Showing papers by "California State University, Long Beach published in 2000"

The empowering leadership questionnaire: the construction and validation of a new scale for measuring leader behaviors

Abstract: This paper describes the construction and empirical evaluation of a new scale for measuring empowering leader behavior. Study One consisted of thorough interviews with external leaders and team members in three organizations. Behaviors elicited in the interviews were classified by researchers into eight categories of leader empowering behavior and the Empowering Leadership Questionnaire (ELQ) was constructed to measure each of these categories. In Study Two, the ELQ was administered to team members and leaders from two organizations. The results indicated that five-factors (Coaching, Informing, Leading By Example, Showing Concern/Interacting with the Team, and Participative Decision-Making) adequately describe the data. In Study Three, we cross-validated the scale in a sample from five organizations and the factor analysis confirmed the five-factor model. The ELQ dimensions were also compared with behaviors measured by two well-established measures of leader behavior. The results indicated that the ELQ dimensions partially overlap with previously identified constructs, but that empowering leadership behavior can not be entirely accounted for by the earlier measures. Definitions and implications for the categories of empowering leader behaviors are offered. Copyright © 2000 John Wiley & Sons, Ltd.

Carbon isotopic evidence for methane hydrate instability during quaternary interstadials

Abstract: Large (about 5 per mil) millennial-scale benthic foraminiferal carbon isotopic oscillations in the Santa Barbara Basin during the last 60,000 years reflect widespread shoaling of sedimentary methane gradients and increased outgassing from gas hydrate dissociation during interstadials. Furthermore, several large, brief, negative excursions (up to -6 per mil) coinciding with smaller shifts (up to -3 per mil) in depth-stratified planktonic foraminiferal species indicate massive releases of methane from basin sediments. Gas hydrate stability was modulated by intermediate-water temperature changes induced by switches in thermohaline circulation. These oscillations were likely widespread along the California margin and elsewhere, affecting gas hydrate instability and contributing to millennial-scale atmospheric methane oscillations.

Correlates of household seismic hazard adjustment adoption.

Abstract: This study examined the relationships of self-reported adoption of 12 seismic hazard adjustments (pre-impact actions to reduce danger to persons and property) with respondents' demographic characteristics, perceived risk, perceived hazard knowledge, perceived protection responsibility, and perceived attributes of the hazard adjustments. Consistent with theoretical predictions, perceived attributes of the hazard adjustments differentiated among the adjustments and had stronger correlations with adoption than any of the other predictors. These results identify the adjustments and attributes that emergency managers should address to have the greatest impact on improving household adjustment to earthquake hazard.

Cognitive impairment in individuals currently using methamphetamine.

Abstract: Although there are increasing reports of methamphetamine use, studies examining the cognitive consequences of methamphetamine have not been performed on a population currently using the drug. To characterize this population, 65 people currently using MA regularly and 65 non-users were given a battery of cognitive tests. The battery included recall, recognition, Digit Symbol, Trail Making A & B, Stroop, Wisconsin Card Sort, backward digit span, and the FAS test of verbal fluency. The methamphetamine users were significantly more impaired on recall tasks, digit symbol, Stroop color words, and Trail Making B, but scores fell within the normal ranges on the other measures.

Social Support Networks of Lesbian, Gay, and Bisexual Adults 60 Years of Age and Older

Abstract: The social support networks of 416 lesbian, gay, and bisexual adults aged 60 to 91 years were examined. Participants averaged 6 people in their support networks, most of whom were close friends. The gender composition of support networks was greatly influenced by the gender of the respondent. Most support network members knew about respondents' sexual orientation. The most common type of support provided by close friends and social acquaintances was socializing support, and the most common support provided by partners, siblings, and other relatives was emotional support. The sexual orientation, gender, and age of network members did not influence respondents' satisfaction with the support received. Participants were more satisfied with support from those who knew of their sexual orientation. The more satisfied respondents felt with the support they received, the less lonely they felt. Those living with domestic partners were less lonely and rated their physical and mental health more positively than those who lived alone.

