection (MGC) Program is a multiinstitutional effort to identify and sequence a cDNA clone containing a complete ORF for each human and mouse gene. ESTs were generated from libraries enriched for full-length cDNAs and analyzed to identify candidate full-ORF clones, which then were sequenced to high accuracy. The MGC has currently sequenced and verified the full ORF for a nonredundant set of >9,000 human and >6,000 mouse genes. Candidate full-ORF clones for an additional 7,800 human and 3,500 mouse genes also have been identified. All MGC sequences and clones are available without restriction through public databases and clone distribution networks (see http:mgc.nci.nih.gov).

Five-factor model of personality and job satisfaction: a meta-analysis.

Abstract: This study reports results of a meta-analysis linking traits from the 5-factor model of personality to overall job satisfaction. Using the model as an organizing framework, 334 correlations from 163 independent samples were classified according to the model. The estimated true score correlations with job satisfaction were .29 for Neuroticism, .25 for Extraversion, .02 for Openness to Experience, .17 for Agreeableness, and .26 for Conscientiousness. Results further indicated that only the relations of Neuroticism and Extraversion with job satisfaction generalized across studies. As a set, the Big Five traits had a multiple correlation of .41 with job satisfaction, indicating support for the validity of the dispositional source of job satisfaction when traits are organized according to the 5-factor model. Research on the dispositional source of job satisfaction has had a spotty history in job satisfaction research. The personological basis of job satisfaction was considered in the earliest treatments of job satisfaction. Hoppock (1935), for example, noted a strong correlation between workers’ emotional adjustment and their levels of job satisfaction. Similarly, Fisher and Hanna (1931) concluded that a large part of dissatisfaction resulted from emotional maladjustment. With some noteworthy exceptions (P. C. Smith, 1955; Weitz, 1952), these early considerations of the dispositional source of job satisfaction lay dormant until the 1980s, when a series of provocative studies (Arvey, Bouchard, Segal, & Abra

Cardiovascular Disease Outcomes During 6.8 Years of Hormone Therapy: Heart and Estrogen/Progestin Replacement Study Follow-up (HERS II)

Abstract: 1.22); HERS II, 1.00 (95% CI, 0.77-1.29); and overall, 0.99 (0.84-1.17). The overall RHs were similar after adjustment for potential confounders and differential use of statins between treatment groups (RH, 0.97; 95% CI, 0.82-1.14), and in analyses restricted to women who were adherent to randomized treatment assignment (RH, 0.96; 95% CI, 0.77-1.19). Conclusions Lower rates of CHD events among women in the hormone group in the final years of HERS did not persist during additional years of follow-up. After 6.8 years, hormone therapy did not reduce risk of cardiovascular events in women with CHD. Postmenopausal hormone therapy should not be used to reduce risk for CHD events in women with CHD.

Heparin-protein interactions

Abstract: Heparin, a sulfated polysaccharide belonging to the family of glycosaminoglycans, has numerous important biological activities, associated with its interaction with diverse proteins. Heparin is widely used as an anticoagulant drug based on its ability to accelerate the rate at which antithrombin inhibits serine proteases in the blood coagulation cascade. Heparin and the structurally related heparan sulfate are complex linear polymers comprised of a mixture of chains of different length, having variable sequences. Heparan sulfate is ubiquitously distributed on the surfaces of animal cells and in the extracellular matrix. It also mediates various physiologic and pathophysiologic processes. Difficulties in evaluating the role of heparin and heparan sulfate in vivo may be partly ascribed to ignorance of the detailed structure and sequence of these polysaccharides. In addition, the understanding of carbohydrate-protein interactions has lagged behind that of the more thoroughly studied protein-protein and protein-nucleic acid interactions. The recent extensive studies on the structural, kinetic, and thermodynamic aspects of the protein binding of heparin and heparan sulfate have led to an improved understanding of heparin-protein interactions. A high degree of specificity could be identified in many of these interactions. An understanding of these interactions at the molecular level is of fundamental importance in the design of new highly specific therapeutic agents. This review focuses on aspects of heparin structure and conformation, which are important for its interactions with proteins. It also describes the interaction of heparin and heparan sulfate with selected families of heparin-binding proteins.