Information Technology for Management: Making Connections for Strategic Advantage

Abstract: From the Publisher: Information Technology for Management, Second Edition Update, shows readers how to harness the power of today's information technologies for strategic advantage" "With a strong focus on managerial issues, the authors explain why IT plays an essential role in any organization's success and how different functional areas can use IT to facilitate problem solving, increase productivity and quality, improve customer service, and enable business process reengineering Throughout the book, fascinating "war stories" and real-world examples make concepts come alive And a Web-based Virtual Company project offers a unique opportunity to put theory into practice

Marketing on the internet - who can benefit from an online marketing approach

Abstract: The research builds upon the literature in electronic commerce and past research in marketing with the objective of understanding factors that impact a product's adaptability to online marketing. A review of marketing channel choice literature reveals a set of factors and channel choice functions that are considered important in making channel decisions. Using this as a basis, four major channel functions, namely, product customization, availability, logistics, and transaction complexity are considered relevant in understanding the implications for Internet marketing. By building upon previous research in the area of channel selection, we provide a means of classifying Internet marketing initiatives based on product characteristics. The classification scheme based on product characteristics can help analyze the significance of each factor on the success of a firm's online marketing approach. Further, the classification scheme is used to discuss decision support implications.

Plasma membrane estrogen receptors signal to antiapoptosis in breast cancer.

Abstract: Chemotherapy or irradiation treatment induces breast cancer cell apoptosis, but this can be limited by estradiol (E2) through unknown mechanisms. To investigate this, we subjected estrogen receptor-expressing human breast cancer cells (MCF-7 and ZR-75–1) to paclitaxel (taxol) or to UV irradiation. Marked increases in cell apoptosis were induced, but these were significantly reversed by incubation with E2. Taxol or UV stimulated c-Jun N-terminal kinase (JNK) activity, which was inhibited by E2. Expression of a dominant-negative Jnk-1 protein strongly prevented taxol- or UV-induced apoptosis, whereas E2 inhibition of apoptosis was reversed by expression of constituitively active Jnk-1. As targets for participation in apoptosis, Bcl-2 and Bcl-xl were phosphorylated in response to JNK activation by taxol or UV; this was prevented by E2. Taxol or UV activated caspase activity in a JNK-dependent fashion and caused the cleavage of procaspase-9 to caspase-9, each inhibited by E2. Independently, the steroid also a...

Failure of a motilin receptor agonist (ABT‐229) to relieve the symptoms of functional dyspepsia in patients with and without delayed gastric emptying: a randomized double‐blind placebo‐controlled trial

Abstract: Introduction: Motilin-receptor agonists are prokinetics; whether they relieve the symptoms of functional dyspepsia is unknown. We aimed to test the efficacy of the motilin agonist ABT-229 in functional dyspepsia patients with and without delayed gastric emptying. Methods: Patients were randomized with postprandial symptoms and documented functional dyspepsia by endoscopy (n=589 in intention-to-treat analysis). Patients were assigned to either the delayed or normal gastric emptying strata, based on a validated 13C octanoic acid breath test. Patients were then further randomized within each strata, to receive one of four doses of ABT-229 (1.25, 2.5, 5 or 10 mg b.d. before breakfast and dinner) or placebo for 4 weeks, following a 2-week baseline. The primary outcome was the assessment of change in symptom severity over the 2 weeks from baseline to final visit, based on a self-report questionnaire measuring severity on visual analogue scales. Results: Baseline characteristics across the treatment arms were very similar. No significant differences in the upper abdominal discomfort severity score (maximum 800 mm) were observed for any active treatment arm vs. placebo (mean change from baseline −139, −141, −145, −160 and −134 mm for placebo, 1.25, 2.5, 5, and 10 mg, respectively, at 4 weeks by intention-to-treat). More patients on placebo reported a good or excellent global response than patients on 1.25 or 5 mg of active therapy (both P < 0.05). The results were very similar in those with and without delayed gastric emptying. Helicobacter pylori status did not predict response. Excluding patients with any baseline heartburn (total remaining n=240), ABT-229 10 mg was inferior to placebo in relief of upper abdominal discomfort. Conclusions: ABT-229 was of no value for relief of symptoms in functional dyspepsia, compared with placebo.

Longitudinal Analysis of the Antecedents of Emergent Spanish Literacy and Middle-School English Reading Achievement of Spanish-Speaking Students

Abstract: Among students entering kindergarten speaking Spanish, those with greater emergent Spanish literacy development and oral English proficiency were better able to maintain grade level performance in Spanish reading, transition more quickly to English reading, and attain a higher level of English reading proficiency in middle school. Non-English speaking student success in learning to read in English does not rest exclusively on primary language input and development, nor is it solely the result of rapid acquisition of English. Both apparently contribute to students' subsequent English reading achievement. Family factors predicting both early Spanish literacy and later English reading were parents' socioeconomic status and family literacy practices, as well as grandparents' educational level. Results suggest that early literacy experiences support subsequent literacy development, regardless of language; and time spent on literacy activity in the native language—whether it takes place at home or at school—is ...

Going the Distance: Using Systems Theory to Design, Implement, and Evaluate a Distance Education Program

Abstract: In the interest of developing a conceptual framework for distance education, the authors describe the use of systems theory concepts in designing, implementing, and evaluating a distance education program. They describe input, throughput, and output factors used in creating and operating the program, as well as the incorporation of feedback in making modifications to the program. The systems perspective allowed the authors to better understand the interaction of variables affecting the operation of the program and where changes can be made to address problems and enhance student learning.

Tsunami features of solid block underwater landslides

Abstract: Near-field and far-field wave features generated by solid block underwater landslides are described qualitatively and quantitatively. The characteristic time of landslide motion and maximum near-field wave amplitude suffice to scale many of these water wave features. Criteria are provided to determine if water waves generated by underwater landslides propagate as deepwater or shallow water waves. Estimates of the dominant far-field wavelength are provided for both cases. A precise location is given for the beginning of far-field wave propagation for deepwater waves. Weakly nonlinear and dispersive effects of shallow water wave propagation are examined. Around 5% of solid block maximum kinetic energy is converted into wave energy.

Spontaneous chirality in simple systems

Abstract: Two simple examples of spontaneous chiral symmetry breaking are presented. The first is close-packed cylindrically confined spheres. As the cylinder diameter is varied, one obtains a variety of chiral phases. The second example involves unconfined dipolar particles with an isotropic attraction, which also exhibits chiral ground states. We speculate that a dilute magnetorheological fluid film, with the addition of smaller particles to provide an attractive entropic interaction, will exhibit a chiral columnar ground state.

Re-validation and shortening of the Functional Assessment of Anorexia/Cachexia Therapy (FAACT) questionnaire.

Abstract: Purpose: The original Functional Assessment of Anorexia/Cachexia Therapy (FAACT) was designed to measure general aspects of quality of life (QOL) as well as specific anorexia/cachexia-related concerns. Our primary purpose was to reduce the number of anorexia/cachexia subscale items in a manner that either retains or improves reliability, validity and precision. Methods: The FAACT was administered using an interactive computer program that allowed immediate entry of the data. A total of 213 patients were recruited. Results: A combined empirical and conceptual approach led to the reduction of the anorexia/cachexia subscale (A/CS) from 18 to 12 items. A 26-item trial outcome index (TOI) combining physical well-being (PWB), functional well-being (FWB), and the A/CS-12 was highly reliable and sensitive to change in performance status rating (PSR). We found that PWB, FWB, and A/CS-12 subscales performed differently. Specifically, PWB and FWB scores decreased in patients whose (PSR) worsened. However, although A/CS-12 scores were responsive to change in PSR over time, average A/CS-12 scores of all patients, even those whose PSR worsened, improved over the course of treatment. Conclusions: Elimination of six items from the anorexia/cachexia subscale of the FAACT was accomplished without loss of internal consistency or sensitivity to change in performance status. The A/CS-12 subscale provides unique, important information not captured by a generic chronic illness questionnaire.

Movement patterns, habitat utilization, home range size and site fidelity of whitesaddle goatfish, Parupeneus porphyreus, in a marine reserve

Abstract: Suitability of small (< 1 km2) marine reserves for protecting a commercially important endemic Hawaiian goatfish, Parupeneus porphyreus, was examined by quantifying goatfish habitat use, home range size and site fidelity in an existing marine reserve (Coconut Island in Kaneohe Bay, Hawaii). Five goatfish equipped with acoustic transmitters were tracked for up to 93 h each over 3–14 days. Daytime habitat use patterns of two of these fish were continuously monitored for one month using a fixed hydrophone hardwired to an onshore computer. Acoustically tagged fish showed consistent diel patterns of behavior, refuging in holes in the reef by day and moving over extensive areas of sand and coral rubble habitat at night. Remote monitoring of daytime habitat use by two goatfish revealed that the same daytime refuge was used by both fish for at least one month (the battery life of the transmitters). Home ranges of all fish were within the boundaries of the Coconut Island reserve suggesting that even small areas containing suitable habitat can make effective reserves for this species. A relatively low abundance of reproductive size P. porphyreus at Coconut Island in comparison with deeper areas may indicate an ontogenetic shift to deeper habitat in this species.