Ecological effects of climate fluctuations.

Abstract: Climate influences a variety of ecological processes. These effects operate through local weather parameters such as temperature, wind, rain, snow, and ocean currents, as well as interactions among these. In the temperate zone, local variations in weather are often coupled over large geographic areas through the transient behavior of atmospheric planetary-scale waves. These variations drive temporally and spatially averaged exchanges of heat, momentum, and water vapor that ultimately determine growth, recruitment, and migration patterns. Recently, there have been several studies of the impact of large-scale climatic forcing on ecological systems. We review how two of the best-known climate phenomena—the North Atlantic Oscillation and

Extensive mosaic structure revealed by the complete genome sequence of uropathogenic Escherichia coli

Abstract: We present the complete genome sequence of uropathogenic Escherichia coli, strain CFT073. A three-way genome comparison of the CFT073, enterohemorrhagic E. coli EDL933, and laboratory strain MG1655 reveals that, amazingly, only 39.2% of their combined (nonredundant) set of proteins actually are common to all three strains. The pathogen genomes are as different from each other as each pathogen is from the benign strain. The difference in disease potential between O157:H7 and CFT073 is reflected in the absence of genes for type III secretion system or phage- and plasmid-encoded toxins found in some classes of diarrheagenic E. coli. The CFT073 genome is particularly rich in genes that encode potential fimbrial adhesins, autotransporters, iron-sequestration systems, and phase-switch recombinases. Striking differences exist between the large pathogenicity islands of CFT073 and two other well-studied uropathogenic E. coli strains, J96 and 536. Comparisons indicate that extraintestinal pathogenic E. coli arose independently from multiple clonal lineages. The different E. coli pathotypes have maintained a remarkable synteny of common, vertically evolved genes, whereas many islands interrupting this common backbone have been acquired by different horizontal transfer events in each strain.

Invited Review: Heat shock proteins: modifying factors in physiological stress responses and acquired thermotolerance

Abstract: Cells from virtually all organisms respond to a variety of stresses by the rapid synthesis of a highly conserved set of polypeptides termed heat shock proteins (HSPs). The precise functions of HSPs are unknown, but there is considerable evidence that these stress proteins are essential for survival at both normal and elevated temperatures. HSPs also appear to play a critical role in the development of thermotolerance and protection from cellular damage associated with stresses such as ischemia, cytokines, and energy depletion. These observations suggest that HSPs play an important role in both normal cellular homeostasis and the stress response. This mini-review examines recent evidence and hypotheses suggesting that the HSPs may be important modifying factors in cellular responses to a variety of physiologically relevant conditions such as hyperthermia, exercise, oxidative stress, metabolic challenge, and aging.

Errors in Estimating Accruals: Implications for Empirical Research

Abstract: This paper examines the impact of measuring accruals as the change in successive balance sheet accounts, as opposed to measuring accruals directly from the statement of cash flows. Our primary finding is that studies using a balance sheet approach to test for earnings management are potentially contaminated by measurement error in accruals estimates. In particular, if the partitioning variable used to indicate the presence of earnings management is correlated with the occurrence of mergers and acquisitions or discontinued operations, tests are biased and researchers are likely to erroneously conclude that earnings management exists when there is none. Additional results show that the errors in balance sheet accruals estimation can confound returns regressions where discretionary and non-discretionary accruals are used as explanatory variables. Moreover, we demonstrate that tests of market mispricing of accruals will be understated due to erroneous classification of “extreme” accruals firms.

Recognizing emotion from facial expressions: psychological and neurological mechanisms.

Abstract: Recognizing emotion from facial expressions draws on diverse psychological processes implemented in a large array of neural structures. Studies using evoked potentials, lesions, and functional imaging have begun to elucidate some of the mechanisms. Early perceptual processing of faces draws on cortices in occipital and temporal lobes that construct detailed representations from the configuration of facial features. Subsequent recognition requires a set of structures, including amygdala and orbitofrontal cortex, that links perceptual representations of the face to the generation of knowledge about the emotion signaled, a complex set of mechanisms using multiple strategies. Although recent studies have provided a wealth of detail regarding these mechanisms in the adult human brain, investigations are also being extended to nonhuman primates, to infants, and to patients with psychiatric disorders.