Does Measured Behavior Reflect STD Risk?: An Analysis of Data From a Randomized Controlled Behavioral Intervention Study

Abstract: Many studies measure sex behavior to determine the efficacy of sexually transmitted disease (STD)/HIV prevention interventions. This studys aim was to determine how well measured behavior reflects STD incidence. Data from a trial (Project RESPECT) were analyzed to compare behavior and incidence of STD (gonorrhea chlamydia syphilis HIV) during two 6-month intervals. A total of 2879 persons had 5062 6-monthly STD exams and interviews; 8.9% had a new STD in 6 months. Incidence was associated with demographic factors but only slightly associated with number of partners and number of unprotected sex acts with occasional partners. Many behaviors had paradoxical associations with STD incidence. After combining behavior variables to compare persons with highest and lowest risk behaviors the STD incidence ratio was only 1.7. Behavioral interventions have prevented STD. The authors found people tend to have safe sex with risky partners and risky sex with safe partners. Therefore it is difficult to extrapolate the disease prevention efficacy of an intervention from a measured effect on behavior alone. (authors)

Mechanism of extracellular calcium regulation of intestinal epithelial tight junction permeability: role of cytoskeletal involvement.

Abstract: Recent studies suggest that an abnormal increase in intestinal tight junction (TJ) permeability may be an important etiologic factor in number of diseases including Crohn's disease, NSAID-associated enteritis, and various infectious diarrheal syndromes. The intracellular processes involved in regulation of intestinal epithelial TJ permeability, however, remain poorly understood. In this study, we used cultured Caco-2 intestinal epithelial cells to examine the intracellular processes involved in extracellular Ca(++) modulation of intestinal epithelial monolayer TJ barrier. Incubation of the filter-grown Caco-2 intestinal monolayers in Ca(++)-free solution (CFS), consisting of modified Krebs-buffer solution containing 0 mM Ca(++) and 1 mM EGTA, resulted in a rapid drop in Caco-2 epithelial resistance and increase in epithelial permeability to paracellular markers mannitol and inulin, indicating an increase in TJ permeability. The increase in Caco-2 TJ permeability was rapidly reversed by the re-introduction of Ca(++) (1.8 mM) into the incubation medium. The CFS-induced increase in Caco-2 TJ permeability was associated with separation of the cytoplasmic and transmembrane TJ proteins, ZO-1 and occludin, and formation of large intercellular openings between the adjoining cells. The CFS-induced modulation of TJ barrier was associated with activation of myosin light chain kinase (MLCK) activity and centripetal retraction of peri-junctional actin and myosin filaments. The inhibition of CFS-induced activation of Caco-2 MLCK with MLCK inhibitor (ML-7) prevented the CFS-induced retraction of actin and myosin filaments and the subsequent alteration of TJ barrier function and structure. Our results suggested that the CFS-induced alteration of TJ proteins and functional increase in TJ permeability was mediated by Caco-2 MLCK activation and the resultant contraction of the peri-junctionally located actin-myosin filaments. Consistent with the role of MLCK in this process, selected inhibitors of Mg(++)-myosin ATPase and metabolic energy, but not protein synthesis inhibitors, also prevented the CFS-induced retraction of actin and myosin filaments and the subsequent increase in TJ permeability. In conclusion, our results indicate that extracellular Ca(++) is crucial for the maintenance of intestinal epithelial TJ barrier function. The removal of extracellular Ca(++) from the incubation medium causes activation of Caco-2 MLCK, which in turn leads to an increase in intestinal monolayer TJ permeability.

Teaching the Nature of Science through Inquiry to Prospective Elementary Teachers: A Tale of Two Researchers

Abstract: The teacher as researcher, Colburn, and the researcher, Bianchini, investigated Colburn's use of inquiry to teach the nature of science to prospective elementary teachers; we attempted to identify those aspects of the nature of science addressed through inquiry instruction and the varied contexts in which such insights arose. We began by videotaping small group inquiries and whole class deliberations during three units of Colburn's inquiry-oriented general science course. We then conducted separate qualitative analyses of the resulting 20 h of videotaped data. Colburn, the teacher and informant, adopted an emic perspective and employed examples of explicit and implicit deliberations and demonstrations of the nature of science to construct his case. Bianchini also used an emic perspective, but examined only what teacher and students explicitly identified as examples of and insights into the nature of science. Taken together, our analyses highlight the difficulties in presenting a cogent and comprehensive picture of the nature of science to students, the teacher's pivotal role in initiating discussions of what science is and how scientists work, and the strengths and limitations of using classroom-based research to investigate nature of science instruction. © 2000 John Wiley & Sons, Inc. J Res Sci Teach 37: 177–209, 2000

Correlated Errors in True Score Models and Their Effect on Coefficient Alpha

Abstract: It is well known that coefficient alpha is an estimate of reliability if its underlying assumptions are met and that it is a lower-bound estimate if the assumption of essential tau equivalency is violated Very little literature addresses the assumption of uncorrelated errors among items and the effect of violating this assumption on alpha True score models are proposed that can account for correlated errors These models allow random measurement errors on earlier items to affect directly or indirectly scores on later items Coefficient alpha may yield spuriously high estimates of reliability if these true score models reflect item responding In practice, it is important to differentiate these models from models in which the errors are correlated because 1 or more factors have been left unspecified If the latter model is an accurate representation of item responding, the assumption of essential tau equivalency is violated and alpha is a lower-bound estimate of reliability

Acquisition of irregular past tense by children with specific language impairment.

Abstract: In this paper we add to what is known about the tense-marking limitations of children with specific language impairment (SLI) by exploring the acquisition of regular and irregular past tense, encompassing the age range of 2;6 to 8;9 (years;months) and comparing the performance of 21 children with SLI to that of 23 control children of the same age and 20 younger control children of equivalent mean length of utterance (MLU) at the outset. The analysis differentiated between the morphophonological component of past tense marking and the morphosyntactic component (finiteness). In the morphosyntactic component, the performance of the SLI group trails that of the two control groups over 3.5 years, whereas in the morphophonological component, the SLI group's performance is equivalent to that of the younger controls. Models of growth curves for regular past tense and irregular finiteness marking show the same pattern, with linear and quadratic components and the child's MLU at the outset as the only predictor. For morphophonological growth the picture changes, with an interaction of linear trend and MLU and the child's receptive vocabulary emerging as a predictor. The findings support a morphosyntactic model, such as the extended optional infinitive (EOI) model, with regard to the limitations in finiteness marking and for affected children.

Normal pressure hydrocephalus: new concepts on etiology and diagnosis.

Abstract: Normal pressure hydrocephalus (NPH) is remarkable for two reasons: 1) it is one of the few treatable causes of dementia, and 2) neuroradiologists are usually involved in making the diagnosis. Hakim and Adams [(1)][1] are generally credited with the initial description of NPH, although it may

Cytochalasin B modulation of Caco-2 tight junction barrier: role of myosin light chain kinase.

Abstract: The intracellular mechanisms that mediate cytochalasin-induced increase in intestinal epithelial tight junction (TJ) permeability are unclear. In this study, we examined the involvement of myosin l...

Magnetic-field-induced structural transitions in a ferrofluid emulsion.

Abstract: A ferrofluid emulsion, subjected to a slowly increasing magnetic field, exhibits a complicated structural behavior: a gas of Brownian particles changes to columnar solid structures due to induced dipole interaction. Two transition (intermediate) structural regimes are observed: (i) randomly distributed chains and particles and (ii) distinct thin columns and randomly distributed chains and particles. Three structural transition magnetic fields are found, one marking each structural transition, from the initial to the final structural regime. A structural diagram of the structural transition magnetic fields, H(C), versus particle volume fractions, straight phi, is constructed experimentally. Theoretical models of scaling calculations, based upon the dominant magnetic interaction in each structural regime, give the three structural transition magnetic-field relations as H(C1) proportional to straight phi(-1/2), H(C2) proportional to straight phi(-1/4), and H(C3) proportional to (straight phi(gamma)/G2)exp(piG/straight phi((gamma/2))), where gamma=0.39 and G=0.29 for our sample. The final end shape of columns and the relative position between columns show that the end-end repulsion between chains is important in the structural formation.