A Longitudinal Investigation of Reading Outcomes in Children with Language Impairments.

Abstract: This investigation examined the reading outcomes of children with language impairments (LI). A large subsample of children who participated in an epidemiologic study of language impairments in kind...

siRNA-mediated gene silencing in vitro and in vivo

Abstract: RNA interference is now established as an important biological strategy for gene silencing, but its application to mammalian cells has been limited by nonspecific inhibitory effects of long dsRNA on translation. Here, we describe a viral-mediated delivery mechanism that results in specific silencing of targeted genes through expression of small interfering RNA (siRNA). We establish proof of principle by markedly diminishing expression of exogenous and endogenous genes in vitro and in vivo in brain and liver, and further apply this strategy to a model system of a major class of neurodegenerative disorders, the polyglutamine diseases, to show reduced polyglutamine aggregation in cells. This viral-mediated strategy should prove generally useful in reducing expression of target genes to model biological processes or to provide therapy for dominant human diseases.

A component of innate immunity prevents bacterial biofilm development

Abstract: Antimicrobial factors form one arm of the innate immune system, which protects mucosal surfaces from bacterial infection. These factors can rapidly kill bacteria deposited on mucosal surfaces and prevent acute invasive infections. In many chronic infections, however, bacteria live in biofilms, which are distinct, matrix-encased communities specialized for surface persistence. The transition from a free-living, independent existence to a biofilm lifestyle can be devastating, because biofilms notoriously resist killing by host defence mechanisms and antibiotics. We hypothesized that the innate immune system possesses specific activity to protect against biofilm infections. Here we show that lactoferrin, a ubiquitous and abundant constituent of human external secretions, blocks biofilm development by the opportunistic pathogen Pseudomonas aeruginosa. This occurs at lactoferrin concentrations below those that kill or prevent growth. By chelating iron, lactoferrin stimulates twitching, a specialized form of surface motility, causing the bacteria to wander across the surface instead of forming cell clusters and biofilms. These findings reveal a specific anti-biofilm defence mechanism acting at a critical juncture in biofilm development, the time bacteria stop roaming as individuals and aggregate into durable communities.

Listening in on bacteria: acyl-homoserine lactone signalling.

Abstract: Bacterial cell-to-cell signalling has emerged as a new area in microbiology. Individual bacterial cells communicate with each other and co-ordinate group activities. Although a lot of detail is known about the mechanisms of a few well-characterized bacterial communication systems, other systems have been discovered only recently. Bacterial intercellular communication has become a target for the development of new anti-virulence drugs.

Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus

Abstract: BACKGROUND Multiple laboratory tests are used to diagnose and manage patients with diabetes mellitus. The quality of the scientific evidence supporting the use of these tests varies substantially. APPROACH An expert committee compiled evidence-based recommendations for the use of laboratory testing for patients with diabetes. A new system was developed to grade the overall quality of the evidence and the strength of the recommendations. Draft guidelines were posted on the Internet and presented at the 2007 Arnold O. Beckman Conference. The document was modified in response to oral and written comments, and a revised draft was posted in 2010 and again modified in response to written comments. The National Academy of Clinical Biochemistry and the Evidence-Based Laboratory Medicine Committee of the American Association for Clinical Chemistry jointly reviewed the guidelines, which were accepted after revisions by the Professional Practice Committee and subsequently approved by the Executive Committee of the American Diabetes Association. CONTENT In addition to long-standing criteria based on measurement of plasma glucose, diabetes can be diagnosed by demonstrating increased blood hemoglobin A 1c (HbA 1c ) concentrations. Monitoring of glycemic control is performed by self-monitoring of plasma or blood glucose with meters and by laboratory analysis of HbA 1c . The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of autoantibodies, urine albumin, insulin, proinsulin, C-peptide, and other analytes are addressed. SUMMARY The guidelines provide specific recommendations that are based on published data or derived from expert consensus. Several analytes have minimal clinical value at present, and their measurement is not recommended.

Mutations in IRF6 cause Van der Woude and popliteal pterygium syndromes.