Super-scale failure of the southern Oregon Cascadia margin

Abstract: —Using SeaBeam bathymetry and multichannel seismic reflection records we have identified three large submarine landslides on the southern Oregon Cascadia margin. The area enclosed by the three arcuate slide scarps is approximately 8000 km2, and involves an estimated 12,000–16,000 km3 of the accretionary wedge. The three arcuate slump escarpments are nearly coincident with the continental shelf edge on their landward margins, spanning the full width of the accretionary wedge. Debris from the slides is buried or partially buried beneath the abyssal plain, covering a subsurface area of at least 8000 km2. The three major slides, called the Heceta, Coos Basin and Blanco slides, display morphologic and structural features typical of submarine landslides. Bathymetry, sidescan sonar, and seismic reflection profiles reveal that regions of the continental slope enclosed by the scarps are chaotic, with poor penetration of seismic energy and numerous diffractions. These regions show little structural coherence, in strong contrast to the fold thrust belt tectonics of the adjacent northern Oregon margin. The bathymetric scarps correlate with listric detachment faults identified on reflection profiles that show large vertical separation and bathymetric relief. Reflection profiles on the adjacent abyssal plain image buried debris packages extending 20–35 km seaward of the base of the continental slope. In the case of the youngest slide, an intersection of slide debris and abyssal plain sediments, rather than a thrust fault, mark the base of slope. The age of the three major slides decreases from south to north, indicated by the progressive northward shallowing of buried debris packages, increasing sharpness of morphologic expression, and southward increase in post-slide reformation of the accretionary wedge. The ages of the events, derived from calculated sedimentation rates in overlying Pleistocene sediments, are approximately 110 ka, 450 ka, and 1210 ka. This series of slides traveled 25–70 km onto the abyssal plain in at least three probably catastrophic events, which may have been triggered by subduction earthquakes. The lack of internal structure in the slide packages, and the considerable distance traveled suggest catastrophic rather than incremental slip, although there could have been multiple events. The slides would have generated large tsunami in the Pacific basin, possibly larger than that generated by an earthquake alone. We have identified a potential future slide off southern Oregon that may be released in a subduction earthquake. The occurrence of the slides and subsequent subduction of the slide debris, along with evidence for margin subsidence implies that basal subduction erosion has occurred over at least the last 1 Ma. The massive failure of the southern Oregon slope may have been the result of the collision of a seamount province or aseismic ridge with the margin, suggested by the age progression of the slides and evidence for subducted basement highs. The lack of latitudinal offset between the oldest slide debris and the corresponding scarp on the continental slope implies that the forearc is translating northward at a substantial fraction of the margin-parallel convergence rate.

Perpetual Care in Cyberspace: A Portrait of Memorials on the Web:

Abstract: This study describes memorials in the newly created “virtual cemeteries.” Web memorials (N = 276) from three cemeteries were coded for demographics about the deceased, characteristics of authors, and issues of content, audience, and theme. While memorials were extremely varied, they were written frequently for the young (M age = 47, SD = 24) and for more males than females. Most deaths were recent, but 7.3 percent had occurred more than twenty years prior to the posting of their memorials. Authors included family members, friends, and others who were typically younger or from the same cohort as the deceased. Most memorials were addressed to the community, but 28.3 percent were written to the dead. The majority of memorials were written as stories or celebrations but other primary themes included: grief/missing the dead, retelling the circumstances of the death, and guilt. Web memorials are discussed as a resource to the bereaved and researchers alike, providing the bereaved with an opportunity to create a...

A population pharmacokinetic analysis of the penetration of the prostate by levofloxacin.

Abstract: Prostatitis has remained a pathological entity that is difficult to treat. Part of the difficulty revolves about the putative offending pathogens. For acute prostatitis, members of the Enterobacteriaceae, particularly Escherichia coli, play a central role, while intracellular pathogens such as Chlamydia are more frequently seen in chronic prostatitis. Consequently, a drug needs to be able to penetrate to this specialized site in both the acute and chronic infection forms of the disease and also have potent activity against the most common causative pathogens, both intracellular and extracellular. Levofloxacin has such an activity profile. We wished to document its ability to penetrate to the site of infection. Patients undergoing prostatectomies were administered 500 mg of levofloxacin orally every 24 h for 2 days prior to surgery, and then on the day of surgery, 500 mg was administered as an hour-long, constant-rate intravenous (i.v.) infusion. A set of blood samples was obtained as guided by stochastic optimal design theory. Prostate biopsy times were determined by randomizing subjects into one of four groups, based on the interval after the i.v. dose. All plasma and prostate drug concentrations were comodeled by a population modeling program, BigNPEM, implemented on the Cray T3E Supercomputer housed at the Supercomputer Center at the University of California at San Diego. Penetration was determined as the ratio of the area under the concentration-time curve (AUC) of levofloxacin in the prostate to the plasma levofloxacin AUC. When calculated from the mean population parameters, this penetration ratio was 2.96. We also performed a 1,000-subject Monte Carlo simulation from the mean parameter vector and covariance matrix. The mean penetration ratio here was 4.14 with a 95% confidence interval of 0.20 to 19.6. Over 70% of the population had a penetration ratio in excess of 1.0. Levofloxacin adequately penetrates a noninflamed prostate and should be evaluated for the therapy of prostatitis.