Abstract: Interferon regulatory factor 6 (IRF6) belongs to a family of nine transcription factors that share a highly conserved helix–turn–helix DNA-binding domain and a less conserved protein-binding domain. Most IRFs regulate the expression of interferon-α and -β after viral infection1, but the function of IRF6 is unknown. The gene encoding IRF6 is located in the critical region for the Van der Woude syndrome (VWS; OMIM 119300) locus at chromosome 1q32–q41 (refs 2,3). The disorder is an autosomal dominant form of cleft lip and palate with lip pits4, and is the most common syndromic form of cleft lip or palate. Popliteal pterygium syndrome (PPS; OMIM 119500) is a disorder with a similar orofacial phenotype that also includes skin and genital anomalies5. Phenotypic overlap6 and linkage data7 suggest that these two disorders are allelic. We found a nonsense mutation in IRF6 in the affected twin of a pair of monozygotic twins who were discordant for VWS. Subsequently, we identified mutations in IRF6 in 45 additional unrelated families affected with VWS and distinct mutations in 13 families affected with PPS. Expression analyses showed high levels of Irf6 mRNA along the medial edge of the fusing palate, tooth buds, hair follicles, genitalia and skin. Our observations demonstrate that haploinsufficiency of IRF6 disrupts orofacial development and are consistent with dominant-negative mutations disturbing development of the skin and genitalia.

The BABAR detector

Abstract: BABAR, the detector for the SLAC PEP-II asymmetric e+e- B Factory operating at the upsilon 4S resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagentic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems, VME- and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.

Social Comparison: Why, With Whom, and With What Effect?

Abstract: Social comparison consists of comparing oneself with others in order to evaluate or to enhance some aspects of the self. Evaluation of ability is concerned with the question “Can I do X?” and relies on the existence of a proxy performer. A proxy's relative standing on attributes vis‐a‐vis the comparer and whether the proxy exerted maximum effort on a preliminary task are variables influencing his or her informational utility. Evaluation of opinions is concerned with the questions “Do I like X?”“Is X correct?” and “Will I like X?” Important variables that affect an individual's use of social comparison to evaluate his or her opinions are the other person's expertise, similarity with the individual, and previous agreement with the individual. Whether social comparison serves a self-enhancement function depends on whether the comparer assimilates or contrasts his or her self relative to superior or inferior others. The kinds of self‐knowledge made cognitively accessible and variables such as mutability of se...

Post-translational disruption of dystroglycan-ligand interactions in congenital muscular dystrophies

Abstract: In the CST, there was a first fixation period of 1 s, followed by a brief presentation (100 ms) of a cue at 208 to the left or to the right The monkey had to maintain his gaze at the fixation spot during a delay period of 1 s The fixation spot then disappeared and the target appeared at the same position as the cue In half of the trials, another spot appeared at the alternative position (distracter) The monkey had to make a saccade to the target position within 500 ms, and was rewarded with a drop of water for a correct saccade After recording neurons in the CST (experiment 2), we re-applied the BST (experiment 1) for at least 80 trials to confirm the reproducibility of neuronal activity Data analysis Pre-target neurons were defined as neurons that showed a statistically reliable increase in the spike count 215 s to 0 s before target onset (‘pre-target window’) as compared with the spike count 2 3s to215 s before target onset All pair-wise comparisons were evaluated by two-tailed t-tests, P , 001 We used the Bonferroni procedure to correct for family-wise error with multiple t-tests To quantify the separation of population distributions from contralateral versus ipsilateral conditions, we calculated the area under the ROC in a sliding window of 200 ms To test the adaptation of saccade latency and pre-target activity to a reversal of position-reward contingency, we compared the second trial after a reversal against the third trial after a reversal (test 1) We also compared the second trial after a reversal against the pooled data from the sixth to twentieth trial (test 2) Both tests consisted of paired twotailed t-tests on the mean data from individual neurons Adaptation was judged complete if there was no significant difference between the measures Tests 1 and 2 produced similar results in all cases For comparison between the two tasks (BST versus CST), we considered the neuronal activity from 2500 to 0 ms before target onset in both tasks, in the computation of absolute firing rates as well as ROC areas